ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Polymer and Materials Science  (13,298)
  • Life and Medical Sciences  (1,859)
  • Kinetics
  • Wiley-Blackwell  (15,164)
  • American Association for the Advancement of Science (AAAS)  (146)
  • American Association of Petroleum Geologists (AAPG)
  • International Union of Crystallography (IUCr)
  • 2000-2004  (104)
  • 1975-1979  (15,206)
Collection
Keywords
Publisher
  • Wiley-Blackwell  (15,164)
  • American Association for the Advancement of Science (AAAS)  (146)
  • American Association of Petroleum Geologists (AAPG)
  • International Union of Crystallography (IUCr)
  • Springer  (24)
Years
Year
  • 1
    Publication Date: 2004-11-06
    Description: Dynamic instability-the switching of a two-state polymer between phases of steady elongation and rapid shortening-is essential to the cellular function of eukaryotic microtubules, especially during chromosome segregation. Since the discovery of dynamic instability 20 years ago, no other biological polymer has been found to exhibit this behavior. Using total internal reflection fluorescence microscopy and fluorescence resonance energy transfer, we observe that the prokaryotic actin homolog ParM, whose assembly is required for the segregation of large, low-copy number plasmids, displays both dynamic instability and symmetrical, bidirectional polymerization. The dynamic instability of ParM is regulated by adenosine triphosphate (ATP) hydrolysis, and filaments are stabilized by a cap of ATP-bound monomers. ParM is not related to tubulin, so its dynamic instability must have arisen by convergent evolution driven by a set of common constraints on polymer-based segregation of DNA.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Garner, Ethan C -- Campbell, Christopher S -- Mullins, R Dyche -- GM61010-01/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2004 Nov 5;306(5698):1021-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉University of California, 600 16th Street, San Francisco, CA 94107, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15528442" target="_blank"〉PubMed〈/a〉
    Keywords: Actins/chemistry ; Adenosine Triphosphate/metabolism ; Bacterial Proteins/*chemistry/physiology/ultrastructure ; Biopolymers/chemistry ; DNA, Bacterial/*metabolism ; Fluorescence Resonance Energy Transfer ; Hydrolysis ; Kinetics ; Microscopy, Fluorescence ; Mutagenesis
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 2004-10-30
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Jordan, Frank -- GM-50380/GM/NIGMS NIH HHS/ -- GM-62330/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2004 Oct 29;306(5697):818-20.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, Rutgers University, Newark, NJ 07102, USA. frjordan@newark.rutgers.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15514144" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Substitution ; Binding Sites ; Dihydrolipoyllysine-Residue Acetyltransferase ; Dimerization ; Geobacillus stearothermophilus/*enzymology ; Glutamic Acid/chemistry ; Hydrogen Bonding ; Hydrogen-Ion Concentration ; Kinetics ; Protein Structure, Quaternary ; Protein Structure, Tertiary ; Protein Subunits ; Protons ; Pyruvate Dehydrogenase (Lipoamide)/*chemistry/*metabolism ; Pyruvate Dehydrogenase Complex/*chemistry/*metabolism ; Thiamine Pyrophosphate/chemistry/*metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2004-05-25
    Description: Tyrosine phosphorylation, regulated by protein tyrosine phosphatases (PTPs) and kinases (PTKs), is important in signaling pathways underlying tumorigenesis. A mutational analysis of the tyrosine phosphatase gene superfamily in human cancers identified 83 somatic mutations in six PTPs (PTPRF, PTPRG, PTPRT, PTPN3, PTPN13, PTPN14), affecting 26% of colorectal cancers and a smaller fraction of lung, breast, and gastric cancers. Fifteen mutations were nonsense, frameshift, or splice-site alterations predicted to result in truncated proteins lacking phosphatase activity. Five missense mutations in the most commonly altered PTP (PTPRT) were biochemically examined and found to reduce phosphatase activity. Expression of wild-type but not a mutant PTPRT in human cancer cells inhibited cell growth. These observations suggest that the mutated tyrosine phosphatases are tumor suppressor genes, regulating cellular pathways that may be amenable to therapeutic intervention.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wang, Zhenghe -- Shen, Dong -- Parsons, D Williams -- Bardelli, Alberto -- Sager, Jason -- Szabo, Steve -- Ptak, Janine -- Silliman, Natalie -- Peters, Brock A -- van der Heijden, Michiel S -- Parmigiani, Giovanni -- Yan, Hai -- Wang, Tian-Li -- Riggins, Greg -- Powell, Steven M -- Willson, James K V -- Markowitz, Sanford -- Kinzler, Kenneth W -- Vogelstein, Bert -- Velculescu, Victor E -- CA 43460/CA/NCI NIH HHS/ -- CA 57345/CA/NCI NIH HHS/ -- CA 62924/CA/NCI NIH HHS/ -- New York, N.Y. -- Science. 2004 May 21;304(5674):1164-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Sidney Kimmel Comprehensive Cancer Center, Howard Hughes Medical Institute, Johns Hopkins University Medical Institutions, Baltimore, MD 21231, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15155950" target="_blank"〉PubMed〈/a〉
    Keywords: Catalytic Domain ; Cell Division ; Codon, Nonsense ; Colorectal Neoplasms/*enzymology/*genetics ; Computational Biology ; *DNA Mutational Analysis ; Exons ; Frameshift Mutation ; Genes, Tumor Suppressor ; Humans ; Kinetics ; Markov Chains ; *Mutation ; Mutation, Missense ; Nerve Tissue Proteins/chemistry/genetics/metabolism ; Phosphorylation ; Protein Tyrosine Phosphatase, Non-Receptor Type 13 ; Protein Tyrosine Phosphatase, Non-Receptor Type 3 ; Protein Tyrosine Phosphatases/chemistry/*genetics/metabolism ; Receptor-Like Protein Tyrosine Phosphatases, Class 5 ; Signal Transduction ; Transfection ; Tyrosine/*metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2004-06-12
    Description: With the use of x-ray absorption spectroscopy, we have found that the Fe-O bond in chloroperoxidase compound II (CPO-II) is much longer than expected for an oxoiron(IV) (ferryl) unit; notably, the experimentally determined bond length of 1.82(1) A accords closely with density functional calculations on a protonated ferryl (Fe(IV)-OH, 1.81 A). The basicity of the CPO-II ferryl [pKa 〉 8.2 (where Ka is the acid dissociation constant)] is attributable to strong electron donation by the axial thiolate. We suggest that the CPO-II protonated ferryl is a good model for the rebound intermediate in the P450 oxygenation cycle;with elevated pKa values after one-electron reduction, thiolate-ligated ferryl radicals are competent to oxygenate saturated hydrocarbons at potentials that can be tolerated by folded polypeptide hosts.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Green, Michael T -- Dawson, John H -- Gray, Harry B -- DK19038/DK/NIDDK NIH HHS/ -- GM26730/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2004 Jun 11;304(5677):1653-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, Pennsylvania State University, PA 16802, USA. mtg10@psu.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15192224" target="_blank"〉PubMed〈/a〉
    Keywords: Chemistry, Physical ; Chloride Peroxidase/*chemistry/metabolism ; Cytochrome P-450 Enzyme System/*chemistry/metabolism ; Electrons ; Fourier Analysis ; Free Radicals ; Horseradish Peroxidase/chemistry/metabolism ; Hydrocarbons/metabolism ; Hydrogen-Ion Concentration ; Hydroxylation ; Iron/*chemistry ; Kinetics ; Ligands ; Organometallic Compounds/*chemistry/metabolism ; Oxidation-Reduction ; Oxygen/*chemistry ; Physicochemical Phenomena ; Protons ; Spectrum Analysis
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2004-12-18
    Description: The inositol pyrophosphates IP7 and IP8 contain highly energetic pyrophosphate bonds. Although implicated in various biologic functions, their molecular sites of action have not been clarified. Using radiolabeled IP7, we detected phosphorylation of multiple eukaryotic proteins. We also observed phosphorylation of endogenous proteins by endogenous IP7 in yeast. Phosphorylation by IP7 is nonenzymatic and may represent a novel intracellular signaling mechanism.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Saiardi, Adolfo -- Bhandari, Rashna -- Resnick, Adam C -- Snowman, Adele M -- Snyder, Solomon H -- DA00074/DA/NIDA NIH HHS/ -- MH068830-02/MH/NIMH NIH HHS/ -- MH18501/MH/NIMH NIH HHS/ -- New York, N.Y. -- Science. 2004 Dec 17;306(5704):2101-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Neuroscience, Johns Hopkins University, School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15604408" target="_blank"〉PubMed〈/a〉
    Keywords: Adenosine Triphosphate/metabolism ; Amino Acid Sequence ; Amino Acid Substitution ; Animals ; Drosophila Proteins/metabolism ; Drosophila melanogaster ; Escherichia coli Proteins/metabolism ; Humans ; Inositol Phosphates/*metabolism ; Kinetics ; Magnesium/metabolism ; Mice ; Molecular Sequence Data ; Mutation ; Nuclear Proteins/chemistry/*metabolism ; Phosphates/metabolism ; Phosphorylation ; Phosphotransferases (Phosphate Group Acceptor)/metabolism ; Protein Kinases/genetics/metabolism ; Proteins/*metabolism ; RNA-Binding Proteins/chemistry/*metabolism ; Saccharomyces cerevisiae/metabolism ; Saccharomyces cerevisiae Proteins/chemistry/*metabolism ; Serine/metabolism ; Signal Transduction ; Temperature
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2004-01-13
    Description: Advances in transition state theory and computer simulations are providing new insights into the sources of enzyme catalysis. Both lowering of the activation free energy and changes in the generalized transmission coefficient (recrossing of the transition state, tunneling, and nonequilibrium contributions) can play a role. A framework for understanding these effects is presented, and the contributions of the different factors, as illustrated by specific enzymes, are identified and quantified by computer simulations. The resulting understanding of enzyme catalysis is used to comment on alternative proposals of how enzymes work.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Garcia-Viloca, Mireia -- Gao, Jiali -- Karplus, Martin -- Truhlar, Donald G -- New York, N.Y. -- Science. 2004 Jan 9;303(5655):186-95.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, MN 55455, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/14716003" target="_blank"〉PubMed〈/a〉
    Keywords: *Catalysis ; Computer Simulation ; Enzymes/*chemistry/*metabolism ; Kinetics ; Mathematics ; Models, Chemical ; Models, Molecular ; Protein Conformation ; Thermodynamics
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2004-04-17
    Description: Pathway optimization is difficult to achieve owing to complex, nonlinear, and largely unknown interactions of enzymes, regulators, and metabolites. We report a pathway reconstruction using RNA display-derived messenger RNA-enzyme fusion molecules. These chimeras are immobilized by hybridization of their messenger RNA end with homologous capture DNA spotted on a substrate surface. Enzymes thus immobilized retain activity proportional to the amount of capture DNA, allowing modulation of the relative activity of pathway enzymes. Entire pathways can thus be reconstructed and optimized in vitro from genomic information. We provide concept validation with the sequential reactions catalyzed by luciferase and nucleoside diphosphate kinase and further illustrate this method with the optimization of the five-step pathway for trehalose synthesis.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Jung, Gyoo Yeol -- Stephanopoulos, Gregory -- New York, N.Y. -- Science. 2004 Apr 16;304(5669):428-31.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemical Engineering, Massachusetts Institute of Technology, Room 56-469, Cambridge, MA 02139, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15087547" target="_blank"〉PubMed〈/a〉
    Keywords: Catalysis ; DNA/genetics/metabolism ; Enzymes, Immobilized/genetics/*metabolism ; Gene Expression ; *Gene Expression Profiling ; *Genetic Engineering ; Glucose/metabolism ; Glucosyltransferases/genetics/metabolism ; Hexokinase/genetics/metabolism ; Kinetics ; Luciferases/genetics/metabolism ; *Metabolism ; Nucleic Acid Hybridization ; Nucleoside-Diphosphate Kinase/genetics/metabolism ; Oligonucleotide Array Sequence Analysis ; Phosphoglucomutase/genetics/metabolism ; Phosphoric Monoester Hydrolases/genetics/metabolism ; *Protein Array Analysis ; Protein Biosynthesis ; RNA, Messenger/*metabolism ; Trehalose/*biosynthesis ; UTP-Glucose-1-Phosphate Uridylyltransferase/genetics/metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 2004-07-17
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉von Hippel, Peter H -- GM-15792/GM/NIGMS NIH HHS/ -- GM-29158/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2004 Jul 16;305(5682):350-2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institute of Molecular Biology and Department of Chemistry, University of Oregon, Eugene, OR 97403, USA. petevh@molbio.uoregon.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15256661" target="_blank"〉PubMed〈/a〉
    Keywords: Bacterial Proteins/*chemistry/*metabolism ; Binding Sites ; DNA, Bacterial/*chemistry/*metabolism ; Diffusion ; Dimerization ; Escherichia coli/chemistry/genetics/metabolism ; Escherichia coli Proteins/chemistry/metabolism ; *Gene Expression Regulation, Bacterial ; Hydrogen Bonding ; Kinetics ; Lac Operon ; Lac Repressors ; Models, Genetic ; Models, Molecular ; Nucleic Acid Conformation ; Operator Regions, Genetic ; Protein Binding ; Protein Conformation ; Protein Structure, Tertiary ; Repressor Proteins/*chemistry/*metabolism ; Static Electricity ; Thermodynamics ; *Transcription, Genetic
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2004-09-18
    Description: Cell migration initiates by extension of the actin cytoskeleton at the leading edge. Computational analysis of fluorescent speckle microscopy movies of migrating epithelial cells revealed this process is mediated by two spatially colocalized but kinematically, kinetically, molecularly, and functionally distinct actin networks. A lamellipodium network assembled at the leading edge but completely disassembled within 1 to 3 micrometers. It was weakly coupled to the rest of the cytoskeleton and promoted the random protrusion and retraction of the leading edge. Productive cell advance was a function of the second colocalized network, the lamella, where actomyosin contraction was integrated with substrate adhesion.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ponti, A -- Machacek, M -- Gupton, S L -- Waterman-Storer, C M -- Danuser, G -- GM67230/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2004 Sep 17;305(5691):1782-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Cell Biology, Scripps Research Institute (TSRI), La Jolla, CA 92037, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15375270" target="_blank"〉PubMed〈/a〉
    Keywords: Actin Cytoskeleton/drug effects/*physiology ; Actins/*physiology ; Animals ; Cell Line ; *Cell Movement ; Cells, Cultured ; Cytochalasin D/pharmacology ; *Depsipeptides ; Epithelial Cells/*physiology/ultrastructure ; Heterocyclic Compounds with 4 or More Rings/pharmacology ; Kinetics ; Macropodidae ; Microscopy, Fluorescence ; Motion Pictures as Topic ; Peptides, Cyclic/pharmacology ; Pseudopodia/*physiology/ultrastructure ; Salamandridae
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2004-03-06
    Description: The motility of molecular motors and the dynamic instability of microtubules are key dynamic processes for mitotic spindle assembly and function. We report here that one of the mitotic kinesins that localizes to chromosomes, Xklp1 from Xenopus laevis, could inhibit microtubule growth and shrinkage. This effect appeared to be mediated by a structural change in the microtubule lattice. We also found that Xklp1 could act as a fast, nonprocessive, plus end-directed molecular motor. The integration of the two properties, motility and inhibition of microtubule dynamics, in one molecule emphasizes the versatile properties of kinesin family members.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bringmann, Henrik -- Skiniotis, Georgios -- Spilker, Annina -- Kandels-Lewis, Stefanie -- Vernos, Isabelle -- Surrey, Thomas -- New York, N.Y. -- Science. 2004 Mar 5;303(5663):1519-22.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Cell Biology and Biophysics Programme, European Molecular Biology Laboratory, Meyerhofstrabetae 1, 69117 Heidelberg, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15001780" target="_blank"〉PubMed〈/a〉
    Keywords: Adenosine Triphosphatases/metabolism ; Adenosine Triphosphate/metabolism ; Adenylyl Imidodiphosphate/metabolism/pharmacology ; Animals ; Centrosome/metabolism ; Chromosomes/metabolism ; Cryoelectron Microscopy ; Dimerization ; Kinetics ; Microtubule-Associated Proteins/chemistry/genetics/*metabolism ; Microtubules/drug effects/metabolism/*physiology/ultrastructure ; Molecular Motor Proteins/*metabolism ; Paclitaxel/pharmacology ; Protein Binding ; Protein Structure, Tertiary ; Recombinant Fusion Proteins/metabolism ; Tubulin/metabolism ; Xenopus Proteins/chemistry/genetics/*metabolism ; Xenopus laevis
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    Publication Date: 2004-05-25
    Description: The herbicide glyphosate is effectively detoxified by N-acetylation. We screened a collection of microbial isolates and discovered enzymes exhibiting glyphosate N-acetyltransferase (GAT) activity. Kinetic properties of the discovered enzymes were insufficient to confer glyphosate tolerance to transgenic organisms. Eleven iterations of DNA shuffling improved enzyme efficiency by nearly four orders of magnitude from 0.87 mM-1 min-1 to 8320 mM-1 min-1. From the fifth iteration and beyond, GAT enzymes conferred increasing glyphosate tolerance to Escherichia coli, Arabidopsis, tobacco, and maize. Glyphosate acetylation provides an alternative strategy for supporting glyphosate use on crops.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Castle, Linda A -- Siehl, Daniel L -- Gorton, Rebecca -- Patten, Phillip A -- Chen, Yong Hong -- Bertain, Sean -- Cho, Hyeon-Je -- Duck, Nicholas -- Wong, James -- Liu, Donglong -- Lassner, Michael W -- New York, N.Y. -- Science. 2004 May 21;304(5674):1151-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Verdia, Inc. Redwood City, CA 94063, USA. linda.castle@verdiainc.com〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15155947" target="_blank"〉PubMed〈/a〉
    Keywords: Acetylation ; Acetyltransferases/chemistry/*genetics/metabolism ; Amino Acid Sequence ; Bacillus/enzymology ; Catalysis ; *DNA Shuffling ; *Directed Molecular Evolution ; Drug Resistance ; Escherichia coli/genetics ; Gene Library ; Genetic Variation ; Glycine/*analogs & derivatives/metabolism/*toxicity ; Herbicides/metabolism/*toxicity ; Kinetics ; Molecular Sequence Data ; Mutagenesis ; *Plants, Genetically Modified/drug effects/genetics ; Recombinant Proteins/metabolism ; Recombination, Genetic ; Tobacco/drug effects/genetics/growth & development ; Transformation, Genetic ; Zea mays/drug effects/genetics/growth & development
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    Publication Date: 2004-06-26
    Description: Rational design of enzymes is a stringent test of our understanding of protein chemistry and has numerous potential applications. Here, we present and experimentally validate the computational design of enzyme activity in proteins of known structure. We have predicted mutations that introduce triose phosphate isomerase activity into ribose-binding protein, a receptor that normally lacks enzyme activity. The resulting designs contain 18 to 22 mutations, exhibit 10(5)- to 10(6)-fold rate enhancements over the uncatalyzed reaction, and are biologically active, in that they support the growth of Escherichia coli under gluconeogenic conditions. The inherent generality of the design method suggests that many enzymes can be designed by this approach.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Dwyer, Mary A -- Looger, Loren L -- Hellinga, Homme W -- New York, N.Y. -- Science. 2004 Jun 25;304(5679):1967-71.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15218149" target="_blank"〉PubMed〈/a〉
    Keywords: Algorithms ; Binding Sites ; Catalysis ; Catalytic Domain ; Computational Biology ; Computer Simulation ; Dihydroxyacetone Phosphate/metabolism ; Dimerization ; Directed Molecular Evolution ; Enzyme Stability ; Escherichia coli/genetics/growth & development/metabolism ; *Escherichia coli Proteins/chemistry/genetics/metabolism ; Glyceraldehyde 3-Phosphate/metabolism ; Glycerol/metabolism ; Hydrogen Bonding ; Kinetics ; Lactates/metabolism ; Ligands ; Models, Molecular ; Molecular Conformation ; Mutation ; *Periplasmic Binding Proteins/chemistry/genetics/metabolism ; Protein Conformation ; *Protein Engineering ; Protons ; *Triose-Phosphate Isomerase/chemistry/metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    Publication Date: 2004-09-14
    Description: We performed molecular dynamics simulations of the collapse of a two-domain protein, the BphC enzyme, into a globular structure to examine how water molecules mediate hydrophobic collapse of proteins. In the interdomain region, liquid water persists with a density 10 to 15% lower than in the bulk, even at small domain separations. Water depletion and hydrophobic collapse occur on a nanosecond time scale, which is two orders of magnitude slower than that found in the collapse of idealized paraffin-like plates. When the electrostatic protein-water forces are turned off, a dewetting transition occurs in the interdomain region and the collapse speeds up by more than an order of magnitude. When attractive van der Waals forces are turned off as well, the dewetting in the interdomain region is more profound, and the collapse is even faster.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zhou, Ruhong -- Huang, Xuhui -- Margulis, Claudio J -- Berne, Bruce J -- GM4330/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2004 Sep 10;305(5690):1605-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Computational Biology Center, IBM Thomas J. Watson Research Center, 1101 Kitchawan Road, Yorktown Heights, NY 10598, USA. ruhongz@us.ibm.com〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15361621" target="_blank"〉PubMed〈/a〉
    Keywords: Computer Simulation ; *Dioxygenases ; Hydrophobic and Hydrophilic Interactions ; Kinetics ; Models, Molecular ; Oxygenases/*chemistry ; Protein Conformation ; *Protein Folding ; *Protein Structure, Tertiary ; Static Electricity ; Surface Properties ; Water/*chemistry
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Publication Date: 2004-03-20
    Description: Voltage-gated potassium (Kv) channels control action potential repolarization, interspike membrane potential, and action potential frequency in excitable cells. It is thought that the combinatorial association between distinct alpha and beta subunits determines whether Kv channels function as non-inactivating delayed rectifiers or as rapidly inactivating A-type channels. We show that membrane lipids can convert A-type channels into delayed rectifiers and vice versa. Phosphoinositides remove N-type inactivation from A-type channels by immobilizing the inactivation domains. Conversely, arachidonic acid and its amide anandamide endow delayed rectifiers with rapid voltage-dependent inactivation. The bidirectional control of Kv channel gating by lipids may provide a mechanism for the dynamic regulation of electrical signaling in the nervous system.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Oliver, Dominik -- Lien, Cheng-Chang -- Soom, Malle -- Baukrowitz, Thomas -- Jonas, Peter -- Fakler, Bernd -- New York, N.Y. -- Science. 2004 Apr 9;304(5668):265-70. Epub 2004 Mar 18.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institute of Physiology, University of Freiburg, Hermann-Herder-Strabetae 7, 79104 Freiburg, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15031437" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Arachidonic Acids/*metabolism/pharmacology ; Brain/physiology ; Cations ; Cell Membrane/metabolism ; Delayed Rectifier Potassium Channels ; Eicosanoic Acids/*metabolism/pharmacology ; Endocannabinoids ; Interneurons/physiology ; Ion Channel Gating/drug effects ; Kinetics ; Membrane Lipids/*metabolism/pharmacology ; Oocytes ; Patch-Clamp Techniques ; Permeability ; Phosphatidylinositol 4,5-Diphosphate/*metabolism/pharmacology ; Polylysine/pharmacology ; Polyunsaturated Alkamides ; Potassium Channels/chemistry/*metabolism/physiology ; Potassium Channels, Voltage-Gated/antagonists & ; inhibitors/chemistry/*metabolism/physiology ; Protein Structure, Tertiary ; Protein Subunits ; Recombinant Proteins/chemistry/metabolism ; Signal Transduction ; Xenopus
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    Publication Date: 2004-10-30
    Description: Thiamine diphosphate (ThDP) is used as a cofactor in many key metabolic enzymes. We present evidence that the ThDPs in the two active sites of the E1 (EC 1.2.4.1) component of the pyruvate dehydrogenase complex communicate over a distance of 20 angstroms by reversibly shuttling a proton through an acidic tunnel in the protein. This "proton wire" permits the co-factors to serve reciprocally as general acid/base in catalysis and to switch the conformation of crucial active-site peptide loops. This synchronizes the progression of chemical events and can account for the oligomeric organization, conformational asymmetry, and "ping-pong" kinetic properties of E1 and other thiamine-dependent enzymes.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Frank, Rene A W -- Titman, Christopher M -- Pratap, J Venkatesh -- Luisi, Ben F -- Perham, Richard N -- New York, N.Y. -- Science. 2004 Oct 29;306(5697):872-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15514159" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Substitution ; Binding Sites ; Catalysis ; Crystallography, X-Ray ; Dihydrolipoyllysine-Residue Acetyltransferase ; Geobacillus stearothermophilus/*enzymology ; Hydrogen-Ion Concentration ; Hydrophobic and Hydrophilic Interactions ; Kinetics ; Models, Molecular ; Mutation ; Phosphorylation ; Protein Conformation ; Protein Folding ; Protein Structure, Quaternary ; Protein Structure, Tertiary ; Protein Subunits/chemistry/metabolism ; Protons ; Pyruvate Dehydrogenase (Lipoamide)/*chemistry/genetics/*metabolism ; Pyruvate Dehydrogenase Complex/*chemistry/*metabolism ; Pyruvic Acid/metabolism ; Thiamine Pyrophosphate/*metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    Publication Date: 2004-10-16
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sosnick, T R -- New York, N.Y. -- Science. 2004 Oct 15;306(5695):411; author reply 411.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, and Molecular Biology, University of Chicago, Chicago, IL 60637, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15486276" target="_blank"〉PubMed〈/a〉
    Keywords: Chemistry, Physical ; Kinetics ; *Microscopy, Atomic Force ; Physicochemical Phenomena ; Polyubiquitin/chemistry ; *Protein Folding ; Ubiquitin/*chemistry
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    Publication Date: 2004-02-21
    Description: Stimulated emission pumping (SEP)-hole filling spectroscopy and SEP-induced population transfer spectroscopy have been used to place narrow bounds on the energy thresholds for isomerization between individual reactant-product isomer pairs involving the seven conformational minima of tryptamine. The thresholds for isomerizing conformer A to all six other conformations divided into three groups at 750 wavenumbers (cm-1)(A--〉B, F), 1000 cm-1 [A--〉C(2)], and 1280 to 1320 cm-1 [A--〉D, E, and C(1)]. The appearance of the first band and the absence of the band below it were used to place upper and lower bounds to the barrier heights for each process. The thresholds for A--〉B and B--〉A isomerizations were also combined to determine the relative energies of these two lowest energy minima. The combined data from all X--〉Y isomerizations identify important isomerization pathways on the potential energy surface linking the minima.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Dian, Brian C -- Clarkson, Jasper R -- Zwier, Timothy S -- New York, N.Y. -- Science. 2004 Feb 20;303(5661):1169-73.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, Purdue University, West Lafayette, IN 47907-2084, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/14976308" target="_blank"〉PubMed〈/a〉
    Keywords: Chemistry, Physical ; Isomerism ; Kinetics ; Molecular Conformation ; Physicochemical Phenomena ; Spectrum Analysis ; Thermodynamics ; Tryptamines/*chemistry
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Publication Date: 2003-04-05
    Description: The ability to visualize, track, and quantify molecules and events in living cells with high spatial and temporal resolution is essential for understanding biological systems. Only recently has it become feasible to carry out these tasks due to the advent of fluorescent protein technology. Here, we trace the development of highly visible and minimally perturbing fluorescent proteins that, together with updated fluorescent imaging techniques, are providing unprecedented insights into the movement of proteins and their interactions with cellular components in living cells.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lippincott-Schwartz, Jennifer -- Patterson, George H -- New York, N.Y. -- Science. 2003 Apr 4;300(5616):87-91.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA. jlippin@helix.nih.gov〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12677058" target="_blank"〉PubMed〈/a〉
    Keywords: *Cell Physiological Phenomena ; Diagnostic Imaging/*methods ; Fluorescence ; Fluorescence Recovery After Photobleaching/methods ; Fluorometry/methods ; Green Fluorescent Proteins ; Kinetics ; Light ; *Luminescent Proteins/chemistry/genetics/metabolism ; Microscopy/*methods ; Microscopy, Fluorescence/*methods ; Mutagenesis ; Protein Engineering ; Proteins/*metabolism ; Recombinant Fusion Proteins ; Spectrometry, Fluorescence
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    Publication Date: 2003-03-01
    Description: The mechanisms that determine how folding attempts are interrupted to target folding-incompetent proteins for endoplasmic reticulum-associated degradation (ERAD) are poorly defined. Here the alpha-mannosidase I-like protein EDEM was shown to extract misfolded glycoproteins, but not glycoproteins undergoing productive folding, from the calnexin cycle. EDEM overexpression resulted in faster release of folding-incompetent proteins from the calnexin cycle and earlier onset of degradation, whereas EDEM down-regulation prolonged folding attempts and delayed ERAD. Up-regulation of EDEM during ER stress may promote cell recovery by clearing the calnexin cycle and by accelerating ERAD of terminally misfolded polypeptides.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Molinari, Maurizio -- Calanca, Verena -- Galli, Carmela -- Lucca, Paola -- Paganetti, Paolo -- New York, N.Y. -- Science. 2003 Feb 28;299(5611):1397-400.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institute for Research in Biomedicine, CH-6500 Bellinzona, Switzerland. Maurizio.molinari@irb.unisi.ch〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12610306" target="_blank"〉PubMed〈/a〉
    Keywords: Aspartic Acid Endopeptidases/chemistry/*metabolism ; Calnexin/*metabolism ; Cell Line ; Down-Regulation ; Electrophoresis, Polyacrylamide Gel ; Endoplasmic Reticulum/*metabolism ; Glycoproteins/chemistry/*metabolism ; Glycosylation ; Humans ; Kinetics ; Membrane Proteins/*metabolism ; Molecular Weight ; Polysaccharides/metabolism ; Protein Conformation ; Protein Folding ; RNA Interference ; Transfection ; Up-Regulation
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 2003-06-28
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Molloy, Justin E -- Veigel, Claudia -- New York, N.Y. -- Science. 2003 Jun 27;300(5628):2045-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Division of Physical Biochemistry, National Institute for Medical Research, The Ridgeway, Mill Hill, London NW7 1AA, UK. jmolloy@nimr.mrc.ac.uk〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12829773" target="_blank"〉PubMed〈/a〉
    Keywords: Actin Cytoskeleton/*metabolism/ultrastructure ; Actins/metabolism ; Adenosine Triphosphate/metabolism ; Binding Sites ; Fluorescent Dyes/metabolism ; Hydrolysis ; Kinetics ; Microscopy, Fluorescence ; Models, Biological ; Molecular Motor Proteins/chemistry/*metabolism ; Myosin Light Chains/chemistry/metabolism ; Myosin Type V/chemistry/*metabolism ; Protein Structure, Tertiary
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    Publication Date: 2003-02-01
    Description: Genetic evidence suggests that inhibition of amyloid fibril formation by small molecules should be effective against amyloid diseases. Known amyloid inhibitors appear to function by shifting the aggregation equilibrium away from the amyloid state. Here, we describe a series of transthyretin amyloidosis inhibitors that functioned by increasing the kinetic barrier associated with misfolding, preventing amyloidogenesis by stabilizing the native state. The trans-suppressor mutation, threonine 119 --〉 methionine 119, which is known to ameliorate familial amyloid disease, also functioned through kinetic stabilization, implying that this small-molecule strategy should be effective in treating amyloid diseases.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hammarstrom, Per -- Wiseman, R Luke -- Powers, Evan T -- Kelly, Jeffery W -- DK 46335/DK/NIDDK NIH HHS/ -- New York, N.Y. -- Science. 2003 Jan 31;299(5607):713-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry and The Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12560553" target="_blank"〉PubMed〈/a〉
    Keywords: Amyloidosis/metabolism/*prevention & control ; Humans ; Hydrogen-Ion Concentration ; Kinetics ; Prealbumin/*antagonists & inhibitors/*chemistry/genetics/metabolism ; Protein Denaturation ; *Protein Folding ; Protein Structure, Quaternary ; Protein Subunits ; Suppression, Genetic ; Thermodynamics
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    Publication Date: 2003-06-14
    Description: We modeled how the charged levels of different transfer RNAs (tRNAs) that carry the same amino acid (isoacceptors) respond when this amino acid becomes growth-limiting. The charged levels will approach zero for some isoacceptors (such as tRNA2Leu) and remain high for others (such as tRNA4Leu), as determined by the concentrations of isoacceptors and how often their codons occur in protein synthesis. The theory accounts for (synonymous) codons for the same amino acid that are used in ribosome-mediated transcriptional attenuation, the choices of synonymous codons in trans-translating transfermessenger RNA, and the overrepresentation of rare codons in messenger RNAs for amino acid biosynthetic enzymes.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Elf, Johan -- Nilsson, Daniel -- Tenson, Tanel -- Ehrenberg, Mans -- New York, N.Y. -- Science. 2003 Jun 13;300(5626):1718-22.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Cell and Molecular Biology, Uppsala University, Biomedical Center, Box 596, 751 24 Uppsala, Sweden.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12805541" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acids/*metabolism ; Amino Acyl-tRNA Synthetases/metabolism ; *Codon ; Escherichia coli/*genetics/growth & development/metabolism ; Escherichia coli Proteins/biosynthesis/genetics ; Frameshifting, Ribosomal ; Gene Expression Regulation, Bacterial ; Kinetics ; Mathematics ; Models, Genetic ; Operon ; *Protein Biosynthesis ; Pyrophosphatases/genetics/metabolism ; RNA, Bacterial/genetics/metabolism ; RNA, Messenger/genetics/metabolism ; RNA, Transfer/genetics/metabolism ; RNA, Transfer, Amino Acyl/genetics/*metabolism ; Ribosomes/metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    Publication Date: 2003-10-11
    Description: We prepared the primary adduct for the reaction of singlet dioxygen (1O2) with an arylphosphine by using the sterically hindered arylphosphine tris(o-methoxyphenyl)phosphine. The resulting phosphadioxirane has a dioxygen molecule triangularly bound to the phosphorus atom. Olefin trapping experiments show that the phosphadioxirane can undergo nonradical oxygen atom-transfer reactions. Under protic conditions, two different intermediates are formed during the reaction of singlet dioxygen with tris(o-methoxyphenyl)phosphine, namely, the corresponding hydroperoxy arylphosphine and a hydroxy phosphorane. Experiments with other arylphosphines possessing different electronic and steric properties demonstrate that the relative stability of the tris(o-methoxyphenyl)phosphadioxirane is due to both steric and electronic effects.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ho, David G -- Gao, Ruomei -- Celaje, Jeff -- Chung, Ha-Yong -- Selke, Matthias -- GM 08101/GM/NIGMS NIH HHS/ -- GM 64104/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2003 Oct 10;302(5643):259-62.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry and Biochemistry, California State University, Los Angeles, Los Angeles, CA 90032, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/14551430" target="_blank"〉PubMed〈/a〉
    Keywords: Chemistry, Physical ; Epoxy Compounds/*chemistry ; Heterocyclic Compounds, 1-Ring/*chemistry ; Kinetics ; Magnetic Resonance Spectroscopy ; Molecular Structure ; Organophosphorus Compounds/*chemistry ; Oxidation-Reduction ; Oxygen/chemistry ; Peroxides/*chemistry ; Phosphines/chemistry ; Phosphorus ; Physicochemical Phenomena ; Singlet Oxygen/chemistry ; Temperature
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    Publication Date: 2003-06-07
    Description: Myosin V is a dimeric molecular motor that moves processively on actin, with the center of mass moving approximately 37 nanometers for each adenosine triphosphate hydrolyzed. We have labeled myosin V with a single fluorophore at different positions in the light-chain domain and measured the step size with a standard deviation of 〈1.5 nanometers, with 0.5-second temporal resolution, and observation times of minutes. The step size alternates between 37 + 2x nm and 37 - 2x, where x is the distance along the direction of motion between the dye and the midpoint between the two heads. These results strongly support a hand-over-hand model of motility, not an inchworm model.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Yildiz, Ahmet -- Forkey, Joseph N -- McKinney, Sean A -- Ha, Taekjip -- Goldman, Yale E -- Selvin, Paul R -- AR26846/AR/NIAMS NIH HHS/ -- AR44420/AR/NIAMS NIH HHS/ -- GM65367/GM/NIGMS NIH HHS/ -- PHS 5 T32 GM08276/PH/PHPPO CDC HHS/ -- R01 GM065367/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2003 Jun 27;300(5628):2061-5. Epub 2003 Jun 5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Center for Biophysics and Computational Biology, University of Illinois, Urbana-Champaign, IL 61801, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12791999" target="_blank"〉PubMed〈/a〉
    Keywords: Actin Cytoskeleton/*metabolism/ultrastructure ; Actins/metabolism ; Adenosine Triphosphate/metabolism ; Binding Sites ; Calmodulin ; Carbocyanines/metabolism ; Catalytic Domain ; Dna ; Fluorescence ; Fluorescent Dyes/metabolism ; Kinetics ; Mathematics ; Microscopy, Fluorescence ; *Models, Biological ; Molecular Motor Proteins/chemistry/*metabolism ; Myosin Light Chains/chemistry/metabolism ; Myosin Type V/chemistry/*metabolism ; Protein Structure, Tertiary ; Rhodamines/metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    Publication Date: 2003-01-18
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Storch, David -- New York, N.Y. -- Science. 2003 Jan 17;299(5605):346; author reply 346.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Biodiversity and Macroecology Group, Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK, and Center for Theoretical Study, Charles University, Jilska 1, 110 00 Prague, Czech Republic. storch@cts.cuni.cz〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12531999" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Body Constitution ; *Ecosystem ; Kinetics ; *Models, Biological ; Population Density ; Temperature ; Thermodynamics
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Publication Date: 2003-03-29
    Description: Acetyl-coenzyme A carboxylases (ACCs) are required for the biosynthesis and oxidation of long-chain fatty acids. They are targets for therapeutics against obesity and diabetes, and several herbicides function by inhibiting their carboxyltransferase (CT) domain. We determined the crystal structure of the free enzyme and the coenzyme A complex of yeast CT at 2.7 angstrom resolution and found that it comprises two domains, both belonging to the crotonase/ClpP superfamily. The active site is at the interface of a dimer. Mutagenesis and kinetic studies reveal the functional roles of conserved residues here. The herbicides target the active site of CT, providing a lead for inhibitor development against human ACCs.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zhang, Hailong -- Yang, Zhiru -- Shen, Yang -- Tong, Liang -- New York, N.Y. -- Science. 2003 Mar 28;299(5615):2064-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biological Sciences, Columbia University, New York, NY 10027, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12663926" target="_blank"〉PubMed〈/a〉
    Keywords: Acetyl-CoA Carboxylase/antagonists & inhibitors/*chemistry/genetics/metabolism ; Amino Acid Sequence ; Binding Sites ; Biotin/chemistry/metabolism ; Catalysis ; Coenzyme A/chemistry/metabolism ; Crystallography, X-Ray ; Dimerization ; Enzyme Inhibitors/metabolism/pharmacology ; Hydrogen Bonding ; Kinetics ; Molecular Sequence Data ; Mutagenesis ; Protein Conformation ; Protein Folding ; Protein Structure, Secondary ; Protein Structure, Tertiary ; Pyridines/metabolism/pharmacology ; Saccharomyces cerevisiae/*enzymology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Publication Date: 2003-02-01
    Description: One function of heterochromatin is the epigenetic silencing by sequestration of genes into transcriptionally repressed nuclear neighborhoods. Heterochromatin protein 1 (HP1) is a major component of heterochromatin and thus is a candidate for establishing and maintaining the transcriptionally repressive heterochromatin structure. Here we demonstrate that maintenance of stable heterochromatin domains in living cells involves the transient binding and dynamic exchange of HP1 from chromatin. HP1 exchange kinetics correlate with the condensation level of chromatin and are dependent on the histone methyltransferase Suv39h. The chromodomain and the chromoshadow domain of HP1 are both required for binding to native chromatin in vivo, but they contribute differentially to binding in euchromatin and heterochromatin. These data argue against HP1 repression of transcription by formation of static, higher order oligomeric networks but support a dynamic competition model, and they demonstrate that heterochromatin is accessible to regulatory factors.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Cheutin, Thierry -- McNairn, Adrian J -- Jenuwein, Thomas -- Gilbert, David M -- Singh, Prim B -- Misteli, Tom -- New York, N.Y. -- Science. 2003 Jan 31;299(5607):721-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12560555" target="_blank"〉PubMed〈/a〉
    Keywords: Amanitins/pharmacology ; Animals ; Binding Sites ; CHO Cells ; Cell Nucleus/metabolism ; Cells, Cultured ; Chromosomal Proteins, Non-Histone/*chemistry/genetics/*metabolism ; Cricetinae ; Dimerization ; Euchromatin/metabolism ; Fluorescence Recovery After Photobleaching ; HeLa Cells ; Heterochromatin/*chemistry/*metabolism ; Histones/metabolism ; Humans ; Hydroxamic Acids/pharmacology ; Kinetics ; Methyltransferases/metabolism ; Mice ; Mice, Knockout ; Protein Structure, Tertiary ; Recombinant Fusion Proteins/metabolism ; Transfection
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    Publication Date: 2003-08-23
    Description: Cell division in many mammalian tissues is associated with specific times of day, but just how the circadian clock controls this timing has not been clear. Here, we show in the regenerating liver (of mice) that the circadian clock controls the expression of cell cycle-related genes that in turn modulate the expression of active Cyclin B1-Cdc2 kinase, a key regulator of mitosis. Among these genes, expression of wee1 was directly regulated by the molecular components of the circadian clockwork. In contrast, the circadian clockwork oscillated independently of the cell cycle in single cells. Thus, the intracellular circadian clockwork can control the cell-division cycle directly and unidirectionally in proliferating cells.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Matsuo, Takuya -- Yamaguchi, Shun -- Mitsui, Shigeru -- Emi, Aki -- Shimoda, Fukuko -- Okamura, Hitoshi -- New York, N.Y. -- Science. 2003 Oct 10;302(5643):255-9. Epub 2003 Aug 21.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Division of Molecular Brain Science, Department of Brain Sciences, Kobe University Graduate School of Medicine, Chuo-ku, Kobe 650-0017, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12934012" target="_blank"〉PubMed〈/a〉
    Keywords: ARNTL Transcription Factors ; Animals ; Basic Helix-Loop-Helix Transcription Factors ; *Biological Clocks ; CDC2 Protein Kinase/genetics/*metabolism ; CLOCK Proteins ; Cell Cycle ; Cell Cycle Proteins/genetics/metabolism ; *Cell Division ; *Circadian Rhythm ; Cryptochromes ; Cyclin B/genetics/*metabolism ; Cyclin B1 ; *Drosophila Proteins ; *Eye Proteins ; Flavoproteins/genetics/metabolism ; Gene Expression Profiling ; Gene Expression Regulation ; Hepatectomy ; Hepatocytes/*cytology/metabolism ; Kinetics ; Liver Regeneration ; Mice ; Mice, Inbred C57BL ; Mitosis ; Nuclear Proteins/genetics/metabolism ; Period Circadian Proteins ; Phosphorylation ; *Photoreceptor Cells, Invertebrate ; Protein-Tyrosine Kinases/genetics/*metabolism ; Receptors, G-Protein-Coupled ; Trans-Activators/genetics/metabolism ; Transcription Factors/genetics/metabolism ; Transcription, Genetic
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 2003-12-20
    Description: Kinesin is a processive motor that takes 8.3-nm center-of-mass steps along microtubules for each adenosine triphosphate hydrolyzed. Whether kinesin moves by a "hand-over-hand" or an "inchworm" model has been controversial. We have labeled a single head of the kinesin dimer with a Cy3 fluorophore and localized the position of the dye to within 2 nm before and after a step. We observed that single kinesin heads take steps of 17.3 +/- 3.3 nm. A kinetic analysis of the dwell times between steps shows that the 17-nm steps alternate with 0-nm steps. These results strongly support a hand-over-hand mechanism, and not an inchworm mechanism. In addition, our results suggest that kinesin is bound by both heads to the microtubule while it waits for adenosine triphosphate in between steps.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Yildiz, Ahmet -- Tomishige, Michio -- Vale, Ronald D -- Selvin, Paul R -- AR42895/AR/NIAMS NIH HHS/ -- AR44420/AR/NIAMS NIH HHS/ -- New York, N.Y. -- Science. 2004 Jan 30;303(5658):676-8. Epub 2003 Dec 18.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Center for Biophysics and Computational Biology, University of Illinois, Urbana-Champaign, IL 61801, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/14684828" target="_blank"〉PubMed〈/a〉
    Keywords: Adenosine Triphosphate ; Carbocyanines ; Dimerization ; Fluorescence ; Fluorescent Dyes ; Humans ; Kinesin/chemistry/genetics/*metabolism ; Kinetics ; Microtubules/*metabolism ; *Models, Biological ; Models, Molecular ; Molecular Motor Proteins/chemistry/genetics/*metabolism ; Mutation ; Protein Conformation
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    Publication Date: 2003-02-15
    Description: Blood oxygen level-dependent functional magnetic resonance imaging uses alterations in brain hemodynamics to infer changes in neural activity. Are these hemodynamic changes regulated at a spatial scale capable of resolving functional columns within the cerebral cortex? To address this question, we made simultaneous measurements of tissue oxygenation and single-cell neural activity within the visual cortex. Results showed that increases in neuronal spike rate were accompanied by immediate decreases in tissue oxygenation. We used this decrease in tissue oxygenation to predict the orientation selectivity and ocular dominance of neighboring neurons. Our results establish a coupling between neural activity and oxidative metabolism and suggest that high-resolution functional magnetic resonance imaging may be used to localize neural activity at a columnar level.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Thompson, Jeffrey K -- Peterson, Matthew R -- Freeman, Ralph D -- EY01175/EY/NEI NIH HHS/ -- EY03176/EY/NEI NIH HHS/ -- T32 EY 07043-24/EY/NEI NIH HHS/ -- New York, N.Y. -- Science. 2003 Feb 14;299(5609):1070-2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Group in Vision Science, School of Optometry, Helen Willis Neuroscience Institute, University of California, Berkeley, CA 94720-2020, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12586942" target="_blank"〉PubMed〈/a〉
    Keywords: Action Potentials ; Animals ; Cats ; Cerebrovascular Circulation ; Dominance, Ocular ; Electrodes, Implanted ; Hemoglobins/metabolism ; Kinetics ; Magnetic Resonance Imaging ; Microelectrodes ; Neurons/*metabolism ; Oxygen/blood ; *Oxygen Consumption ; Photic Stimulation ; Visual Cortex/cytology/*metabolism/physiology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    Publication Date: 2003-03-01
    Description: A single antibody was shown to adopt different binding-site conformations and thereby bind unrelated antigens. Analysis by both x-ray crystallography and pre-steady-state kinetics revealed an equilibrium between different preexisting isomers, one of which possessed a promiscuous, low-affinity binding site for aromatic ligands, including the immunizing hapten. A subsequent induced-fit isomerization led to high-affinity complexes with a deep and narrow binding site. A protein antigen identified by repertoire selection made use of an unrelated antibody isomer with a wide, shallow binding site. Conformational diversity, whereby one sequence adopts multiple structures and multiple functions, can increase the effective size of the antibody repertoire but may also lead to autoimmunity and allergy.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉James, Leo C -- Roversi, Pietro -- Tawfik, Dan S -- New York, N.Y. -- Science. 2003 Feb 28;299(5611):1362-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Centre for Protein Engineering, Medical Research Council Centre, Hills Road, Cambridge CB2 2HQ, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12610298" target="_blank"〉PubMed〈/a〉
    Keywords: 2,4-Dinitrophenol/immunology ; Amino Acid Sequence ; Antibodies, Monoclonal/chemistry/immunology ; Antibody Diversity ; *Antibody Specificity ; Antigen-Antibody Complex ; Antigen-Antibody Reactions ; Antigens/*immunology ; Binding Sites, Antibody ; Cross Reactions ; Crystallization ; Crystallography, X-Ray ; Dimerization ; Haptens/immunology ; Hydrogen Bonding ; Immunoglobulin E/*chemistry/*immunology ; Immunoglobulin Fragments/chemistry/immunology ; Isomerism ; Kinetics ; Ligands ; Models, Molecular ; Molecular Sequence Data ; Peptide Library ; Protein Conformation ; Recombinant Proteins/immunology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    Publication Date: 2003-08-30
    Description: Lambda exonuclease processively degrades one strand of duplex DNA, moving 5'-to-3' in an ATP-independent fashion. When examined at the single-molecule level, the speeds of digestion were nearly constant at 4 nanometers per second (12 nucleotides per second), interspersed with pauses of variable duration. Long pauses, occurring at stereotypical locations, were strand-specific and sequence-dependent. Pause duration and probability varied widely. The strongest pause, GGCGAT TCT, was identified by gel electrophoresis. Correlating single-molecule dwell positions with sequence independently identified the motif GGCGA. This sequence is found in the left lambda cohesive end, where exonuclease inhibition may contribute to the reduced recombination efficiency at that end.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1539570/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1539570/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Perkins, Thomas T -- Dalal, Ravindra V -- Mitsis, Paul G -- Block, Steven M -- GM 57035/GM/NIGMS NIH HHS/ -- HG 011821-01/HG/NHGRI NIH HHS/ -- R01 GM057035/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2003 Sep 26;301(5641):1914-8. Epub 2003 Aug 28.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biological Sciences, Stanford University, Stanford, CA 94305, USA. tperkins@jila.colorado.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12947034" target="_blank"〉PubMed〈/a〉
    Keywords: Bacteriophage lambda/enzymology ; Base Pairing ; *Base Sequence ; Binding Sites ; Consensus Sequence ; DNA/*chemistry/*metabolism ; Electrophoresis, Polyacrylamide Gel ; Exodeoxyribonucleases/*metabolism ; Hydrogen Bonding ; Kinetics ; Models, Chemical ; Oligodeoxyribonucleotides/chemistry/metabolism ; Polymerase Chain Reaction ; Probability ; Stochastic Processes ; Time Factors ; Viral Proteins
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    Publication Date: 2003-08-30
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Blackburn, G Michael -- Williams, Nicholas H -- Gamblin, Steven J -- Smerdon, Stephen J -- New York, N.Y. -- Science. 2003 Aug 29;301(5637):1184; author reply 1184.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Krebs Institute, University of Sheffield, Sheffield, S3 7HF, UK. g.m.blackburn@shef.ac.uk〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12947182" target="_blank"〉PubMed〈/a〉
    Keywords: Binding Sites ; Catalysis ; Chemistry, Physical ; Crystallization ; Crystallography, X-Ray ; Fluorine Compounds/chemistry ; Kinetics ; Magnesium Compounds/chemistry ; Phosphates/chemistry ; Phosphoglucomutase/*chemistry/*metabolism ; Phosphoranes/chemistry ; Phosphorus/*chemistry ; Physicochemical Phenomena ; Protein Conformation ; Thermodynamics
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 2003-10-25
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wang, Lei -- New York, N.Y. -- Science. 2003 Oct 24;302(5645):584-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA. lewang@ucsd.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/14576413" target="_blank"〉PubMed〈/a〉
    Keywords: Alanine/analogs & derivatives/metabolism ; Awards and Prizes ; Codon ; Codon, Nonsense ; Codon, Terminator ; Escherichia coli/*genetics/metabolism ; *Genetic Code ; Kinetics ; Methanococcus/enzymology/genetics ; Methyltyrosines/*metabolism ; Mutation ; Naphthalenes/metabolism ; *Protein Biosynthesis ; RNA, Transfer/genetics/metabolism ; RNA, Transfer, Tyr/genetics/metabolism ; Suppression, Genetic ; Tetrahydrofolate Dehydrogenase/genetics/metabolism ; Tyrosine-tRNA Ligase/genetics/*metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    Publication Date: 2003-03-15
    Description: Biocatalysis has emerged as an important tool in the industrial synthesis of bulk chemicals, pharmaceutical and agrochemical intermediates, active pharmaceuticals, and food ingredients. However, the number and diversity of the applications are modest, perhaps in part because of perceived or real limitations of biocatalysts, such as limited enzyme availability, substrate scope, and operational stability. Recent scientific breakthroughs in genomics, directed enzyme evolution, and the exploitation of biodiversity should help to overcome these limitations. As a result, we expect many new industrial applications of biocatalysis to be realized, from single-step enzymatic conversions to customized multistep microbial synthesis by means of metabolic pathway engineering.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Schoemaker, Hans E -- Mink, Daniel -- Wubbolts, Marcel G -- New York, N.Y. -- Science. 2003 Mar 14;299(5613):1694-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉DSM Research, Life Science Products, Post Office Box 18, 6160 MD Geleen, Netherlands. hans.schoemaker@dsm.com〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12637735" target="_blank"〉PubMed〈/a〉
    Keywords: *Biotechnology ; Carbon/chemistry ; *Catalysis ; *Chemical Industry ; Chemistry, Organic ; Computational Biology ; Directed Molecular Evolution ; Ecosystem ; Enzyme Stability ; Enzymes/*chemistry/*metabolism ; Genetic Engineering ; Kinetics ; Organic Chemistry Phenomena ; Oxidation-Reduction ; Protein Engineering ; Recombinant Proteins/chemistry/metabolism ; Substrate Specificity ; Technology, Pharmaceutical
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    Publication Date: 2003-02-01
    Description: Heterochromatin protein 1 (HP1beta), a key component of condensed DNA, is strongly implicated in gene silencing and centromeric cohesion. Heterochromatin has been considered a static structure, stabilizing crucial aspects of nuclear organization and prohibiting access to transcription factors. We demonstrate here, by fluorescence recovery after photobleaching, that a green fluorescent protein-HP1beta fusion protein is highly mobile within both the euchromatin and heterochromatin of ex vivo resting murine T cells. Moreover, T cell activation greatly increased this mobility, indicating that such a process may facilitate (hetero)chromatin remodeling and permit access of epigenetic modifiers and transcription factors to the many genes that are consequently derepressed.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Festenstein, Richard -- Pagakis, Stamatis N -- Hiragami, Kyoko -- Lyon, Debbie -- Verreault, Alain -- Sekkali, Belaid -- Kioussis, Dimitris -- New York, N.Y. -- Science. 2003 Jan 31;299(5607):719-21.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉CSC Gene Control Mechanisms and Disease Group, Division of Medicine, Imperial College School of Medicine, Hammersmith Campus, Du Cane Road, London W12 ONN, UK. r.festenstein@ic.ac.uk〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12560554" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Binding Sites ; Cells, Cultured ; Chromosomal Proteins, Non-Histone/*metabolism ; Dimerization ; Euchromatin/*metabolism ; Fluorescence ; Fluorescence Recovery After Photobleaching ; Heterochromatin/*metabolism ; Histones/metabolism ; Kinetics ; Lymphocyte Activation ; Methylation ; Mice ; Microscopy, Confocal ; T-Lymphocytes/*metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 2003-04-19
    Description: The sequencing of complete genomes provides a list that includes the proteins responsible for cellular regulation. However, this does not immediately reveal what these proteins do, nor how they are assembled into the molecular machines and functional networks that control cellular behavior. The regulation of many different cellular processes requires the use of protein interaction domains to direct the association of polypeptides with one another and with phospholipids, small molecules, or nucleic acids. The modular nature of these domains, and the flexibility of their binding properties, have likely facilitated the evolution of cellular pathways. Conversely, aberrant interactions can induce abnormal cellular behavior and disease. The fundamental properties of protein interaction domains are discussed in this review and in detailed reviews on individual domains at Science's STKE at http://www.sciencemag.org/cgi/content/full/300/5618/445/DC1.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Pawson, Tony -- Nash, Piers -- New York, N.Y. -- Science. 2003 Apr 18;300(5618):445-52.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, Ontario M5G 1X5, Canada. pawson@mshri.on.ca〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12702867" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Motifs ; Animals ; Binding Sites ; Catalytic Domain ; *Cell Physiological Phenomena ; Cell Polarity ; Enzymes/chemistry/metabolism ; Evolution, Molecular ; Kinetics ; Protein Binding ; Protein Processing, Post-Translational ; Protein Structure, Secondary ; *Protein Structure, Tertiary ; Protein Transport ; Proteins/*chemistry/*metabolism ; Proteomics ; Receptors, Cell Surface/metabolism ; Repetitive Sequences, Amino Acid ; *Signal Transduction
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    Publication Date: 2003-08-30
    Description: We used a multiplexed approach based on flow-stretched DNA to monitor the enzymatic digestion of lambda-phage DNA by individual bacteriophage lambda exonuclease molecules. Statistical analyses of multiple single-molecule trajectories observed simultaneously reveal that the catalytic rate is dependent on the local base content of the substrate DNA. By relating single-molecule kinetics to the free energies of hydrogen bonding and base stacking, we establish that the melting of a base from the DNA is the rate-limiting step in the catalytic cycle. The catalytic rate also exhibits large fluctuations independent of the sequence, which we attribute to conformational changes of the enzyme-DNA complex.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉van Oijen, Antoine M -- Blainey, Paul C -- Crampton, Donald J -- Richardson, Charles C -- Ellenberger, Tom -- Xie, X Sunney -- 5R01GM61577-03/GM/NIGMS NIH HHS/ -- R01GM55390-07/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2003 Aug 29;301(5637):1235-8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12947199" target="_blank"〉PubMed〈/a〉
    Keywords: Bacteriophage lambda/*enzymology ; Base Composition ; Base Sequence ; Binding Sites ; Catalysis ; DNA, Single-Stranded/chemistry/*metabolism ; DNA, Viral/chemistry/*metabolism ; Exodeoxyribonucleases/chemistry/*metabolism ; Hydrogen Bonding ; Hydrolysis ; Kinetics ; Nucleic Acid Conformation ; Protein Conformation ; Thermodynamics ; Viral Proteins
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 2003-08-30
    Description: The seminal hypotheses proposed over the years for enzymatic catalysis are scrutinized. The historical record is explored from both biochemical and theoretical perspectives. Particular attention is given to the impact of molecular motions within the protein on the enzyme's catalytic properties. A case study for the enzyme dihydrofolate reductase provides evidence for coupled networks of predominantly conserved residues that influence the protein structure and motion. Such coupled networks have important implications for the origin and evolution of enzymes, as well as for protein engineering.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Benkovic, Stephen J -- Hammes-Schiffer, Sharon -- GM13306/GM/NIGMS NIH HHS/ -- GM24129/GM/NIGMS NIH HHS/ -- GM56207/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2003 Aug 29;301(5637):1196-202.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, 152 Davey Laboratory, Pennsylvania State University, University Park, PA 16802, USA. sjb1@psu.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12947189" target="_blank"〉PubMed〈/a〉
    Keywords: Binding Sites ; Catalysis ; Computer Simulation ; Crystallography, X-Ray ; Enzymes/*chemistry/*metabolism ; Kinetics ; Models, Chemical ; Nuclear Magnetic Resonance, Biomolecular ; Protein Conformation ; Tetrahydrofolate Dehydrogenase/*chemistry/*metabolism ; Thermodynamics
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    Publication Date: 2003-12-06
    Description: Kinesin is a double-headed motor protein that moves along microtubules in 8-nanometer steps. Two broad classes of model have been invoked to explain kinesin movement: hand-over-hand and inchworm. In hand-over-hand models, the heads exchange leading and trailing roles with every step, whereas no such exchange is postulated for inchworm models, where one head always leads. By measuring the stepwise motion of individual enzymes, we find that some kinesin molecules exhibit a marked alternation in the dwell times between sequential steps, causing these motors to "limp" along the microtubule. Limping implies that kinesin molecules strictly alternate between two different conformations as they step, indicative of an asymmetric, hand-over-hand mechanism.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1523256/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1523256/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Asbury, Charles L -- Fehr, Adrian N -- Block, Steven M -- R01 GM051453/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2003 Dec 19;302(5653):2130-4. Epub 2003 Dec 4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biological Sciences, Stanford University, Stanford, CA 94305, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/14657506" target="_blank"〉PubMed〈/a〉
    Keywords: Adenosine Triphosphate/metabolism ; Animals ; Computer Simulation ; Decapodiformes/enzymology ; Dimerization ; Drosophila Proteins/chemistry/physiology ; Drosophila melanogaster/*enzymology ; Humans ; Kinesin/*chemistry/*physiology ; Kinetics ; Microspheres ; Microtubules/metabolism ; Models, Molecular ; Molecular Motor Proteins/*chemistry/*physiology ; Movement ; Protein Conformation ; Protein Structure, Secondary ; Protein Structure, Tertiary ; Recombinant Proteins/chemistry ; Rotation
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    Publication Date: 2003-03-22
    Description: Mechanical unfolding trajectories for single molecules of the Tetrahymena thermophila ribozyme display eight intermediates corresponding to discrete kinetic barriers that oppose mechanical unfolding with lifetimes of seconds and rupture forces between 10 and 30 piconewtons. Barriers are magnesium dependent and correspond to known intra- and interdomain interactions. Several barrier structures are "brittle," breakage requiring high forces but small (1 to 3 nanometers) deformations. Barrier crossing is stochastic, leading to variable unfolding paths. The response of complex RNA structures to locally applied mechanical forces may be analogous to the responses of RNA during translation, messenger RNA export from the nucleus, and viral replication.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1503549/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1503549/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Onoa, Bibiana -- Dumont, Sophie -- Liphardt, Jan -- Smith, Steven B -- Tinoco, Ignacio Jr -- Bustamante, Carlos -- GM-10840/GM/NIGMS NIH HHS/ -- GM-32543/GM/NIGMS NIH HHS/ -- R01 GM010840/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2003 Mar 21;299(5614):1892-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physics and Department of Molecular and Cell Biology and Howard Hughes Medical Institute.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12649482" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Catalytic Domain ; Kinetics ; Magnesium ; Mutation ; Nucleic Acid Conformation ; Oligonucleotides, Antisense ; RNA, Catalytic/*chemistry/genetics ; Tetrahymena thermophila/*enzymology ; Thermodynamics
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    Publication Date: 2003-05-24
    Description: Numerous agents attack DNA, forming lesions that impair normal replication. Specialized DNA polymerases transiently replace the replicative polymerase and copy past lesions, thus generating mutations, the major initiating cause of cancer. We monitored, in Escherichia coli, the kinetics of replication of both strands of DNA molecules containing a single replication block in either the leading or lagging strand. Despite a block in the leading strand, lagging-strand synthesis proceeded further, implying transient uncoupling of concurrent strand synthesis. Replication through the lesion requires specialized DNA polymerases and is achieved with similar kinetics and efficiencies in both strands.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Pages, Vincent -- Fuchs, Robert P -- New York, N.Y. -- Science. 2003 May 23;300(5623):1300-3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Cancerogenese et Mutagenese Moleculaire et Structurale, Unite Propre de Recherche 9003; Centre National de la Recherche Scientifique, Ecole Superieure de Biotechnologie Boulevard S. Brant, 67400 Strasbourg, France.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12764199" target="_blank"〉PubMed〈/a〉
    Keywords: 2-Acetylaminofluorene/metabolism ; DNA Adducts/metabolism ; *DNA Damage ; DNA Polymerase II/genetics/metabolism ; DNA Repair ; *DNA Replication ; DNA, Bacterial/*biosynthesis ; DNA-Directed DNA Polymerase/genetics/metabolism ; Escherichia coli/genetics/*metabolism ; Escherichia coli Proteins ; Guanine/metabolism ; Kinetics ; *Plasmids ; SOS Response (Genetics)
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    Publication Date: 2003-05-10
    Description: The essential transition metal ions are avidly accumulated by cells, yet they have two faces: They are put to use as required cofactors, but they also can catalyze cytotoxic reactions. Several families of proteins are emerging that control the activity of intracellular metal ions and help confine them to vital roles. These include integral transmembrane transporters, metalloregulatory sensors, and diffusible cytoplasmic metallochaperone proteins that protect and guide metal ions to targets. It is becoming clear that many of these proteins use atypical coordination chemistry to accomplish their unique goals. The different coordination numbers, types of coordinating residues, and solvent accessibilities of these sites are providing insight into the inorganic chemistry of the cytoplasm.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Finney, Lydia A -- O'Halloran, Thomas V -- R01 GM038784/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2003 May 9;300(5621):931-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, Molecular Biology and Cell Biology, Northwestern University, Evanston, IL 60208-3113, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12738850" target="_blank"〉PubMed〈/a〉
    Keywords: Bacteria/metabolism ; Binding Sites ; Carrier Proteins/chemistry/*metabolism ; Copper/chemistry/metabolism ; Cytoplasm/*metabolism ; Homeostasis ; Ion Transport ; Iron/chemistry/metabolism ; Kinetics ; Metalloproteins/chemistry/*metabolism ; Metals/chemistry/*metabolism ; Mitochondria/metabolism ; Nickel/chemistry/metabolism ; Saccharomyces cerevisiae/metabolism ; Thermodynamics ; Transition Elements/chemistry/*metabolism ; Zinc/metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    Publication Date: 2003-08-30
    Description: In order to investigate the behavior of single molecules under conditions far from equilibrium, we have coupled a microfabricated laminar-flow mixer to a confocal optical system. This combination enables time-resolved measurement of Forster resonance energy transfer after an abrupt change in solution conditions. Observations of a small protein show the evolution of the intramolecular distance distribution as folding progresses. This technique can expose subpopulations, such as unfolded protein under conditions favoring the native structure, that would be obscured in equilibrium experiments.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lipman, Everett A -- Schuler, Benjamin -- Bakajin, Olgica -- Eaton, William A -- New York, N.Y. -- Science. 2003 Aug 29;301(5637):1233-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, Building 5, Room 104, National Institutes of Health, Bethesda, MD 20892-0520, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12947198" target="_blank"〉PubMed〈/a〉
    Keywords: Bacterial Proteins/*chemistry ; Cold Temperature ; Diffusion ; Energy Transfer ; Fluorescence ; Fluorescence Resonance Energy Transfer ; Kinetics ; Models, Molecular ; Protein Conformation ; Protein Denaturation ; *Protein Folding ; Thermodynamics ; Thermotoga maritima/*chemistry
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    Publication Date: 2003-09-27
    Description: The RNA interference (RNAi) pathway is initiated by processing long double-stranded RNA into small interfering RNA (siRNA). The siRNA-generating enzyme was purified from Drosophila S2cells and consists of two stoichiometric subunits: Dicer-2(DCR-2) and a previously unknown protein that we named R2D2. R2D2 is homologous to the Caenorhabditis elegans RNAi protein RDE-4. Association with R2D2 does not affect the enzymatic activity of DCR-2. Rather, the DCR-2/R2D2 complex, but not DCR-2 alone, binds to siRNA and enhances sequence-specific messenger RNA degradation mediated by the RNA-initiated silencing complex (RISC). These results indicate that R2D2 bridges the initiation and effector steps of the Drosophila RNAi pathway by facilitating siRNA passage from Dicer to RISC.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Liu, Qinghua -- Rand, Tim A -- Kalidas, Savitha -- Du, Fenghe -- Kim, Hyun-Eui -- Smith, Dean P -- Wang, Xiaodong -- DC02539/DC/NIDCD NIH HHS/ -- New York, N.Y. -- Science. 2003 Sep 26;301(5641):1921-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Howard Hughes Medical Institute and Department of Biochemistry, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/14512631" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Sequence ; Animals ; Argonaute Proteins ; Biotinylation ; Caenorhabditis elegans/genetics/metabolism ; Caenorhabditis elegans Proteins/chemistry ; Cell Line ; Chemical Precipitation ; Drosophila Proteins/chemistry/genetics/*isolation & purification/*metabolism ; Drosophila melanogaster/*genetics/metabolism ; Electrophoretic Mobility Shift Assay ; Endoribonucleases/genetics/isolation & purification/*metabolism ; Kinetics ; Molecular Sequence Data ; Mutation ; Protein Structure, Tertiary ; RNA Helicases/genetics/*isolation & purification/*metabolism ; *RNA Interference ; RNA, Double-Stranded/metabolism ; RNA, Messenger/metabolism ; RNA, Small Interfering/*metabolism ; RNA-Binding Proteins/chemistry/genetics/isolation & purification/*metabolism ; RNA-Induced Silencing Complex/isolation & purification/metabolism ; Recombinant Proteins/metabolism ; Ribonuclease III
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    Publication Date: 2003-10-04
    Description: Nitric oxide (NO) serves as a signal in plants. An Arabidopsis mutant (Atnos1) was identified that had impaired NO production, organ growth, and abscisic acid-induced stomatal movements. Expression of AtNOS1 with a viral promoter in Atnos1 mutant plants resulted in overproduction of NO. Purified AtNOS1 protein used the substrates arginine and nicotinamide adenine dinucleotide phosphate and was activated by Ca2+ and calmodulin-like mammalian endothelial nitric oxide synthase and neuronal nitric oxide synthase, yet it is a distinct enzyme with no sequence similarities to any mammalian isoform. Thus, AtNOS1 encodes a distinct nitric oxide synthase that regulates growth and hormonal signaling in plants.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Guo, Fang-Qing -- Okamoto, Mamoru -- Crawford, Nigel M -- GM 40672/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2003 Oct 3;302(5642):100-3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Section of Cell and Developmental Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/14526079" target="_blank"〉PubMed〈/a〉
    Keywords: Abscisic Acid/*pharmacology ; Amino Acid Sequence ; Arabidopsis/*enzymology/*genetics/growth & development ; Arabidopsis Proteins/chemistry/*genetics/isolation & purification/*metabolism ; Enzyme Inhibitors/pharmacology ; Genes, Plant ; Kinetics ; Light ; Molecular Sequence Data ; Mutation ; NG-Nitroarginine Methyl Ester/pharmacology ; Nitric Oxide/*metabolism ; Nitric Oxide Donors/pharmacology ; Nitric Oxide Synthase/chemistry/*genetics/isolation & purification/*metabolism ; Nitroprusside/pharmacology ; Plant Epidermis/drug effects/physiology ; Plant Leaves/enzymology/growth & development/physiology ; Plant Roots/growth & development ; Plant Shoots/growth & development ; *Signal Transduction
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 2002-12-03
    Description: The gastric pathogen Helicobacter pylori is known to be able to use molecular hydrogen as a respiratory substrate when grown in the laboratory. We found that hydrogen is available in the gastric mucosa of mice and that its use greatly increased the stomach colonization by H. pylori. Hydrogenase activity in H. pylori is constitutive but increased fivefold upon incubation with hydrogen. Hydrogen concentrations measured in the stomachs of live mice were found to be 10 to 50 times as high as the H. pylori affinity for hydrogen. A hydrogenase mutant strain is much less efficient in its colonization of mice. Therefore, hydrogen present in animals as a consequence of normal colonic flora is an energy-yielding substrate that can facilitate the maintenance of a pathogenic bacterium.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Olson, Jonathan W -- Maier, Robert J -- New York, N.Y. -- Science. 2002 Nov 29;298(5599):1788-90.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Microbiology, University of Georgia, Athens, GA 30602, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12459589" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Catechol 2,3-Dioxygenase ; Colon/metabolism/microbiology ; *Dioxygenases ; Energy Metabolism ; Fermentation ; Gastric Mucosa/*metabolism/*microbiology ; Gene Expression Regulation, Bacterial ; Genes, Reporter ; Helicobacter pylori/growth & development/*metabolism ; Hydrogen/*metabolism ; Hydrogenase/genetics/*metabolism ; Kinetics ; Mice ; Mutation ; Oxidation-Reduction ; Oxygenases/genetics/metabolism ; Transcription, Genetic
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    Publication Date: 2002-03-02
    Description: The second messenger cyclic adenosine monophosphate (cAMP) is the most important modulator of sympathetic control over cardiac contractility. In cardiac myocytes and many other cell types, however, cAMP transduces the signal generated upon stimulation of various receptors and activates different cellular functions, raising the issue of how specificity can be achieved. In the general field of signal transduction, the view is emerging that specificity is guaranteed by tight localization of signaling events. Here, we show that in neonatal rat cardiac myocytes, beta-adrenergic stimulation generates multiple microdomains with increased concentration of cAMP in correspondence with the region of the transverse tubule/junctional sarcoplasmic reticulum membrane. The restricted pools of cAMP show a range of action as small as approximately 1 micrometer, and free diffusion of the second messenger is limited by the activity of phosphodiesterases. Furthermore, we demonstrate that such gradients of cAMP specifically activate a subset of protein kinase A molecules anchored in proximity to the T tubule.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zaccolo, Manuela -- Pozzan, Tullio -- TCP00089/Telethon/Italy -- New York, N.Y. -- Science. 2002 Mar 1;295(5560):1711-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biomedical Sciences and Venetian Institute for Molecular Medicine, University of Padua, Via Orus 2, 35129 Padua, Italy. manuela.zaccolo@unipd.it〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11872839" target="_blank"〉PubMed〈/a〉
    Keywords: 1-Methyl-3-isobutylxanthine/pharmacology ; A Kinase Anchor Proteins ; Adaptor Proteins, Signal Transducing ; Animals ; Animals, Newborn ; Cells, Cultured ; Colforsin/pharmacology ; Cyclic AMP/*metabolism ; Cyclic AMP-Dependent Protein Kinases/metabolism ; Fluorescence ; Green Fluorescent Proteins ; Intracellular Membranes/metabolism ; Kinetics ; Luminescent Proteins ; Myocardium/*cytology/*metabolism/ultrastructure ; Norepinephrine/pharmacology ; Phosphodiesterase Inhibitors/pharmacology ; Proto-Oncogene Proteins/pharmacology ; Rats ; Receptors, Adrenergic, beta/*metabolism ; Recombinant Fusion Proteins/metabolism ; Sarcoplasmic Reticulum/*metabolism ; Second Messenger Systems ; Transfection
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    Publication Date: 2002-09-14
    Description: We report a photoactivatable variant of the Aequorea victoria green fluorescent protein (GFP) that, after intense irradiation with 413-nanometer light, increases fluorescence 100 times when excited by 488-nanometer light and remains stable for days under aerobic conditions. These characteristics offer a new tool for exploring intracellular protein dynamics by tracking photoactivated molecules that are the only visible GFPs in the cell. Here, we use the photoactivatable GFP both as a free protein to measure protein diffusion across the nuclear envelope and as a chimera with a lysosomal membrane protein to demonstrate rapid interlysosomal membrane exchange.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Patterson, George H -- Lippincott-Schwartz, Jennifer -- New York, N.Y. -- Science. 2002 Sep 13;297(5588):1873-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12228718" target="_blank"〉PubMed〈/a〉
    Keywords: Aerobiosis ; Amino Acid Substitution ; Antigens, CD/metabolism ; Cell Nucleus/metabolism ; Cytoplasm/metabolism ; *Fluorescence ; Green Fluorescent Proteins ; Intracellular Membranes/metabolism ; Kinetics ; *Light ; Luminescent Proteins/*chemistry/genetics/isolation & purification/*metabolism ; Lysosome-Associated Membrane Glycoproteins ; Lysosomes/*metabolism ; Membrane Glycoproteins/metabolism ; Nuclear Envelope/metabolism ; Protein Engineering ; Protein Transport ; Proteins/*metabolism ; Recombinant Fusion Proteins/metabolism ; Spectrometry, Fluorescence
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    Publication Date: 2002-03-09
    Description: Time courses of translocation of fluorescently conjugated proteins to the plasma membrane were simultaneously measured in thousands of individual rat basophilic leukemia cells. We found that the C2 domain---a calcium-sensing, lipid-binding protein module that is an essential regulator of protein kinase C and numerous other proteins---targeted proteins to the plasma membrane transiently if calcium was released from internal stores, and persistently in response to entry of extracellular calcium across the plasma membrane. The C2 domain translocation time courses of stimulated cells clustered into only two primary modes. Hence, the reversible recruitment of families of signaling proteins from one cellular compartment to another is a rapid bifurcation mechanism for inducing discrete states of cellular signaling networks.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Teruel, Mary N -- Meyer, Tobias -- CA83229/CA/NCI NIH HHS/ -- GM062144/GM/NIGMS NIH HHS/ -- HG00057/HG/NHGRI NIH HHS/ -- New York, N.Y. -- Science. 2002 Mar 8;295(5561):1910-2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular Pharmacology, Stanford University Medical School, 269 Campus Drive, Stanford, CA 94305, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11884760" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Bacterial Proteins ; Calcium/*metabolism ; *Calcium Signaling ; Cell Membrane/*metabolism ; Cytosol/metabolism ; Fluorescence ; Fluorescent Dyes ; Isoenzymes/chemistry/*metabolism ; Kinetics ; Luminescent Proteins ; Platelet Activating Factor/pharmacology ; Protein Binding ; Protein Kinase C/chemistry/*metabolism ; Protein Structure, Tertiary ; *Protein Transport ; Rats ; Receptors, Cell Surface/*metabolism ; Recombinant Fusion Proteins/metabolism ; Software ; Thapsigargin/pharmacology ; Transfection ; Tumor Cells, Cultured
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    Publication Date: 2002-12-03
    Description: The Survival of Motor Neurons (SMN) protein, the product of the spinal muscular atrophy-determining gene, is part of a large macromolecular complex (SMN complex) that functions in the assembly of spliceosomal small nuclear ribonucleoproteins (snRNPs). Using cell extracts and purified components, we demonstrated that the SMN complex is necessary and sufficient to mediate the ATP-dependent assembly of the core of seven Sm proteins on uridine-rich, small nuclear ribonucleic acids (U snRNAs). In vitro experiments revealed strict requirements for ordered binding of the Sm proteins and the U snRNAs to the SMN complex. Importantly, the SMN complex is necessary to ensure that Sm cores assemble only on correct RNA targets and prevent their otherwise promiscuous association with other RNAs. Thus, the SMN complex functions as a specificity factor essential for the efficient assembly of Sm proteins on U snRNAs and likely protects cells from illicit, and potentially deleterious, nonspecific binding of Sm proteins to RNAs.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Pellizzoni, Livio -- Yong, Jeongsik -- Dreyfuss, Gideon -- New York, N.Y. -- Science. 2002 Nov 29;298(5599):1775-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Howard Hughes Medical Institute and Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104-6148, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12459587" target="_blank"〉PubMed〈/a〉
    Keywords: Adenosine Triphosphate/metabolism ; Carrier Proteins/metabolism ; Cell Extracts ; Cyclic AMP Response Element-Binding Protein ; DEAD Box Protein 20 ; DEAD-box RNA Helicases ; HeLa Cells ; Humans ; Kinetics ; Models, Biological ; Nerve Tissue Proteins/isolation & purification/*metabolism ; Nuclear Proteins/metabolism ; Oligoribonucleotides/metabolism ; Protein Binding ; RNA Helicases/metabolism ; RNA, Small Nuclear/*metabolism ; RNA-Binding Proteins ; Ribonucleoproteins, Small Nuclear/isolation & purification/*metabolism ; SMN Complex Proteins
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    Publication Date: 2002-05-25
    Description: We have studied the correlation between structural dynamics and function of the hairpin ribozyme. The enzyme-substrate complex exists in either docked (active) or undocked (inactive) conformations. Using single-molecule fluorescence methods, we found complex structural dynamics with four docked states of distinct stabilities and a strong memory effect where each molecule rarely switches between different docked states. We also found substrate cleavage to be rate-limited by a combination of conformational transitions and reversible chemistry equilibrium. The complex structural dynamics quantitatively explain the heterogeneous cleavage kinetics common to many catalytic RNAs. The intimate coupling of structural dynamics and function is likely a general phenomenon for RNA.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zhuang, Xiaowei -- Kim, Harold -- Pereira, Miguel J B -- Babcock, Hazen P -- Walter, Nils G -- Chu, Steven -- GM62357/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2002 May 24;296(5572):1473-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physics, Stanford University, Stanford, CA 94305, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12029135" target="_blank"〉PubMed〈/a〉
    Keywords: Carbocyanines/metabolism ; Catalysis ; Enzymes, Immobilized ; Fluorescence ; Hydrogen Bonding ; Kinetics ; Nepovirus/genetics ; Nucleic Acid Conformation ; RNA, Catalytic/*chemistry/*metabolism ; RNA, Satellite ; RNA, Viral/*chemistry/*metabolism ; Spectrometry, Fluorescence ; Thermodynamics
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 2002-02-23
    Description: Internal protein dynamics are intimately connected to enzymatic catalysis. However, enzyme motions linked to substrate turnover remain largely unknown. We have studied dynamics of an enzyme during catalysis at atomic resolution using nuclear magnetic resonance relaxation methods. During catalytic action of the enzyme cyclophilin A, we detect conformational fluctuations of the active site that occur on a time scale of hundreds of microseconds. The rates of conformational dynamics of the enzyme strongly correlate with the microscopic rates of substrate turnover. The present results, together with available structural data, allow a prediction of the reaction trajectory.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Eisenmesser, Elan Zohar -- Bosco, Daryl A -- Akke, Mikael -- Kern, Dorothee -- GM62117/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2002 Feb 22;295(5559):1520-3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, Brandeis University, Waltham, MA 02454, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11859194" target="_blank"〉PubMed〈/a〉
    Keywords: Binding Sites ; Catalysis ; Cyclophilin A/*chemistry/*metabolism ; Hydrogen Bonding ; Isomerism ; Kinetics ; Mathematics ; Models, Molecular ; Nuclear Magnetic Resonance, Biomolecular ; Protein Binding ; Protein Conformation
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    Publication Date: 2002-02-09
    Description: Light synchronizes mammalian circadian rhythms with environmental time by modulating retinal input to the circadian pacemaker-the suprachiasmatic nucleus (SCN) of the hypothalamus. Such photic entrainment requires neither rods nor cones, the only known retinal photoreceptors. Here, we show that retinal ganglion cells innervating the SCN are intrinsically photosensitive. Unlike other ganglion cells, they depolarized in response to light even when all synaptic input from rods and cones was blocked. The sensitivity, spectral tuning, and slow kinetics of this light response matched those of the photic entrainment mechanism, suggesting that these ganglion cells may be the primary photoreceptors for this system.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Berson, David M -- Dunn, Felice A -- Takao, Motoharu -- EY12793/EY/NEI NIH HHS/ -- New York, N.Y. -- Science. 2002 Feb 8;295(5557):1070-3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Neuroscience, Brown University, Providence, RI, 02912 USA. David_Berson@brown.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11834835" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Axons/ultrastructure ; *Biological Clocks ; *Circadian Rhythm ; Dendrites/ultrastructure ; Isoquinolines ; Kinetics ; Light ; *Light Signal Transduction ; Patch-Clamp Techniques ; Rats ; Rats, Sprague-Dawley ; Retinal Ganglion Cells/chemistry/cytology/*physiology ; Rod Opsins/analysis/physiology ; Suprachiasmatic Nucleus/cytology/*physiology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    Publication Date: 2002-08-24
    Description: Insulin secretion from intact mouse pancreatic islets was investigated with two-photon excitation imaging. Insulin granule exocytosis occurred mainly toward the interstitial space, away from blood vessels. The fusion pore was unusually stable with a lifetime of 1.8 seconds. Opening of the 1.4-nanometer-diameter pore was preceded by unrestricted lateral diffusion of lipids along the inner wall of the pore, supporting the idea that this structure is composed of membrane lipids. When the pore dilated to 12 nanometers, the granules rapidly flattened and discharged their contents. Thus, our methodology reveals fusion pore dynamics in intact tissues at nanometer resolution.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Takahashi, Noriko -- Kishimoto, Takuya -- Nemoto, Tomomi -- Kadowaki, Takashi -- Kasai, Haruo -- New York, N.Y. -- Science. 2002 Aug 23;297(5585):1349-52.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Cell Physiology, National Institute for Physiological Sciences, and the Graduate University of Advanced Studies, Myodaiji, Okazaki 444-8585, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12193788" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Cell Membrane/physiology/*ultrastructure ; Cell Polarity ; Colforsin/pharmacology ; Diffusion ; *Exocytosis ; Extracellular Space ; Fluorescence ; Glucose/pharmacology ; Guinea Pigs ; Image Processing, Computer-Assisted ; Insulin/*secretion ; Intracellular Membranes/physiology/ultrastructure ; Islets of Langerhans/blood supply/*physiology/secretion/*ultrastructure ; Kinetics ; Membrane Fusion ; Membrane Lipids/physiology ; Mice ; Mice, Inbred ICR ; Permeability ; Pyridinium Compounds ; Quaternary Ammonium Compounds ; Rhodamines ; Secretory Vesicles/physiology/*ultrastructure
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 2002-11-26
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Couzin, Jennifer -- New York, N.Y. -- Science. 2002 Nov 22;298(5598):1538.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12446883" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Cell Nucleus/*metabolism ; Computer Simulation ; Fluorescent Dyes ; Genes ; Kinetics ; Microscopy ; Models, Genetic ; Pol1 Transcription Initiation Complex Proteins/metabolism ; RNA Polymerase I/*metabolism ; RNA Polymerase II/metabolism ; *Transcription, Genetic
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    Publication Date: 2002-04-16
    Description: A practical, inexpensive, green chemical process for degrading environmental pollutants is greatly needed, especially for persistent chlorinated pollutants. Here we describe the activation of hydrogen peroxide by tetraamidomacrocylic ligand (TAML) iron catalysts, to destroy the priority pollutants pentachlorophenol (PCP) and 2,4,6-trichlorophenol (TCP). In water, in minutes, under ambient conditions of temperature and pressure, PCP and TCP are completely destroyed at catalyst:substrate ratios of 1:715 and 1:2000, respectively. The fate of about 90% of the carbon and about 99% of the chlorine has been determined in each case. Neither dioxins nor any other toxic compounds are detectable products, and the catalysts themselves show low toxicity.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gupta, Sayam Sen -- Stadler, Matthew -- Noser, Christopher A -- Ghosh, Anindya -- Steinhoff, Bradley -- Lenoir, Dieter -- Horwitz, Colin P -- Schramm, Karl-Werner -- Collins, Terrence J -- GM44867-05/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2002 Apr 12;296(5566):326-8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA 15213, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11951040" target="_blank"〉PubMed〈/a〉
    Keywords: Catalysis ; Chlorine Compounds/chemistry ; Chlorophenols/*chemistry ; Dioxins/chemistry ; Environmental Pollutants ; Ferric Compounds/*chemistry/toxicity ; Gas Chromatography-Mass Spectrometry ; Heterocyclic Compounds with 4 or More Rings/*chemistry/toxicity ; Hydrogen Peroxide/*chemistry ; Hydrogen-Ion Concentration ; Kinetics ; Magnetic Resonance Spectroscopy ; Oxidation-Reduction ; Pentachlorophenol/*chemistry ; Pressure ; Spectrometry, Mass, Electrospray Ionization ; Temperature
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    Publication Date: 2002-11-26
    Description: We have analyzed the kinetics of assembly and elongation of the mammalian RNA polymerase I complex on endogenous ribosomal genes in the nuclei of living cells with the use of in vivo microscopy. We show that components of the RNA polymerase I machinery are brought to ribosomal genes as distinct subunits and that assembly occurs via metastable intermediates. With the use of computational modeling of imaging data, we have determined the in vivo elongation time of the polymerase, and measurements of recruitment and incorporation frequencies show that incorporation of components into the assembling polymerase is inefficient. Our data provide a kinetic and mechanistic framework for the function of a mammalian RNA polymerase in living cells.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Dundr, Miroslav -- Hoffmann-Rohrer, Urs -- Hu, Qiyue -- Grummt, Ingrid -- Rothblum, Lawrence I -- Phair, Robert D -- Misteli, Tom -- New York, N.Y. -- Science. 2002 Nov 22;298(5598):1623-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉National Cancer Institute (NCI), National Institutes of Health, Bethesda, MD 20892, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12446911" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Catalytic Domain ; Cell Line ; Cell Nucleolus/metabolism ; Cell Nucleus/*metabolism ; Computer Simulation ; DNA, Ribosomal/genetics ; Fluorescence ; Fluorescence Recovery After Photobleaching ; Fluorescent Dyes ; Green Fluorescent Proteins ; Haplorhini ; Humans ; In Situ Hybridization, Fluorescence ; Kinetics ; Least-Squares Analysis ; Luminescent Proteins ; Microscopy ; Pol1 Transcription Initiation Complex Proteins/metabolism ; Probability ; Promoter Regions, Genetic ; Protein Subunits ; RNA Polymerase I/genetics/*metabolism ; Recombinant Fusion Proteins/metabolism ; *Transcription, Genetic ; Transfection
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    Publication Date: 2002-08-31
    Description: The latitudinal gradient of increasing biodiversity from poles to equator is one of the most prominent but least understood features of life on Earth. Here we show that species diversity can be predicted from the biochemical kinetics of metabolism. We first demonstrate that the average energy flux of populations is temperature invariant. We then derive a model that quantitatively predicts how species diversity increases with environmental temperature. Predictions are supported by data for terrestrial, freshwater, and marine taxa along latitudinal and elevational gradients. These results establish a thermodynamic basis for the regulation of species diversity and the organization of ecological communities.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Allen, Andrew P -- Brown, James H -- Gillooly, James F -- New York, N.Y. -- Science. 2002 Aug 30;297(5586):1545-8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA. drewa@unm.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12202828" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Body Constitution ; *Ecosystem ; Kinetics ; *Models, Biological ; Plants ; Temperature ; Thermodynamics
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    Publication Date: 2002-01-19
    Description: The separate components of nucleocytoplasmic transport have been well characterized, including the key regulatory role of Ran, a guanine nucleotide triphosphatase. However, the overall system behavior in intact cells is difficult to analyze because the dynamics of these components are interdependent. We used a combined experimental and computational approach to study Ran transport in vivo. The resulting model provides the first quantitative picture of Ran flux between the nuclear and cytoplasmic compartments in eukaryotic cells. The model predicts that the Ran exchange factor RCC1, and not the flux capacity of the nuclear pore complex (NPC), is the crucial regulator of steady-state flux across the NPC. Moreover, it provides the first estimate of the total in vivo flux (520 molecules per NPC per second and predicts that the transport system is robust.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Smith, Alicia E -- Slepchenko, Boris M -- Schaff, James C -- Loew, Leslie M -- Macara, Ian G -- GM-50526/GM/NIGMS NIH HHS/ -- NCRR-RR13186/RR/NCRR NIH HHS/ -- NIH-GM-20438/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2002 Jan 18;295(5554):488-91.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Center for Cell Signaling, Department of Pharmacology, University of Virginia, Charlottesville, VA 22908, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11799242" target="_blank"〉PubMed〈/a〉
    Keywords: Active Transport, Cell Nucleus ; Animals ; *Cell Cycle Proteins ; Cell Line ; Cell Nucleus/metabolism ; *Computer Simulation ; Cricetinae ; Cytoplasm/metabolism ; Diffusion ; Fluorescence ; Guanine Nucleotide Exchange Factors/metabolism ; Guanosine Triphosphate/metabolism ; Kinetics ; Mathematics ; *Models, Biological ; Mutation ; Nuclear Pore/*metabolism ; *Nuclear Proteins ; Nucleocytoplasmic Transport Proteins/metabolism ; Recombinant Proteins/metabolism ; Temperature ; ran GTP-Binding Protein/genetics/*metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    Publication Date: 2002-08-06
    Description: The vibrational dynamics of the retinal chromophore all-trans-to-13-cis photoisomerization in bacteriorhodopsin has been studied with mid-infrared absorption spectroscopy at high time resolution (about 200 femtoseconds). After photoexcitation of light-adapted bacteriorhodopsin, the transient infrared absorption was probed in a broad spectral region, including vibrations with dominant C-C, C=C, and C=NH stretching mode amplitude. All photoproduct modes, especially those around 1190 reciprocal-centimeters that are indicative for a 13-cis configuration of the chromophore, rise with a time constant of approximately 0.5 picosecond. The results presented give direct vibrational-spectroscopic evidence for the isomerization taking place within 0.5 picosecond, as has been suggested by previous optical femtosecond time-resolved experiments but questioned recently by picosecond time-resolved vibrational spectroscopy experiments.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Herbst, Johannes -- Heyne, Karsten -- Diller, Rolf -- New York, N.Y. -- Science. 2002 Aug 2;297(5582):822-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institut fur Experimentalphysik, Freie Universitat Berlin, Arnimallee 14, 14195 Berlin, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12161649" target="_blank"〉PubMed〈/a〉
    Keywords: Bacteriorhodopsins/*chemistry/*metabolism ; Binding Sites ; Isomerism ; Kinetics ; Light ; Photochemistry ; Retinaldehyde/*chemistry/*metabolism ; Spectrophotometry, Infrared/*methods ; Spectroscopy, Fourier Transform Infrared ; Time Factors ; Vibration
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    Publication Date: 2002-05-25
    Description: Pyrrolysine is a lysine derivative encoded by the UAG codon in methylamine methyltransferase genes of Methanosarcina barkeri. Near a methyltransferase gene cluster is the pylT gene, which encodes an unusual transfer RNA (tRNA) with a CUA anticodon. The adjacent pylS gene encodes a class II aminoacyl-tRNA synthetase that charges the pylT-derived tRNA with lysine but is not closely related to known lysyl-tRNA synthetases. Homologs of pylS and pylT are found in a Gram-positive bacterium. Charging a tRNA(CUA) with lysine is a likely first step in translating UAG amber codons as pyrrolysine in certain methanogens. Our results indicate that pyrrolysine is the 22nd genetically encoded natural amino acid.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Srinivasan, Gayathri -- James, Carey M -- Krzycki, Joseph A -- New York, N.Y. -- Science. 2002 May 24;296(5572):1459-62.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Microbiology, Ohio State University, Columbus, OH 43210, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/12029131" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Sequence ; Amino Acyl-tRNA Synthetases/chemistry/*genetics/metabolism ; Anticodon ; Archaeal Proteins ; Base Sequence ; Catalytic Domain ; *Codon ; Codon, Terminator ; Kinetics ; Lysine/analogs & derivatives/chemistry/*genetics/metabolism ; Methanosarcina barkeri/chemistry/enzymology/*genetics ; Methyltransferases/genetics/metabolism ; Molecular Sequence Data ; Nucleic Acid Conformation ; Protein Biosynthesis ; RNA, Archaeal/chemistry/genetics/metabolism ; RNA, Transfer/chemistry/*genetics/metabolism ; Recombinant Proteins/metabolism ; Sequence Alignment
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    Publication Date: 2002-03-02
    Description: Protein folding and unfolding are coupled to a range of biological phenomena, from the regulation of cellular activity to the onset of neurodegenerative diseases. Defining the nature of the conformations sampled in nonnative proteins is crucial for understanding the origins of such phenomena. We have used a combination of nuclear magnetic resonance (NMR) spectroscopy and site-directed mutagenesis to study unfolded states of the protein lysozyme. Extensive clusters of hydrophobic structure exist within the wild-type protein even under strongly denaturing conditions. These clusters involve distinct regions of the sequence but are all disrupted by a single point mutation that replaced residue Trp62 with Gly located at the interface of the two major structural domains in the native state. Thus, nativelike structure in the denatured protein is stabilized by the involvement of Trp62 in nonnative and long-range interactions.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Klein-Seetharaman, Judith -- Oikawa, Maki -- Grimshaw, Shaun B -- Wirmer, Julia -- Duchardt, Elke -- Ueda, Tadashi -- Imoto, Taiji -- Smith, Lorna J -- Dobson, Christopher M -- Schwalbe, Harald -- New York, N.Y. -- Science. 2002 Mar 1;295(5560):1719-22.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Massachusetts Institute of Technology, Department of Chemistry, Francis Bitter Magnet Laboratory, 170 Albany Street, Cambridge, MA 02139, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11872841" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Substitution ; Animals ; Chickens ; Cysteine/chemistry ; Disulfides/chemistry ; Glycine/chemistry ; Hydrophobic and Hydrophilic Interactions ; Kinetics ; Muramidase/*chemistry/genetics ; Mutagenesis, Site-Directed ; Nuclear Magnetic Resonance, Biomolecular ; Point Mutation ; *Protein Conformation ; Protein Denaturation ; *Protein Folding ; Protein Structure, Secondary ; Protein Structure, Tertiary ; Tryptophan/chemistry
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 64
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 2002-03-23
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Koshland, Daniel E Jr -- New York, N.Y. -- Science. 2002 Mar 22;295(5563):2215-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3206, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11910092" target="_blank"〉PubMed〈/a〉
    Keywords: Adaptation, Physiological ; Animals ; Biological Evolution ; DNA/physiology ; Energy Metabolism ; Feedback, Physiological ; Humans ; Kinetics ; *Life ; Origin of Life ; Reproduction ; Substrate Specificity ; *Terminology as Topic ; Thermodynamics
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 65
    Publication Date: 2001-03-27
    Description: Receptor-mediated activation of heterotrimeric GTP-binding proteins (G-proteins) was visualized in living Dictyostelium discoideum cells by monitoring fluorescence resonance energy transfer (FRET) between alpha- and beta- subunits fused to cyan and yellow fluorescent proteins. The G-protein heterotrimer rapidly dissociated and reassociated upon addition and removal of chemoattractant. During continuous stimulation, G-protein activation reached a dose-dependent steady-state level. Even though physiological responses subsided, the activation did not decline. Thus, adaptation occurs at another point in the signaling pathway, and occupied receptors, whether or not they are phosphorylated, catalyze the G-protein cycle. Construction of similar energy-transfer pairs of mammalian G-proteins should enable direct in situ mechanistic studies and applications such as drug screening and identifying ligands of newly found G-protein-coupled receptors.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Janetopoulos, C -- Jin, T -- Devreotes, P -- GM28007/GM/NIGMS NIH HHS/ -- GM34933/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2001 Mar 23;291(5512):2408-11.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biological Chemistry, Johns Hopkins Medical Institutions, Baltimore, MD 21205, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11264536" target="_blank"〉PubMed〈/a〉
    Keywords: 8-Bromo Cyclic Adenosine Monophosphate/pharmacology ; Animals ; Bacterial Proteins ; Cyclic AMP/metabolism/*pharmacology ; Deoxyadenine Nucleotides/pharmacology ; Dictyostelium/*metabolism ; Energy Transfer ; Fluorescence ; Guanosine 5'-O-(3-Thiotriphosphate)/pharmacology ; Heterotrimeric GTP-Binding Proteins/*metabolism ; Kinetics ; Ligands ; Luminescent Proteins ; Microscopy, Fluorescence ; Phosphorylation ; Receptors, Cyclic AMP/*metabolism ; Recombinant Fusion Proteins/metabolism ; *Signal Transduction ; Spectrometry, Fluorescence ; Transformation, Genetic
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 66
    Publication Date: 2001-01-06
    Description: All aspects of cellular RNA metabolism and the replication of many viruses require DExH/D proteins that manipulate RNA in a manner that requires nucleoside triphosphates. Although DExH/D proteins have been shown to unwind purified RNA duplexes, most RNA molecules in the cellular environment are complexed with proteins. It has therefore been speculated that DExH/D proteins may also affect RNA-protein interactions. We demonstrate that the DExH protein NPH-II from vaccinia virus can displace the protein U1A from RNA in an active adenosine triphosphate-dependent fashion. NPH-II increases the rate of U1A dissociation by more than three orders of magnitude while retaining helicase processivity. This indicates that DExH/D proteins can effectively catalyze protein displacement from RNA and thereby participate in the structural reorganization of ribonucleoprotein assemblies.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Jankowsky, E -- Gross, C H -- Shuman, S -- Pyle, A M -- New York, N.Y. -- Science. 2001 Jan 5;291(5501):121-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA. 02115, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11141562" target="_blank"〉PubMed〈/a〉
    Keywords: 3' Untranslated Regions/metabolism ; Acid Anhydride Hydrolases/chemistry/*metabolism ; Adenosine Triphosphate/metabolism ; Base Sequence ; Binding Sites ; Kinetics ; Models, Molecular ; Molecular Sequence Data ; Nucleic Acid Conformation ; Nucleoside-Triphosphatase ; Protein Binding ; Protein Conformation ; RNA/chemistry/*metabolism ; RNA Helicases/chemistry/*metabolism ; *RNA-Binding Proteins ; Ribonucleoprotein, U1 Small Nuclear/*metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 67
    Publication Date: 2001-07-21
    Description: The promoters of cell adhesion are ligands, which are often attached to flexible tethers that bind to surface receptors on adjacent cells. Using a combination of Monte Carlo simulations, diffusion reaction theory, and direct experiments (surface force measurements) of the biotin-streptavidin system, we have quantified polymer chain dynamics and the kinetics and spatial range of tethered ligand-receptor binding. The results show that the efficiency of strong binding does not depend solely on the molecular architecture or binding energy of the receptor-ligand pair, nor on the equilibrium configuration of the polymer tether, but rather on its "rare" extended conformations.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Jeppesen, C -- Wong, J Y -- Kuhl, T L -- Israelachvili, J N -- Mullah, N -- Zalipsky, S -- Marques, C M -- GM-17876/GM/NIGMS NIH HHS/ -- GM-47334/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2001 Jul 20;293(5529):465-8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Materials Research Laboratory, Department of Chemical Engineering, University of California, Santa Barbara, CA 93106, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11463908" target="_blank"〉PubMed〈/a〉
    Keywords: Biotin/*chemistry/metabolism ; Chemistry, Physical ; Diffusion ; Kinetics ; Ligands ; Mathematics ; Monte Carlo Method ; Physicochemical Phenomena ; Polyethylene Glycols ; Polymers/*chemistry ; Protein Conformation ; Streptavidin/*chemistry/metabolism ; Surface Properties ; Thermodynamics
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 68
    Publication Date: 2001-11-17
    Description: Proteins are transported from the endoplasmic reticulum (ER) in vesicles formed by coat protein complex II (COPII). Soluble secretory proteins are thought to leave the ER in these vesicles by "bulk flow" or through recognition by hypothetical shuttling receptors. We found that Erv29p, a conserved transmembrane protein, was directly required for packaging glycosylated pro-alpha-factor (gpalphaf) into COPII vesicles in Saccharomyces cerevisiae. Further, an Erv29p-gpalphaf complex was isolated from ER-derived transport vesicles. In vivo, export of gpalphaf from the ER was saturable and depended on the expression level of Erv29p. These results indicate that membrane receptors can link soluble cargo proteins to the COPII coat.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Belden, W J -- Barlowe, C -- New York, N.Y. -- Science. 2001 Nov 16;294(5546):1528-31.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry, Dartmouth Medical School, Hanover, NH 03755, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11711675" target="_blank"〉PubMed〈/a〉
    Keywords: COP-Coated Vesicles/*metabolism ; Carboxypeptidases/metabolism ; Cathepsin A ; Cross-Linking Reagents ; Dimerization ; Endoplasmic Reticulum/*metabolism ; Glycosylation ; Golgi Apparatus/metabolism ; Kinetics ; Membrane Proteins/chemistry/genetics/isolation & purification/*metabolism ; Membrane Transport Proteins ; Peptides/chemistry/genetics/isolation & purification/*metabolism ; Precipitin Tests ; Protein Folding ; Protein Precursors/chemistry/isolation & purification/*metabolism ; Protein Transport ; Qb-SNARE Proteins ; Saccharomyces cerevisiae/genetics/*metabolism/ultrastructure ; *Saccharomyces cerevisiae Proteins ; Solubility ; Succinimides/pharmacology ; *Vesicular Transport Proteins
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 69
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 2001-12-18
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Berendsen, H J -- New York, N.Y. -- Science. 2001 Dec 14;294(5550):2304-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Nijenborgh 4, 9747 AG Groningen, Netherlands. berendsen@chem.rug.nl〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11743188" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Motifs ; Aquaporin 1 ; Aquaporins/chemistry/*metabolism ; Bacterial Outer Membrane Proteins/chemistry/*metabolism ; Cell Membrane Permeability ; *Computational Biology ; *Computer Simulation ; *Escherichia coli Proteins ; Hydrogen Bonding ; Kinetics ; Lipid Bilayers ; *Models, Biological ; Permeability ; Static Electricity ; Time Factors ; Water/*metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 70
    Publication Date: 2001-02-07
    Description: The disulfide reducing enzymes glutathione reductase and thioredoxin reductase are highly conserved among bacteria, fungi, worms, and mammals. These proteins maintain intracellular redox homeostasis to protect the organism from oxidative damage. Here we demonstrate the absence of glutathione reductase in Drosophila melanogaster, identify a new type of thioredoxin reductase, and provide evidence that a thioredoxin system supports GSSG reduction. Our data suggest that antioxidant defense in Drosophila, and probably in related insects, differs fundamentally from that in other organisms.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kanzok, S M -- Fechner, A -- Bauer, H -- Ulschmid, J K -- Muller, H M -- Botella-Munoz, J -- Schneuwly, S -- Schirmer, R -- Becker, K -- New York, N.Y. -- Science. 2001 Jan 26;291(5504):643-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Center of Biochemistry, Im Neuenheimer Feld 328, Heidelberg University, D-69120 Heidelberg, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11158675" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Motifs ; Amino Acid Sequence ; Animals ; Binding Sites ; Drosophila melanogaster/*enzymology/genetics/metabolism ; Genes, Insect ; Glutathione/*metabolism ; Glutathione Disulfide/metabolism ; Glutathione Reductase/*metabolism ; Humans ; Kinetics ; Molecular Sequence Data ; Mutation ; NADP/metabolism ; Oxidation-Reduction ; Sequence Alignment ; Species Specificity ; Substrate Specificity ; Thioredoxin-Disulfide Reductase/antagonists & ; inhibitors/chemistry/*genetics/*metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 71
    Publication Date: 2001-11-03
    Description: The bacterial macrolide rapamycin is an efficacious anticancer agent against solid tumors. In a hypoxic environment, the increase in mass of solid tumors is dependent on the recruitment of mitogens and nutrients. When nutrient concentrations change, particularly those of essential amino acids, the mammalian Target of Rapamycin (mTOR) functions in regulatory pathways that control ribosome biogenesis and cell growth. In bacteria, ribosome biogenesis is independently regulated by amino acids and adenosine triphosphate (ATP). Here we demonstrate that the mTOR pathway is influenced by the intracellular concentration of ATP, independent of the abundance of amino acids, and that mTOR itself is an ATP sensor.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Dennis, P B -- Jaeschke, A -- Saitoh, M -- Fowler, B -- Kozma, S C -- Thomas, G -- New York, N.Y. -- Science. 2001 Nov 2;294(5544):1102-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉The Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058, Basel, Switzerland.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11691993" target="_blank"〉PubMed〈/a〉
    Keywords: Adaptor Proteins, Signal Transducing ; Adenosine Triphosphate/*metabolism ; Amino Acids/metabolism ; Androstadienes/pharmacology ; Carrier Proteins/metabolism ; Cell Line ; Deoxyglucose/pharmacology ; Enzyme Activation ; Homeostasis ; Humans ; Insulin/pharmacology ; Kinetics ; Phosphoproteins/metabolism ; Phosphorylation ; Protein Kinases/*metabolism ; RNA, Transfer, Amino Acyl/metabolism ; Recombinant Fusion Proteins/metabolism ; Ribosomal Protein S6 Kinases/antagonists & inhibitors/metabolism ; Ribosomes/metabolism ; Rotenone/pharmacology ; Signal Transduction ; Sirolimus/pharmacology ; TOR Serine-Threonine Kinases
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 72
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 2001-05-02
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Fernandez, J M -- Chu, S -- Oberhauser, A F -- New York, N.Y. -- Science. 2001 Apr 27;292(5517):653-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physiology and Biophysics, Mayo Foundation, Rochester, MN 55905, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11330326" target="_blank"〉PubMed〈/a〉
    Keywords: Chemistry, Physical ; Elasticity ; Ion Channels/chemistry ; Kinetics ; *Nucleic Acid Conformation ; Physicochemical Phenomena ; RNA/*chemistry ; RNA Stability ; RNA, Catalytic/*chemistry ; Stress, Mechanical ; Thermodynamics
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 73
    Publication Date: 2001-12-01
    Description: The first step in processing olfactory information, before neural filtering, is the physical capture of odor molecules from the surrounding fluid. Many animals capture odors from turbulent water currents or wind using antennae that bear chemosensory hairs. We used planar laser-induced fluorescence to reveal how lobster olfactory antennules hydrodynamically alter the spatiotemporal patterns of concentration in turbulent odor plumes. As antennules flick, water penetrates their chemosensory hair array during the fast downstroke, carrying fine-scale patterns of concentration into the receptor area. This spatial pattern, blurred by flow along the antennule during the downstroke, is retained during the slower return stroke and is not shed until the next flick.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Koehl, M A -- Koseff, J R -- Crimaldi, J P -- McCay, M G -- Cooper, T -- Wiley, M B -- Moore, P A -- New York, N.Y. -- Science. 2001 Nov 30;294(5548):1948-51.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Integrative Biology, University of California, Berkeley, CA 94720-3140, USA. cnidaria@socrates.berkeley.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11729325" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Chemoreceptor Cells/physiology ; Fluorescence ; Kinetics ; Lasers ; Nephropidae/*physiology ; *Odors ; Smell/physiology ; *Water Movements
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 74
    Publication Date: 2001-11-03
    Description: In the exocytosis of neurotransmitter, fusion pore opening represents the first instant of fluid contact between the vesicle lumen and extracellular space. The existence of the fusion pore has been established by electrical measurements, but its molecular composition is unknown. The possibility that synaptotagmin regulates fusion pores was investigated with amperometry to monitor exocytosis of single dense-core vesicles. Overexpression of synaptotagmin I prolonged the time from fusion pore opening to dilation, whereas synaptotagmin IV shortened this time. Both synaptotagmin isoforms reduced norepinephrine flux through open fusion pores. Thus, synaptotagmin interacts with fusion pores, possibly by associating with a core complex of membrane proteins and/or lipid.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wang, C T -- Grishanin, R -- Earles, C A -- Chang, P Y -- Martin, T F -- Chapman, E R -- Jackson, M B -- New York, N.Y. -- Science. 2001 Nov 2;294(5544):1111-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physiology, University of Wisconsin Medical School, University of Wisconsin, Madison, WI 53706, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11691996" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Calcium/metabolism ; Calcium Channels, P-Type/metabolism ; Calcium Channels, Q-Type/metabolism ; *Calcium-Binding Proteins ; Cell Membrane Structures/*metabolism ; Chromogranins/metabolism ; Electrophysiology ; *Exocytosis ; Kinetics ; *Membrane Fusion ; Membrane Glycoproteins/*metabolism ; Membrane Potentials ; Nerve Tissue Proteins/*metabolism ; Neurotransmitter Agents/*metabolism ; Norepinephrine/metabolism ; PC12 Cells ; Protein Isoforms ; Rats ; Recombinant Fusion Proteins/metabolism ; Secretory Vesicles/*metabolism ; Synaptic Transmission ; Synaptic Vesicles/metabolism ; Synaptotagmin I ; Synaptotagmins
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 75
    Publication Date: 2001-09-08
    Description: Recently we reported that antibodies can generate hydrogen peroxide (H2O2) from singlet molecular oxygen (1O2*). We now show that this process is catalytic, and we identify the electron source for a quasi-unlimited generation of H2O2. Antibodies produce up to 500 mole equivalents of H2O2 from 1O2*, without a reduction in rate, and we have excluded metals or Cl- as the electron source. On the basis of isotope incorporation experiments and kinetic data, we propose that antibodies use H2O as an electron source, facilitating its addition to 1O2* to form H2O3 as the first intermediate in a reaction cascade that eventually leads to H2O2. X-ray crystallographic studies with xenon point to putative conserved oxygen binding sites within the antibody fold where this chemistry could be initiated. Our findings suggest a protective function of immunoglobulins against 1O2* and raise the question of whether the need to detoxify 1O2* has played a decisive role in the evolution of the immunoglobulin fold.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wentworth , P Jr -- Jones, L H -- Wentworth, A D -- Zhu, X -- Larsen, N A -- Wilson, I A -- Xu, X -- Goddard , W A 3rd -- Janda, K D -- Eschenmoser, A -- Lerner, R A -- CA27489/CA/NCI NIH HHS/ -- GM43858/GM/NIGMS NIH HHS/ -- HD 36385/HD/NICHD NIH HHS/ -- New York, N.Y. -- Science. 2001 Sep 7;293(5536):1806-11.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11546867" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Antibodies, Catalytic/chemistry/*metabolism ; Binding Sites ; Catalysis ; Conserved Sequence ; Crystallography, X-Ray ; Humans ; Hydrogen Peroxide/*metabolism ; Kinetics ; Models, Molecular ; Oxidants/chemistry/*metabolism ; Oxidation-Reduction ; Oxygen/*metabolism ; Protein Conformation ; Singlet Oxygen ; Spectrometry, Mass, Electrospray Ionization ; Thermodynamics ; Tryptophan/metabolism ; Ultraviolet Rays ; Water/*chemistry/*metabolism ; Xenon/metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 76
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 2001-03-14
    Description: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Will, C L -- Luhrmann, R -- New York, N.Y. -- Science. 2001 Mar 9;291(5510):1916-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Cellular Biochemistry Department, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Gottingen, Germany. cwill1@gwdg.de〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11245200" target="_blank"〉PubMed〈/a〉
    Keywords: Acid Anhydride Hydrolases/*metabolism ; Adenosine Triphosphatases/metabolism ; Adenosine Triphosphate/metabolism ; DEAD-box RNA Helicases ; Fungal Proteins/metabolism ; Kinetics ; Nucleoside-Triphosphatase ; RNA Nucleotidyltransferases/metabolism ; RNA Precursors/metabolism ; RNA, Double-Stranded/*metabolism ; RNA, Small Nuclear/*metabolism ; *RNA-Binding Proteins ; Ribonucleoprotein, U1 Small Nuclear/*metabolism ; Ribonucleoproteins/metabolism ; Ribonucleoproteins, Small Nuclear/*metabolism ; Saccharomyces cerevisiae/genetics/metabolism ; *Saccharomyces cerevisiae Proteins ; Spliceosomes/*metabolism ; Vaccinia virus/genetics/metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 77
    Publication Date: 2001-06-26
    Description: The temporal pattern and relative timing of action potentials among neocortical neurons may carry important information. However, how cortical circuits detect or generate coherent activity remains unclear. Using paired recordings in rat neocortical slices, we found that the firing of fast-spiking cells can reflect the spiking pattern of single-axon pyramidal inputs. Moreover, this property allowed groups of fast-spiking cells interconnected by electrical and gamma-aminobutyric acid (GABA)-releasing (GABAergic) synapses to detect the relative timing of their excitatory inputs. These results indicate that networks of fast-spiking cells may play a role in the detection and promotion of synchronous activity within the neocortex.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Galarreta, M -- Hestrin, S -- EY09120/EY/NEI NIH HHS/ -- EY12114/EY/NEI NIH HHS/ -- New York, N.Y. -- Science. 2001 Jun 22;292(5525):2295-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Comparative Medicine, Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA. galarreta@stanford.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11423653" target="_blank"〉PubMed〈/a〉
    Keywords: Action Potentials ; Animals ; Axons/physiology ; Excitatory Postsynaptic Potentials ; Female ; In Vitro Techniques ; Interneurons/*physiology ; Kinetics ; Male ; Neocortex/cytology/*physiology ; Nerve Net/*physiology ; Pyramidal Cells/*physiology ; Rats ; Rats, Sprague-Dawley ; Synapses/physiology ; *Synaptic Transmission ; Time Factors ; gamma-Aminobutyric Acid/*metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 78
    Publication Date: 2001-12-26
    Description: The transfer of a hydrogen atom-a proton and an electron-is a fundamental process in chemistry and biology. A variety of hydrogen atom transfer reactions, involving iron complexes, phenols, hydroxylamines, tBuOOH, toluene, and related radicals, are shown to follow the Marcus cross relation. Thus, the Marcus theory formalism based on ground-state energetics and self-exchange rates, originally developed for electron transfer processes, is also valuable for hydrogen atom transfer. Compounds that undergo slow proton transfer (C-H bonds) or slow electron transfer (cobalt complexes) also undergo slow hydrogen atom transfer. Limitations of this approach are also discussed.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Roth, J P -- Yoder, J C -- Won, T J -- Mayer, J M -- 1 F32 GM63383-01/GM/NIGMS NIH HHS/ -- 2 R01 GM50422-05/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2001 Dec 21;294(5551):2524-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195-1700, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11752572" target="_blank"〉PubMed〈/a〉
    Keywords: Chemistry, Physical ; Cobalt/chemistry ; Cyclic N-Oxides/chemistry ; Electrons ; Ferric Compounds/chemistry ; Ferrous Compounds/chemistry ; Free Radicals ; Hydrogen/*chemistry ; Imidazoles/chemistry ; Kinetics ; Magnetic Resonance Spectroscopy ; Mathematics ; Oxidation-Reduction ; Physicochemical Phenomena ; Protons ; Pyrimidines/chemistry ; Thermodynamics
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 79
    Publication Date: 2001-03-10
    Description: Assessing the energy costs of development in extreme environments is important for understanding how organisms can exist at the margins of the biosphere. Macromolecular turnover rates of RNA and protein were measured at -1.5 degrees C during early development of an Antarctic sea urchin. Contrary to expectations of low synthesis with low metabolism at low temperatures, protein and RNA synthesis rates exhibited temperature compensation and were equivalent to rates in temperate sea urchin embryos. High protein metabolism with a low metabolic rate is energetically possible in this Antarctic sea urchin because the energy cost of protein turnover, 0.45 joules per milligram of protein, is 1/25th the values reported for other animals.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Marsh, A G -- Maxson , R E Jr -- Manahan, D T -- New York, N.Y. -- Science. 2001 Mar 9;291(5510):1950-2. Epub 2001 Feb 15.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11239152" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Antarctic Regions ; Blastocyst/metabolism ; Cold Temperature ; Embryo, Nonmammalian/metabolism ; Energy Metabolism ; Half-Life ; Kinetics ; *Oxygen Consumption ; *Protein Biosynthesis ; Proteins/metabolism ; RNA/*biosynthesis/metabolism ; RNA, Messenger/biosynthesis/metabolism ; Sea Urchins/*embryology/growth & development/*metabolism ; Temperature
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 80
    Publication Date: 2001-07-07
    Description: The existence of a large number of receptors coupled to heterotrimeric guanine nucleotide binding proteins (G proteins) raises the question of how a particular receptor selectively regulates specific targets. We provide insight into this question by identifying a prototypical macromolecular signaling complex. The beta(2) adrenergic receptor was found to be directly associated with one of its ultimate effectors, the class C L-type calcium channel Ca(v)1.2. This complex also contained a G protein, an adenylyl cyclase, cyclic adenosine monophosphate-dependent protein kinase, and the counterbalancing phosphatase PP2A. Our electrophysiological recordings from hippocampal neurons demonstrate highly localized signal transduction from the receptor to the channel. The assembly of this signaling complex provides a mechanism that ensures specific and rapid signaling by a G protein-coupled receptor.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Davare, M A -- Avdonin, V -- Hall, D D -- Peden, E M -- Burette, A -- Weinberg, R J -- Horne, M C -- Hoshi, T -- Hell, J W -- AG00213/AG/NIA NIH HHS/ -- AG17502/AG/NIA NIH HHS/ -- GM08688/GM/NIGMS NIH HHS/ -- GM56900/GM/NIGMS NIH HHS/ -- HL61645/HL/NHLBI NIH HHS/ -- NS35563/NS/NINDS NIH HHS/ -- NS39444/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 2001 Jul 6;293(5527):98-101.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pharmacology, University of Wisconsin, Madison, WI 53706, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11441182" target="_blank"〉PubMed〈/a〉
    Keywords: Adenylyl Cyclases/metabolism ; Adrenergic beta-2 Receptor Agonists ; Albuterol/pharmacology ; Animals ; Calcium Channels, L-Type/genetics/*metabolism ; Cell Line ; Cell Membrane/metabolism ; Cyclic AMP-Dependent Protein Kinases/metabolism ; Electric Conductivity ; Fluorescent Antibody Technique ; Heterotrimeric GTP-Binding Proteins/metabolism ; Humans ; Isoproterenol/pharmacology ; Kinetics ; Macromolecular Substances ; Neurons/cytology/drug effects/enzymology/metabolism ; Phosphoprotein Phosphatases/metabolism ; Precipitin Tests ; Prosencephalon/cytology/metabolism ; Protein Binding ; Pyramidal Cells/cytology/drug effects/enzymology/metabolism ; Rats ; Receptors, Adrenergic, beta-2/genetics/*metabolism ; *Signal Transduction ; Substrate Specificity
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 81
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 2001-02-07
    Description: We describe a heptameric protein pore that has been engineered to accommodate two different cyclodextrin adapters simultaneously within the lumen of a transmembrane beta barrel. The volume between the adapters is a cavity of approximately 4400 cubic angstroms. Analysis of single-channel recordings reveals that individual charged organic molecules can be pulled into the cavity by an electrical potential. Once trapped, an organic molecule shuttles back and forth between the adapters for hundreds of milliseconds. Such self-assembling nanostructures are of interest for the fabrication of multianalyte sensors and could provide a means to control chemical reactions.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Gu, L Q -- Cheley, S -- Bayley, H -- New York, N.Y. -- Science. 2001 Jan 26;291(5504):636-40.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Medical Biochemistry and Genetics, Texas A&M University System Health Science Center, College Station, TX 77843, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11158673" target="_blank"〉PubMed〈/a〉
    Keywords: Adamantane/*analogs & derivatives/*chemistry/metabolism ; Bacterial Toxins/*chemistry/metabolism ; Binding Sites ; Cyclodextrins/*chemistry/metabolism ; Dicarboxylic Acids/*chemistry/metabolism ; Electric Conductivity ; Hemolysin Proteins/*chemistry/metabolism ; Kinetics ; Membrane Potentials ; Models, Molecular ; Mutagenesis, Site-Directed ; Protein Conformation ; *Protein Engineering ; Thermodynamics ; *beta-Cyclodextrins
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 82
    Publication Date: 2001-10-27
    Description: Single-molecule imaging techniques were used to reveal the binding of individual cyclic adenosine 3',5'-monophosphate molecules to heterotrimeric guanine nucleotide-binding protein coupled receptors on the surface of living Dictyostelium discoideum cells. The binding sites were uniformly distributed and diffused rapidly in the plane of the membrane. The probabilities of individual association and dissociation events were greater for receptors at the anterior end of the cell. Agonist-induced receptor phosphorylation had little effect on any of the monitored properties, whereas G protein coupling influenced the binding kinetics. These observations illustrate the dynamic properties of receptors involved in gradient sensing and suggest that these may be polarized in chemotactic cells.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ueda, M -- Sako, Y -- Tanaka, T -- Devreotes, P -- Yanagida, T -- New York, N.Y. -- Science. 2001 Oct 26;294(5543):864-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Recognition and Formation, Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Corporation (JST)., Osaka 562-0035, Japan. ueda@phys1.med.osaka-u.ac.jp〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11679673" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Carbocyanines/metabolism ; Cell Membrane/metabolism ; *Chemotaxis ; Cyclic AMP/*metabolism ; Dictyostelium/cytology/genetics/metabolism/*physiology ; Diffusion ; Guanosine Diphosphate/pharmacology ; Guanosine Triphosphate/pharmacology ; Heterotrimeric GTP-Binding Proteins/genetics/*metabolism ; Kinetics ; Microscopy, Fluorescence ; Mutation ; Phosphorylation ; Pseudopodia/metabolism ; Receptors, Cyclic AMP/*metabolism ; *Signal Transduction
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 83
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 2001-01-06
    Description: Neurons encode information and communicate via action potentials, which are generated following the summation of synaptic events. It is commonly assumed that action potentials reset the membrane potential completely, allowing another round of synaptic integration to begin. We show here that the conductances underlying the action potential act instead as a variable reset of synaptic integration. The strength of this reset is cell type-specific and depends on the kinetics, location, and timing of the synaptic input. As a consequence, distal synapses, as well as inputs mediated by N-methyl-d-aspartate receptor activation, can contribute disproportionately to synaptic integration during action potential firing.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hausser, M -- Major, G -- Stuart, G J -- New York, N.Y. -- Science. 2001 Jan 5;291(5501):138-41.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physiology, University College London, Gower Street, London WC1E 6BT, UK. m.hausser@ucl.ac.uk〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11141567" target="_blank"〉PubMed〈/a〉
    Keywords: *Action Potentials/drug effects ; Animals ; Computer Simulation ; Dendrites/drug effects/physiology ; Electric Stimulation ; *Excitatory Postsynaptic Potentials/drug effects ; Kinetics ; Magnesium/pharmacology ; Models, Neurological ; Neocortex/cytology/physiology ; Patch-Clamp Techniques ; Purkinje Cells/*physiology ; Pyramidal Cells/*physiology ; Rats ; Receptors, AMPA/physiology ; Receptors, N-Methyl-D-Aspartate/physiology ; Synapses/physiology ; *Synaptic Transmission ; Tetrodotoxin/pharmacology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 84
    Publication Date: 2001-04-28
    Description: Here we use mechanical force to induce the unfolding and refolding of single RNA molecules: a simple RNA hairpin, a molecule containing a three-helix junction, and the P5abc domain of the Tetrahymena thermophila ribozyme. All three molecules (P5abc only in the absence of Mg2+) can be mechanically unfolded at equilibrium, and when kept at constant force within a critical force range, are bi-stable and hop between folded and unfolded states. We determine the force-dependent equilibrium constants for folding/unfolding these single RNA molecules and the positions of their transition states along the reaction coordinate.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Liphardt, J -- Onoa, B -- Smith, S B -- Tinoco, I Jr -- Bustamante, C -- GM-10840/GM/NIGMS NIH HHS/ -- GM-32543/GM/NIGMS NIH HHS/ -- R01 GM010840/GM/NIGMS NIH HHS/ -- R01 GM010840-42/GM/NIGMS NIH HHS/ -- R01 GM010840-43/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2001 Apr 27;292(5517):733-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, Howard Hughes Medical Institute, University of California, Berkeley, CA 94720, USA. jliphard@alice.berkeley.gov〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11326101" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Base Sequence ; Edetic Acid ; Kinetics ; Magnesium ; Microspheres ; Molecular Sequence Data ; *Nucleic Acid Conformation ; Polystyrenes ; RNA/*chemistry ; RNA Stability ; RNA, Catalytic/*chemistry ; Stress, Mechanical ; Tetrahymena thermophila ; Thermodynamics
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 85
    Publication Date: 2001-12-12
    Description: Calcium (Ca2+) influx through Ca2+-permeable ion channels plays a pivotal role in a variety of neuronal signaling processes, and negative-feedback control of this influx by Ca2+ itself is often equally important for modulation of such signaling. Negative modulation by Ca2+ through calmodulin (CaM) on cyclic nucleotide-gated (CNG) channels underlies the adaptation of olfactory receptor neurons to odorants. We show that this feedback requires two additional subunits of the native olfactory channel, CNGA4 and CNGB1b, even though the machinery for CaM binding and modulation is present in the principal subunit CNGA2. This provides a rationale for the presence of three distinct subunits in the native olfactory channel and underscores the subtle link between the molecular make-up of an ion channel and the physiological function it subserves.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bradley, J -- Reuter, D -- Frings, S -- New York, N.Y. -- Science. 2001 Dec 7;294(5549):2176-8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Institut fur Biologische Informationsverarbeitung, Forschungszentrum Julich, 52425 Julich, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11739960" target="_blank"〉PubMed〈/a〉
    Keywords: *Adaptation, Physiological ; Animals ; Calcium/metabolism/pharmacology ; Calcium Signaling ; Calmodulin/*metabolism/pharmacology ; Cell Line ; Cyclic AMP/*metabolism ; Cyclic Nucleotide-Gated Cation Channels ; Feedback, Physiological ; Humans ; Ion Channel Gating ; Ion Channels/metabolism/*physiology ; Kinetics ; *Odors ; Olfactory Receptor Neurons/*physiology ; Patch-Clamp Techniques ; Photolysis ; Protein Subunits ; Rats ; Recombinant Proteins/metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 86
    Publication Date: 2001-12-12
    Description: Heteromultimeric cyclic nucleotide-gated (CNG) channels play a central role in the transduction of odorant signals and subsequent adaptation. The contributions of individual subunits to native channel function in olfactory receptor neurons remain unclear. Here, we show that the targeted deletion of the mouse CNGA4 gene, which encodes a modulatory CNG subunit, results in a defect in odorant-dependent adaptation. Channels in excised membrane patches from the CNGA4 null mouse exhibited slower Ca2+-calmodulin-mediated channel desensitization. Thus, the CNGA4 subunit accelerates the Ca2+-mediated negative feedback in olfactory signaling and allows rapid adaptation in this sensory system.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2885906/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2885906/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Munger, S D -- Lane, A P -- Zhong, H -- Leinders-Zufall, T -- Yau, K W -- Zufall, F -- Reed, R R -- R37 EY006837/EY/NEI NIH HHS/ -- R37 EY006837-13/EY/NEI NIH HHS/ -- R37 EY006837-14/EY/NEI NIH HHS/ -- New York, N.Y. -- Science. 2001 Dec 7;294(5549):2172-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Howard Hughes Medical Institute, Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11739959" target="_blank"〉PubMed〈/a〉
    Keywords: 1-Methyl-3-isobutylxanthine/pharmacology ; *Adaptation, Physiological ; Animals ; Calcium/*metabolism ; Calcium Signaling ; Calmodulin/*metabolism ; Cyclic AMP/metabolism ; Cyclic Nucleotide-Gated Cation Channels ; Cyclohexanols/pharmacology ; Electrophysiology ; Gene Targeting ; Ion Channel Gating ; Ion Channels/*genetics/*physiology ; Kinetics ; Mice ; Mice, Inbred C57BL ; *Monoterpenes ; *Odors ; Olfactory Bulb/physiology ; Olfactory Mucosa/physiology ; Olfactory Receptor Neurons/metabolism/*physiology ; Protein Subunits ; Terpenes/pharmacology
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 87
    Publication Date: 2001-05-12
    Description: In eukaryotic cells, microtubules and their associated motor proteins can be organized into various large-scale patterns. Using a simplified experimental system combined with computer simulations, we examined how the concentrations and kinetic parameters of the motors contribute to their collective behavior. We observed self-organization of generic steady-state structures such as asters, vortices, and a network of interconnected poles. We identified parameter combinations that determine the generation of each of these structures. In general, this approach may become useful for correlating the morphogenetic phenomena taking place in a biological system with the biophysical characteristics of its constituents.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Surrey, T -- Nedelec, F -- Leibler, S -- Karsenti, E -- New York, N.Y. -- Science. 2001 May 11;292(5519):1167-71.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Cell Biology and Biophysics Program, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11349149" target="_blank"〉PubMed〈/a〉
    Keywords: Adenosine Triphosphate/metabolism ; Animals ; Antibodies ; Biopolymers/chemistry/metabolism ; *Computer Simulation ; *Drosophila Proteins ; Guanosine Triphosphate/metabolism ; Kinesin/chemistry/metabolism ; Kinetics ; Macromolecular Substances ; Microtubules/*chemistry/drug effects/*metabolism ; Models, Molecular ; Molecular Motor Proteins/*chemistry/*metabolism ; Paclitaxel/pharmacology ; Protein Structure, Quaternary/drug effects ; Tubulin/chemistry/metabolism ; Viscosity
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 88
    Publication Date: 2001-02-07
    Description: The motility of kinesin motors is explained by a "hand-over-hand" model in which two heads of kinesin alternately repeat single-headed and double-headed binding with a microtubule. To investigate the binding mode of kinesin at the key nucleotide states during adenosine 5'-triphosphate (ATP) hydrolysis, we measured the mechanical properties of a single kinesin-microtubule complex by applying an external load with optical tweezers. Both the unbinding force and the elastic modulus in solutions containing AMP-PNP (an ATP analog) were twice the value of those in nucleotide-free solution or in the presence of both AMP-PNP and adenosine 5'-diphosphate. Thus, kinesin binds through two heads in the former and one head in the latter two states, which supports a major prediction of the hand-over-hand model.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kawaguchi, K -- Ishiwata, S -- New York, N.Y. -- Science. 2001 Jan 26;291(5504):667-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physics, School of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11158681" target="_blank"〉PubMed〈/a〉
    Keywords: Adenosine Diphosphate/*metabolism ; Adenosine Triphosphate/metabolism ; Adenylyl Imidodiphosphate/*metabolism ; Animals ; Cattle ; Elasticity ; Kinesin/*metabolism ; Kinetics ; Microtubules/metabolism ; Models, Biological ; Swine
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 89
    Publication Date: 2001-10-06
    Description: Oligonucleotide microarrays were used to map the detailed topography of chromosome replication in the budding yeast Saccharomyces cerevisiae. The times of replication of thousands of sites across the genome were determined by hybridizing replicated and unreplicated DNAs, isolated at different times in S phase, to the microarrays. Origin activations take place continuously throughout S phase but with most firings near mid-S phase. Rates of replication fork movement vary greatly from region to region in the genome. The two ends of each of the 16 chromosomes are highly correlated in their times of replication. This microarray approach is readily applicable to other organisms, including humans.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Raghuraman, M K -- Winzeler, E A -- Collingwood, D -- Hunt, S -- Wodicka, L -- Conway, A -- Lockhart, D J -- Davis, R W -- Brewer, B J -- Fangman, W L -- New York, N.Y. -- Science. 2001 Oct 5;294(5540):115-21.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Genetics, Department of Mathematics, University of Washington, Seattle, WA 98195, USA. raghu@u.washington.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/11588253" target="_blank"〉PubMed〈/a〉
    Keywords: Algorithms ; Base Sequence ; Centromere/metabolism ; Chromosomes, Fungal/genetics/*metabolism ; *DNA Replication ; DNA, Fungal/*biosynthesis/genetics/metabolism ; DNA, Intergenic ; Fourier Analysis ; *Genome, Fungal ; Kinetics ; Nucleic Acid Hybridization ; Oligonucleotide Array Sequence Analysis ; *Replication Origin ; *S Phase ; Saccharomyces cerevisiae/cytology/*genetics/metabolism ; Telomere/metabolism ; Transcription, Genetic
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 90
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 1589-1593 
    ISSN: 1434-193X
    Keywords: Azaallenium ions ; Azaallylium ions ; Iminium ion ; Kinetics ; Linear Free Energy Relationships ; Ab initio calculations ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The rate constants for the reactions of the 2-azaallenium ion 1b+, the 2-azaallylium ion 2a+ and the iminium ion 3+ with different nucleophiles were determined by 1H NMR spectroscopy. By correlation with the Linear Free Enthalpy Relationship (LFER) lg k20°C = s (E + N), developed by Mayr and Patz, the electrophilicity parameters E(1b+) = -3.7, E(2a+) ≍ -16 and E(3+) = -10.43 were obtained. They show that the relative reactivities of these ions are approximately 1012:1:106. Quantum chemical calculations (ab initio, DFT) of the methyl anion affinities for the ions 1b+,2a+ and3+ are in agreement with the experimental E values. The X-ray structure of 3+·CF3SO3- is reported for the first time; it shows no strong interaction between the cation and the anion.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 91
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 1345-1351 
    ISSN: 1434-193X
    Keywords: Kinetics ; Photochemistry ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The photochemical reaction of thionine (Th) with an organic reductant such as thioureas was studied in absolute methanol at constant temperature 25±0.1°C. Spectrophotometric methods were adopted for the determination of the values of absorbances in the presence of extremely dissociated, undissociated and partially dissociated acridine in absolute methanol. The acidity of the reaction solution H0 was controlled by using acetate buffer solutions. The effect of variables like concentration of thiourea, acidity and temperature on quantum yield (φ) was studied and the results were interpreted in terms of reaction mechanism. It was found that the quantum yield of the reactions of thionine with thiourea is controlled by two equilibria between (i) triplet state of thionine with proton and protonated triplet state of thionine, and (ii) protonated triplet state of thionine with reductant and associated complex (Th·H2T++·AH2).
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 92
    ISSN: 1434-193X
    Keywords: Tautomerism ; Ketones ; Kinetics ; Ionizations ; Semiempirical calculations ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The equilibrium constant for the keto-enol tautomerism of 3-nitrobutan-2-one KT = [enol]/[ketone] has been measured in water as 4.57 × 10-3 (pKT = 2.34) by combining the rate constants for ketonisation of the enolate form and pKa of the ketone at 25 °C. The rates of ketonisation were measured by a rapid kinetic technique and the pKa was determined spectrophotometrically and potentiometrically as 5.15. A comparison with 2-butanone and acetone shows a strong influence of the nitro group in enhancing the acidity of the substrate and in stabilizing the enol relative to the keto tautomer. By means of semiempirical AM1 calculations, good correlations were found between the atomic charge on the acidic hydrogens and the pKa (in water at 25 °C) of both tautomeric forms for a number of simple ketones whose pKas and pKTs are available in the literature. The agreement of experimental acidity constants of the enol, pKaEH, the ketone, pKaKH, and the tautomeric constant, pKT, with predicted values is satisfactory.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 93
    ISSN: 1434-193X
    Keywords: Nucleotides ; Thiophosphates ; Hydrolyses ; Reaction mechanisms ; Kinetics ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Hydrolysis of the cis-methyl ester of 3′-deoxy-3′-thiothymidine 3′-S,5′-O-cyclic(phosphorothiolate) (1a) has been followed by HPLC and MS. At pH 〈 2 hydrolysis of the thiophosphate triester moiety is acid-catalyzed (first order), while between pH = 2 and 5 the reaction is pH-independent and at pH 〉 5 first order in hydroxide ion. The uncatalyzed and acid-catalyzed reactions yield two thiophosphate diesters, the 3′-S,5′-O-cyclic phosphorothiolate 2 and 3′-S-phosphorothiolate methyl ester 3, in a 9:1 and 1:3 molar ratio, respectively. The hydroxide ion catalyzed reaction gives the endocyclic P-O and P-S bond-cleavage products (3 and 4, respectively) in a 1:2 molar ratio. The pH-independent reaction is suggested to take place by attack of a water molecule on the carbon atom and concomitant C-O bond rupture, whereas the alkaline and acidic reactions involve attack of the nucleophile on the phosphorus atom and formation of a pseudorotating thiophosphorane intermediate. Under acidic conditions, cleavage of the N-glycosidic linkage competes with the phosphoester hydrolysis, corresponding to 20% of the hydrolysis products at pH 〈 1.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 94
    Publication Date: 2000-01-05
    Description: The nematode pharynx has a potassium channel with unusual properties, which allows the muscles to repolarize quickly and with the proper delay. Here, the Caenorhabditis elegans exp-2 gene is shown to encode this channel. EXP-2 is a Kv-type (voltage-activated) potassium channel that has inward-rectifying properties resembling those of the structurally dissimilar human ether-a-go-go-related gene (HERG) channel. Null and gain-of-function mutations affect pharyngeal muscle excitability in ways that are consistent with the electrophysiological behavior of the channel, and thereby demonstrate a direct link between the kinetics of this unusual channel and behavior.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3791429/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3791429/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Davis, M W -- Fleischhauer, R -- Dent, J A -- Joho, R H -- Avery, L -- HL46154/HL/NHLBI NIH HHS/ -- NS28407/NS/NINDS NIH HHS/ -- R01 HL046154/HL/NHLBI NIH HHS/ -- New York, N.Y. -- Science. 1999 Dec 24;286(5449):2501-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9148, USA. wdavis@biology.utah.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/10617464" target="_blank"〉PubMed〈/a〉
    Keywords: Action Potentials ; Animals ; Caenorhabditis elegans/genetics/*physiology ; Feeding Behavior ; Genes, Helminth ; Genes, Reporter ; Ion Channel Gating ; Kinetics ; Membrane Potentials ; Models, Molecular ; Muscles/metabolism ; Mutation ; Neurons/metabolism ; Oocytes/metabolism ; Pharyngeal Muscles/physiology ; Potassium Channels/chemistry/genetics/*physiology ; Protein Conformation ; RNA, Complementary/genetics ; Recombinant Fusion Proteins/biosynthesis ; Xenopus laevis
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 95
    Publication Date: 2000-04-25
    Description: Major histocompatibility complex class II (MHC II) molecules capture peptides within the endocytic pathway to generate T cell receptor (TCR) ligands. Immature dendritic cells (DCs) sequester intact antigens in lysosomes, processing and converting antigens into peptide-MHC II complexes upon induction of DC maturation. The complexes then accumulate in distinctive, nonlysosomal MHC II+ vesicles that appear to migrate to the cell surface. Although the vesicles exclude soluble lysosomal contents and antigen-processing machinery, many contain MHC I and B7 costimulatory molecules. After arrival at the cell surface, the MHC and costimulatory molecules remain clustered. Thus, transport of peptide-MHC II complexes by DCs not only accomplishes transfer from late endocytic compartments to the plasma membrane, but does so in a manner that selectively concentrates TCR ligands and costimulatory molecules for T cell contact.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Turley, S J -- Inaba, K -- Garrett, W S -- Ebersold, M -- Unternaehrer, J -- Steinman, R M -- Mellman, I -- AI-13013/AI/NIAID NIH HHS/ -- AI-34098/AI/NIAID NIH HHS/ -- AI-39672/AI/NIAID NIH HHS/ -- New York, N.Y. -- Science. 2000 Apr 21;288(5465):522-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Cell Biology and Section of Immunobiology, Ludwig Institute for Cancer Research, Yale University School of Medicine, 333 Cedar Street, Post Office Box 208002, New Haven, CT 06520-8002, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/10775112" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Antibodies, Monoclonal ; *Antigen Presentation ; Antigens, CD/immunology/metabolism ; Antigens, CD86 ; B-Lymphocytes/immunology/metabolism ; Bicyclo Compounds, Heterocyclic/pharmacology ; Biological Transport ; Cell Membrane/immunology/metabolism ; Cells, Cultured ; Dendritic Cells/*immunology/*metabolism ; Endocytosis ; Endosomes/immunology/metabolism ; Histocompatibility Antigens Class I/immunology/metabolism ; Histocompatibility Antigens Class II/immunology/*metabolism ; Kinetics ; Ligands ; Lipopolysaccharides/immunology ; Lysosomes/immunology/metabolism ; Membrane Glycoproteins/immunology/metabolism ; Mice ; Mice, Inbred C3H ; Muramidase/immunology/*metabolism ; Peptide Fragments/immunology/*metabolism ; Receptors, Antigen, T-Cell/metabolism ; Thiazoles/pharmacology ; Thiazolidines
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 96
    Publication Date: 2000-06-02
    Description: The mechanism by which a signal recognition particle (SRP) and its receptor mediate protein targeting to the endoplasmic reticulum or to the bacterial plasma membrane is evolutionarily conserved. In Escherichia coli, this reaction is mediated by the Ffh/4.5S RNA ribonucleoprotein complex (Ffh/4.5S RNP; the SRP) and the FtsY protein (the SRP receptor). We have quantified the effects of 4.5S RNA on Ffh-FtsY complex formation by monitoring changes in tryptophan fluorescence. Surprisingly, 4.5S RNA facilitates both assembly and disassembly of the Ffh-FtsY complex to a similar extent. These results provide an example of an RNA molecule facilitating protein-protein interactions in a catalytic fashion.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Peluso, P -- Herschlag, D -- Nock, S -- Freymann, D M -- Johnson, A E -- Walter, P -- GM 26494/GM/NIGMS NIH HHS/ -- GM 32384/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2000 Jun 2;288(5471):1640-3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Howard Hughes Medical Institute and Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/10834842" target="_blank"〉PubMed〈/a〉
    Keywords: Bacterial Proteins/chemistry/*metabolism ; Catalysis ; Escherichia coli/metabolism ; *Escherichia coli Proteins ; Guanosine Diphosphate/metabolism ; Guanosine Triphosphate/metabolism ; Guanylyl Imidodiphosphate/metabolism ; Kinetics ; Models, Chemical ; Nucleic Acid Conformation ; Protein Binding ; Protein Conformation ; Protein Structure, Tertiary ; RNA, Bacterial/chemistry/*metabolism ; Receptors, Cytoplasmic and Nuclear/chemistry/*metabolism ; Ribonucleoproteins/chemistry/metabolism ; Signal Recognition Particle/chemistry/*metabolism ; Spectrometry, Fluorescence ; Thermodynamics ; Tryptophan
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 97
    Publication Date: 2000-02-26
    Description: Many protein enzymes use general acid-base catalysis as a way to increase reaction rates. The amino acid histidine is optimized for this function because it has a pK(a) (where K(a) is the acid dissociation constant) near physiological pH. The RNA enzyme (ribozyme) from hepatitis delta virus catalyzes self-cleavage of a phosphodiester bond. Reactivity-pH profiles in monovalent or divalent cations, as well as distance to the leaving-group oxygen, implicate cytosine 75 (C75) of the ribozyme as the general acid and ribozyme-bound hydrated metal hydroxide as the general base in the self-cleavage reaction. Moreover, C75 has a pK(a) perturbed to neutrality, making it "histidine-like." Anticooperative interaction is observed between protonated C75 and a metal ion, which serves to modulate the pK(a) of C75. General acid-base catalysis expands the catalytic repertoire of RNA and may provide improved rate acceleration.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Nakano, S -- Chadalavada, D M -- Bevilacqua, P C -- GM58709/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2000 Feb 25;287(5457):1493-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Chemistry, Pennsylvania State University, University Park, PA 16802, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/10688799" target="_blank"〉PubMed〈/a〉
    Keywords: Base Pairing ; Binding Sites ; Calcium/metabolism ; Catalysis ; Cobalt/metabolism ; Crystallography, X-Ray ; Hepatitis Delta Virus/*chemistry/enzymology ; Hydrogen Bonding ; Hydrogen-Ion Concentration ; Kinetics ; Magnesium/metabolism ; Metals/metabolism ; Models, Chemical ; Models, Molecular ; Nucleic Acid Conformation ; Protons ; RNA, Catalytic/chemistry/*metabolism ; RNA, Viral/chemistry/metabolism ; Static Electricity ; Thermodynamics
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 98
    Publication Date: 2000-03-31
    Description: Using an optical-trap/flow-control video microscopy technique, we followed transcription by single molecules of Escherichia coli RNA polymerase in real time over long template distances. These studies reveal that RNA polymerase molecules possess different intrinsic transcription rates and different propensities to pause and stop. The data also show that reversible pausing is a kinetic intermediate between normal elongation and the arrested state. The conformational metastability of RNA polymerase revealed by this single-molecule study of transcription has direct implications for the mechanisms of gene regulation in both bacteria and eukaryotes.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Davenport, R J -- Wuite, G J -- Landick, R -- Bustamante, C -- GM-32543/GM/NIGMS NIH HHS/ -- GM-38660/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2000 Mar 31;287(5462):2497-500.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/10741971" target="_blank"〉PubMed〈/a〉
    Keywords: DNA, Bacterial/genetics/*metabolism ; DNA-Directed RNA Polymerases/*metabolism ; Escherichia coli/enzymology/*genetics ; Kinetics ; Microscopy, Video ; Models, Genetic ; Optics and Photonics ; RNA, Bacterial/genetics ; RNA, Messenger/*genetics ; Templates, Genetic ; *Transcription, Genetic
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 99
    facet.materialart.
    Unknown
    American Association for the Advancement of Science (AAAS)
    Publication Date: 2000-07-07
    Description: In Neurospora crassa, white collar 1 (WC-1), a transcriptional activator and positive clock element, is rhythmically expressed from a nonrhythmic steady-state pool of wc-1 transcript, consistent with posttranscriptional regulation of rhythmicity. Mutations in frq influence both the level and periodicity of WC-1 expression, and driven FRQ expression not only depresses its own endogenous levels, but positively regulates WC-1 synthesis with a lag of about 8 hours, a delay similar to that seen in the wild-type clock. FRQ thus plays dual roles in the Neurospora clock and thereby, with WC-1, forms a second feedback loop that would promote robustness and stability in this circadian system. The existence also of interlocked loops in Drosophila melanogaster and mouse clocks suggests that such interlocked loops may be a conserved aspect of circadian timing systems.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lee, K -- Loros, J J -- Dunlap, J C -- MH44651/MH/NIMH NIH HHS/ -- R37-GM 34985/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2000 Jul 7;289(5476):107-10.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Genetics, Dartmouth Medical School, Hanover, NH 03755-3844, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/10884222" target="_blank"〉PubMed〈/a〉
    Keywords: Amino Acid Sequence ; Animals ; *Circadian Rhythm ; DNA-Binding Proteins/biosynthesis/chemistry/genetics/*metabolism ; Darkness ; Feedback ; Fungal Proteins/genetics/*metabolism ; Gene Expression Regulation, Fungal ; Humans ; Kinetics ; Light ; Molecular Sequence Data ; Mutation ; Neurospora crassa/genetics/metabolism/*physiology ; Phosphorylation ; RNA, Fungal/genetics/metabolism ; RNA, Messenger/genetics/metabolism ; Sequence Alignment ; Signal Transduction ; Transcription Factors/biosynthesis/chemistry/genetics/*metabolism
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 100
    Publication Date: 2000-08-26
    Description: Prion proteins can serve as genetic elements by adopting distinct physical and functional states that are self-perpetuating and heritable. The critical region of one prion protein, Sup35, is initially unstructured in solution and then forms self-seeded amyloid fibers. We examined in vitro the mechanism by which this state is attained and replicated. Structurally fluid oligomeric complexes appear to be crucial intermediates in de novo amyloid nucleus formation. Rapid assembly ensues when these complexes conformationally convert upon association with nuclei. This model for replicating protein-based genetic information, nucleated conformational conversion, may be applicable to other protein assembly processes.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Serio, T R -- Cashikar, A G -- Kowal, A S -- Sawicki, G J -- Moslehi, J J -- Serpell, L -- Arnsdorf, M F -- Lindquist, S L -- GM025874/GM/NIGMS NIH HHS/ -- GM57840/GM/NIGMS NIH HHS/ -- P41-RR017777/RR/NCRR NIH HHS/ -- New York, N.Y. -- Science. 2000 Aug 25;289(5483):1317-21.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular Genetics and Cell Biology, Howard Hughes Medical Institute, University of Chicago, Chicago, IL 60637, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/10958771" target="_blank"〉PubMed〈/a〉
    Keywords: Amyloid/*chemistry ; Biopolymers/chemistry ; Centrifugation, Density Gradient ; Circular Dichroism ; Electrophoresis, Polyacrylamide Gel ; Endopeptidases/metabolism ; Fungal Proteins/*chemistry/metabolism/ultrastructure ; Kinetics ; Light ; Micelles ; Microscopy, Atomic Force ; Microscopy, Electron ; Models, Chemical ; Peptide Termination Factors ; Prions/*chemistry/metabolism/ultrastructure ; Protein Conformation ; Protein Folding ; *Saccharomyces cerevisiae Proteins ; Scattering, Radiation ; Solubility ; Sonication
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...