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
  • Articles  (996)
  • Mutation  (996)
  • American Association for the Advancement of Science (AAAS)  (986)
  • Springer  (10)
  • American Chemical Society (ACS)
  • Elsevier
  • Wiley
  • 2020-2024
  • 2020-2022
  • 2015-2019  (58)
  • 1995-1999  (602)
  • 1990-1994  (262)
  • 1980-1984  (53)
  • 1975-1979  (21)
  • 1940-1944
  • 1935-1939
  • Chemistry and Pharmacology  (993)
  • Computer Science  (987)
  • Natural Sciences in General  (986)
  • Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition  (2)
  • Law
Collection
  • Articles  (996)
Publisher
Years
Year
Topic
  • 1
    ISSN: 1432-0789
    Keywords: Mungbean ; Vigna radiata ; Nitrogen fixation ; Hydrogen uptake ; Mutation ; Nitrosoguanidine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract H2 uptake activity was well distributed in Rhizobium sp. strains isolated from nodules of mung-bean (Vigna radiata L.). Two effective strains, RMP1 und RMP2, exhibiting significantly higher H2 uptake activity were subjected to mutagenesis with nitrosoguanidine. The respective mutation frequencies were 0.18 and 0.19%. Three Hup- mutants each of RMP1 und RMP2 were compared with the wild-type parent strains under pot culture experiments to evaluate the significance of the H2 uptake system in biological N2 fixation. Nodulation capabilities, plant growth characteristics, and the chlorophyll content of the leaves were significantly reduced in the plants treated with Hup- mutants. Nitrogenase activity in Hup- nodules was reduced by 8–41%. Similarly, N accumulation was also reduced singificantly.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-1327
    Keywords: Key words High-potential ; Iron-sulfur protein ; Redox ; Mutation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract  The recombinant high-potential iron-sulfur protein (HiPIP) iso-I from Ectothiorhodospira halophila has been mutated at position 68. The αC of Val 68 is within a 0.6-nm sphere from the closest iron ion of the cluster. The valine residue has been replaced by a negatively charged glutamate residue (V68E) and by a positively charged lysine residue (V68K). With respect to the recombinant wild-type protein the reduction potentials of the V68E and V68K variants are –21±2 and +29±2 mV respectively (200 mM NaCl, pH 7, 25  °C). The solution structure of the V68E mutant was solved up to a pairwise RMSD of 66 pm for backbone atoms and 138 pm for all heavy atoms. The structure of the variant is very similar to that of recombinant wild type, indicating that the observed changes in reduction potentials are largely due to the effect of the introduced charges. It is proposed that the valence distribution within the oxidized iron-sulfur cluster is affected only slightly by the change in charge at position 68, but consistently with a simple electrostatic model.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    The journal of membrane biology 139 (1994), S. 203-212 
    ISSN: 1432-1424
    Keywords: Mg2+ current ; Mutation ; Paramecium ; Intracellular Mg2+ homeostasis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract “Eccentric” is a newly-isolated mutant of Paramecium tetraurelia that fails to swim backwards in response to Mg2+. In the wild type, this backward swimming results from Mg2+ influx via a Mg2+-specific ion conductance (I Mg. Voltage-clamp analysis confirmed that, as suspected, step changes in membrane potential over a physiological range fail to elicit I Mg from eccentric. Further electrophysiological investigation revealed a number of additional ion-current defects in eccentric: (i) The Ca2+ current activated upon depolarization inactivates more slowly in eccentric than in the wild type, and it requires longer to recover from this inactivation. (ii) The Ca2+-dependent Na+ current deactivates significantly faster in the mutant, (iii) The two K+ currents observed upon hyperpolarization are reduced by 〉60% in eccentric. It is difficult to envision how these varied pleiotropic effects could result from loss of a single ion current. Rather, they suggest that the eccentric mutation affects a global regulatory system. Two plausible hypotheses are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Artificial life and robotics 3 (1999), S. 242-245 
    ISSN: 1614-7456
    Keywords: Mutation ; Self-reproduction ; Evolvability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract A self-reproduction process is described and discussed via a network model of machines and description tapes. The emergence of a core network which dynamically sustains the rewriting processes of machines on tapes is reported. The structures of the core networks are generic, and include Eigen's hypercycle as a special case. In the cell assembly model, where each cell contains machines and tapes, we show that the instability of the core network in some cells is sustained by those cells with stable core networks. The instability of the core network is transfered to its offspring when the cells divide. What is inherited here is not the patterns of tapes, but the way machines read tapes in a core network.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1573-4986
    Keywords: α(1,3/1,4)fucosyltransferase ; Fuc-TIII ; Lewis-negative allele ; Chimera ; Mutation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Recently, we found three novel missense mutations, G484A (Asp162Asn), G667A (Gly223Arg), and G808A (Val270Met), present in a Lewis-negative allele (le484,667,808) from an African (Xhosa) population. To define the relative contribution of each of the three mutations in the le484,667,808 allele for inactivation of the FUT3-encoded enzyme, we made chimeric FUT3 containing each of the three mutations. A transient expression study indicated that COS7 cells transfected with the FUT3 construct containing the G484A mutation expressed the Lewis antigen and had about 20% enzyme activity as compared with COS7 cells transfected with the wild type FUT3 allele, whereas COS7 cells transfected with the FUT3 construct containing either the G667A mutation or the G808A mutation did not express the Lewis antigen and showed no detectable α(1,3/1,4)fucosyltransferase activity. These results suggest that the G667A and/or the G808A missense mutations of FUT3 alleles are responsible for the inactivation of the FUT3-encoded enzyme.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Pharmacy world & science 16 (1994), S. 55-61 
    ISSN: 1573-739X
    Keywords: AMP deaminase/deliciency ; Deficiency diseases ; Genetics, biochemical ; Mutation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract In man, there are at least four isoforms of adenosine monophosphate deaminase (AMPD): myoadenylate deaminase in skeletal muscle, the L isoform in liver, and the E1 and E2 isoforms in erythrocytes. Myoadenylafe deaminase is encoded by the AMPD1 gene located on chromosome 1 p13-p21, the L isoform by the AMPD2 gene, and both isoforms in erythrocytes by the AMPD3 gene. Myoadenylate deaminase deficiency is found in 2–3% of all muscle biopsies. The inborn type of myoadenylate deaminase deficiency is caused by a single mutant allele harbouring two mutations: C34→T (Gin→Stop) and C143→T (Pro-48→Leu). Population studies revealed a frequency of the mutant allele of 0.12 in Caucasian Americans and Germans. The C34→T mutation is located in exon 2, which is alternatively spliced in part of the AMPD1 transcript in human muscle. Since the second mutation does not affect enzyme function, alternatively spliced mRNA encodes a catalytically active enzyme. Only one patient with a disorder linked to liver AMPD has been described so far. In this patient the decreased inhibition of this enzyme by GTP resulted in uric acid overproduction and gout. A complete lack of erythrocyte AMPD activity is found in asymptomatic subjects. The molecular basis of both disorders is not yet known.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Pharmacy world & science 17 (1995), S. 149-151 
    ISSN: 1573-739X
    Keywords: Antibiotics ; Communicable diseases ; Drug resistance, microbial ; Mutation ; Transduction, genetic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The development of resistance to antimicrobial agents by many bacterial pathogens has compromised traditional therapeutic regimens, making treatment of infections more difficult and frequently more expensive. Three factors have contributed to the development and spread of resistance: mutations in common genes that extend their spectrum of resistance, transfer of resistance genes among diverse microorganisms and increases in selective pressures in and outside of the hospital environment that enhance the development of resistant organisms. Some new resistance mechanisms are difficult to detect in the laboratory. Thus, resistant microorganisms may go unnoticed until they are widely disseminated in a hospital. The challenge for pharmacists, microbiologists and physicians is not only to contain the spread of existing resistant organisms, but also to prevent the emergence of new resistant pathogens by encouraging the rational and prudent use of antimicrobial agents.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Plant and soil 82 (1984), S. 427-438 
    ISSN: 1573-5036
    Keywords: Mutant ; Mutation ; Nitrate ; Nitrate reductase ; Nodulation ; Pisum sativum L. ; Rhizobium leguminosarum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary In pea (Pisum sativum L.), mutants could be induced, modified in the symbiotic interaction withRhizobium leguminosarum. Among 250 M2-families, two nodulation resistant mutants (K5 and K9) were obtained. In mutant K5 the nodulation resistance was monogenic recessive and not Rhizobium strain specific. Out of 220 M2-families one mutant nod3 was found which could form nodules at high nitrate concentrations (15 mM KNO3). This mutant nodulated abundantly with severalRhizobium strains, both in the absence and presence of nitrate. Probably as the result of a pleiotropic effect, its root morphology was also changed. Among 1800 M2-families, five nitrate reductase deficient mutants were obtained and one of them (mutant E1) was used to study the inhibitory effect of nitrate on nodulation and nitrogen fixation. The results of the present investigation show that pea mutants which are modified in their symbiosis withRhizobium leguminosarum, can readily be obtained. The significance of such mutants for fundamental studies of the legume-Rhizobium symbiosis and for applications in plant breeding is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1573-3904
    Keywords: Cartilage oligomeric matrix protein ; Coiled coils ; Mutation ; Pentamer ; Thrombospondin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The assembly domain of cartilage oligomeric matrixprotein (COMP) forms an α-helical coiled coilhomopentamer with a conserved polar glutamine in theinterior (d) position. We substituted Gln54 forapolar Leu in the recombinant fragment of the rat COMPdomain. Biochemical studies and circular dichroism(CD) spectroscopy showed that the mutant, similarly tothe wild-type (w.t.) peptide, forms spontaneously anα-helical pentamer. Thermal transitions of thew.t. and mutant pentamers were analyzed by CDspectroscopy and differential scanning calorimetry.The Gln54Leu mutation increased the thermal stabilityof the pentamer with reduced disulfide bonds from73 °C to 104 °C. The denaturation of thedisulfide bonded w.t. pentamer was observed at108 °C while the mutant pentamer cannot bedenatured up to 120 °C (the apparatus limit).Thus, by Gln54Leu mutation we found a way tosignificantly stabilize the coiled coil pentamer,making this peptide even more attractive as an oligomerization tool for various biotechnological applications.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1573-3904
    Keywords: Cartilage oligomeric matrix protein ; Coiled coils ; Mutation ; Pentamer ; Thrombospondin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The assembly domain of cartilage oligomeric matrix protein (COMP) forms an α-helical coiled coil homopentamer with a conserved polar glutamine in the interior (d) position. We substituted Gln54 for apolar Leu in the recombinant fragment of the rat COMP domain. Biochemical studies and circular dichroism (CD) spectroscopy showed that the mutant, similarly to the wild-type (w.t.) peptide, forms spontaneously an α-helical pentamer. Thermal transitions of the w.t. and mutant pentamers were analyzed by CD spectroscopy and differential scanning calorimetry. The Gln54Leu mutation increased the thermal stability of the pentamer with reduced disulfide bonds from 73°C to 104°C. The denaturation of the disulfide bonded w.t. pentamer was observed at 108°C while the mutant pentamer cannot be denatured up to 120°C (the apparatus limit). Thus, by Gln54Leu mutation we found a way to significantly stabilize the coiled coil pentamer, making this peptide even more attractive as an oligomerization tool for various biotechnological applications.
    Type of Medium: Electronic Resource
    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...