ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Electrophoresis 16 (1995), S. 1225-1230 
    ISSN: 0173-0835
    Keywords: Testis ; Spermatogenesis ; Two-dimensional polyacrylamide gel electrophoresis ; Protein map ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Spermatogenesis is a process in the testis that involves meiotic cell division and spermiogenesis. The mechanisms of regulation and its associated proteins are mostly unknown. This publication shows the two-dimensional (2-D) gel electrophoresis protein map obtained from rat testis using nonlinear 3.5-10 immobilized pH gradients for the first-dimensional separation. Eighteen proteins were successfully identified in the SWISS-PROT protein database using amino acid analysis of proteins recovered from polyvinylidene difluoride (PVDF) membranes and verified for one of them by comparison with Anderson's rat liver reference map. Fourteen new polypeptides were identified and four were previously known. Two of these new proteins were closely related to the spermatogenetic process. T-complex protein 1 is expressed in large amounts in germ cells. Androgen-dependent sperm-coating glycoprotein is secreted by epididymal cells. In order to detect changes in protein expression during meiosis and spermiogenesis, spermatocytes and round spermatid cell populations were purified by centrifugal elutriation and compared. In this way several proteins not found in the spermatocyte 2-D images could be highlighted. The sperm-coating glycoprotein was thus shown to be present in large amounts in round spermatids.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 0173-0835
    Keywords: Proteome ; Automation ; Two-dimensional polyacrylamide gel electrophoresis ; Mass spectrometry ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: The development of automated, high throughput technologies for the rapid identification of proteins is essential for large-scale proteome projects. While a degree of automation already exists in some stages of the protein identification process, such as automated acquisition of matrix assisted laser desorption ionisation  -  time of flight (MALDI-TOF) mass spectra, efficient interfaces between different stages are still lacking. We report the development of a highly automated, integrated system for large scale identification of proteins separated by two-dimensional gel electrophoresis (2-DE), based on peptide mass fingerprinting. A prototype robotic system was used to image and excise 288 protein spots from an amido black stained polyvinylidene difluoride (PVDF) blot. Protein samples were enzymatically digested with a commercial automated liquid handling system. MALDI-TOF mass spectrometry was used to acquire mass spectra automatically, and the data analysed with novel automated peptide mass fingerprinting database interrogation software. Using this highly automated system, we were able to identify 95 proteins on the basis of peptide mass fingerprinting, isoelectric point and molecular weight, in a period of less than ten working days. Advantages, problems, and future developments in robotic excision systems, liquid handling, and automated database interrogation software are discussed.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 0173-0835
    Keywords: Proteome ; Genome ; Two-dimensional polyacrylamide gel electrophoresis ; Post-translational modifications ; Vector maps ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 0173-0835
    Keywords: Proteome ; Two-dimensional polyacrylamide gel electrophoresis ; Protein hydrophobicity ; Protein copy number ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Two-dimensional (2-D) gel electrophoresis is often used in proteome projects to provide a global view of the proteins expressed in any cell or tissue type. Here we have investigated the effects of protein hydrophobicity and cellular protein copy number on a protein's presence or absence on a two-dimensional gel. The average hydropathy values of all known proteins from Bacillus subtilis, Escherichia coli and Saccharomyces cerevisiae were calculated, thus defining the range of protein hydrophobicity and hydrophilicity in these organisms. The average hydropathy values were then calculated for a total of 427 proteins from these species, which had been identified elsewhere on 2-D gels. Strikingly, it was seen that no highly hydrophobic proteins, as defined by average hydrophobicity values, have been found to date on 2-D gel separations of whole cell lysates. A clear hydrophobicity cutoff point was seen, above which current 2-D electrophoresis methods appear not to be useful for protein separation. The effect of cellular protein copy number on a protein's presence on a 2-D gel was investigated by means of a graphical model. This model showed how variations in protein loading and copy number per cell interact to determine the quantity of a protein that will be present on a 2-D gel. Considering the current maximum in 2-D gel loading capacity, it was found that 2-D probably can not visualize or produce analytical quantities of proteins present at less than 1000 copies per cell. We conclude that further developments of 2-D electrophoresis techniques are desirable to enable the visualization and analysis of all proteins expressed by a cell or tissue.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 0173-0835
    Keywords: Two-dimensional polyacrylamide gel electrophoresis ; Escherichia coli ; SWISS-2DPAGE database ; Immobilized pH gradient ; Sequence tag ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: The combination of two-dimensional polyacrylamide gel electrophoresis (2-DPAGE), computer image analysis and several protein identification techniques allowed the Escherichia coli SWISS-2DPAGE database to be established. This is part of the ExPASy molecular biology server accessible through the WWW at the URL address http://www.expasy.ch/ch2d/ch2d-top.html. Here we report recent progress in the development of the E. coli SWISS-2DPAGE database. Proteins were separated with immobilized pH gradients in the first dimension and sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the second dimension. To increase the resolution of the separation and thus the number of identified proteins, a variety of wide and narrow range immobilized pH gradients were used in the first dimension. Micropreparative gels were electroblotted onto polyvinylidene difluoride membranes and spots were visualized by amido black staining. Protein identification techniques such as amino acid composition analysis, gel comparison and microsequencing were used, as well as a recently described Edman “sequence tag” approach. Some of the above identification techniques were coupled with database searching tools. Currently 231 polypeptides are identified on the E. coli SWISS-2DPAGE map: 64 have been identified by N-terminal microsequencing, 39 by amino acid composition, and 82 by sequence tag. Of 153 proteins putatively identified by gel comparison, 65 have been confirmed. Many proteins have been identified using more than one technique. Faster progress in the E. coli proteome project will now be possible with advances in biochemical methodology and with the completion of the entire E. coli genome.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 0173-0835
    Keywords: Protein identification ; Two-dimensional polyacrylamide gel electrophoresis ; Peptide mass fingerprinting ; Sequence tag ; Amino acid composition ; Proteomics ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Recent increases in the number of genome sequencing projects means that the amount of protein sequence in databases is increasing at an astonishing pace. In proteome studies, this is facilitating the identification of proteins from molecularly well-defined organisms. However, in studies of proteins from the majority of organisms, proteins must be identified by comparing analytical data to sequences in databases from other species. This process is known as cross-species protein identification. Here we present a new program, MultiIdent, which uses multiple protein parameters such as amino acid composition, peptide masses, sequence tags, estimated protein pI and mass, to achieve cross-species protein identification. The program is structured so that protein amino acid composition, which is highly conserved across species boundaries, first generates a set of candidate proteins. These proteins are then queried with other protein parameters such as sequence tags and peptide masses. A final list of database entries which considers all analytical parameters is presented, ranked by an integrated score. We illustrate the power of the approach with the identification of a set of standard proteins, and the identification of proteins from dog heart separated by two-dimensional gel electrophoresis. The MultiIdent program is available on the world-wide web at: http://www.expasy.ch/sprot/multiident.html.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 0173-0835
    Keywords: Immunobloting ; Two-dimensional polyacrylamide gel electrophoresis ; Immobilized pH gradient ; Protein identification ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Cell dysfunction or dysregulation in cancer generally results from complex gene interactions, numerous cellular events and environmental influences which modify gene expression or post-translational protein modifications. Genetic analysis in itself cannot always predict or diagnose multigenic diseases. The major technical difficulty is thus to detect, identify and measure simultaneously the expression of several genes and the post-translational modifications of their products. In order to progress to this direction, this paper describes a simple immunoblot method using several monoclonal antibodies to simultaneously analyze oncogene expression and cell cycle specific checkpoints in patient solid biopsies and transformed cell lines. One mg of normal human liver biopsy and HEPG2 (hepatoblastoma-derived cell line) protein samples have been separated by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) and transferred onto polyvinylidene difluoride (PVDF) membranes. The membranes were stained with amido black, scanned and tested separately with the nine monoclonal antibodies p53, c-myc, PCNA, MEK1, pan-ras, Cip1, Cdc2, Kip1, and TCTP. The nine antibodies of interest were then combined to form a mixture, and simultaneously used as the primary antibodies. This antibody mixture simultaneously detected the nine proteins of interest or both samples and it demonstrated the extensive expression changes and the presence of various isoforms most likely due to post-translational modifications of gene products.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 0173-0835
    Keywords: Calcium-binding protein ; Two-dimensional polyacrylamide gel electrophoresis ; Growth related protein ; Post-translational modification ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: The translationally controlled tumor protein (TCTP) is a growth-related protein which is regulated at the translational level. It is present in mammals, higher plants and Saccharomyces cerevisiae. This study was undertaken to localize and further characterize the TCTP in human cell lysates using two-dimensional gel electrophoresis, monoclonal antibodies, and 45Ca-gel overlay. TCTP was found in several healthy and tumoral cells including erythrocytes, hepatocytes, macrophages, platelets, keratinocytes, erythroleukemia cells, gliomas, melanomas, hepatoblastomas, and lymphomas. It could not be detected in kidney and renal cell carcinoma (RCC). A monoclonal antibody raised against TCTP detected three isoforms likely due to post-translational modifications. A calcium binding property was found as well as heat stability and cytoplasmic localization. The high degree of homology from plants to man and its expression in many tissues suggests that TCTP most likely has a cell housekeeping function.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 0173-0835
    Keywords: Glycoprotein ; Two-dimensional polyacrylamide gel electrophoresis ; α1-Antitrypsin ; α2-HS Glycoprotein ; Protein isoforms ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Two-dimensional (2-D) electrophoresis is the preferred method for separating the glycoforms of proteins. The isoforms usually present as ‘trains’ of spots in the first dimension and may also differ in molecular weight. The primary goal for analyzing the carbohydrate content of glycoprotein spots is to understand the ‘rules’ which govern the migration of glycoproteins in 2-D electrophoresis. These rules can then be used to produce predictive vectors to interpret changes in glycosylation patterns. Techniques for the analysis of oligosaccharides released from glycoproteins which have been electroblotted to PVDF membrane after one-dimensional (1-D) and 2-D preparative gel electrophoresis are described. The oligosaccharides are removed enzymatically (PNGase F of N-linked oligosaccharides) or chemically (β-elimination of O-linked oligosaccharides) and separated by high performance anion exchange chromatography (HPAEC-PAD) and identified by electrospray ionization mass spectrometry (ESI-MS) or analyzed directly by ESI-MS. After enzymic removal of the N-linked oligosaccharides the protein spots can be further analyzed by Edman sequence tagging for identification and quantitation of the protein and by acid hydrolysis for monosaccharide analysis of the O-linked oligosaccharides. These approaches have been proved on 1-D PAGE electroblotted bovine fetuin and human glycophorin A and then used to analyze two abundant proteins which separate as glycoforms on 2-D PAGE preparative narrow range (pH 4.5-5.5) blots of human plasma: α2-HS glycoprotein (human fetuin) and α1-antitrypsin (α1-protease inhibitor). It is apparent that both the macroheterogeneity (site occupation) and microheterogeneity (diversity of structures) of the glycosylation contribute to the separation of protein isoforms in 2-D PAGE.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 0173-0835
    Keywords: Two-dimensional polyacrylamide gel electrophoresis ; Human blood platelets ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Two-dimensional (2-D) maps of cytosol and enriched-membrane platelet proteins has allowed the identification of more than 25 spots by three different methods: matching of the platelet gels with other 2-D reference maps, immunoblotting with chemiluminescence detection, and N-terminal sequencing. Different G protein (guanosine triphosphate-binding protein) subunits, cytoskeletal proteins, and proteins common to the human liver, red blood cells and plasma were identified. The two platelet protein maps presented here contribute to the project of identification of human cell and body fluid proteins. They may serve as working tools since platelets are popular models for the study of central nervous system neurotransmitter systems and stimulus-response coupling mechanisms.
    Additional Material: 4 Ill.
    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...