Brief Description:
Proteome analysis is the determination of the protein complement expressed by the genome of a specific cell type. It is valuable in that mRNA expression does not correlate directly to protein expression levels and proteins are modified post-transcription. Post-transcription modifications such as phosphorylation, glycosylation and sulfation can dramatically change the action of a protein. Thus to understand what exactly is going on inside a cell defining the exact proteome of the cell is necessary.
Generally, it is done by taking a crude protein mixture and performing 2-dimentional electrophoresis for separation and then mass spectroscopy for identification. The most common dimensions used are the isoelectric point of the protein, where a pH gradient causes separation and SDS-PAGE (polyacrylamide gel electrophoresis), where proteins are denatured and separated based on size. Mass spectroscopy can help identify the proteins by fragmenting the individual peptides.
Application in Wine Microbiology:
Proteome analysis is useful in determining the current status of an organism. When S. cerevisiae is under stress, for example, certain proteins are produced which can help the yeast survive. This sort of determination may help the winemaker determine why there was a stuck fermentation. Also, it may help the geneticist determine whether or not a gene of interest is producing the appropriate protein.
References:
- Haynes, P. A., S. P. Gygi, D. Figeys, and R. Aebersold. 1998. Proteome analysis: Biological assay or data archive?Electrophoresis 19:1862-1871.
- Hodges, P. E., A. H. Mckee, B. P. Davis, W. E. Payne, and J. I. Garrels. 1999 The Yeast Proteome Database (YPD): a model for the organization and presentation of genome-wide functional data. Nucleic Acid Res. 27:69-73.
- Nobel, H., L. Lawrie, S. Brue, F. Klis, M. Davis, H. Alloush, and P. Coote. 2001. Parallel and comparative analysis of the proteome and trsncriptome of sorbic acid-stressed Saccharomyces cerevisiae. Yeast 18:1413-1428.
- Pandey, A., and M. Mann. 2000. Proteomics to study genes and genomes. Nature 405; 837-846.