Characterisation of bacterial proteomes by two-dimensional electrophoresis Review Article

The recent determination of the complete genome nucleic acid sequences for a number of different bacteria has provided an opportunity to investigate gene expression on a global scale for these organisms. The determination of the proteome for an organism is one way by which such a global analysis can be achieved. Proteomics aims at defining all of the proteins expressed by an organism, thus permitting the analysis of gene expression at the level of protein synthesis. Two major developments have contributed toward the success of proteomics. These are, firstly, the ability to analyze complex protein mixtures by two-dimensional electrophoresis (2DE) under highly reproducible conditions and, secondly, the development of sensitive methods of protein characterization compatible with the amounts of protein resolved by 2DE. The latter techniques permit the identification of a protein and its linkage to a specific gene sequence. This review describes the application of proteomics in bacteriology and its potential for the molecular characterization of bacteria for which either complete or partial genomic sequences are known. The characterization of the bacterial proteome through protein analysis using 2DE has been applied to look at bacterial global gene expression for a number of specific research areas including the interactions of bacteria with eukaryotic cells and bacterial stress responses. Examples of these applications will be discussed, as will be the potential future applications for proteomics in complementing the data derived from genome nucleic acid sequencing.