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A comprehensive two‐dimensional map of cytosolic proteins of Bacillus subtilis
Author(s) -
Büttner Knut,
Bernhardt Jörg,
Scharf Christian,
Schmid Roland,
Mäder Ulrike,
Eymann Christine,
Antelmann Heike,
Völker Andrea,
Völker Uwe,
Hecker Michael
Publication year - 2001
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/1522-2683(200108)22:14<2908::aid-elps2908>3.0.co;2-m
Subject(s) - proteome , proteomics , isoelectric point , biochemistry , biology , uniprot , bacillus subtilis , isoelectric focusing , two dimensional gel electrophoresis , chemistry , enzyme , gene , genetics , bacteria
Proteomics relying on two‐dimensional (2‐D) gel electrophoresis of proteins followed by spot identification with mass spectrometry is an excellent experimental tool for physiological studies opening a new perspective for understanding overall cell physiology. This is the intriguing outcome of a method introduced by Klose and O'Farrell independently 25 years ago. Physiological proteomics requires a 2‐D reference map on which most of the main proteins were identified. In this paper, we present such a reference map with more than 300 entries for Bacillus subtilis proteins with an isoelectric point (p I ) between 4 and 7. The most abundant proteins of exponentially growing cells were compiled and shown to perform mainly housekeeping functions in glycolysis, tricarboxylic acid cycle (TCC), amino acid biosynthesis and translation as well as protein quality control. Furthermore, putative post‐translational modifications were shown at a large scale, with 47 proteins in total forming more than one spot. In a few selected cases evidence for phosphorylation of these proteins is presented. The proteome analysis in the standard p I range was complemented by either stretching the most crowded regions in a narrow pH gradient 4.5–5.5, or by adding other fractions of the total B. subtilis proteome such as alkaline proteins as well as extracellular proteins. A big challenge for future studies is to provide an experimental protocol covering the fraction of intrinsic membrane proteins that almost totally escaped detection by the experimental procedure used in this study.*