Fractional Analysis of Escherichia coli O157:H7 by Mass Spectrometry- Based Proteomics.

摘要

This report is required for the U.S. Army Edgewood Chemical Biological Center In-House Laboratory Independent Research project Membrane Vesicles and Extracellular Proteins in Antibiotic Resistance and Virulence . Certain extracellular proteins of pathogenic bacteria have been shown to function in survival mechanisms such as host immune system modulation (Vranakis, et al., July 27, 2011, J. Proteome Res. DOI 10.1021/pr200422f) and biofilm formation (Ostrowski, A., et al., 2011, J. Bacteriol. 193:4043). To begin to address this possibility, we have analyzed Escherichia coli O157:H7 protein fractions by liquid chromatography-tandem mass spectrometry, followed by biochemical pathway mapping using the Kyoto Encyclopedia of Genes and Genomes. The fimbriae-specific subset included proteins involved in carbohydrate metabolism, which are important in providing energy for fimbriae motion. Moreover, inositol monophosphatase (IMP), which has a role in streptomycin synthesis, and a glucose-specific phosphotransferase system (G-PTS), involved in environmental processing, were also identified. IMP, G-PTS, and a putative stress protein, recently identified in the suspension, are expected to function as part of the bacterial survival mechanisms. This research should provide fundamental knowledge regarding extracellular proteins produced by Gram- negative bacteria. The identification of molecular level components important for survival could prove useful in arenas such as vaccine and antibiotic development.