| Abstract
| - Helicobacter pylori is an important human gastricpathogen for which the entire genome sequence is known.This microorganism displays a uniquely complex patternof binding to complex carbohydrates presented on hostmucosal surfaces and other tissues, through adhesionmolecules (adhesins) on the microbial cell surface. Adhesins and other membrane-associated proteins are important targets for vaccine development. The identificationand characterization of cell-surface proteins expressed byH. pylori is a prerequisite for the development of vaccinesdesigned to interfere with bacterial colonization of hosttissues. However, identification of membrane proteins isdifficult using a traditional proteomics approach employing 2D-PAGE. We have used a novel approach in theidentification of microbial proteins that employs a rapidpreparative two-dimensional electrophoretic separationfollowed by mass spectrometry and database searches.No pre-enrichment of bacterial membranes was required.The entire process, from sample preparation to proteinidentification, can be completed in less than 18 hours,and the presence of proteins can be monitored after boththe first- and second-dimensional separations using massspectrometry. We were able to identify 40 proteins froma detergent-solubilized H. pylori preparation; over one-third of these were membrane or membrane-associatedproteins. A functionally characterized low-abundancemembrane protein, the Leb-binding adhesin, was foundin this group. The use of this rapid 2D electrophoreticseparation in proteomic studies of H. pylori is expectedto speed up the identification of expressed virulenceproteins and vaccine targets in this and other microbialpathogens.
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