Application of two-dimensional electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry for proteomic analysis of the sexually transmitted parasite Trichomonas vaginalis

Trichomonas vaginalis is a sexually transmitted protozoan parasite that infects the human urogenital tract causing trichomoniasis, a worldwide disease. In this work, a fresh clinical isolate of T. vaginalis was used for study of the protein expression in this species. Two‐dimensional gel electrophoresis (2‐DE) and MALDI‐TOF/TOF mass spectrometry (MS) were employed to create a reference map of soluble proteins in the pH range 4–7. A set of 116 proteins belonging to functional classes expressed in high and low abundance was identified by peptide mass fingerprinting and tandem MS. These identifications corresponded to 67 different proteins, suggesting that post‐translational modifications are common phenomena in T. vaginalis. Identified proteins were classified into 16 groups according to biological processes. Among detected proteins we identified the major enzymes involved in both cytosolic and hydrogenosomal metabolic pathways, as well as putative protein targets for new drug design. In addition, this analysis allows validation of previous gene predictions confirming the expression of 15 hypothetical proteins. Finally, the findings here reported represent the first reference proteome map of T. vaginalis and the first steps towards the description of a comprehensive proteome map of this parasite. Copyright © 2007 John Wiley & Sons, Ltd.