Proteomic Analysis of Mycobacterium tuberculosis Protein-Mannosyltransferase Knock-Out Mutant.

This project focused in the proteomic characterization of the secreted proteome of a Rv1002c (Protein mannosyltransferase) knock-out mutant and its wild type counterpart. The analysis was carried out using a M. tuberculosis ΔleuDΔpanCD auxotroph Rv1002c wild type compared to M. tuberculosis ΔleuDΔpanCDΔRv1002c. Both strains were grown in triplicate and their whole cell lysate (WCL) and secreted proteins (CFP) where purified, trypsin digested and characterized by liquid-chromatography coupled with tandem mass spectrometry (LC-MS/MS). Three replicate injections were performed for each of the sampels. The resulting spectra were searched against an M. tuberculosis database and relative protein abundance was determined using normalized spectral counts. Protein abundance differences were tested by Student’s t test. Abundance of 39 secreted proteins was significantly different between the WT and the ΔRv1002c. Decrease abundance of known glycoproteins, including several lipoglycoproteins was observed in the ΔRv1002c strain. In the WCL, 61 proteins presented significantly different abundance between the WT and the ΔRv1002c strains, including 4 proteins that were completely absent in the mutant (Rv2510c, PknF, Mpt70 and CeoC).