Food vacuole proteome of P. berghei heme pathway ferrochelatase knockout parasite by LC-MS/MS

LC-MS/MS of in-solution trypsin digested FV protein extracts was carried out for the FVs isolated from PbWT and PbFCKO parasites. The FV preparations had signature FV proteins such as plasmepsin IV, berghepain, aminopeptidases, subunits of vacuolar-type H+ATPase (V-type H ATPase), together with parasitophorous vacuolar (PV) proteins including exported protein 1 (Exp1), Exp2, early transcribed membrane protein, PV1, PV5 (lipocalin) etc., and Rab GTPases associated with cytostome-FV trafficking. A total number of 251 and 201 proteins could be identified for WT (P1) and FCKO (P2) FVs, respectively, and 175 proteins were common between them suggesting an overall consistency in the preparations. The results obtained have suggested that the FV proteome in FCKO parasites is compromised. None of the subunits of V-type H+ATPase - a proton pump maintaining the acidic pH of FV could be detected in FCKO FVs indicating the lower abundance of these proteins. In addition, berghepain-2 - a cysteine protease involved in Hb degradation could not be detected in FCKO FVs.