Antimony is an important drug for the treatment of Leishmania parasite infections. In several countries, the emergence of drug-resistant Leishmania species has reduced the effectiveness of this drug. The mechanism of clinical drug resistance is unclear. The aim of this work was to identify mitochondrial proteome alterations associated with resistance against antimonial. A combination of cell fractionation, liquid chromatography-tandem mass spectrometry (LC-MS/MS), and Label-Free Quantification was used to characterize the mitochondrial protein composition of Leishmania tropica field isolates resistant and sensitive to meglumine antimoniate. LC-MS/MS analysis resulted in the identification of about 1200 proteins of the Leishmania tropica mitochondrial proteome. Various criteria were used to allocate about 40% proteins to mitochondrial proteome. Comparative quantitative proteomic analysis of the sensitive and the resistant strains showed proteins with differential abundance in resistance species are involved in TCA and aerobic respiration enzymes, stress proteins, lipid metabolism enzymes, and translation. These results showed that the mechanism of antimony resistance in Leishmania spp. field isolate may be associated with alteration in enzymes involved in mitochondrial pathways.
Keywords: LC-MS/MS; Leishmania; Meglumine antimoniate; Mitochondrial proteomics.