LOCALIZATION OF THE PLASMA-MEMBRANE AND MITOCHONDRIAL H+-ATPASES IN LEISHMANIA DONOVANI PROMASTIGOTES

Immunochemical methods were used to characterize the proton-translocating ATPases (H+-ATPases) of the plasma membrane and mitochondrion of Leishmania donovani promastigotes. Antisera directed against the plasma membrane H+-ATPase of Saccharomyces cerevisiae reacted with a 66 kDa membrane protein of L. donovani promastigotes. By immunocytochemistry, the antiserum was shown to label the cell and flagellar surface of promastigotes as well as the Golgi apparatus and the membrane of intracellular organelles. The target antigen was shown to possess ATPase activity resembling the leishmanial H+-ATPase activity. Antisera raised against the beta-subunit of the F0F1-ATPase of Escherichia coli reacted with a 56 kDa protein in L. donovani promastigotes. Ultrastructurally, the anti-beta-subunit antibody was exclusively associated with the mitochondrion in these cells. This antiserum immunoprecipitates ATP hydrolytic activity typical of the F1 beta-subunit activity of the mitochondria of higher eukaryotes.