SPERMINE ACTION ON MITOCHONDRIAL H-ATPASE ACTIVITY AND PROLIFERATION RATE OF TRYPANOSOMA-CRUZI()

Activity of H+-ATPase of Trypanosoma cruzi (RA strain) submitochondria l particles is increased in parasites which have a low spermine conten t caused by growing in a polyamine free medium or in a medium containi ng inhibitors of polyamine synthesis. Under these conditions, the prol iferation rate is markedly decreased. Kinetics of the enzyme inhibitio n by spermine indicates a non-competitive inhibition. Spermine, throug h its action on the H+-ATPase hydrophobic environment, affects the enz yme activity. Together with the ATPase protein inhibitor, this could b e a mechanism regulating ATP levels needed for the parasite proliferat ion.