Catalytic and activating protons follow different pathways in the H(+)-ATPase of potato tuber mitochondria.

The effect of some F0F1 inhibitors on the activation of the H(+)-ATPase by the electrochemical proton gradient was investigated in mitochondria extracted from potato tubers. Transient activated state of the ATPase was revealed by addition of ATP and of the detergent lauryldimethylamine oxide (LDAO) to energized mitochondria. Venturicidin, tri-n-butyltin and aurovertin at high concentrations did not affect the process of delta mu H(+)-activation, whereas oligomycin fully blocked it. The results support the idea of separate pathways or binding sites for catalytic and activating protons.