Kinetic analysis of proton translocation catalyzed by F0F1 ATPase

Kinetic analysis of both proton translocating and steady-state ATP hydrolytic activities catalyzed by F0F1 ATPase in submitochondrial particles were carried out over an ATP concentration range of 1-2000 microM. The results were examined in relation to the prediction based on the alternate binding change model proposed by Gresser et al. [(1982) J. Biol. Chem. 257, 12030-12038] in which energy transduction occurs only at the tri-site catalytic cycle. The present results essentially contrast with the model and rather indicate that if the alternate binding mechanism holds for the ATP hydrolytic reaction, the proton translocation should be coupled to at least both bi-site and tri-site cycles.