Disulfide cross-linking of subunits F1-γ and F0I-PVP(b) results in asymmetric effects on proton translocation in the mitochondrial ATP synthase.

AbstractA study is presented on the effect of diamide-induced disulfide cross-linking of F1-γ and F0I-PVP(b) subunits on proton translocation in the mitochondrial ATP synthase. The results show that, upon cross-linking of these subunits, whilst proton translocation from the A side to the B F1 side is markedly accelerated with decoupling of oxidative phosphorylation, proton translocation in the reverse direction, driven by either ATP hydrolysis or a diffusion potential, is unaffected. These observations reveal further peculiarities of the mechanism of energy transfer in the ATP synthase of coupling membranes