The conditions for optimal rates of ATP hydrolysis catalyzed by the chloroplast ATP-synthase (ATPase), CF0F1, after isolation and reconstitution into asolectin liposomes have been investigated. The rate of ATP hydrolysis was measured either after oxidation of CF0F1 (by incubation with iodosobenzoate) or after reduction of CFoF, (by incubation with dithiothreitol). In both cases a rate of about 1-2 ATP (CF0F1·s)-1 was observed under uncoupled conditions. If the proteoliposomes are first energized by an acid-base transition and a K+ /valinomycin diffusion potential, the uncoupled rate of ATP hydrolysis is about 1-2 ATP (CF0F1 ·s) 1 for the oxidized enzyme and about 20 for the reduced species. This rate is about a factor 2 smaller than that observed in chloroplasts under the same conditions
No takes yet. Share an insight, caveat, or question.
Schmidt et al. (1987) studied this question.