Effect of membrane voltage on the plasma membrane H(+)-ATPase of Saccharomyces cerevisiae.

摘要: A novel system for generating large interior positive membrane potentials in proteoliposomes was used to examine the effects of voltage on reconstituted plasma H(+)-ATPase from Saccharomyces cerevisiae. The potential-generating dependent upon lipophilic electron carrier tetracyanoquinodimethane, located within bilayer, mediate flow vesicle entrapped ascorbate external K3Fe(CN)6. Membrane potential formation followed by potential-dependent probe oxonol V and found rapidly reach a steady-state which lasted at least 90 s. approximately 254 mV determined under optimal conditions ATP hydrolysis wild-type inhibited 34 46% these conditions. In contrast, had little effect pma1-105 mutant enzyme suggesting that it is defective electrogenic proton translocation. Applied also alter sensitivity vanadate concentrations less than 50 microM. These data suggest coupling between charge-transfer domains establish solid basis future probing properties yeast H(+)-ATPase.