Concentration gradient effects of sodium and lithium ions and deuterium isotope effects on the activities of H+-ATP synthase from chloroplasts.

ABSTRACT: We explored the concentration gradient effects of the sodium and lithium ions and the deuterium isotope's effects on the activities of H(+)-ATP synthase from chloroplasts (CF(0)F(1)). We found that the sodium concentration gradient can drive the ATP synthesis reaction of CF(0)F(1). In contrast, the lithium ion can be an efficient enzyme-inhibitor by blocking the entrance channel of the ion translocation pathway in CF(0). In the presence of sodium or lithium ions and with the application of a membrane potential, unexpected enzyme behaviors of CF(0)F(1) were evident. To account for these observations, we propose that both of the sodium and lithium ions could undergo localized hydrolysis reactions in the chemical environment of the ion channel of CF(0). The protons generated locally could pro

SUBMITTER: Chen MF 

PROVIDER: S-EPMC2907681 | biostudies-literature | 2009 Mar

REPOSITORIES: biostudies-literature