title: The Na+/e- stoichiometry of the Na+-motive NADH:quinone oxidoreductase in Vibrio alginolyticus.
abstract: A method is proposed to estimate the stoichiometries of primary Na+-pumps in intact bacterial cells. It is based on technique when the H+/e- stoichiometry is measured in the presence of protophorous uncoupler and in the absence of penetrating ions other than H+. Under these conditions, the H+ influx discharges membrane potential generated by the Na+ pump so the Na+/e- and H+/e- ratios become equal. Using this approach it is shown that the Na+/e- ratio for the Na+-motive NADH:quinone oxidoreductase of Vibrio alginolyticus is equal to 0.71 +/- 0.06. The Na+/e- stoichiometry appears to be approximately 1, provided that the contribution of the non-coupled NADH:quinone oxidoreductase, which is resistant to low HQNO concentrations, is taken into account.
authors.affiliation: Department of Bioenergetics, A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russia.
authors.forename: A V
authors.initials: AV
authors.lastname: Bogachev
authors.forename: R A
authors.initials: RA
authors.lastname: Murtazina
authors.forename: V P
authors.initials: VP
authors.lastname: Skulachev
mesh_terms: D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000493:pharmacokinetics; D002463:Cell Membrane Permeability / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000737:chemistry* / Q000187:drug effects; D010100:Oxygen / Q000493:pharmacokinetics; D018892:Proton-Motive Force / Q000187:drug effects; D000254:Sodium-Potassium-Exchanging ATPase / Q000737:chemistry* / Q000187:drug effects; D013691:Tellurium / Q000493:pharmacokinetics; D013816:Thermodynamics; D014733:Vibrio / Q000737:chemistry / Q000201:enzymology*
chemical_list: D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; C038436:bis(tetraphenylphosphonium)tetracyanato-bis-4-methoxy-4-phenyltellurate(IV); D016660:NAD(P)H Dehydrogenase (Quinone); D000254:Sodium-Potassium-Exchanging ATPase; D013691:Tellurium; D010100:Oxygen