Generation of the electrochemical potential of Na+ by the Na+-motive NADH oxidase in inverted membrane vesicles of Vibrio alginolyticus.
Inverted membrane vesicles prepared from Vibrio alginolyticus generated a membrane potential (positive inside) and accumulated Na+ by the oxidation of NADH. Generation of the membrane potential required Na+ and was inhibited by 2-heptyl-4-hydroxyquinoline N-oxide, a specific inhibitor of the Na+-dependent NADH oxidase. Collapse of the membrane potential by valinomycin stimulated the uptake of Na+. In contrast, accumulation of H+ was not detected under all the conditions tested. These results suggest that only Na+ is translocated by the Na+-dependent NADH oxidase of V. alginolyticus.
Tokuda
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Udagawa
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Unemoto
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D002462:Cell Membrane / Q000201:enzymology; D004563:Electrochemistry; D006863:Hydrogen-Ion Concentration; D006912:Hydroxyquinolines / Q000494:pharmacology; D007473:Ion Channels / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009247:NADH, NADPH Oxidoreductases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism* / Q000494:pharmacology; D014634:Valinomycin / Q000494:pharmacology; D014733:Vibrio / Q000201:enzymology*
D006912:Hydroxyquinolines; D007473:Ion Channels; D009097:Multienzyme Complexes; C001333:2-(n-heptyl)-4-hydroxyquinoline N-oxide; D014634:Valinomycin; D012964:Sodium; C023107:NADH oxidase; D009247:NADH, NADPH Oxidoreductases