title: Presence of a sodium-translocating ATPase in membrane vesicles of the homoacetogenic bacterium Acetobacterium woodii.
abstract: Inverted membrane vesicles of the homoacetogenic bacterium Acetobacterium woodii catalyzed the hydrolysis of ATP with a rate of 100-150 nmol.min-1.mg protein-1. The ATPase was stimulated 1.4-1.6-fold by NaCl and inhibited by N,N'-dicyclohexylcarbodiimide tributyltin or azide. The degree of inhibition caused by F0-directed but not F1-directed inhibitors was affected by the Na+ concentration in the medium. These experiments indicated the presence of a sodium-translocating ATPase. This was verified by transport studies. Upon addition of ATP to inverted vesicles, 22Na+ was actively transported into the intravesicular space up to a 24-fold accumulation. Na+ transport was inhibited by the sodium ionophore N,N,N',N',-tetracyclohexyl-1,2-phenyl-enedioxydiacetamide but stimulated by valinomycin with potassium whereas the protonophore 3,5,-di-tert-butyl-4-hydroxybenzylidenemalonitrile was without effect. N,N'-dicyclohexylcarbodiimide and tributyltin inhibited 22Na+ transport. These experiments are in accordance with a primary electrogenic Na+ transport as catalyzed by a F1F0-ATPase.
authors.affiliation: Institut für Mikrobiologie, Göttingen, Federal Republic of Germany.
authors.forename: R
authors.initials: R
authors.lastname: Heise
authors.forename: V
authors.initials: V
authors.lastname: Müller
authors.forename: G
authors.initials: G
authors.lastname: Gottschalk
mesh_terms: D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D001386:Azides / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D027682:Cation Transport Proteins; D002462:Cell Membrane / Q000201:enzymology; D004024:Dicyclohexylcarbodiimide / Q000494:pharmacology; D016987:Gram-Positive Rods / Q000201:enzymology*; D006868:Hydrolysis; D007700:Kinetics; D009570:Nitriles / Q000494:pharmacology; D006180:Proton-Translocating ATPases / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D013379:Substrate Specificity; D014220:Trialkyltin Compounds / Q000494:pharmacology; D014634:Valinomycin / Q000494:pharmacology
chemical_list: D001386:Azides; D027682:Cation Transport Proteins; D009570:Nitriles; D014220:Trialkyltin Compounds; D014634:Valinomycin; C011559:tributyltin; C001784:SF 6847; D004024:Dicyclohexylcarbodiimide; D000255:Adenosine Triphosphate; D012964:Sodium; D000251:Adenosine Triphosphatases; C021838:sodium-translocating ATPase; D006180:Proton-Translocating ATPases