Presence of a sodium-translocating ATPase in membrane vesicles of the homoacetogenic bacterium Acetobacterium woodii.
Eur J Biochem
; 206(2): 553-7, 1992 Jun 01.
Article
in En
| MEDLINE
| ID: mdl-1534543
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.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Gram-Positive Rods
/
Adenosine Triphosphatases
/
Cation Transport Proteins
Language:
En
Journal:
Eur J Biochem
Year:
1992
Document type:
Article