Purification and properties of a novel azide-sensitive ATPase of Exiguobacterium aurantiacum.
Exiguobacterium aurantiacum BL77/1 possesses at least two distinct membrane-bound ATPases. One of them was solubilized with decanoyl N-methylglucamide, a non-ionic detergent, and purified by successive chromatography on DEAE-Sepharose and hydroxyapatite. The purified ATPase appears to consist of a single polypeptide component with an apparent molecular mass of 54 kDa. Among the triphosphates of various nucleosides tested, ATP was the best substrate. The enzyme exhibited a Km of 0.5 mM for ATP and a Vmax of 109 micromol ATP (mg protein)(-1) min(-1); the optimum pH for activity was near 6.5. The enzyme was sensitive to azide and inactivated by N,N'-dicyclohexylcarbodiimide. Analysis of the inhibition kinetics by N,N'-dicyclohexylcarbodiimide suggested that binding of the drug to a single carboxyl group per ATPase molecule is sufficient for inactivation.
Suga
S
S
Department of Chemistry, Faculty of Science, Chiba University, Yayoi, Japan.
Koyama
N
N
D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D001386:Azides / Q000494:pharmacology*; D001421:Bacteria, Anaerobic / Q000201:enzymology*; D001426:Bacterial Proteins / Q000187:drug effects / Q000302:isolation & purification; D004024:Dicyclohexylcarbodiimide / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D008565:Membrane Proteins / Q000187:drug effects / Q000302:isolation & purification; D013379:Substrate Specificity
D001386:Azides; D001426:Bacterial Proteins; D008565:Membrane Proteins; D004024:Dicyclohexylcarbodiimide; D000251:Adenosine Triphosphatases