title: Possible involvement of cysteine and histidine residues in the (NH4+ + Na+)-activated ATPase of an anaerobic alkaliphile, Amphibacillus xylanus.
abstract: Effect of various inhibitors on the (NH4+ + Na+)-activated ATPase of an anaerobic alkaliphile, Ep01(a strain of Amphibacillus xylanus), was examined. Among the chemicals tested, the enzyme was drastically inactivated by p-chloromercuribenzoic acid and diethyl pyrocarbonate. The ATPase activity of the enzyme, which was inactivated by p-chloromercuribenzoic acid and diethyl pyrocarbonate, was remarkably restored by beta-mercaptoethanol and hydroxylamine, respectively, suggesting the involvement of cysteine and histidine residues in the enzyme activity. Analysis of the inhibition kinetics by diethyl pyrocarbonate indicated that modification of a single histidine residue per ATPase molecule was sufficient to inactivate the enzyme.
authors.affiliation: Department of Chemistry, Faculty of Science, Chiba University, Yayoi, Chiba 263, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Okano
authors.forename: T
authors.initials: T
authors.lastname: Maeki
authors.forename: N
authors.initials: N
authors.lastname: Koyama
mesh_terms: D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D001421:Bacteria, Anaerobic / Q000201:enzymology*; D001665:Binding Sites; D003545:Cysteine; D006639:Histidine; D013329:Structure-Activity Relationship
chemical_list: D006639:Histidine; D000251:Adenosine Triphosphatases; D003545:Cysteine