Properties of membrane adenosine triphosphatase of the obligately anaerobic bacterium Veillonella alcalescens.

Some properties of membrane ATPase activity in Veillonella alcalescens were examined. Mg2+ is required for the activity of the enzyme, and Ca2+ also activates the enzyme to some degree. Of the nucleotide triphosphates, GTP and ITP were hydrolyzed to a lesser extent than ATP. The apparent Km for ATP hydrolysis was 0.25 to 0.63 mM. ADP inhibited the enzyme and the kinetic data of its inhibition showed that the presence of ADP resulted in positive cooperativity. The enzyme activity was strongly inhibited by DCCD, azide, fusidic acid and the antibody to purified soluble ATPase from the thermophilic bacterium PS3. Oligomycin, dinitrophenol, and ouabain showed no significant effect.