Smirnova I N, Baykov A A, Avaeva S M
FEBS Lett. 1986 Sep 29;206(1):121-4. doi: 10.1016/0014-5793(86)81352-7.
Baker's yeast inorganic pyrophosphatase has been found to catalyze Mg2+-dependent hydrolysis of imidodiphosphate yielding phosphate and amidophosphate. The reaction proceeds linearly in the presteady state. The catalytic constant is maximal at pH 9.0 and equals 0.5 min-1. Kinetic titrations of the enzyme with imidodiphosphate and Mg2+ have provided direct evidence for the involvement of three Mg2+ per active site in the transition state of the pyrophosphatase reaction.
