Biochemical and Biophysical Research Communications 1985-08-15

A transition-state-analog inhibitor influences zinc-binding by Aeromonas aminopeptidase.

J O Baker, J M Prescott

Index: Biochem. Biophys. Res. Commun. 130(3) , 1154-60, (1985)

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Abstract

The transition-state-analog inhibitor, 1-butaneboronic acid, markedly enhances the uptake of one g-atom of Zn2+ ions from a metal ion buffer system by Zn-depleted Aeromonas aminopeptidase. In contrast, a substrate-analog inhibitor, n-valeramide, does not perturb the equilibrium between Zn2+ ions and the enzyme in a metal ion buffer system. These results establish a role for metal ions in the binding of 1-butaneboronic acid to Aeromonas amino-peptidase and strongly imply that a bound Zn2+ ion interacts directly with substrate during catalysis but not during initial binding of substrate.