title: A transition-state-analog inhibitor influences zinc-binding by Aeromonas aminopeptidase.
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.
mesh_terms: D000333:Aeromonas / Q000201:enzymology*; D000626:Aminopeptidases / Q000378:metabolism*; D001667:Binding, Competitive; D001896:Boron Compounds; D001897:Boronic Acids / Q000494:pharmacology*; D003956:Dialysis; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008954:Models, Biological; D011485:Protein Binding; D015032:Zinc / Q000378:metabolism*
chemical_list: D001896:Boron Compounds; D001897:Boronic Acids; C030433:n-butylboronic acid; D000626:Aminopeptidases; D015032:Zinc