Read/Search this Article
An aminopeptidaase of Flavobacterium sp. K172 was purified to homogeneity and its physicochemical and enzymatic characteristics were studied. The molecular weight of the enzyme was determined to be 80,000 by Sephadex G-200 column chromatography and that of its subunit was estimated at 43,000 by sodium dodecyl sulfate polyacrylamide gel electrophoresis.This aminopeptidase was a zinc-enzyme in which Zn^<2+> could be replaced by Co^<2+>.The enzyme was inhibited by 2.2μM ethylenediaminetetraacetate, and 0.15 mM o-phenanthroline, and the enzyme inactivated by o-phenanthroline was reactivated by the addition of either zinc chloride or cobaltous chloride.The enzyme hydrolyzed a variety of peptides with free amino termini. A strong substrate specificity for the amino terminal amino acid of the peptides was not observed.In the hydrolysis of oligopeptides, the dipeptide was hydrolyzed more slowly than other oligopeptides.