Isolation and characterization of an L-amino acid acylase fromAspergillus oryzae

A scheme of isolating a highly purified L-amino acylase fromAspergillus oryzae is described which excludes extraction of the enzyme from the preparation “Amilorizin,” fractionation with ethanol, chromatography on DEAE-cellulose, and gel filtration through Sephadex G-200 and Bio-Gel P-300. The enzyme, as purified 1240-fold, has a molecular weight of 118,000, apparently consists of two subunits with a molecular weight of 60,000, is stable in the pH range of 7–10 and has an optimum pH of 8.9 and a pI of 4.0. Its amino acid composition has been determined and its substrate specificity has been studied. The acylase is a metalloenzyme: Co^2+` ions in concentrations of 10^?4–5·10^?5 M increase the rate of hydrolysis of N-acetyl-L-amino acids three- to fourfold. It shows differences in its molecular and functional properties from acylase I obtained from porcine kidney.