Purification and Characterization of 1,2-α-Mannosidase of Aspergillus oryzae

Publisher Website
Google Scholar
Abstract
1,2-α-Mannosidase was purified approximately 1,400-fold from an enzyme product of Aspergillus oryzae. The enzyme showed a single band in disc gel electropho-resis and the molecular weight was estimated to be about 49,000 daltons by gel exclusion chromatography. The substrate specificity of the enzyme was examined with mannooligosaccharides, yeast mannan, glycopeptides, and a glycoprotein. The α-(1→2)-linking mannose residues located at the nonreducing-ends of the substrates were selectively removed by the enzyme, whereas p-nitrophenyl α-D-mannopyrano-side was completely stable to the enzyme. α-(1→2)-Linking mannose residues in intact bovine pancreatic ribonuclease B were also removed completely with the enzyme. The enzyme showed an optimum pH in the range of pH 4.9 to 5.3 and had a Km value of 0.57 idm with 1,2-α-mannobiose. The present α-mannosidase was quite stable, and the activity was inhibited by D-mannono-γ-lactone and by heavy metal ions, including zinc ions.

This publication has 1 reference indexed in Scilit: