Improved purification of Aspergillus oryzae 1,2-alpha-mannosidase by using mannan gel affinity chromatography

In order to facilitate the purification of 1,2-alpha-mannosidase from an enzyme product of Aspergillus oryzae, we have devised a rapid and simple procedure. A partially purified enzyme preparation obtained from the A. oryzae enzyme product, by means of ammonium sulfate fractionation followed by CM-Sephadex C-50 chromatography, was subjected to affinity chromatography with baker's yeast mannan gel as an adsorbent. 1,2-alpha-Mannosidase was retarded and well separated from the major protein peak on the affinity column. After a second affinity chromatography under the same conditions, 1,2-alpha-mannosidase was finally purified 7,500-fold with a 22.9% yield. The enzyme preparation thus obtained was quite suitable for the structural analysis of glycoconjugates.