Purification and properties of alpha-glucosidase from Mucor racemosus

An α-glucosidase has been isolated from the mycelia of Mucor racemosus, by a procedure including extraction with urea, fractionation with acetone, treatment with MnCl2, and successive separation on columns of DEAE-cellulose and SP-Sephadex C–50. The purified enzyme was homogeneous on polyacrylamide gel electrophoresis, gel electrofocusing and ultracentrifugation. The sedimentation constant of the enzyme was 6.2 S, and its molecular weight was between 114,000 and 97,000. The pH optimum of the enzyme was in the pH range of 4.0 to 6.0, and the temperature optimum was 50°C. The purified enzyme was stable in the pH range of 4.0 to 7.0, and also stable up to 45°C. The enzyme also catalyzed the transfer of α-glucosyl residue from maltose to riboflavin.