Comparative biochemical studies on .ALPHA.-glucosidases. VIII. Purification and some properties of flint corn .ALPHA.-glucosidase.

An α-glucosidase was purified from flint corn by precipitation with ammonium sulfate, chromatographies on CM-cellulose and Hydroxylapatite and gel-filtrations on Sephadex G-100. The purified enzyme was homogeneous in ultracentrifugal and disc electrophoretic analysis. The sedimentation coefficient was calculated to be 6.5 S. The molecular weight was estimated to be approximately 6.5×104 by gel-filtration technique. The optimal pH was found to be 3.6 for both maltose and soluble starch. The enzyme lost about 80% of the activity by incubation at 60°C for 10min. The ratio of velocity of hydrolysis for maltose, phenyl-α-glucoside and soluble starch was estimated to be 100:14.3:6.1 in this order. The α-glucosidase hydrolyzed soluble starch exo-wisely.