Purification and Some Properties of Pig Liver Acid α-Glucosidase

Abstract

An acid α-glucosidase was purified from pig liver by fractionation with ammonium sulfate, chromatographies on DEAE-Sepharose, Sephadex G-100 and Bio-Gel P-150, and preparative disc electrophoresis. The molecular weight was estimated to be 1 × 10⁵ by sodium dodecylsulfate-disc electrophoresis. The optimum pH was found to be 4.5. The α-glucosidase showed a high activity not only toward maltose but also toward α-glucans, soluble starch, glycogen, amylopectin, β-limit dextrin and amylose. The Km values for maltose and glycogen were 6.7mM and 10mg/ml, respectively, and the ratio of maximum velocities of hydrolysis of the two substrates was 100:71.3, in that order.
The purified enzyme from pig liver was a typical acid α-glucosidase of mammalian origin.