Purification and Properties of Wall-bound α-Glucosidase from Suspension-cultured Rice Cells

Abstract

Wall-bound α-glucosidase (EC 3.2.1.20) has been solubilized from suspension-cultured rice cells with Sumyzyme C and Pectolyase Y-23 and isolated by a procedure including fractionation with ammonium sulfate, Sephadex G-100 column chromatography, CM-cellulose column chroraatography, Sephadex G-200 column chromatography, and preparative disc gel electrophoresis. The molecular weight of the enzyme was 64, 000. The enzyme readily hydrolyzed maltose, maltotriose, and amylose, but hydrolyzed isomaltose and soluble starch more slowly. The Michaelis constant for maltose of the enzyme was estimated to be 0.272 mM. The enzyme produced panose as the main α-glucosyltransferred product from maltose.