Abstract
α-Glucosidase has been isolated from Bacillus cereus in ultracentrifugally and electrophoretically homogeneous form, and its properties have been investigated. The enzyme has a sedimentation constant of 1.4S and a molecular weight of 12, 000. The highly purified enzyme splits α-D-(1→4)-glucosidic linkages in maltose, maltotriose, and phenyl α-maltoside, but shows little or no activity toward polysaccharides, such as amylose, amylopectin, glycogen and soluble starch. The enzyme has α-glucosyltransferase activity, the main transfer product from maltose being maltotriose. The enzyme can also catalyze the transfer of α-glucosyl residue from maltose to riboflavin. On the basis of inhibition studies with diazonium-1-Htetrazole, rose bengal and p-chloromercuribenzoate, it is assumed that the enzyme contains both histidine and cysteine residues in the active center.
