Purification and properties of alpha-glucosidase from millet seeds

Two forms of alpha-glucosidase (EC 3.2.1.20), designated as I and II, have been isolated from millet (Panicum miliaceum L.) seeds by a procedure including fractionation with ammonium sulphate, CM-cellulofine column chromatography, Sephadex G-100 column chromatography, preparative isoelectric focusing and preparative disc gel electrophoresis. The two enzymes showed identical M(r), calculated to be 85 000 on SDS-PAGE and 93 000 on gel filtration. The two enzymes readily hydrolysed maltose and malto-oligosaccharides, and native starch weakly. The two enzymes hydrolysed amylose liberating alpha-glucose.