Purification and characterization of .BETA.-amylase from ginseng.

Abstract

β-Amylase activity was found in ginseng for the first time. β-Amylase was purified to apparent homogeneity on polyacrylamide slab gel from ginseng powder by dialysis of the crude extract and by column chromatography on diethylaminoethyl (DEAE)-Sephadex A-50, Sephadex G-100 and hydroxyapatite. The β-amylase was most active at pH 5.0 and 50°C. The molecular weight of the enzyme was estimated to be 63 kilodaltons (kDa) by both Sephadex G-100 column chromatography and sodium dodecyl sulfate gel electrophoresis. The isoelectric point of the enzyme was pH 5.3. Amino acid analysis indicated that the enzyme was composed of 512 amino acid residues. The content of neutral sugars was 8.5%, and no amino sugar was detected.