title: Transglycosylation reactions of Bacillus stearothermophilus maltogenic amylase with acarbose and various acceptors.
abstract: It was observed that Bacillus stearothermophilus maltogenic amylase cleaved the first glycosidic bond of acarbose to produce glucose and a pseudotrisaccharide (PTS) that was transferred to C-6 of the glucose to give an alpha-(1-->6) glycosidic linkage and the formation of isoacarbose. The addition of a number of different carbohydrates to the digest gave transfer products in which PTS was primarily attached alpha-(1-->6) to D-glucose, D-mannose, D-galactose, and methyl alpha-D-glucopyranoside. With D-fructopyranose and D-xylopyranose, PTS was linked alpha-(1-->5) and alpha-(1-->4), respectively. PTS was primarily transferred to C-6 of the nonreducing residue of maltose, cellobiose, lactose, and gentiobiose. Lesser amounts of alpha-(1-->3) and/or alpha-(1-->4) transfer products were also observed for these carbohydrate acceptors. The major transfer product to sucrose gave PTS linked alpha-(1-->4) to the glucose residue. alpha,alpha-Trehalose gave two major products with PTS linked alpha-(1-->6) and alpha-(1-->4). Maltitol gave two major products with PTS linked alpha-(1-->6) and alpha-(1-->4) to the glucopyranose residue. Raffinose gave two major products with PTS linked alpha-(1-->6) and alpha-(1-->4) to the D-galactopyranose residue. Maltotriose gave two major products with PTS linked alpha-(1-->6) and alpha-(1-->4) to the nonreducing end glucopyranose residue. Xylitol gave PTS linked alpha-(1-->5) as the major product and D-glucitol gave PTS linked alpha-(1-->6) as the only product. The structures of the transfer products were determined using thin-layer chromatography, high-performance ion chromatography, enzyme hydrolysis, methylation analysis and 13C NMR spectroscopy. The best acceptor was gentiobiose, followed closely by maltose and cellobiose, and the weakest acceptor was D-glucitol.
authors: Department of Food Science and Technology and Research Center for New Bio-Materials in Agriculture, Seoul National University, Suwon, South Korea. parkkh@plaza.snu.ac.kr
authors: K H
authors: KH
authors: Park
authors: M J
authors: MJ
authors: Kim
authors: H S
authors: HS
authors: Lee
authors: N S
authors: NS
authors: Han
authors: D
authors: D
authors: Kim
authors: J F
authors: JF
authors: Robyt
mesh_terms: D020909:Acarbose; D000681:Amylases / Q000378:metabolism*; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002475:Cellobiose / Q000378:metabolism; D002855:Chromatography, Thin Layer; D004187:Disaccharides / Q000378:metabolism; D005632:Fructose / Q000378:metabolism; D001411:Geobacillus stearothermophilus / Q000201:enzymology*; D005947:Glucose / Q000378:metabolism; D006031:Glycosylation; D007785:Lactose / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008320:Maltose / Q000378:metabolism; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000096:biosynthesis*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013379:Substrate Specificity; D014312:Trisaccharides / Q000378:metabolism*
chemical_list: D004187:Disaccharides; D009844:Oligosaccharides; D011993:Recombinant Fusion Proteins; D014312:Trisaccharides; D002475:Cellobiose; D005632:Fructose; D008320:Maltose; D000681:Amylases; C100052:gentiobiose; D005947:Glucose; D007785:Lactose; D020909:Acarbose