title: Enzymatic synthesis of p-nitrophenyl 4(5)-O-beta-D-galactosyl-alpha-maltopentaoside as a substrate for human alpha-amylases.
abstract: Enzymatic modification at the nonreducing end D-glucosyl residue of p-nitrophenyl alpha-maltopentaoside was developed by using the transglycosylation of beta-D-galactosidase from Bacillus circulans. The enzyme regioselectively synthesized p-nitrophenyl 4(5)-O-beta-D-galactosyl-alpha-maltopentaoside (a yield of 12.0% based on the amount of p-nitrophenyl alpha-maltopentaoside added) on a preparative scale from lactose as a donor and p-nitrophenyl alpha-maltopentaoside as an acceptor. It revealed that the nonreducing end galactosyl group of p-nitrophenyl 4(5)-O-beta-D-galactosyl-alpha-maltopentaoside did not prohibit the action of human salivary and pancreatic alpha-amylases. This derivative was shown to be very suitable as a novel substrate for analytical use of human alpha-amylase assay in serum through a conjugated reaction involving glucoamylase and alpha-D-glucosidase.
authors.affiliation: Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Usui
authors.forename: K
authors.initials: K
authors.lastname: Ogawa
authors.forename: H
authors.initials: H
authors.lastname: Nagai
authors.forename: H
authors.initials: H
authors.lastname: Matsui
mesh_terms: D000681:Amylases / Q000097:blood*; D001407:Bacillus / Q000201:enzymology; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D005087:Glucan 1,4-alpha-Glucosidase / Q000378:metabolism; D005959:Glucosidases / Q000378:metabolism; D006031:Glycosylation; D006801:Humans; D006868:Hydrolysis; D007785:Lactose / Q000378:metabolism; D008969:Molecular Sequence Data; D009578:Nitrobenzenes / Q000138:chemical synthesis* / Q000378:metabolism*; D009844:Oligosaccharides / Q000138:chemical synthesis* / Q000378:metabolism*; D016339:Spectrometry, Mass, Fast Atom Bombardment; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D009578:Nitrobenzenes; D009844:Oligosaccharides; C075378:4-nitrophenyl 4(5)-O-galactosylmaltopentaoside; C075379:4-nitrophenyl maltopentaoside; D000681:Amylases; D005959:Glucosidases; D001616:beta-Galactosidase; D005087:Glucan 1,4-alpha-Glucosidase; D007785:Lactose