title: Effect of a p-nitro group of phenyl-maltooligosaccharide substrate on the change of action specificity of lysine-modified porcine pancreatic alpha-amylase.
abstract: The effect of chemical modification of lysine residues on the activity of porcine pancreatic alpha-amylase (PPA) was examined, using p-nitrophenyl-alpha-D-maltoside, p-nitrophenyl-alpha-D-maltotrioside, phenyl-alpha-D-maltoside and phenyl-alpha-D-maltotrioside as substrates. Chemical modification of PPA with trinitrobenzenesulfonic acid enhanced the kcat/Km values for p-nitrophenyl substrates, but not for phenyl substrates. Thus, this effect is substituent selective. Considering the productive binding modes of substrates to PPA, the p-nitro group of the substrate and the modified lysine residues of the enzyme would non-ionically interact with each other to stabilize the productive binding mode.
authors.affiliation: Department of Food Science and Technology, Faculty of Agriculture, Kyoto University, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Yamashita
authors.forename: H
authors.initials: H
authors.lastname: Nakatani
authors.forename: B
authors.initials: B
authors.lastname: Tonomura
mesh_terms: D000818:Animals; D005947:Glucose / Q000737:chemistry; D005960:Glucosides / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D008239:Lysine / Q000494:pharmacology*; D008320:Maltose / Q000031:analogs & derivatives / Q000737:chemistry*; D009578:Nitrobenzenes / Q000737:chemistry; D009844:Oligosaccharides / Q000737:chemistry* / Q000378:metabolism / Q000493:pharmacokinetics; D010179:Pancreas / Q000201:enzymology*; D013329:Structure-Activity Relationship; D013379:Substrate Specificity; D013552:Swine; D014312:Trisaccharides / Q000737:chemistry / Q000378:metabolism / Q000493:pharmacokinetics; D000516:alpha-Amylases / Q000737:chemistry / Q000378:metabolism*
chemical_list: C093419:4-nitrophenylmaltotrioside; D005960:Glucosides; D009578:Nitrobenzenes; D009844:Oligosaccharides; D014312:Trisaccharides; C093417:phenylmaltoside; C036988:4-nitrophenylmaltoside; C016654:phenylmaltotrioside; D008320:Maltose; D000516:alpha-Amylases; D005947:Glucose; D008239:Lysine