title: Specificity of maltase to maltose in three different directions of reaction: hydrolytic, vanillyl alcohol glucoside and vanillyl alcohol isomaltoside synthesis.
abstract: Vanillyl alcohol glucoside is very attractive molecule due to its very powerful physiological activity. In this article, a detailed kinetic study of transglucosylation of vanillyl alcohol was performed. It was demonstrated that this reaction is very efficient (selectivity factor is 149) and occurred by a ping-pong mechanism with inhibition by glucose acceptor. At low concentration of vanillyl alcohol one additional transglucosylation product was detected. Its structure was determined to be α-isomaltoside of vanillyl alcohol, indicating that vanillyl alcohol glucoside is a product of the first transglucosylation reaction and a substrate for second, so the whole reaction mechanism was proposed. It was demonstrated that the rate of isomaltoside synthesis is two orders of magnitude smaller than glucoside synthesis, and that maltase has interestingly high K(m) value to maltose when vanillyl alcohol glucoside is second transglucosylation substrate.
authors.affiliation: Faculty of Chemistry, Department of Biochemistry, University of Belgrade, Studentski trg 12, Belgrade, Serbia.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Dimitrijević
authors.forename: Dušan
authors.initials: D
authors.lastname: Veličković
authors.forename: Nenad
authors.initials: N
authors.lastname: Milosavić
authors.forename: Dejan
authors.initials: D
authors.lastname: Bezbradica
mesh_terms: D001592:Benzyl Alcohols / Q000737:chemistry / Q000378:metabolism*; D001709:Biotechnology / Q000379:methods*; D006031:Glycosylation; D006868:Hydrolysis; D007700:Kinetics; D008320:Maltose / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D013379:Substrate Specificity; D000520:alpha-Glucosidases / Q000378:metabolism*
chemical_list: D001592:Benzyl Alcohols; D008320:Maltose; D000520:alpha-Glucosidases; C024078:vanillyl alcohol