The function of the 5-hydroxymethyl group of lactose in enzymatic hydrolysis with beta-galactosidase from E. coli.
A series of 6-substituted methyl lactoside derivatives together with methyl allolactoside and (6S)-methyl [6-2H]lactoside have been synthesized and characterized by NMR spectroscopy. All compounds were tested as substrates for the enzyme beta-galactosidase from E. coli using progress curve kinetic methology both in single-substrate and competition experiments. The results show that the hydrolysis of methyl lactoside to a large extent takes place through an intramolecular transglycosidation reaction via allolactoside. Furthermore, methyl 6-amino-6-deoxy-D-glucopyranoside proved to be an ihibitor for the enzymatic hydrolysis.
Adelhorst
K
K
Department of Organic Chemistry, Technical University, Lyngby, Denmark.
Bock
K
K
D004926:Escherichia coli / Q000201:enzymology*; D006031:Glycosylation; D006868:Hydrolysis; D007700:Kinetics; D007785:Lactose / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D013329:Structure-Activity Relationship; D013379:Substrate Specificity; D001616:beta-Galactosidase / Q000378:metabolism*
D001616:beta-Galactosidase; D007785:Lactose