Acceptor specificity of cellobiose phosphorylase from Cellvibrio gilvus: synthesis of three branched trisaccharides.
Cellobiose phosphorylase from Cellvibrio gilvus was examined for its acceptor specificity in the synthetic reaction with glucose-1-phosphate, using substrates in which the C-6 substituent of D-Glc had been altered. A range of disaccharides were also tested for acceptor specificity but only those with (1-->6)-linkages were successful acceptors. Melibiose, gentiobiose, isomaltose and also the monosaccharide glucuronamide were found to react with cellobiose phosphorylase and glucose-1-phosphate giving beta-D-Glcp-(1-->4)-[alpha-D-Galp-(1-->6)]-D-Glcp, beta-D-Glcp-(1-->4)-[beta-D-Glcp-(1-->6)]-D-Glcp, beta-D-Glcp-(1-->4)-[alpha-D-Glcp-(1-->6)]-D-Glcp and beta-D-Glcp-(1-->4)-D-GlcUNp, respectively. These products were purified using a range of chromatographic methods and characterised by NMR and FAB-MS. This is the first time cellobiose phosphorylase has been shown to synthesise trisaccharides.
National Food Research Institute, Ibaraki, Japan.
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Percy
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Ono
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Hayashi
D002240:Carbohydrate Sequence; D004187:Disaccharides / Q000378:metabolism; D005958:Glucosephosphates / Q000378:metabolism; D005964:Glucosyltransferases / Q000378:metabolism*; D006088:Gram-Negative Aerobic Bacteria / Q000201:enzymology*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013379:Substrate Specificity; D014312:Trisaccharides / Q000096:biosynthesis*
D004187:Disaccharides; D005958:Glucosephosphates; D014312:Trisaccharides; C031590:glucose-1-phosphate; D005964:Glucosyltransferases; C034714:cellobiose phosphorylase