Technological development of oligosaccharide units as biomaterials of life science

Our purpose is to prepare oligosaccharide units library folowing practical synthesis of biologically important oligosaccharides essentially for developing glycobology and glycottechnolog.The synthesis of possible array of linkages of(1-3)，(1-4)and(1-6)ofβ-D-Gal-D-GlcNAc andβ-D-Gal-D-GalNAc was done by using some readily availableβ-D-galactosidases.The preparation of the galactosyl-disaccharide units library led to the enzymatic synthesis of trisaccharides containing GlcNAc；β-D-GlcNAc-(1-3)-β-D-Gal-(1-4)-GlcNAc as a common unit of polylacto-saminoglycan andβ-D-Gal-(1-3)-[β-D-GlcNAc-(1-6)]-α-D-GalNAc-OC Ii D26I D2H I D24I D2NO I D22E D2-p as carbohyate of mucyit of core。Transglycosylation of L-Fuc to LacNAc and lactose utilizingα-L-fucosidases also producedα-L-fucosyl-N-acetyllactosamine and 3‘-O-α-L-fucosyllactose。Furthermore，as a synthetic strategy of human milk oligosaccharide，Lacto-N-tetraose(β-D-Gal-(1-3)-β-D-GlcNAc-(1-3)-β-D-Gal-(1-4)-D-Glc)and lacto-N-neotetraose(β-D-Gal-(1-4)-β-D-GlcNAc-(1-3)-β-D-Gal-(1-4)-D-Glc)were practically synthesized by a combination of glycosyltransferase alcatalyzed reaction and glycosidase-catalyzed transglycosylation from lactose as an initial substede.Chemo-enzymatic synthesis of glycopeptides carrying LacNAc unit as a model of asialoglycoprotein，andβ-D-Gal-(1-3)-α-D-GalNAc andα-NeuAc-(1-3)-β-D-Gal-(1-3)-α-D-GalNAc units as models of mucin-type glycoproteins was carried out by introducing these oigosaccharides as side chain into polyglutamic acid as main chain.The artgificial glycopolypeptides were shown to be useful as probes of carbohydrate recognition and modeling in the analysis of glycoprotein-lectin interactions.

Our purpose is to prepare oligosaccharide units library folowing practical synthesis of biologically important oligosaccharides essentially for developing glycobology and glycottechnolog. The synthesis of possible array of linkages of (1-3), (1-4) and (1-6) of β-D-Gal-D-GlcNAc and β-D-Gal-D-GalNAc was done by using some readily available β-D-galactosidases. The preparation of the galactosyl-disaccharide units library led to the enzymatic synthesis of trisaccharides containing GlcNAc; β-D-GlcNAc-(1-3)-β-D-Gal-(1-4)-GlcNAc as a common unit of polylacto- saminoglycan and β-D-Gal-(1-3)-[β-D-GlcNAc-(1-6)]-α-D-GalNAc-OCィイD26ィエD2HィイD24ィエD2NOィイD22ィエD2-p as a carbohydrate unit of mucin type 2 core. Transglycosylation of L-Fuc to LacNAc and lactose utilizing α-L-fucosidases also produced α-L-fucosyl-N-acetyllactosamine and 3'-O-α-L-fucosyllactose. Furthermore, as a synthetic strategy of human milk oligosaccharide, lacto-N-tetraose (β-D-Gal-(1-3)-β-D-GlcNAc-(1-3)-β-D-Gal-(1-4)-D-Glc)and lacto-N-neotetraose(β-D-Gal-(1-4)-β-D-GlcNAc-(1-3)-β-D-Gal-(1-4)-D-Glc) were practically synthesized by a combination of glycosyltransferase catalyzed reaction and glycosidase-catalyzed transglycosylation from lactose as an initial substance.Such synthetic oligosaccharides available in large amounts were used to synthesize glycopolymer. chemo-enzymatic synthesis of glycopeptides carrying LacNAc unit as a model of asialoglycoprotein, and β-D-Gal-(1-3)-α-D-GalNAc and α-NeuAc-(1-3)-β-D-Gal-(1-3)-α-D-GalNAc units as models of mucin-type glycoproteins was carried out by introducing these oigosaccharides as side chain into polyglutamic acid as main chain. The artgificial glycopolypeptides were shown to be useful as probes of carbohydrate recognition and modeling in the analysis of glycoprotein-lectin interactions.