Enzymic transfer of 6-modified D-galactosyl residues: synthesis of biantennary penta- and hepta-saccharides having two 6-deoxy-D-galactose residues at the nonreducing end and evaluation of 6-deoxy-D-galactosyl transfer to glycoprotein using bovine beta-(1-->4)-galactosyltransferase and UDP-6-deoxy-D-galactose.
UDP-6-Deoxy-D-galactose and UDP-6-deoxy-6-fluoro-D-galactose were synthesized and their transfer to 2-acetamido-2-deoxy-D-glucose (N-acetyl-D-glucosamine) by beta-(1-->4)-galactosyltransferase was examined. The transfer rates of 6-deoxy-D-galactose and 6-deoxy-6-fluoro-D-galactose were 1.3 and 0.2% of that of D-galactosyl transfer, respectively. The 2-acetamido-4-O-(6-deoxy-beta-D-galactopyranosyl)-2-deoxy-D-glucopyranose (6'-deoxy-N-acetyllactosamine) and methyl 2-acetamido-4-O-(6-deoxy-6-fluoro-beta-D-galactopyranosyl)-2-deoxy-D- glucopyranoside (6'-deoxy-6'-fluoro-N-acetyllactosamine) were synthesized enzymatically in 30 and 59% yields, respectively. Further, 6-deoxy-D-galactose could be completely transferred to N-linked type biantennary oligosaccharides having two N-acetyl-D-glucosaminyl residues at the nonreducing end to give the corresponding penta- and hepta-saccharides in 55 and 57% yields, respectively. An assay of 6-deoxy-D-galactosyl transfer using asialo agalacto alpha 1-acid glycoprotein as an acceptor suggested that 6-deoxy-D-galactose was transferred to about 30% of the N-acetyl-D-glucosaminyl residues in the N-linked oligosaccharides of the glycoprotein.
Kajihara
Y
Y
Department of Life Science, Faculty of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan.
Endo
T
T
Ogasawara
H
H
Kodama
H
H
Hashimoto
H
H
D000117:Acetylglucosamine / Q000378:metabolism; D000818:Animals; D001212:Asialoglycoproteins / Q000737:chemistry / Q000378:metabolism; D002240:Carbohydrate Sequence; D002417:Cattle; D005260:Female; D005643:Fucose / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D007788:Lactose Synthase / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D014531:Uridine Diphosphate Galactose / Q000378:metabolism
D001212:Asialoglycoproteins; D009844:Oligosaccharides; D005643:Fucose; D014531:Uridine Diphosphate Galactose; D007788:Lactose Synthase; D000117:Acetylglucosamine