Galactosyl transferases of baby hamster kidney (BHK) cells. Characterization of two oligosaccharide products synthesised using bovine asialo submaxillary-gland mucin as acceptor.
Extracts of BHK (baby hamster kidney) cells catalyse incorporation of galactose from UDP-galactose into asialo bovine submaxillary gland mucin. The galactosylated oligosaccharide products were released by alkaline-borohydride treatment and purified by Bio-Gel P2 chromatography and high-performance liquid chromatography. The structures of the oligosaccharide sequences synthesised have been identified unequivocally by high resolution 500 MHz 1H-NMR as galactosyl-(beta 1----3) N-acetylgalactosamine and galactosyl (beta 1----4) N-acetylglucosaminyl (beta 1----3)-N-acetylgalactosamine. Characterization of the latter sequence shows the presence in bovine mucin of the type III core sequence N-acetylglucosamine-(beta 1----3) N-acetylgalactosamine. Fractionation of BHK cell extracts on alpha-lactalbumin-Agarose has shown that the (beta 1----4)-galactosyl transferase responsible for synthesis of the trisaccharide binds to alpha-lactalbumin, a modulator of the (beta 1----4)-galactosyl transferase involved in N-glycan assembly. The evidence that the same transferase activity may be responsible for galactose transfer to both O-glycans and N-glycans is discussed.
D000818:Animals; D001212:Asialoglycoproteins; D001665:Binding Sites; D002417:Cattle; D055598:Chemical Phenomena; D002621:Chemistry; D002847:Chromatography, Agarose; D002851:Chromatography, High Pressure Liquid; D006224:Cricetinae; D004187:Disaccharides / Q000096:biosynthesis*; D005700:Galactosyltransferases / Q000378:metabolism*; D007668:Kidney / Q000201:enzymology*; D009682:Magnetic Resonance Spectroscopy; D009077:Mucins / Q000378:metabolism*; D009844:Oligosaccharides / Q000096:biosynthesis*; D012756:Sheep; D013363:Submandibular Gland / Q000378:metabolism; D014312:Trisaccharides / Q000096:biosynthesis*
D001212:Asialoglycoproteins; D004187:Disaccharides; D009077:Mucins; D009844:Oligosaccharides; D014312:Trisaccharides; C043016:acetylglucosaminyl(1-3)acetylgalactosamine; C043015:galactopyranosyl(1-4)acetylglucosaminyl(1-3)acetylgalactosamine; D005700:Galactosyltransferases