Galactosyl- -N-acetylglucosamine

Spiro, R.G., Yasumoto, Y., and Bhoyroo, V., 1996, Characterization of a rat liver Golgi sulphotransferase responsible for the 6-O-sulphation of N-acetylglucosamine residues in beta-linkage to mannose role in assembly of sialyl-galactosyl-N-acetylglucosamine 6-sulphate sequence of N-linked oligosaccharides. Biochem. J. 319, 209-216... 

The FucT III transfers an L-fucose unit from GDP-fucose onto the 4-OH-group of a galactosylated N-acetylglucosamine in an a-niode to give the Lewis trisaccharide or the sialyl-Lewis tetrasaccharide, respectively (Fig. 13). 

Morrison JF, Ebner KE. Studies on galactosyltransferase. Kinetic investigations with n-acetylglucosamine as the galactosyl group acceptor. J. Biol. Chem. 1971 246 3977-3984. 

The transfer galactosylation with /3-galactosidase from Bacillus circulans for the synthesis of N-acetyllactosamine starting from lactose and N-acetylglucosamine [44] has been studied. When performing the reaction in an aqueous system the problem of this approach lies in the secondary hydrolysis of the product by the same enzyme. As a consequence, yields are less than 30%, and it is important to separate enzyme and product when the maximum yield is obtained. By addition of 25% v/v of [MMIM][MeS04] as a water-miscible co-solvent the water activity of the medium is decreased and, consequently, the secondary hydrolysis of the... 

N,N -X> -Ac 2-Acetamido-2-deoxy-a-D-galactopyranosyl-( 1 ->3 )-p-D-galacto-pyranosyl- (I - 3) -2-acetamido-2-deoxy-D-glucose. 3 -a- H-Acetylgalactosaminyl-3-p-galactosyl- ti-acetylglucosamine [5536-47-0]... 

It should be noted that the sialyl- and fucosyltransferases of pork hver have identical substrate specificities, i.e., both enzymes require a terminal galactosyl residue Unked (fi, l- 4) to a penultimate N-acetylglucosa-mine residue. Thus the ratio of siaUc acid to fucose in plasma glycoproteins is due at least in part to a competition between the two transferases for available galactosyl-()3, 1->4)-N-acetylglucosamine sites. There is no evidence that structures internal to this disaccharide play a major role in either fucose or siahc acid incorporation. 

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