Glycosyltransferase activities of Ehrlich ascites tumor cells: detection, isolation, and characterization using...

Detergent extracts of Ehrlich tumor cell membranes exhibit a host of glycosyltransferase activities which have been investigated using oligosaccharides immobilized to Synsorb beads as acceptors. Glycosidase digestions in combination with methylation analysis of the insoluble products have demonstrated the presence of an alpha(1,3)-galactosyltransferase and a beta(1,3)-N-acetylglucosaminyltransferase, enzymes that utilize N-acetyllactosamine as their acceptor substrate. The two enzymes are presumably involved in the biosynthesis of alpha-D-galactosyl-terminated poly-N-acetyllactosamine glycans that occur on the surface of Ehrlich cells. In addition, a beta-galactosyltransferase acting on N-acetylglucosamine and a separate beta-N-acetylglucosaminyltransferase that is capable of incorporating GlcNAc into the trisaccharide beta-D-GlcNAc(1,3)-beta-D-Gal(1,4)-beta-D-Glc-Synsorb have been identified. The Ehrlich cell alpha- and beta-galactosyltransferases have been separated by chromatography on beta-GlcNAc-Synsorb beads. In the presence of MnCl2 and UDP the beta-galactosyltransferase is specifically adsorbed to the monosaccharide column whereas the alpha-galactosyltransferase passes through unretarded.