N-acetyl-beta-D-glucosaminyltransferases related to the synthesis of mucin-type glycoproteins in human ovarian tissue.
The presence of N-acetyl-beta-D-glucosaminyltransferases in microsome preparations from human ovarian tissues was investigated with UDP-GlcNAc and several synthetic oligosaccharides as acceptors. The products were identified by paper chromatography and the linkage of the 2-acetamido-2-deoxy-beta-D-glucopyranosyl group incorporated into oligosaccharides was determined by exoglycosidase digestions, 1H-n.m.r. spectroscopy, and methylation analysis. These results showed that ovarian microsome preparations contain both beta-(1----3)- and beta-(1----6)-N-acetyl-D-glucosaminyltransferase activities which might be involved in the synthesis of mucin-type glycoproteins. Substrate competition tests suggested that both UDP-GlcNAc:-Bn glycoside of beta-D-GlcpNAc-(1----6)-alpha-D-GalpNAc [GlcNAc to GalNAc] and -Bn glycoside of beta-D-Galp-(1----3)-[beta-D-GlcNAc-(1----6)]-alpha-D-GalpNAc [GlcNAc to Gal] beta-(1----3)-N-acetyl-D-glucosaminyltransferase activities reside in a single enzyme species.
D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002250:Carbon Radioisotopes; D005260:Female; D005964:Glucosyltransferases / Q000378:metabolism*; D006801:Humans; D008861:Microsomes / Q000201:enzymology*; D009077:Mucins / Q000096:biosynthesis*; D017351:N-Acetylglucosaminyltransferases; D009844:Oligosaccharides / Q000138:chemical synthesis; D010053:Ovary / Q000201:enzymology*; D013379:Substrate Specificity; D014316:Tritium
D002250:Carbon Radioisotopes; D009077:Mucins; D009844:Oligosaccharides; D014316:Tritium; D005964:Glucosyltransferases; D017351:N-Acetylglucosaminyltransferases; C027732:UDP-N-acetylglucosamine-mucin acetylglucosaminyltransferase