Reaction: UDP-α-D-galactose + N-acetyl-β-D-glucosaminylglycopeptide = UDP + β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosaminylglycopeptide
Other name(s): UDP-galactose—glycoprotein galactosyltransferase; glycoprotein 4-β-galactosyl-transferase; β-N-acetyl-β1-4-galactosyltransferase; thyroid glycoprotein β-galactosyltransferase; glycoprotein β-galactosyltransferase; thyroid galactosyltransferase; uridine diphosphogalactose-glycoprotein galactosyltransferase; β-N-acetylglucosaminyl-glycopeptide β-1,4-galactosyltransferase; GalT; UDP-galactose:N-acetyl-β-D-glucosaminylglycopeptide β-1,4-galactosyltransferase; UDP-galactose:N-acetyl-β-D-glucosaminylglycopeptide 4-β-galactosyltransferase
Systematic name: UDP-α-D-galactose:N-acetyl-β-D-glucosaminylglycopeptide 4-β-galactosyltransferase
Comments: Terminal N-acetyl-β-D-glucosaminyl residues in polysaccharides, glycoproteins and glycopeptides can act as acceptor. High activity is shown towards such residues in branched-chain polysaccharides when these are linked by β-1,6-links to galactose residues; lower activity towards residues linked to galactose by β-1,3-links. A component of EC 2.4.1.22 (lactose synthase).
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 37237-43-7
References:
1. Beyer, T.A., Sadler, J.E., Rearick, J.I., Paulson, J.C. and Hill, R.L. Glucosyltransferases and their uses in assessing oligosaccharide structure and structure-function relationship. Adv. Enzymol. 52 (1981) 23-175. [PMID: 6784450]
2. Blanken, W.M., Hooghwinkel, G.J.M. and van den Eijnden, D.H. Biosynthesis of blood-group I and i substances. Specificity of bovine colostrum β-N-acetyl-D-glucosaminide β1→4 galactosyltransferase. Eur. J. Biochem. 127 (1982) 547-552. [PMID: 6816588]
3. Blanken, W.M. and van den Eijnden, D.H. Biosynthesis of terminal Gal α 1→3Gal β 1→4GlcNAc-R oligosaccharide sequences on glycoconjugates. Purification and acceptor specificity of a UDP-Gal:N-acetyllactosaminide α 1→3-galactosyltransferase from calf thymus. J. Biol. Chem. 260 (1985) 12927-12934. [PMID: 3932335]
4. Spiro, M.H. and Spiro, R.G. Glycoprotein biosynthesis: studies on thyroglobulin. Thyroid galactosyltransferase. J. Biol. Chem. 243 (1968) 6529-6537. [PMID: 5726898]