The Enzyme Database

Displaying entries 1-50 of 1771.

<< Previous | Next >>    printer_iconPrintable version



EC 2.4.1.228     Relevance: 100%
Accepted name: lactosylceramide 4-α-galactosyltransferase
Reaction: UDP-α-D-galactose + β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = UDP + α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
For diagram of globotetraosylceramide biosynthesis, click here
Glossary: lactosylceramide = β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
Other name(s): Galβ1-4Glcβ1-Cer α1,4-galactosyltransferase; globotriaosylceramide/CD77 synthase; histo-blood group Pk UDP-galactose; UDP-galactose:lactosylceramide 4II-α-D-galactosyltransferase; UDP-galactose:β-D-galactosyl-(1→4)-D-glucosyl(1↔1)ceramide 4II-α-D-galactosyltransferase; UDP-galactose:β-D-galactosyl-(1→4)-D-glucosyl-(1↔1)-ceramide 4II-α-D-galactosyltransferase
Systematic name: UDP-α-D-galactose:β-D-galactosyl-(1→4)-D-glucosyl-(1↔1)-ceramide 4II-α-D-galactosyltransferase
Comments: For explanation of superscript II in systematic name, see 2-carb.37.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 52725-57-2
References:
1.  Bailly, P., Piller, F., Cartron, J.P., Leroy, Y. and Fournet, B. Identification of UDP-galactose: lactose (lactosylceramide) α-4 and β-3 galactosyltransferases in human kidney. Biochem. Biophys. Res. Commun. 141 (1986) 84–91. [DOI] [PMID: 3099784]
2.  Steffensen, R., Carlier, K., Wiels, J., Levery, S.B., Stroud, M., Cedergren, B., Nilsson Sojka, B., Bennett, E.P., Jersild, C. and Clausen, H. Cloning and expression of the histo-blood group Pk UDP-galactose: Galβ1-4Glcβ1-Cer α1,4-galactosyltransferase. Molecular genetic basis of the p phenotype. J. Biol. Chem. 275 (2000) 16723–16729. [DOI] [PMID: 10747952]
3.  Kojima, Y., Fukumoto, S., Furukawa, K., Okajima, T., Wiels, J., Yokoyama, K., Suzuki, Y., Urano, T., Ohta, M. and Furukawa, K. Molecular cloning of globotriaosylceramide/CD77 synthase, a glycosyltransferase that initiates the synthesis of globo series glycosphingolipids. J. Biol. Chem. 275 (2000) 15152–15156. [DOI] [PMID: 10748143]
[EC 2.4.1.228 created 2002]
 
 
EC 2.4.1.206     Relevance: 97.9%
Accepted name: lactosylceramide 1,3-N-acetyl-β-D-glucosaminyltransferase
Reaction: UDP-N-acetyl-α-D-glucosamine + β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = UDP + N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
For diagram of lactotetraosylceramide biosynthesis, click here
Glossary: lactosylceramide = β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
lactotriosylceramide = N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
Other name(s): LA2 synthase; β1→3-N-acetylglucosaminyltransferase; uridine diphosphoacetylglucosamine-lactosylceramide β-acetylglucosaminyltransferase; lactosylceramide β-acetylglucosaminyltransferase; UDP-N-acetyl-D-glucosamine:D-galactosyl-1,4-β-D-glucosylceramide β-1,3-acetylglucosaminyltransferase; UDP-N-acetyl-D-glucosamine:β-D-galactosyl-(1→4)-β-D-glucosyl(1↔1)ceramide 3-β-N-acetylglucosaminyltransferase; UDP-N-acetyl-D-glucosamine:β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide 3-β-N-acetylglucosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-glucosamine:β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide 3-β-N-acetylglucosaminyltransferase (configuration-inverting)
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 83682-80-8
References:
1.  Gottfries, J., Percy, A.K., Maansson, J.-E., Fredman, P., Wilkstrand, C.J., Friedman, H.S., Bigner, D.D. and Svennerholm, L. Glycolipids and glycosyltransferases in permanent cell lines established from human medulloblastomas. Biochim. Biophys. Acta 1081 (1991) 253–261. [DOI] [PMID: 1825612]
2.  Holmes, E.H., Hakomori, S. and Ostrander, G.K. Synthesis of type 1 and 2 lacto series glycolipid antigens in human colonic adenocarcinoma and derived cell lines is due to activation of a normally unexpressed β1→3N-acetylglucosaminyltransferase. J. Biol. Chem. 262 (1987) 15649–15658. [PMID: 2960671]
3.  Percy, A.K., Gottfries, J., Vilbergsson, G., Maansson, J.E. and Svennerholm, J. Glycosphingolipid glycosyltransferases in human fetal brain. J. Neurochem. 56 (1991) 1461–1465. [DOI] [PMID: 1901591]
[EC 2.4.1.206 created 1992]
 
 
EC 3.2.1.47      
Deleted entry: galactosylgalactosylglucosylceramidase. Now known to be catalyzed by EC 3.2.1.22, α-galactosidase.
[EC 3.2.1.47 created 1972, modified 2011, deleted 2021]
 
 
EC 2.4.1.165     Relevance: 95%
Accepted name: N-acetylneuraminylgalactosylglucosylceramide β-1,4-N-acetylgalactosaminyltransferase
Reaction: UDP-N-acetyl-α-D-galactosamine + α-N-acetylneuraminyl-(2→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = UDP + N-acetyl-β-D-galactosaminyl-(1→4)-[α-N-acetylneuraminyl-(2→3)]-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
For diagram of ganglioside biosynthesis, click here
Other name(s): uridine diphosphoacetylgalactosamine-acetylneuraminyl(α2→3)galactosyl(β1→4)glucosyl β1→4-acetylgalactosaminyltransferase; UDP-N-acetyl-D-galactosamine:N-acetylneuraminyl-2,3-α-D-galactosyl-1,4-β-D-glucosylceramide β-1,4-N-acetylgalactosaminyltransferase; UDP-N-acetyl-D-galactosamine:N-acetylneuraminyl-(2→3)-α-D-galactosyl-(1→4)-β-D-glucosyl(1↔1)ceramide 4-β-N-acetylgalactosaminyltransferase; UDP-N-acetyl-D-galactosamine:N-acetylneuraminyl-(2→3)-α-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide 4-β-N-acetylgalactosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-galactosamine:α-N-acetylneuraminyl-(2→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide 4-β-N-acetylgalactosaminyltransferase
Comments: Requires Mn2+. Only substances containing sialic acid residues can act as acceptors; bovine fetuin is the best acceptor tested.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 109136-50-7
References:
1.  Chien, J.-L., Williams, T. and Basu, S. Biosynthesis of a globoside-type glycosphingolipid by a β-N-acetylgalactosaminyltransferase from embryonic chicken brain. J. Biol. Chem. 248 (1973) 1778–1785. [PMID: 4632917]
2.  Piller, F., Blanchard, D., Huet, M. and Cartron, J.-P. Identification of a α-NeuAc-(2-3)-β-D-galactopyranosyl N-acetyl-β-D-galactosaminyltransferase in human kidney. Carbohydr. Res. 149 (1986) 171–184. [DOI] [PMID: 2425965]
3.  Takeya, A., Hosomi, O. and Kogure, T. Identification and characterization of UDP-GalNAc: NeuAc α2-3Gal β1-4Glc(NAc) β1-4(GalNAc to Gal)N-acetylgalactosaminyltransferase in human blood plasma. J. Biochem. (Tokyo) 101 (1987) 251–259. [PMID: 3106337]
[EC 2.4.1.165 created 1989]
 
 
EC 2.4.99.2      
Transferred entry: β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminide α-2,3-sialyltransferase. Now EC 2.4.3.2, β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminide α-2,3-sialyltransferase
[EC 2.4.99.2 created 1976, modified 1986, deleted 2022]
 
 
EC 2.4.3.2     Relevance: 93.1%
Accepted name: β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminide α-2,3-sialyltransferase
Reaction: CMP-N-acetyl-β-neuraminate + a β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminyl-R = CMP + an N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminyl-R
For diagram of ganglioside biosynthesis, click here
Glossary: a β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminyl-(1→4)-[N-acetyl-α-neuraminyl-(2→3)]-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = gangloside GM1a
an N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminyl-(1→4)-[N-acetyl-α-neuraminyl-(2→3)]-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = gangloside GD1a
Other name(s): CMP-N-acetylneuraminate:D-galactosyl-N-acetyl-D-galactosaminyl-(N-acetylneuraminyl)-D-galactosyl-D-glucosyl-(1↔1)-ceramide N-acetylneuraminyltransferase (ambiguous); monosialoganglioside sialyltransferase; CMP-N-acetylneuraminate:a β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminyl-(1→4)-[α-N-acetylneuraminyl-(2→3)]-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide N-acetyl-β-neuraminyltransferase
Systematic name: CMP-N-acetyl-β-neuraminate:a β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminyl-R α-(2→3)-N-acetylneuraminyltransferase (configuration-inverting)
Comments: The enzyme recognizes the sequence β-D-galactosyl-(1→3)-N-acetyl-D-galactosaminyl (known as type 1 histo-blood group precursor disaccharide) in non-reducing termini of glycan moieties in glycoproteins and glycolipids [1]. When acting on gangloside GM1a, it forms gangloside GD1a [2].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 60202-12-2
References:
1.  Rearick, J.I., Sadler, J.E., Paulson, J.C. and Hill, R.L. Enzymatic characterization of β D-galactoside α2→3 sialyltransferase from porcine submaxillary gland. J. Biol. Chem. 254 (1979) 4444–4451. [PMID: 438198]
2.  Yip, M.C.M. The enzymic synthesis of disialoganglioside: rat brain cytidine-5′-monophospho-N-acetylneuraminic acid: monosialoganglioside (GM1) sialyltransferase. Biochim. Biophys. Acta 306 (1973) 298–306. [DOI] [PMID: 4351506]
[EC 2.4.3.2 created 1976 as EC 2.4.99.2, modified 1986, modified 2017, transferred 2022 to EC 2.4.3.2]
 
 
EC 2.4.1.164      
Transferred entry: galactosyl-N-acetylglucosaminylgalactosylglucosyl-ceramide β-1,6-N-acetylglucosaminyltransferase, now included with EC 2.4.1.150, N-acetyllactosaminide β-1,6-N-acetylglucosaminyltransferase
[EC 2.4.1.164 created 1989, deleted 2016]
 
 
EC 2.4.1.79     Relevance: 91.1%
Accepted name: globotriaosylceramide 3-β-N-acetylgalactosaminyltransferase
Reaction: UDP-N-acetyl-α-D-galactosamine + α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = UDP + N-acetyl-β-D-galactosaminyl-(1→3)-α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
For diagram of globotetraosylceramide biosynthesis, click here. For diagram of reaction, click here
Glossary: α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = globotriaosylceramide = Pk antigen
N-acetyl-β-D-galactosaminyl-(1→3)-α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = globotetraosylceramide = globoside = P antigen
Other name(s): uridine diphosphoacetylgalactosamine-galactosylgalactosylglucosylceramide acetylgalactosaminyltransferase; globoside synthetase; UDP-N-acetylgalactosamine:globotriaosylceramide β-3-N-acetylgalactosaminyltransferase; galactosylgalactosylglucosylceramide β-D-acetylgalactosaminyltransferase; UDP-N-acetylgalactosamine:globotriaosylceramide β1,3-N-acetylgalactosaminyltransferase; globoside synthase; gUDP-N-acetyl-D-galactosamine:D-galactosyl-1,4-D-galactosyl-1,4-D-glucosylceramide β-N-acetyl-D-galactosaminyltransferase; β3GalNAc-T1; UDP-N-acetyl-D-galactosamine:α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosylceramide 3III-β-N-acetyl-D-galactosaminyltransferase; UDP-N-acetyl-D-galactosamine:α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide 3III-β-N-acetyl-D-galactosaminyltransferase; UDP-N-acetyl-D-galactosamine:α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide III3-β-N-acetyl-D-galactosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-galactosamine:α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide III3-β-N-acetyl-D-galactosaminyltransferase
Comments: Globoside is a neutral glycosphingolipid in human erythrocytes and has blood-group-P-antigen activity [4]. The enzyme requires a divalent cation for activity, with Mn2+ required for maximal activity [3]. UDP-GalNAc is the only sugar donor that is used efficiently by the enzyme: UDP-Gal and UDP-GlcNAc result in very low enzyme activity [3]. Lactosylceramide, globoside and gangliosides GM3 and GD3 are not substrates [4]. For explanation of the superscripted ’3′ in the systematic name, see GL-5.3.4.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 62213-46-1
References:
1.  Chien, J.-L., Williams, T. and Basu, S. Biosynthesis of a globoside-type glycosphingolipid by a β-N-acetylgalactosaminyltransferase from embryonic chicken brain. J. Biol. Chem. 248 (1973) 1778–1785. [PMID: 4632917]
2.  Ishibashi, T., Kijimoto, S. and Makita, A. Biosynthesis of globoside and Forssman hapten from trihexosylceramide and properties of β-N-acetyl-galactosaminyltransferase of guinea pig kidney. Biochim. Biophys. Acta 337 (1974) 92–106. [DOI] [PMID: 4433547]
3.  Taniguchi, N. and Makita, A. Purification and characterization of UDP-N-acetylgalactosamine: globotriaosylceramide β-3-N-acetylgalactosaminyltransferase, a synthase of human blood group P antigen, from canine spleen. J. Biol. Chem. 259 (1984) 5637–5642. [PMID: 6425294]
4.  Okajima, T., Nakamura, Y., Uchikawa, M., Haslam, D.B., Numata, S.I., Furukawa, K., Urano, T. and Furukawa, K. Expression cloning of human globoside synthase cDNAs. Identification of β3Gal-T3 as UDP-N-acetylgalactosamine:globotriaosylceramide β1,3-N-acetylgalactosaminyltransferase. J. Biol. Chem. 275 (2000) 40498–40503. [DOI] [PMID: 10993897]
[EC 2.4.1.79 created 1976, modified 2006]
 
 
EC 2.4.1.275     Relevance: 90.6%
Accepted name: neolactotriaosylceramide β-1,4-galactosyltransferase
Reaction: UDP-α-D-galactose + N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = UDP + β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
For diagram of neolactotetraosylceramide biosynthesis, click here
Glossary: N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = neolactotriaosylceramide
Other name(s): β4Gal-T4; UDP-galactose:N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide β-1,4-galactosyltransferase; lactotriaosylceramide β-1,4-galactosyltransferase (incorrect)
Systematic name: UDP-α-D-galactose:N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide 4-β-D-galactosyltransferase
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc
References:
1.  Schwientek, T., Almeida, R., Levery, S.B., Holmes, E.H., Bennett, E. and Clausen, H. Cloning of a novel member of the UDP-galactose:β-N-acetylglucosamine β1,4-galactosyltransferase family, β4Gal-T4, involved in glycosphingolipid biosynthesis. J. Biol. Chem. 273 (1998) 29331–29340. [DOI] [PMID: 9792633]
[EC 2.4.1.275 created 2011, modified 2013]
 
 
EC 2.4.1.179     Relevance: 90.1%
Accepted name: lactosylceramide β-1,3-galactosyltransferase
Reaction: UDP-α-D-galactose + β-D-galactosyl-(1→4)-β-D-glucosyl-R = UDP + β-D-galactosyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-R
For diagram of glycolipid biosynthesis, click here
Glossary: lactosylceramide = β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
Other name(s): uridine diphosphogalactose-lactosylceramide β1→3-galactosyltransferase; UDP-galactose:D-galactosyl-1,4-β-D-glucosyl-R β-1,3-galactosyltransferase; UDP-galactose:D-galactosyl-(1→4)-β-D-glucosyl-R 3-β-galactosyltransferase; UDP-α-D-galactose:D-galactosyl-(1→4)-β-D-glucosyl-R 3-β-galactosyltransferase
Systematic name: UDP-α-D-galactose:β-D-galactosyl-(1→4)-β-D-glucosyl-R 3-β-galactosyltransferase
Comments: R may be an oligosaccharide or a glycolipid; lactose can also act as acceptor, but more slowly. Involved in the elongation of oligosaccharide chains, especially in glycolipids.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 106769-64-6
References:
1.  Bailly, P., Piller, F. and Cartron, J.-P. Characterization and specific assay for a galactoside β-3-galactosyltransferase of human kidney. Eur. J. Biochem. 173 (1988) 417–422. [DOI] [PMID: 3129295]
[EC 2.4.1.179 created 1989]
 
 
EC 2.4.1.88     Relevance: 88.9%
Accepted name: globoside α-N-acetylgalactosaminyltransferase
Reaction: UDP-N-acetyl-α-D-galactosamine + N-acetyl-β-D-galactosaminyl-(1→3)-α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = UDP + N-acetyl-α-D-galactosaminyl-(1→3)-N-acetyl-β-D-galactosaminyl-(1→3)-α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
For diagram of globotetraosylceramide biosynthesis, click here
Other name(s): uridine diphosphoacetylgalactosamine-globoside α-acetylgalactosaminyltransferase; Forssman synthase; globoside acetylgalactosaminyltransferase; UDP-N-acetyl-D-galactosamine:N-acetyl-D-galactosaminyl-1,3-D-galactosyl-1,4-D-galactosyl-1,4-D-glucosylceramide α-N-acetyl-D-galactosaminyltransferase; UDP-N-acetyl-D-galactosamine:N-acetyl-D-galactosaminyl-(1→3)-D-galactosyl-(1→4)-D-galactosyl-(1→4)-D-glucosyl-(1↔1)-ceramide α-N-acetyl-D-galactosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-galactosamine:N-acetyl-β-D-galactosaminyl-(1→3)-α-D-galactosyl-(1→4)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide α-N-acetyl-D-galactosaminyltransferase
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 52037-97-5
References:
1.  Kijimoto, S., Ishibashi, T. and Makita, A. Biosynthesis of Forssman hapten from globoside by α-N-acetylgalactosaminyltransferase of guinea pig tissues. Biochem. Biophys. Res. Commun. 56 (1974) 177–184. [DOI] [PMID: 4823436]
[EC 2.4.1.88 created 1976]
 
 
EC 2.4.99.11      
Deleted entry: lactosylceramide α-2,6-N-sialyltransferase. Now included with EC 2.4.3.1, β-galactoside α-(2,6)-sialyltransferase
[EC 2.4.99.11 created 1992, deleted 2017]
 
 
EC 2.4.1.62     Relevance: 87.3%
Accepted name: ganglioside galactosyltransferase
Reaction: UDP-α-D-galactose + an N-acetyl-β-D-galactosaminyl-(1→4)-[α-N-acetylneuraminyl-(2→3)]-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = UDP + a β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminyl-(1→4)-[α-N-acetylneuraminyl-(2→3)]-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
For diagram of ganglioside biosynthesis, click here
Glossary: N-acetyl-β-D-galactosaminyl-(1→4)-[α-N-acetylneuraminyl-(2→3)]-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = ganglioside GM2
a β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminyl-(1→4)-[α-N-acetylneuraminyl-(2→3)]-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = gangloside GM1a
Other name(s): UDP-galactose—ceramide galactosyltransferase; uridine diphosphogalactose-ceramide galactosyltransferase; UDP galactose-LAC Tet-ceramide α-galactosyltransferase; UDP-galactose-GM2 galactosyltransferase; uridine diphosphogalactose-GM2 galactosyltransferase; uridine diphosphate D-galactose:glycolipid galactosyltransferase; UDP-galactose:N-acetylgalactosaminyl-(N-acetylneuraminyl) galactosyl-glucosyl-ceramide galactosyltransferase; UDP-galactose-GM2 ganglioside galactosyltransferase; GM1-synthase; UDP-galactose:N-acetyl-D-galactosaminyl-(N-acetylneuraminyl)-D-galactosyl-D-glucosyl-N-acylsphingosine β-1,3-D-galactosyltransferase; UDP-galactose:N-acetyl-D-galactosaminyl-(N-acetylneuraminyl)-D-galactosyl-(1→4)-β-D-glucosyl-N-acylsphingosine 3-β-D-galactosyltransferase
Systematic name: UDP-α-D-galactose:N-acetyl-β-D-galactosaminyl-(1→4)-[α-N-acetylneuraminyl-(2→3)]-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide 3-β-D-galactosyltransferase
Comments: The substrate is also known as gangloside GM2, the product as gangloside GM1a
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 37217-28-0
References:
1.  Basu, S., Kaufman, B. and Roseman, S. Conversion of Tay-Sachs ganglioside to monosialoganglioside by brain uridine diphosphate D-galactose: glycolipid galactosyltransferase. J. Biol. Chem. 240 (1965) 4115–4117. [PMID: 5842076]
2.  Yip, G.B. and Dain, J.A. The enzymic synthesis of ganglioside. II. UDP-galactose: N-acetylgalactosaminyl-(N-acetylneuraminyl)galactosyl-glucosyl-ceramide galactosyltransferase in rat brain. Biochim. Biophys. Acta 206 (1970) 252–260. [DOI] [PMID: 4987145]
3.  Yip, M.C.M. and Dain, J.A. Frog brain uridine diphosphate galactose-N-acetylgalactosaminyl-N-acetylneuraminylgalactosylglucosylceramide galactosyltransferase. Biochem. J. 118 (1970) 247–252. [PMID: 5484669]
[EC 2.4.1.62 created 1972, modified 2013]
 
 
EC 2.4.1.163      
Transferred entry: β-galactosyl-N-acetylglucosaminylgalactosylglucosyl-ceramide β-1,3-acetylglucosaminyltransferase, now included in EC 2.4.1.149, N-acetyllactosaminide β-1,3-N-acetylglucosaminyltransferase
[EC 2.4.1.163 created 1989, deleted 2016]
 
 
EC 2.4.1.86     Relevance: 86.2%
Accepted name: N-acetyl-β-D-glucosaminide β-(1,3)-galactosyltransferase
Reaction: UDP-α-D-galactose + N-acetyl-β-D-glucosaminyl-R = UDP + β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminyl-R
For diagram of lactotetraosylceramide biosynthesis, click here
Other name(s): B3GALT1 (gene name); uridine diphosphogalactose-acetyl-glucosaminylgalactosylglucosylceramide galactosyltransferase; GalT-4; UDP-galactose:N-acetyl-D-glucosaminyl-1,3-D-galactosyl-1,4-D-glucosylceramide β-D-galactosyltransferase; UDP-galactose:N-acetyl-D-glucosaminyl-(1→3)-D-galactosyl-(1→4)-D-glucosylceramide 3-β-D-galactosyltransferase; UDP-galactose:N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosylceramide 3-β-D-galactosyltransferase; UDP-galactose:N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosyl(1↔1)ceramide 3-β-D-galactosyltransferase; UDP-galactose:N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide 3-β-D-galactosyltransferase; glucosaminylgalactosylglucosylceramide β-galactosyltransferase; UDP-α-D-galactose:N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide 3-β-D-galactosyltransferase
Systematic name: UDP-α-D-galactose:N-acetyl-β-D-glucosaminyl-R 3-β-D-galactosyltransferase
Comments: The enzyme transfers galactose from UDP-α-D-galactose to the 3-position of substrates with a non-reducing terminal N-acetyl-β-D-glucosamine (β-GlcNAc) residue. It can act on both glycolipids and glycoproteins, generating a structure known as the type 1 histo-blood group antigen precursor.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 9073-46-5
References:
1.  Basu, M. and Basu, S. Enzymatic synthesis of a tetraglycosylceramide by a galactosyltransferase from rabbit bone marrow. J. Biol. Chem. 247 (1972) 1489–1495. [PMID: 4335001]
2.  Basu, M., Presper, K.A., Basu, S., Hoffman, L.M. and Brooks, S.E. Differential activities of glycolipid glycosyltransferases in Tay-Sachs disease: studies in cultured cells from cerebrum. Proc. Natl. Acad. Sci. USA 76 (1979) 4270–4274. [DOI] [PMID: 291963]
3.  Amado, M., Almeida, R., Carneiro, F., Levery, S.B., Holmes, E.H., Nomoto, M., Hollingsworth, M.A., Hassan, H., Schwientek, T., Nielsen, P.A., Bennett, E.P. and Clausen, H. A family of human β3-galactosyltransferases. Characterization of four members of a UDP-galactose:β-N-acetyl-glucosamine/β-nacetyl-galactosamine β-1,3-galactosyltransferase family. J. Biol. Chem. 273 (1998) 12770–12778. [DOI] [PMID: 9582303]
4.  Amado, M., Almeida, R., Schwientek, T. and Clausen, H. Identification and characterization of large galactosyltransferase gene families: galactosyltransferases for all functions. Biochim. Biophys. Acta 1473 (1999) 35–53. [DOI] [PMID: 10580128]
5.  Bardoni, A., Valli, M. and Trinchera, M. Differential expression of β1,3galactosyltransferases in human colon cells derived from adenocarcinomas or normal mucosa. FEBS Lett. 451 (1999) 75–80. [DOI] [PMID: 10356986]
[EC 2.4.1.86 created 1976, modified 2017]
 
 
EC 2.4.99.10      
Transferred entry: neolactotetraosylceramide α-2,3-sialyltransferase. Now included in EC 2.4.3.6, N-acetyllactosaminide α-2,3-sialyltransferase
[EC 2.4.99.10 created 1986, deleted 2017]
 
 
EC 2.4.3.9     Relevance: 84.4%
Accepted name: lactosylceramide α-2,3-sialyltransferase
Reaction: CMP-N-acetylneuraminate + β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide = CMP + α-N-acetylneuraminyl-(2→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
For diagram of ganglioside biosynthesis (pathway to GM2), click here
Glossary: lactosylceramide = β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
Other name(s): cytidine monophosphoacetylneuraminate-lactosylceramide α2,3- sialyltransferase; CMP-acetylneuraminate-lactosylceramide-sialyltransferase; CMP-acetylneuraminic acid:lactosylceramide sialyltransferase; CMP-sialic acid:lactosylceramide-sialyltransferase; cytidine monophosphoacetylneuraminate-lactosylceramide sialyltransferase; ganglioside GM3 synthetase; GM3 synthase; GM3 synthetase; SAT 1; CMP-N-acetylneuraminate:lactosylceramide α-2,3-N-acetylneuraminyltransferase; CMP-N-acetylneuraminate:β-D-galactosyl-(1→4)-β-D-glucosyl(1↔1)ceramide α-(2→3)-N-acetylneuraminyltransferase
Systematic name: CMP-N-acetylneuraminate:β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide α-(2→3)-N-acetylneuraminyltransferase
Comments: Lactose cannot act as acceptor.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 125752-90-1
References:
1.  Basu, S., Kaufman, B. and Roseman, S. Enzymatic synthesis of glucocerebroside by a glucosyltransferase from embryonic chicken brain. J. Biol. Chem. 248 (1973) 1388–1394. [PMID: 4631392]
2.  Fishman, P.H., Bradley, R.M. and Henneberry, R.C. Butyrate-induced glycolipid biosynthesis in HeLa cells: properties of the induced sialyltransferase. Arch. Biochem. Biophys. 172 (1976) 618–626. [DOI] [PMID: 4022]
3.  Higashi, H., Basu, M. and Basu, S. Biosynthesis in vitro of disialosylneolactotetraosylceramide by a solubilized sialyltransferase from embryonic chicken brain. J. Biol. Chem. 260 (1985) 824–828. [PMID: 3838172]
[EC 2.4.3.9 created 1984 as EC 2.4.99.9, modified 1986, transferred 2022 to EC 2.4.3.9]
 
 
EC 2.4.99.9      
Transferred entry: lactosylceramide α-2,3-sialyltransferase. Now EC 2.4.3.9, lactosylceramide α-2,3-sialyltransferase
[EC 2.4.99.9 created 1984, modified 1986, deleted 2022]
 
 
EC 2.4.1.274     Relevance: 75.7%
Accepted name: glucosylceramide β-1,4-galactosyltransferase
Reaction: UDP-α-D-galactose + β-D-glucosyl-(1↔1)-ceramide = UDP + β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide
For diagram of glycolipid biosynthesis, click here
Other name(s): lactosylceramide synthase; uridine diphosphate-galactose:glucosyl ceramide β 1-4 galactosyltransferase; UDP-Gal:glucosylceramide β1→4galactosyltransferase; GalT-2 (misleading); UDP-galactose:β-D-glucosyl-(1↔1)-ceramide β-1,4-galactosyltransferase
Systematic name: UDP-α-D-galactose:β-D-glucosyl-(1↔1)-ceramide 4-β-D-galactosyltransferase
Comments: Involved in the synthesis of several different major classes of glycosphingolipids.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc
References:
1.  Chatterjee, S. and Castiglione, E. UDPgalactose:glucosylceramide β1→4-galactosyltransferase activity in human proximal tubular cells from normal and familial hypercholesterolemic homozygotes. Biochim. Biophys. Acta 923 (1987) 136–142. [DOI] [PMID: 3099851]
2.  Trinchera, M., Fiorilli, A. and Ghidoni, R. Localization in the Golgi apparatus of rat liver UDP-Gal:glucosylceramide β1→4galactosyltransferase. Biochemistry 30 (1991) 2719–2724. [PMID: 1900430]
3.  Chatterjee, S., Ghosh, N. and Khurana, S. Purification of uridine diphosphate-galactose:glucosyl ceramide, β 1-4 galactosyltransferase from human kidney. J. Biol. Chem. 267 (1992) 7148–7153. [PMID: 1551920]
4.  Nomura, T., Takizawa, M., Aoki, J., Arai, H., Inoue, K., Wakisaka, E., Yoshizuka, N., Imokawa, G., Dohmae, N., Takio, K., Hattori, M. and Matsuo, N. Purification, cDNA cloning, and expression of UDP-Gal: glucosylceramide β-1,4-galactosyltransferase from rat brain. J. Biol. Chem. 273 (1998) 13570–13577. [DOI] [PMID: 9593693]
5.  Takizawa, M., Nomura, T., Wakisaka, E., Yoshizuka, N., Aoki, J., Arai, H., Inoue, K., Hattori, M. and Matsuo, N. cDNA cloning and expression of human lactosylceramide synthase. Biochim. Biophys. Acta 1438 (1999) 301–304. [DOI] [PMID: 10320813]
[EC 2.4.1.274 created 2011]
 
 
EC 3.2.1.107     Relevance: 72.3%
Accepted name: protein-glucosylgalactosylhydroxylysine glucosidase
Reaction: [collagen]-(5R)-5-O-[α-D-glucosyl-(1→2)-β-D-galactosyl]-5-hydroxy-L-lysine + H2O = D-glucose + [collagen]-(5R)-5-O-(β-D-galactosyl)-5-hydroxy-L-lysine
Other name(s): PGGHG (gene name); 2-O-α-D-glucopyranosyl-5-O-α-D-galactopyranosylhydroxy-L-lysine glucohydrolase; protein-α-D-glucosyl-1,2-β-D-galactosyl-L-hydroxylysine glucohydrolase; protein-α-D-glucosyl-(1→2)-β-D-galactosyl-L-hydroxylysine glucohydrolase
Systematic name: [collagen]-(5R)-5-O-[α-D-glucosyl-(1→2)-β-D-galactosyl]-5-hydroxy-L-lysine glucohydrolase
Comments: The enzyme specifically hydrolyses glucose from α-D-glucosyl-(1→2)-β-D-galactosyl disaccharide units that are linked to hydroxylysine residues of collagen and collagen-like proteins. Acetylation of the ε-amino group of the glycosylated hydroxylysine abolishes activity.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 72829-45-9
References:
1.  Hamazaki, H. and Hotta, K. Purification and characterization of an α-glucosidase specific for hydroxylysine-linked disaccharide of collagen. J. Biol. Chem. 254 (1979) 9682–9687. [PMID: 385589]
2.  Hamazaki, H. and Hotta, K. Enzymatic hydrolysis of disaccharide unit of collagen. Isolation of 2-O-α-D-glucopyranosyl-O-β-D-galactopyranosyl-hydroxylysine glucohydrolase from rat spleens. Eur. J. Biochem. 111 (1980) 587–591. [DOI] [PMID: 7460918]
3.  Sternberg, M. and Shapiro, R.G. Studies on the catabolism of the hydroxylysine-linked disaccharide units of basement membranes and collagens. Isolation and characterization of a rat kidney α-glucosidase of high specificity. J. Biol. Chem. 254 (1979) 10329–10336. [PMID: 385599]
4.  Hamazaki, H. and Hamazaki, M.H. Catalytic site of human protein-glucosylgalactosylhydroxylysine glucosidase: Three crucial carboxyl residues were determined by cloning and site-directed mutagenesis. Biochem. Biophys. Res. Commun. 469 (2016) 357–362. [DOI] [PMID: 26682924]
[EC 3.2.1.107 created 1984]
 
 
EC 2.4.1.149     Relevance: 67%
Accepted name: N-acetyllactosaminide β-1,3-N-acetylglucosaminyltransferase
Reaction: UDP-N-acetyl-α-D-glucosamine + β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosaminyl-R = UDP + N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosaminyl-R
Other name(s): uridine diphosphoacetylglucosamine-acetyllactosaminide β1→3-acetylglucosaminyltransferase; poly-N-acetyllactosamine extension enzyme; Galβ1→4GlcNAc-R β1→3 N-acetylglucosaminyltransferase; UDP-GlcNAc:GalR β-D-3-N-acetylglucosaminyltransferase; N-acetyllactosamine β(1-3)N-acetylglucosaminyltransferase; UDP-GlcNAc:Galβ1→4GlcNAcβ-Rβ1→3-N-acetylglucosaminyltransferase; GnTE; UDP-N-acetyl-D-glucosamine:β-D-galactosyl-1,4-N-acetyl-D-glucosamine β-1,3-acetyl-D-glucosaminyltransferase; β-galactosyl-N-acetylglucosaminylgalactosylglucosyl-ceramide β-1,3-acetylglucosaminyltransferase; UDP-N-acetyl-D-glucosamine:β-D-galactosyl-(1→4)-N-acetyl-D-glucosamine 3-β-N-acetyl-D-glucosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-glucosamine:β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosaminyl-R 3-β N-acetylglucosaminyltransferase (configuration-inverting)
Comments: Acts on β-galactosyl-1,4-N-acetylglucosaminyl termini on glycoproteins, glycolipids, and oligosaccharides.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 85638-39-7
References:
1.  Van den Eijnden, D.H., Winterwerp, H., Smeeman, P. and Schiphorst, W.E.C.M. Novikoff ascites tumor cells contain N-acetyllactosaminide β1→3 and β1→6 N-acetylglucosaminyltransferase activity. J. Biol. Chem. 258 (1983) 3435–3437. [PMID: 6219989]
2.  Basu, M. and Basu, S. Biosynthesis in vitro of Ii core glycosphingolipids from neolactotetraosylceramide by β 1-3- and β 1-6-N-acetylglucosaminyltransferases from mouse T-lymphoma. J. Biol. Chem. 259 (1984) 12557–12562. [PMID: 6238026]
3.  Takeya, A., Hosomi, O. and Kogure, T. The presence of N-acetyllactosamine and lactose: β (1-3)N-acetylglucosaminyltransferase activity in human urine. Jpn. J. Med. Sci. Biol. 38 (1985) 1–8. [PMID: 3160874]
[EC 2.4.1.149 created 1984 (EC 2.4.1.163 created 1989, incorporated 2016), modified 2016]
 
 
EC 2.4.1.135     Relevance: 66.1%
Accepted name: galactosylgalactosylxylosylprotein 3-β-glucuronosyltransferase
Reaction: UDP-α-D-glucuronate + [protein]-3-O-(β-D-galactosyl-(1→3)-β-D-galactosyl-(1→4)-β-D-xylosyl)-L-serine = UDP + [protein]-3-O-(β-D-GlcA-(1→3)-β-D-Gal-(1→3)-β-D-Gal-(1→4)-β-D-Xyl)-L-serine
For diagram of heparan and chondroitin biosynthesis (early stages), click here
Glossary: [protein]-3-O-(β-D-GlcA-(1→3)-β-D-Gal-(1→3)-β-D-Gal-(1→4)-β-D-Xyl)-L-serine = [protein]-3-O-(β-D-glucuronosyl-(1→3)-β-D-galactosyl-(1→3)-β-D-galactosyl-(1→4)-β-D-xylosyl)-L-serine
Other name(s): glucuronosyltransferase I; uridine diphosphate glucuronic acid:acceptor glucuronosyltransferase; UDP-glucuronate:3-β-D-galactosyl-4-β-D-galactosyl-O-β-D-xylosyl-protein D-glucuronosyltransferase; UDP-glucuronate:3-β-D-galactosyl-4-β-D-galactosyl-O-β-D-xylosylprotein D-glucuronosyltransferase
Systematic name: UDP-α-D-glucuronate:[protein]-3-O-(β-D-galactosyl-(1→3)-β-D-galactosyl-(1→4)-β-D-xylosyl)-L-serine D-glucuronosyltransferase (configuration-inverting)
Comments: Involved in the biosynthesis of the linkage region of glycosaminoglycan chains as part of proteoglycan biosynthesis (chondroitin, dermatan and heparan sulfates). Requires Mn2+.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 227184-75-0
References:
1.  Helting, J. and Roden, L. Biosynthesis of chondroitin sulfate. II. Glucuronosyl transfer in the formation of the carbohydrate-protein linkage region. J. Biol. Chem. 244 (1969) 2799–2805. [PMID: 5770003]
2.  Helting, T. Biosynthesis of heparin. Solubilization and partial purification of uridine diphosphate glucuronic acid: acceptor glucuronosyltransferase from mouse mastocytoma. J. Biol. Chem. 247 (1972) 4327–4332. [PMID: 4260846]
3.  Kitagawa, H., Tone, Y., Tamura, J., Neumann, K.W., Ogawa, T., Oka, S., Kawasaki, T. and Sugahara, K. Molecular cloning and expression of glucuronyltransferase I involved in the biosynthesis of the glycosaminoglycan-protein linkage region of proteoglycans. J. Biol. Chem. 273 (1998) 6615–6618. [DOI] [PMID: 9506957]
[EC 2.4.1.135 created 1984, modified 2002, modified 2016]
 
 
EC 2.4.1.152     Relevance: 65.6%
Accepted name: 4-galactosyl-N-acetylglucosaminide 3-α-L-fucosyltransferase
Reaction: GDP-β-L-fucose + β-D-galactosyl-(1→4)-N-acetyl-D-glucosaminyl-R = GDP + β-D-galactosyl-(1→4)-[α-L-fucosyl-(1→3)]-N-acetyl-D-glucosaminyl-R
For diagram of fucosylneolactotetraosylceramide biosynthesis, click here
Other name(s): Lewis-negative α-3-fucosyltransferase; plasma α-3-fucosyltransferase; guanosine diphosphofucose-glucoside α1→3-fucosyltransferase; galactoside 3-fucosyltransferase; GDP-L-fucose:1,4-β-D-galactosyl-N-acetyl-D-glucosaminyl-R 3-L-fucosyltransferase; GDP-β-L-fucose:1,4-β-D-galactosyl-N-acetyl-D-glucosaminyl-R 3-L-fucosyltransferase; GDP-β-L-fucose:1,4-β-D-galactosyl-N-acetyl-D-glucosaminyl-R 3-α-L-fucosyltransferase; GDP-β-L-fucose:(1→4)-β-D-galactosyl-N-acetyl-D-glucosaminyl-R 3-α-L-fucosyltransferase
Systematic name: GDP-β-L-fucose:β-D-galactosyl-(1→4)-N-acetyl-D-glucosaminyl-R 3-α-L-fucosyltransferase (configuration-inverting)
Comments: Normally acts on a glycoconjugate where R (see reaction) is a glycoprotein or glycolipid. This enzyme fucosylates on O-3 of an N-acetylglucosamine that carries a galactosyl group on O-4, unlike EC 2.4.1.65, 3-galactosyl-N-acetylglucosaminide 4-α-L-fucosyltransferase, which fucosylates on O-4 of an N-acetylglucosamine that carries a galactosyl group on O-3.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 39279-34-0
References:
1.  Johnson, P.H., Yates, A.D. and Watkins, W.M. Human salivary fucosyltransferase: evidence for two distinct α-3-L-fucosyltransferase activities one of which is associated with the Lewis blood Le gene. Biochem. Biophys. Res. Commun. 100 (1981) 1611–1618. [DOI] [PMID: 7295318]
2.  Schachter, H., Narasimhan, S., Gleeson, P. and Vella, G. Glycosyltransferases involved in elongation of N-glycosidically linked oligosaccharides of the complex or N-acetyllactosamine type. Methods Enzymol. 98 (1983) 98–134. [PMID: 6366476]
3.  Ma, B., Wang, G., Palcic, M.M., Hazes, B. and Taylor, D.E. C-terminal amino acids of Helicobacter pylori α1,3/4 fucosyltransferases determine type I and type II transfer. J. Biol. Chem. 278 (2003) 21893–21900. [DOI] [PMID: 12676935]
[EC 2.4.1.152 created 1984, modified 2002, modified 2019]
 
 
EC 3.2.1.62     Relevance: 65.5%
Accepted name: glycosylceramidase
Reaction: (1) a β-D-glucosyl-N-acylsphingosine + H2O = a ceramide + β-D-glucose
(2) a β-D-galactosyl-N-acylsphingosine + H2O = a ceramide + β-D-galactose
(3) a flavonoid-O-β-D-glucoside + H2O = a flavonoid + β-D-glucose
For diagram of phloretin biosynthesis, click here and for diagram of glycolipid biosynthesis, click here
Glossary: a ceramide = an N-acylsphingosine
Other name(s): phlorizin hydrolase; phloretin-glucosidase; glycosyl ceramide glycosylhydrolase; cerebrosidase; phloridzin β-glucosidase; lactase-phlorizin hydrolase; phloridzin glucosidase; LPH (gene name); LCT (gene name); glycosyl-N-acylsphingosine glycohydrolase
Systematic name: β-D-glucosyl-N-acylsphingosine glycohydrolase (configuration-retaining)
Comments: The enzyme, found in the intestinal mucosa, hydrolyses β-D-glucosyl and β-D-galactosyl residues from a very broad range of substrates using a retaining mechanism. Characterized substrates include glucosyl- and galactosyl-ceramides [3], O3-, O4′ and O7-glucosylated flavonoids [6], and the 2′-O-glucosylated dihydrochalcone phlorizin [1]. The enzyme includes two glycosyl hydrolase domains, both belonging to the GH1 family. While one domain is responsible for the activity described here, the other catalyses the reaction of EC 3.2.1.108, lactase [4,5]. cf. EC 3.2.1.45, glucosylceramidase and EC 3.2.1.46, galactosylceramidase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 9033-10-7
References:
1.  Malathi, P. and Crane, R.K. Phlorizin hydrolase: a β-glucosidase of hamster intestinal brush border membrane. Biochim. Biophys. Acta 173 (1969) 245–256. [DOI] [PMID: 5774775]
2.  Lorenz-Meyer, H., Blum, A.L., Haemmerli, H.P. and Semenza, G. A second enzyme defect in acquired lactase deficiency: lack of small-intestinal phlorizin-hydrolase. Eur. J. Clin. Invest. 2 (1972) 326–331. [DOI] [PMID: 5082068]
3.  Leese, H.J. and Semenza, G. On the identity between the small intestinal enzymes phlorizin hydrolase and glycosylceramidase. J. Biol. Chem. 248 (1973) 8170–8173. [DOI] [PMID: 4752949]
4.  Zecca, L., Mesonero, J.E., Stutz, A., Poiree, J.C., Giudicelli, J., Cursio, R., Gloor, S.M. and Semenza, G. Intestinal lactase-phlorizin hydrolase (LPH): the two catalytic sites; the role of the pancreas in pro-LPH maturation. FEBS Lett. 435 (1998) 225–228. [DOI] [PMID: 9762914]
5.  Arribas, J.C., Herrero, A.G., Martin-Lomas, M., Canada, F.J., He, S. and Withers, S.G. Differential mechanism-based labeling and unequivocal activity assignment of the two active sites of intestinal lactase/phlorizin hydrolase. Eur. J. Biochem. 267 (2000) 6996–7005. [DOI] [PMID: 11106409]
6.  Nemeth, K., Plumb, G.W., Berrin, J.G., Juge, N., Jacob, R., Naim, H.Y., Williamson, G., Swallow, D.M. and Kroon, P.A. Deglycosylation by small intestinal epithelial cell β-glucosidases is a critical step in the absorption and metabolism of dietary flavonoid glycosides in humans. Eur J Nutr 42 (2003) 29–42. [DOI] [PMID: 12594539]
[EC 3.2.1.62 created 1972, modified 1976, modified 2022]
 
 
EC 2.4.3.7     Relevance: 63.2%
Accepted name: α-N-acetylneuraminyl-2,3-β-galactosyl-1,3-N-acetylgalactosaminide 6-α-sialyltransferase
Reaction: CMP-N-acetylneuraminate + N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→3)-N-acetyl-D-galactosaminyl-R = CMP + N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→3)-[N-acetyl-α-neuraminyl-(2→6)]-N-acetyl-D-galactosaminyl-R
For diagram of reaction, click here
Other name(s): sialyltransferase; cytidine monophosphoacetylneuraminate-(α-N-acetylneuraminyl-2,3-β-galactosyl-1,3)-N-acetylgalactosaminide-α-2,6-sialyltransferase; α-N-acetylneuraminyl-2,3-β-galactosyl-1,3-N-acetyl-galactosaminide α-2,6-sialyltransferase; SIAT7; ST6GALNAC; (α-N-acetylneuraminyl-2,3-β-galactosyl-1,3)-N-acetyl-galactosaminide 6-α-sialyltransferase; CMP-N-acetylneuraminate:(α-N-acetylneuraminyl-2,3-β-D-galactosyl-1,3)-N-acetyl-D-galactosaminide α-2,6-N-acetylneuraminyl-transferase
Systematic name: CMP-N-acetylneuraminate:N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→3)- N-acetyl-D-galactosaminide galactosamine-6-α-N-acetylneuraminyltransferase
Comments: Attaches N-acetylneuraminic acid in α-2,6-linkage to N-acetylgalactosamine only when present in the structure of α-N-acetylneuraminyl-(2→3)-β-galactosyl-(1→3)-N-acetylgalactosaminyl-R, where R may be protein or p-nitrophenol. Not identical with EC 2.4.3.3 α-N-acetylgalactosaminide α-2,6-sialyltransferase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 129924-24-9
References:
1.  Bergh, M.L.E., Hooghwinkel, G.J.M. and Van den Eijnden, D.H. Biosynthesis of the O-glycosidically linked oligosaccharide chains of fetuin. Indications for an α-N-acetylgalactosaminide α2→6 sialyltransferase with a narrow acceptor specificity in fetal calf liver. J. Biol. Chem. 258 (1983) 7430–7436. [PMID: 6190802]
[EC 2.4.3.7 created 1984 as EC 2.4.99.7, modified 1986, modified 2004, transferred 2022 to EC 2.4.3.7]
 
 
EC 2.4.1.87     Relevance: 63%
Accepted name: N-acetyllactosaminide 3-α-galactosyltransferase
Reaction: UDP-α-D-galactose + β-D-galactosyl-(1→4)-β-N-acetyl-D-glucosaminyl-R = UDP + α-D-galactosyl-(1→3)-β-D-galactosyl-(1→4)-β-N-acetylglucosaminyl-R (where R can be OH, an oligosaccharide or a glycoconjugate)
Other name(s): α-galactosyltransferase; UDP-Gal:β-D-Gal(1,4)-D-GlcNAc α(1,3)-galactosyltransferase; UDP-Gal:N-acetyllactosaminide α(1,3)-galactosyltransferase; UDP-Gal:N-acetyllactosaminide α-1,3-D-galactosyltransferase; UDP-Gal:Galβ1→4GlcNAc-R α1→3-galactosyltransferase; UDP-galactose-acetyllactosamine α-D-galactosyltransferase; UDPgalactose:β-D-galactosyl-β-1,4-N-acetyl-D-glucosaminyl-glycopeptide α-1,3-D-galactosyltransferase; glucosaminylglycopeptide α-1,3-galactosyltransferase; uridine diphosphogalactose-acetyllactosamine α1→3-galactosyltransferase; uridine diphosphogalactose-acetyllactosamine galactosyltransferase; uridine diphosphogalactose-galactosylacetylglucosaminylgalactosylglucosylceramide galactosyltransferase; β-D-galactosyl-N-acetylglucosaminylglycopeptide α-1,3-galactosyltransferase; UDP-galactose:N-acetyllactosaminide 3-α-D-galactosyltransferase; UDP-galactose:β-D-galactosyl-1,4-β-N-acetyl-D-glucosaminyl-R 3-α-D-galactosyltransferase; UDP-galactose:β-D-galactosyl-(1→4)-β-N-acetyl-D-glucosaminyl-R 3-α-D-galactosyltransferase
Systematic name: UDP-α-D-galactose:β-D-galactosyl-(1→4)-β-N-acetyl-D-glucosaminyl-R 3-α-D-galactosyltransferase
Comments: Acts on β-galactosyl-1,4-N-acetylglucosaminyl termini on asialo-α1-acid glycoprotein and N-acetyllactosamine (β-D-galactosyl-1,4-N-acetyl-β-D-glucosamine), but not on 2′-fucosylated-N-acetyllactosamine. The non-reducing terminal N-acetyllactosamine residues of glycoproteins can also act as acceptor. Now includes EC 2.4.1.124 and EC 2.4.1.151.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 128449-51-4
References:
1.  Basu, M. and Basu, S. Enzymatic synthesis of a blood group B-related pentaglycosylceramide by an α-galactosyltransferase from rabbit bone marrow. J. Biol. Chem. 248 (1973) 1700–1706. [PMID: 4632915]
2.  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]
3.  Blake, D.A. and Goldstein, I.J. An α-D-galactosyltransferase activity in Ehrlich ascites tumor cells. Biosynthesis and characterization of a trisaccharide (α-D-galactose-(1→3)-N-acetyllactosamine). J. Biol. Chem. 256 (1981) 5387–5393. [PMID: 6787040]
[EC 2.4.1.87 created 1976, modified 1989, modified 2002 (EC 2.4.1.124 created 1984, incorporated 2002, EC 2.4.1.151 created 1984, incorporated 2002)]
 
 
EC 2.4.99.7      
Transferred entry: α-N-acetylneuraminyl-2,3-β-galactosyl-1,3-N-acetylgalactosaminide 6-α-sialyltransferase. Now EC 2.4.3.7, α-N-acetylneuraminyl-2,3-β-galactosyl-1,3-N-acetylgalactosaminide 6-α-sialyltransferase
[EC 2.4.99.7 created 1984, modified 1986, modified 2004, deleted 2022]
 
 
EC 2.4.99.1      
Transferred entry: β-galactoside α-(2,6)-sialyltransferase. Now EC 2.4.3.1, β-galactoside α-(2,6)-sialyltransferase
[EC 2.4.99.1 created 1972, modified 1976, modified 1986, modified 2017 (EC 2.4.99.11 created 1992, incorporated 2017), deleted 2022]
 
 
EC 2.4.3.1     Relevance: 61.7%
Accepted name: β-galactoside α-(2,6)-sialyltransferase
Reaction: CMP-N-acetyl-β-neuraminate + β-D-galactosyl-R = CMP + N-acetyl-α-neuraminyl-(2→6)-β-D-galactosyl-R
Other name(s): ST6Gal-I; CMP-N-acetylneuraminate:β-D-galactosyl-1,4-N-acetyl-β-D-glucosamine α-2,6-N-acetylneuraminyltransferase; lactosylceramide α-2,6-N-sialyltransferase; CMP-N-acetylneuraminate:β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosamine α-(2→6)-N-acetylneuraminyltransferase; β-galactoside α-2,6-sialyltransferase
Systematic name: CMP-N-acetyl-β-neuraminate:β-D-galactoside α-(2→6)-N-acetylneuraminyltransferase (configuration-inverting)
Comments: The enzyme acts on the terminal non-reducing β-D-galactosyl residue of the oligosaccharide moiety of glycoproteins and glycolipids.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 9075-81-4
References:
1.  Spiro, M.H. and Spiro, R.G. Glycoprotein biosynthesis: studies on thyroglobulin. Thyroid sialyltransferase. J. Biol. Chem. 243 (1968) 6520–6528. [PMID: 5726897]
2.  Hickman, J., Ashwell, G., Morell, A.G., van der Hamer, C.J.A. and Scheinberg, I.H. Physical and chemical studies on ceruloplasmin. 8. Preparation of N-acetylneuraminic acid-1-14C-labeled ceruloplasmin. J. Biol. Chem. 245 (1970) 759–766. [PMID: 4313609]
3.  Bartholomew, B.A., Jourdian, G.W. and Roseman, S. The sialic acids. XV. Transfer of sialic acid to glycoproteins by a sialyltransferase from colostrum. J. Biol. Chem. 248 (1973) 5751–5762. [PMID: 4723915]
4.  Paulson, J.C., Beranek, W.E. and Hill, R.L. Purification of a sialyltransferase from bovine colostrum by affinity chromatography on CDP-agarose. J. Biol. Chem. 252 (1977) 2356–2362. [PMID: 849932]
5.  Schachter, H., Narasimhan, S., Gleeson, P. and Vella, G. Glycosyltransferases involved in elongation of N-glycosidically linked oligosaccharides of the complex or N-acetyllactosamine type. Methods Enzymol. 98 (1983) 98–134. [PMID: 6366476]
6.  Albarracin, I., Lassaga, F.E. and Caputto, R. Purification and characterization of an endogenous inhibitor of the sialyltransferase CMP-N-acetylneuraminate: lactosylceramide α2,6-N-acetylneuraminyltransferase (EC 2.4.99.-). Biochem. J. 254 (1988) 559–565. [PMID: 2460092]
[EC 2.4.3.1 created 1972 as EC 2.4.99.1, modified 1976, modified 1986, modified 2017 (EC 2.4.99.11 created 1992, incorporated 2016), modified 2017, transferred 2021 to EC 2.4.3.1]
 
 
EC 2.4.3.10     Relevance: 61.1%
Accepted name: N-acetylglucosaminide α-(2,6)-sialyltransferase
Reaction: CMP-N-acetyl-β-neuraminate + N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminyl-R = CMP + N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→3)-[N-acetyl-α-neuraminyl-(2→6)]-N-acetyl-β-D-glucosaminyl-R
Other name(s): α-N-acetylneuraminyl-2,3-β-galactosyl-1,3-N-acetylglucosaminide 6-α-sialyltransferase; N-acetylglucosaminide (α 2→6)-sialyltransferase; ST6GlcNAc
Systematic name: CMP-N-acetylneuraminate:N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminide N-acetyl-β-D-glucosamine-6-α-N-acetylneuraminyltransferase (configuration-inverting)
Comments: Attaches N-acetylneuraminic acid in α-2,6-linkage to N-acetyl-β-D-glucosamine. The enzyme from rat liver also acts on β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminyl residues, but more slowly.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc
References:
1.  Paulson, J.C., Weinstein, J. and de Souza-e-Silva, U. Biosynthesis of a disialylated sequence in N-linked oligosaccharides: identification of an N-acetylglucosaminide (α 2→6)-sialyltransferase in Golgi apparatus from rat liver. Eur. J. Biochem. 140 (1984) 523–530. [PMID: 6547092]
[EC 2.4.3.10 created 2020 as EC 2.4.99.22, transferred 2022 to EC 2.4.3.10]
 
 
EC 2.4.99.22      
Transferred entry: N-acetylglucosaminide α-(2,6)-sialyltransferase. Now EC 2.4.3.10, N-acetylglucosaminide α-(2,6)-sialyltransferase
[EC 2.4.99.22 created 2020, deleted 2022]
 
 
EC 2.4.1.69     Relevance: 61.1%
Accepted name: type 1 galactoside α-(1,2)-fucosyltransferase
Reaction: GDP-β-L-fucose + β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminyl-R = GDP + α-L-fucosyl-(1→2)-β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminyl-R
For diagram of lactotetraosylceramide biosynthesis, click here
Other name(s): galactoside 2-α-L-fucosyltransferase (ambiguous); blood group H α-2-fucosyltransferase (ambiguous); guanosine diphosphofucose-galactoside 2-L-fucosyltransferase; α-(1→2)-L-fucosyltransferase (ambiguous); α-2-fucosyltransferase (ambiguous); α-2-L-fucosyltransferase (ambiguous); blood-group substance H-dependent fucosyltransferase (ambiguous); guanosine diphosphofucose-glycoprotein 2-α-fucosyltransferase (ambiguous); guanosine diphosphofucose-β-D-galactosyl-α-2-L-fucosyltransferase (ambiguous); guanosine diphosphofucose-galactosylacetylglucosaminylgalactosylglucosylceramide α-L-fucosyltransferase (ambiguous); guanosine diphosphofucose-glycoprotein 2-α-L-fucosyltransferase (ambiguous); secretor-type β-galactoside α1→2fucosyltransferase; β-galactoside α1→2fucosyltransferase (ambiguous); GDP-β-L-fucose:β-D-galactosyl-R 2-α-L-fucosyltransferase (ambiguous); FUT2 (gene name); GDP-β-L-fucose:β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-β-D-glucosyl-(1↔1)-ceramide 2-α-L-fucosyltransferase
Systematic name: GDP-β-L-fucose:β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminyl-R α-(1,2)-L-fucosyltransferase (configuration-inverting)
Comments: The enzyme acts on a glycoconjugates where R (see reaction) is a glycoprotein or glycosphingolipid. The recognized moiety of the substrate is known as a type 1 histo-blood group antigen precursor disaccharide, and the action of the enzyme produces an H type 1 antigen. In humans the main enzyme performing this reaction is encoded by the FUT2 gene (also known as the Secretor gene), which is also able to act on type 2 substrates (see EC 2.4.1.344). The enzyme from the bacterium Helicobacter pylori cannot act on type 2 substrates.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 56093-23-3
References:
1.  Beyer, T.A. and Hill, R.L. Enzymatic properties of the β-galactoside α1→2 fucosyltransferase from porcine submaxillary gland. J. Biol. Chem. 255 (1980) 5373–5379. [PMID: 7372640]
2.  Beyer, T.A., Sadler, J.E. and Hill, R.L. Purification to homogeneity of H blood group β-galactoside α1→2 fucosyltransferase from porcine submaxillary gland. J. Biol. Chem. 255 (1980) 5364–5372. [PMID: 6246105]
3.  Kumazaki, T. and Yoshida, A. Biochemical evidence that secretor gene, Se, is a structural gene encoding a specific fucosyltransferase. Proc. Natl. Acad. Sci. USA 81 (1984) 4193–4197. [DOI] [PMID: 6588382]
4.  Koda, Y., Soejima, M., Wang, B. and Kimura, H. Structure and expression of the gene encoding secretor-type galactoside 2-α-L-fucosyltransferase (FUT2). Eur. J. Biochem. 246 (1997) 750–755. [DOI] [PMID: 9219535]
5.  Wang, G., Boulton, P.G., Chan, N.W., Palcic, M.M. and Taylor, D.E. Novel Helicobacter pylori α1,2-fucosyltransferase, a key enzyme in the synthesis of Lewis antigens. Microbiology 145 (1999) 3245–3253. [DOI] [PMID: 10589734]
[EC 2.4.1.69 created 1972 (EC 2.4.1.89 created 1976, incorporated 1984), modified 2002, modified 2017]
 
 
EC 2.4.99.6      
Transferred entry: N-acetyllactosaminide α-2,3-sialyltransferase. Now EC 2.4.3.6, N-acetyllactosaminide α-2,3-sialyltransferase
[EC 2.4.99.6 created 1984, modified 1986 (EC 2.4.99.10 created 1986, incorporated 2017), deleted 2022]
 
 
EC 2.4.3.6     Relevance: 60.4%
Accepted name: N-acetyllactosaminide α-2,3-sialyltransferase
Reaction: CMP-N-acetyl-β-neuraminate + β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosaminyl-R = CMP + N-acetyl-α-neuraminyl-(2→3)-β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosaminyl-R
Other name(s): cytidine monophosphoacetylneuraminate-β-galactosyl(1→4)acetylglucosaminide α2→3-sialyltransferase; α2→3 sialyltransferase (ambiguous); SiaT (ambiguous); CMP-N-acetylneuraminate:β-D-galactosyl-1,4-N-acetyl-D-glucosaminyl-glycoprotein α-2,3-N-acetylneuraminyltransferase; neolactotetraosylceramide α-2,3-sialyltransferase; CMP-N-acetylneuraminate:β-D-galactosyl-(1→4)-N-acetyl-D-glucosaminyl-glycoprotein α-(2→3)-N-acetylneuraminyltransferase
Systematic name: CMP-N-acetyl-β-neuraminate:β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosaminyl-R (2→3)-N-acetyl-α-neuraminyltransferase (configuration-inverting)
Comments: The enzyme recognizes the sequence β-D-galactosyl-(1→4)-N-acetyl-D-glucosaminyl (known as type 2 histo-blood group precursor disaccharide) in non-reducing termini of glycan moieties in glycoproteins and glycolipids. The enzyme from chicken brain was shown to act on neolactotetraosylceramide, producing ganglioside LM1 [2].
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 77537-85-0
References:
1.  Van den Eijnden, D.H. and Schiphorst, W.E.C.M. Detection of β-galactosyl(1→4)N-acetylglucosaminide α(2→3)-sialyltransferase activity in fetal calf liver and other tissues. J. Biol. Chem. 256 (1981) 3159–3162. [PMID: 7204397]
2.  Basu, M., Basu, S., Stoffyn, A. and Stoffyn, P. Biosynthesis in vitro of sialyl(α2-3)neolactotetraosylceramide by a sialyltransferase from embryonic chicken brain. J. Biol. Chem. 257 (1982) 12765–12769. [PMID: 7130178]
[EC 2.4.3.6 created 1984 as EC 2.4.99.6, modified 1986 (EC 2.4.99.10 created 1986, incorporated 2017), transferred 2022 to EC 2.4.3.6]
 
 
EC 3.1.1.26     Relevance: 60%
Accepted name: galactolipase
Reaction: 1,2-diacyl-3-β-D-galactosyl-sn-glycerol + 2 H2O = 3-β-D-galactosyl-sn-glycerol + 2 carboxylates
Other name(s): galactolipid lipase; polygalactolipase; galactolipid acylhydrolase
Systematic name: 1,2-diacyl-3-β-D-galactosyl-sn-glycerol acylhydrolase
Comments: Also acts on 2,3-di-O-acyl-1-O-(6-O-α-D-galactosyl-β-D-galactosyl)-D-glycerol, and phosphatidylcholine and other phospholipids.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 37278-40-3
References:
1.  Helmsing, P.J. Purification and properties of galactolipase. Biochim. Biophys. Acta 178 (1969) 519–533. [DOI] [PMID: 5784904]
2.  Hirayama, O., Matsuda, H., Takeda, H., Maenaka, K. and Takatsuka, H. Purification and properties of a lipid acyl-hydrolase from potato tubers. Biochim. Biophys. Acta 384 (1975) 127–137. [DOI] [PMID: 236765]
[EC 3.1.1.26 created 1972]
 
 
EC 2.4.1.134     Relevance: 59.7%
Accepted name: galactosylxylosylprotein 3-β-galactosyltransferase
Reaction: UDP-α-D-galactose + [protein]-3-O-(β-D-galactosyl-(1→4)-β-D-xylosyl)-L-serine = UDP + [protein]-3-O-(β-D-galactosyl-(1→3)-β-D-galactosyl-(1→4)-β-D-xylosyl)-L-serine
For diagram of heparan and chondroitin biosynthesis (early stages), click here
Other name(s): galactosyltransferase II; uridine diphosphogalactose-galactosylxylose galactosyltransferase; UDP-galactose:4-β-D-galactosyl-O-β-D-xylosylprotein 3-β-D-galactosyltransferase; UDP-α-D-galactose:4-β-D-galactosyl-O-β-D-xylosylprotein 3-β-D-galactosyltransferase
Systematic name: UDP-α-D-galactose:[protein]-3-O-(β-D-galactosyl-(1→4)-β-D-xylosyl)-L-serine (configuration-inverting)
Comments: Involved in the biosynthesis of the linkage region of glycosaminoglycan chains as part of proteoglycan biosynthesis (chondroitin, dermatan and heparan sulfates). Requires Mn2+.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 56626-21-2, 56626-19-8
References:
1.  Robinson, J.A. and Robinson, H.C. Initiation of chondroitin sulphate synthesis by β-D-galactosides. Substrates for galactosyltransferase II. Biochem. J. 227 (1985) 805–814. [PMID: 3924029]
2.  Schwartz, N.B. and Roden, L. Biosynthesis of chondroitin sulfate. Solubilization of chondroitin sulfate glycosyltransferases and partial purification of uridine diphosphate-D-galactose:D-xylose galactosyltransferase. J. Biol. Chem. 250 (1975) 5200–5207. [PMID: 1150655]
3.  Bai, X., Zhou, D., Brown, J.R., Crawford, B.E., Hennet, T. and Esko, J.D. Biosynthesis of the linkage region of glycosaminoglycans: cloning and activity of galactosyltransferase II, the sixth member of the β1,3-galactosyltransferase family (β3GalT6). J. Biol. Chem. 276 (2001) 48189–48195. [DOI] [PMID: 11551958]
[EC 2.4.1.134 created 1984, modified 2002]
 
 
EC 2.4.1.184     Relevance: 59.1%
Accepted name: galactolipid galactosyltransferase
Reaction: 2 a 1,2-diacyl-3-O-(β-D-galactosyl)-sn-glycerol = a 1,2-diacyl-3-O-[β-D-galactosyl-(1→6)-β-D-galactosyl]-sn-glycerol + a 1,2-diacyl-sn-glycerol
For diagram of galactosyl diacylglycerol, click here
Glossary: a 1,2-diacyl-3-O-(β-D-galactosyl)-sn-glycerol = monogalactosyldiacylglycerol
Other name(s): galactolipid-galactolipid galactosyltransferase; galactolipid:galactolipid galactosyltransferase; interlipid galactosyltransferase; GGGT; DGDG synthase (ambiguous); digalactosyldiacylglycerol synthase (ambiguous); 3-(β-D-galactosyl)-1,2-diacyl-sn-glycerol:mono-3-(β-D-galactosyl)-1,2-diacyl-sn-glycerol β-D-galactosyltransferase; 3-(β-D-galactosyl)-1,2-diacyl-sn-glycerol:3-(β-D-galactosyl)-1,2-diacyl-sn-glycerol β-D-galactosyltransferase; SFR2 (gene name)
Systematic name: 1,2-diacyl-3-O-(β-D-galactosyl)-sn-glycerol:1,2-diacyl-3-O-(β-D-galactosyl)-sn-glycerol β-D-galactosyltransferase
Comments: The enzyme converts monogalactosyldiacylglycerol to digalactosyldiacylglycerol, trigalactosyldiacylglycerol and tetragalactosyldiacylglycerol. All residues are connected by β linkages. The activity is localized to chloroplast envelope membranes, but it does not contribute to net galactolipid synthesis in plants, which is performed by EC 2.4.1.46, monogalactosyldiacylglycerol synthase, and EC 2.4.1.241, digalactosyldiacylglycerol synthase. Note that the β,β-digalactosyldiacylglycerol formed by this enzyme is different from the more common α,β-digalactosyldiacylglycerol formed by EC 2.4.1.241. The enzyme provides an important mechanism for the stabilization of the chloroplast membranes during freezing and drought stress.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 66676-74-2
References:
1.  Dorne, A.-J., Block, M.A., Joyard, J. and Douce, R. The galactolipid-galactolipid galactosyltransferase is located on the outer surface of the outer-membrane of the chloroplast envelope. FEBS Lett. 145 (1982) 30–34.
2.  Heemskerk, J.W.M., Wintermans, J.F.G.M., Joyard, J., Block, M.A., Dorne, A.-J. and Douce, R. Localization of galactolipid:galactolipid galactosyltransferase and acyltransferase in outer envelope membrane of spinach chloroplasts. Biochim. Biophys. Acta 877 (1986) 281–289.
3.  Heemskerk, J.W.M., Jacobs, F.H.H. and Wintermans, J.F.G.M. UDPgalactose-independent synthesis of monogalactosyldiacylglycerol. An enzymatic activity of the spinach chloroplast envelope. Biochim. Biophys. Acta 961 (1988) 38–47. [DOI]
4.  Kelly, A.A., Froehlich, J.E. and Dörmann, P. Disruption of the two digalactosyldiacylglycerol synthase genes DGD1 and DGD2 in Arabidopsis reveals the existence of an additional enzyme of galactolipid synthesis. Plant Cell 15 (2003) 2694–2706. [DOI] [PMID: 14600212]
5.  Benning, C. and Ohta, H. Three enzyme systems for galactoglycerolipid biosynthesis are coordinately regulated in plants. J. Biol. Chem. 280 (2005) 2397–2400. [DOI] [PMID: 15590685]
6.  Fourrier, N., Bedard, J., Lopez-Juez, E., Barbrook, A., Bowyer, J., Jarvis, P., Warren, G. and Thorlby, G. A role for SENSITIVE TO FREEZING2 in protecting chloroplasts against freeze-induced damage in Arabidopsis. Plant J. 55 (2008) 734–745. [DOI] [PMID: 18466306]
7.  Moellering, E.R., Muthan, B. and Benning, C. Freezing tolerance in plants requires lipid remodeling at the outer chloroplast membrane. Science 330 (2010) 226–228. [DOI] [PMID: 20798281]
[EC 2.4.1.184 created 1990, modified 2005, modified 2015]
 
 
EC 2.4.1.247     Relevance: 59.1%
Accepted name: β-D-galactosyl-(1→4)-L-rhamnose phosphorylase
Reaction: β-D-galactosyl-(1→4)-L-rhamnose + phosphate = L-rhamnose + α-D-galactose 1-phosphate
Other name(s): D-galactosyl-β1→4-L-rhamnose phosphorylase; GalRhaP
Systematic name: β-D-galactosyl-(1→4)-L-rhamnose:phosphate 1-α-D-galactosyltransferase
Comments: The enzyme from Clostridium phytofermentans is also active towards towards β-D-galactosyl derivatives of L-mannose, L-lyxose, D-glucose, 2-deoxy-D-glucose, and D-galactose in this order. Differs from 1,3-β-galactosyl-N-acetylhexosamine phosphorylase (EC 2.4.1.211) in being active towards L-rhamnose and inactive towards N-acetyl hexosamine derivatives.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 1236189-79-9
References:
1.  Nakajima, M., Nishimoto, M. and Kitaoka, M. Characterization of three β-galactoside phosphorylases from Clostridium phytofermentans: discovery of D-galactosyl-β1→4-L-rhamnose phosphorylase. J. Biol. Chem. 284 (2009) 19220–19227. [DOI] [PMID: 19491100]
[EC 2.4.1.247 created 2009]
 
 
EC 2.4.3.5     Relevance: 58.2%
Accepted name: galactosyldiacylglycerol α-2,3-sialyltransferase
Reaction: CMP-N-acetyl-β-neuraminate + 1,2-diacyl-3-β-D-galactosyl-sn-glycerol = CMP + 1,2-diacyl-3-[3-(N-acetyl-α-D-neuraminyl)-β-D-galactosyl]-sn-glycerol
Systematic name: CMP-N-acetyl-β-neuraminate:1,2-diacyl-3-β-D-galactosyl-sn-glycerol N-acetylneuraminyltransferase
Comments: The β-D-galactosyl residue of the oligosaccharide of glycoproteins may also act as acceptor.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 80237-98-5
References:
1.  Pieringer, J., Keech, S. and Pieringer, R.A. Biosynthesis in vitro of sialosylgalactosyldiacylglycerol by mouse brain microsomes. J. Biol. Chem. 256 (1981) 12306–12309. [PMID: 7298658]
2.  Weinstein, J., de Souza-e-Silva, U. and Paulson, J.C. Purification of a Gal β1→4GlcNAc α2→6 sialyltransferase and a Gal β1→3(4)GlcNAc α2→3 sialyltransferase to homogeneity from rat liver. J. Biol. Chem. 257 (1982) 13835–13844. [PMID: 7142179]
3.  Weinstein, J., de Souza-e-Silva, U. and Paulson, J.C. Sialylation of glycoprotein oligosaccharides N-linked to asparagine. Enzymatic characterization of a Gal β1→3(4)GlcNAc α2→3 sialyltransferase and a Gal β1→4GlcNAc α2→6 sialyltransferase from rat liver. J. Biol. Chem. 257 (1982) 13845–13853. [PMID: 7142180]
[EC 2.4.3.5 created 1984 as EC 2.4.99.5, modified 1986, transferred 2022 to EC 2.4.3.5]
 
 
EC 2.4.99.5      
Transferred entry: galactosyldiacylglycerol α-2,3-sialyltransferase. Now EC 2.4.3.5, galactosyldiacylglycerol α-2,3-sialyltransferase
[EC 2.4.99.5 created 1984, modified 1986, deleted 2022]
 
 
EC 2.4.1.150     Relevance: 57.7%
Accepted name: N-acetyllactosaminide β-1,6-N-acetylglucosaminyltransferase
Reaction: UDP-N-acetyl-α-D-glucosamine + β-D-Gal-(1→4)-β-D-GlcNAc-(1→3)-β-D-Gal-(1→4)-β-D-GlcNAc-R = UDP + β-D-Gal-(1→4)-β-D-GlcNAc-(1→3)-[β-D-GlcNAc-(1→6)]-β-D-Gal-(1→4)-β-D-GlcNAc-R
Glossary: β-D-galactosyl-(1→4)-N-acetyl-D-glucosaminyl-R = type 2 precursor disaccharide
Other name(s): GCNT2 (gene name); GCNT3 (gene name); IGnT; I-branching β1,6-N-acetylglucosaminyltransferase; N-acetylglucosaminyltransferase; uridine diphosphoacetylglucosamine-acetyllactosaminide β1→6-acetylglucosaminyltransferase; Galβ1→4GlcNAc-R β1→6 N-acetylglucosaminyltransferase; UDP-N-acetyl-D-glucosamine:β-D-galactosyl-1,4-N-acetyl-D-glucosaminide β-1,6-N-acetyl-D-glucosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-glucosamine:β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→4)-N-acetyl-β-D-glucosaminide 6-β-N-acetylglucosaminyltransferase (configuration-inverting)
Comments: The enzyme acts on poly-N-acetyllactosamine [glycan chains of β-D-galactosyl-(1→4)-N-acetyl-D-glucosamine units connected by β(1,3) linkages] attached to proteins or lipids. It transfers a GlcNAc residue by β(1,6)-linkage to galactosyl residues close to non-reducing terminals, introducing a branching pattern known as I branching.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 85638-40-0
References:
1.  Van den Eijnden, D.H., Winterwerp, H., Smeeman, P. and Schiphorst, W.E.C.M. Novikoff ascites tumor cells contain N-acetyllactosaminide β1→3 and β1→6 N-acetylglucosaminyltransferase activity. J. Biol. Chem. 258 (1983) 3435–3437. [PMID: 6219989]
2.  Basu, M. and Basu, S. Biosynthesis in vitro of Ii core glycosphingolipids from neolactotetraosylceramide by β 1-3- and β 1-6-N-acetylglucosaminyltransferases from mouse T-lymphoma. J. Biol. Chem. 259 (1984) 12557–12562. [PMID: 6238026]
3.  Piller, F., Cartron, J.P., Maranduba, A., Veyrieres, A., Leroy, Y. and Fournet, B. Biosynthesis of blood group I antigens. Identification of a UDP-GlcNAc:GlcNAc β1-3Gal(-R) β1-6(GlcNAc to Gal) N-acetylglucosaminyltransferase in hog gastric mucosa. J. Biol. Chem. 259 (1984) 13385–13390. [PMID: 6490658]
4.  Bierhuizen, M.F., Maemura, K., Kudo, S. and Fukuda, M. Genomic organization of core 2 and I branching β-1,6-N-acetylglucosaminyltransferases. Implication for evolution of the β-1,6-N-acetylglucosaminyltransferase gene family. Glycobiology 5 (1995) 417–425. [DOI] [PMID: 7579796]
5.  Ujita, M., McAuliffe, J., Suzuki, M., Hindsgaul, O., Clausen, H., Fukuda, M.N. and Fukuda, M. Regulation of I-branched poly-N-acetyllactosamine synthesis. Concerted actions by I-extension enzyme, I-branching enzyme, and β1,4-galactosyltransferase I. J. Biol. Chem. 274 (1999) 9296–9304. [DOI] [PMID: 10092606]
6.  Yeh, J.C., Ong, E. and Fukuda, M. Molecular cloning and expression of a novel β-1,6-N-acetylglucosaminyltransferase that forms core 2, core 4, and I branches. J. Biol. Chem. 274 (1999) 3215–3221. [DOI] [PMID: 9915862]
[EC 2.4.1.150 created 1984 (EC 2.4.1.164 created 1989, incorporated 2016), modified 2017]
 
 
EC 2.4.1.223     Relevance: 57.5%
Accepted name: glucuronosyl-galactosyl-proteoglycan 4-α-N-acetylglucosaminyltransferase
Reaction: UDP-N-acetyl-α-D-glucosamine + [protein]-3-O-(β-D-GlcA-(1→3)-β-D-Gal-(1→3)-β-D-Gal-(1→4)-β-D-Xyl)-L-serine = UDP + [protein]-3-O-(α-D-GlcNAc-(1→4)-β-D-GlcA-(1→3)-β-D-Gal-(1→3)-β-D-Gal-(1→4)-β-D-Xyl)-L-serine
For diagram of heparan biosynthesis (later stages), click here
Glossary: [protein]-3-O-(β-D-GlcA-(1→3)-β-D-Gal-(1→3)-β-D-Gal-(1→4)-β-D-Xyl)-L-serine = [protein]-3-O-(β-D-glucuronosyl-(1→3)-β-D-galactosyl-(1→3)-β-D-galactosyl-(1→4)-β-D-xylosyl)-L-serine
Other name(s): α-N-acetylglucosaminyltransferase I; α1,4-N-acetylglucosaminyltransferase; glucuronosylgalactosyl-proteoglycan 4-α-N-acetylglucosaminyltransferase; UDP-N-acetyl-D-glucosamine:β-D-glucuronosyl-(1→3)-β-D-galactosyl-(1→3)-β-D-galactosyl-(1→4)-β-D-xylosyl-proteoglycan 4IV-α-N-acetyl-D-glucosaminyltransferase; glucuronyl-galactosyl-proteoglycan 4-α-N-acetylglucosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-glucosamine:[protein]-3-O-(β-D-GlcA-(1→3)-β-D-Gal-(1→3)-β-D-Gal-(1→4)-β-D-Xyl)-L-serine 4IV-α-N-acetyl-D-glucosaminyltransferase (configuration-retaining)
Comments: Enzyme involved in the initiation of heparin and heparan sulfate synthesis, transferring GlcNAc to the (GlcA-Gal-Gal-Xyl-)Ser core. Apparently products of both the human EXTL2 and EXTL3 genes can catalyse this reaction. In Caenorhabditis elegans, the product of the rib-2 gene displays this activity as well as that of EC 2.4.1.224, glucuronosyl-N-acetylglucosaminyl-proteoglycan 4-α-N-acetylglucosaminyltransferase. For explanation of the use of a superscript in the systematic name, see 2-Carb-37.2.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 179241-74-8
References:
1.  Kitagawa, H., Shimakawa, H. and Sugahara, K. The tumor suppressor EXT-like gene EXTL2 encodes an α1,4-N-acetylhexosaminyltransferase that transfers N-acetylgalactosamine and N-acetylglucosamine to the common glycosaminoglycan-protein linkage region. The key enzyme for the chain initiation of heparan sulfate. J. Biol. Chem. 274 (1999) 13933–13937. [DOI] [PMID: 10318803]
2.  Kitagawa, H., Egusa, N., Tamura, J.I., Kusche-Gullberg, M., Lindahl, U. and Sugahara, K. rib-2, a Caenorhabditis elegans homolog of the human tumor suppressor EXT genes encodes a novel α1,4-N-acetylglucosaminyltransferase involved in the biosynthetic initiation and elongation of heparan sulfate. J. Biol. Chem. 276 (2001) 4834–4838. [DOI] [PMID: 11121397]
[EC 2.4.1.223 created 2002, modified 2016]
 
 
EC 2.4.1.66     Relevance: 56.2%
Accepted name: procollagen glucosyltransferase
Reaction: UDP-α-D-glucose + [procollagen]-(5R)-5-O-(β-D-galactosyl)-5-hydroxy-L-lysine = UDP + [procollagen]-(5R)-5-O-[α-D-glucosyl-(1→2)-β-D-galactosyl]-5-hydroxy-L-lysine
Other name(s): galactosylhydroxylysine glucosyltransferase; collagen glucosyltransferase; collagen hydroxylysyl glucosyltransferase; galactosylhydroxylysyl glucosyltransferase; UDP-glucose-collagenglucosyltransferase; uridine diphosphoglucose-collagen glucosyltransferase; UDP-glucose:5-(D-galactosyloxy)-L-lysine-procollagen D-glucosyltransferase; UDP-glucose:(2S,5R)-5-O-(β-D-galactosyl)-5-hydroxy-L-lysine-[procollagen] D-glucosyltransferase
Systematic name: UDP-α-D-glucose:[procollagen]-(5R)-5-O-(β-D-galactosyl)-5-hydroxy-L-lysine 2-α-D-glucosyltransferase (configuration-retaining)
Comments: Involved in the synthesis of carbohydrate units in the complement system (cf. EC 2.4.1.50 procollagen galactosyltransferase).
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 9028-08-4
References:
1.  Bosmann, H.B. and Eylar, E.H. Attachment of carbohydrate to collagen. Isolation, purification and properties of the glucosyl transferase. Biochem. Biophys. Res. Commun. 30 (1968) 89–94. [DOI] [PMID: 5637038]
2.  Bosmann, H.B. and Eylar, E.H. Collagen-glucosyl transferase in fibriblasts transformed by oncogenic viruses. Nature 218 (1968) 582–583. [PMID: 4968368]
3.  Butler, W.T. and Cunningham, L.W. Evidence for the linkage of a disaccharide to hydroxylysine in tropocollagen. J. Biol. Chem. 241 (1966) 3882–3888. [PMID: 4288358]
4.  Kivirikko, K.I. and Myllyla, R. In: Hall, D.A. and Jackson, D.S. (Ed.), International Review of Connective Tissue Research, vol. 8, Academic Press, New York, 1979, p. 23.
5.  Sricholpech, M., Perdivara, I., Nagaoka, H., Yokoyama, M., Tomer, K.B. and Yamauchi, M. Lysyl hydroxylase 3 glucosylates galactosylhydroxylysine residues in type I collagen in osteoblast culture. J. Biol. Chem. 286 (2011) 8846–8856. [DOI] [PMID: 21220425]
[EC 2.4.1.66 created 1972]
 
 
EC 2.4.1.146     Relevance: 55.9%
Accepted name: β-1,3-galactosyl-O-glycosyl-glycoprotein β-1,3-N-acetylglucosaminyltransferase
Reaction: UDP-N-acetyl-α-D-glucosamine + 3-O-{β-D-galactosyl-(1→3)-[N-acetyl-β-D-glucosaminyl-(1→6)]-N-acetyl-α-D-galactosaminyl}-L-seryl/threonyl-[protein] = UDP + 3-O-{N-acetyl-β-D-glucosaminyl-(1→3)-β-D-galactosyl-(1→3)-[N-acetyl-β-D-glucosaminyl-(1→6)]-N-acetyl-α-D-galactosaminyl}-L-seryl/threonyl-[protein]
Glossary: core 2 = 3-O-{β-D-galactosyl-(1→3)-[N-acetyl-β-D-glucosaminyl-(1→6)]-N-acetyl-α-D-galactosaminyl}-L-seryl/threonyl-[protein]
Other name(s): O-glycosyl-oligosaccharide-glycoprotein N-acetylglucosaminyltransferase II; uridine diphosphoacetylglucosamine-mucin β(1→3)-acetylglucosaminyltransferase (elongating); elongation 3β-GalNAc-transferase; UDP-N-acetyl-D-glucosamine:O-glycosyl-glycoprotein (N-acetyl-D-glucosamine to β-D-galactose of β-D-galactosyl-1,3-(N-acetyl-D-glucosaminyl-1,6)-N-acetyl-D-galactosaminyl-R) β-1,3-N-acetyl-D-glucosaminyltransferase; UDP-N-acetyl-D-glucosamine:β-D-galactosyl-(1→3)-[N-acetyl-D-glucosaminyl-(1→6)]-N-acetyl-D-galactosaminyl-R 3-β-N-acetyl-D-glucosaminyltransferase; B3GNT3 (gene name)
Systematic name: UDP-N-acetyl-α-D-glucosamine:3-O-{β-D-galactosyl-(1→3)-[N-acetyl-β-D-glucosaminyl-(1→6)]-N-acetyl-α-D-galactosaminyl}-L-seryl/threonyl-[protein] 3-β-N-acetyl-D-glucosaminyltransferase (configuration-inverting)
Comments: The enzyme catalyses the addition of N-acetyl-α-D-glucosamine to the core 2 structure of O-glycans.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 87927-99-9
References:
1.  Brockhausen, I., Rachaman, E.S., Matta, K.L. and Schachter, H. The separation by liquid chromatography (under elevated pressure) of phenyl, benzyl, and O-nitrophenyl glycosides of oligosaccharides. Analysis of substrates and products for four N-acetyl-D-glucosaminyl-transferases involved in mucin synthesis. Carbohydr. Res. 120 (1983) 3–16. [DOI] [PMID: 6226356]
2.  Shiraishi, N., Natsume, A., Togayachi, A., Endo, T., Akashima, T., Yamada, Y., Imai, N., Nakagawa, S., Koizumi, S., Sekine, S., Narimatsu, H. and Sasaki, K. Identification and characterization of three novel β 1,3-N-acetylglucosaminyltransferases structurally related to the β 1,3-galactosyltransferase family. J. Biol. Chem. 276 (2001) 3498–3507. [PMID: 11042166]
[EC 2.4.1.146 created 1984, modified 2018]
 
 
EC 2.4.1.65     Relevance: 55.1%
Accepted name: 3-galactosyl-N-acetylglucosaminide 4-α-L-fucosyltransferase
Reaction: GDP-β-L-fucose + β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminyl-R = GDP + β-D-galactosyl-(1→3)-[α-L-fucosyl-(1→4)]-N-acetyl-β-D-glucosaminyl-R
For diagram of reaction, click here
Other name(s): (Lea)-dependent (α-3/4)-fucosyltransferase; α(1,3/1,4) fucosyltransferase III; α-(1→4)-L-fucosyltransferase; α-4-L-fucosyltransferase; β-acetylglucosaminylsaccharide fucosyltransferase; FucT-II; Lewis α-(1→3/4)-fucosyltransferase; Lewis blood group α-(1→3/4)-fucosyltransferase; Lewis(Le) blood group gene-dependent α-(1→3/4)-L-fucosyltransferase; blood group Lewis α-4-fucosyltransferase; blood-group substance Lea-dependent fucosyltransferase; guanosine diphosphofucose-β-acetylglucosaminylsaccharide 4-α-L-fucosyltransferase; guanosine diphosphofucose-glycoprotein 4-α-L-fucosyltransferase; guanosine diphosphofucose-glycoprotein 4-α-fucosyltransferase; 3-α-galactosyl-N-acetylglucosaminide 4-α-L-fucosyltransferase; GDP-β-L-fucose:3-β-D-galactosyl-N-acetyl-D-glucosaminyl-R 4I-α-L-fucosyltransferase; GDP-L-fucose:3-β-D-galactosyl-N-acetyl-D-glucosaminyl-R 4I-α-L-fucosyltransferase
Systematic name: GDP-β-L-fucose:β-D-galactosyl-(1→3)-N-acetyl-β-D-glucosaminyl-R 4I-α-L-fucosyltransferase (configuration-inverting)
Comments: This enzyme is the product of the Lewis blood group gene. Normally acts on a glycoconjugate where R (see reaction) is a glycoprotein or glycolipid. Although it is a 4-fucosyltransferase, it has a persistent 3-fucosyltransferase activity towards the glucose residue in free lactose. This enzyme fucosylates on O-4 of an N-acetylglucosamine that carries a galactosyl group on O-3, unlike EC 2.4.1.152, 4-galactosyl-N-acetylglucosaminide 3-α-L-fucosyltransferase, which fucosylates on O-3 of an N-acetylglucosamine that carries a galactosyl group on O-4. Enzymes catalysing the 4-α-fucosylation of the GlcNAc in β-D-Gal-(1→3)-β-GlcNAc sequences (with some activity also as 3-α-fucosyltransferases) are present in plants, where the function in vivo is the modification of N-glycans. In addition, the fucTa gene of Helicobacter strain UA948 encodes a fucosyltransferase with both 3-α- and 4-α-fucosyltransferase activities.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 37277-69-3
References:
1.  Prieels, J.-P., Monnom, D., Dolmans, M., Beyer, T.A. and Hill, R.L. Co-purification of the Lewis blood group N-acetylglucosaminide α1→4 fucosyltransferase and an N-acetylglucosaminide α1→3 fucosyltransferase from human milk. J. Biol. Chem. 256 (1981) 10456–10463. [PMID: 7287719]
2.  Rasko, D.A., Wang, G., Palcic, M.M. and Taylor, D.E. Cloning and characterization of the α(1,3/4) fucosyltransferase of Helicobacter pylori. J. Biol. Chem. 275 (2000) 4988–4994. [DOI] [PMID: 10671538]
3.  Wilson, I.B.H. Identification of a cDNA encoding a plant Lewis-type α1,4-fucosyltransferase. Glycoconj. J. 18 (2001) 439–447. [PMID: 12084979]
4.  Ma, B., Wang, G., Palcic, M.M., Hazes, B. and Taylor, D.E. C-terminal amino acids of Helicobacter pylori α1,3/4 fucosyltransferases determine type I and type II transfer. J. Biol. Chem. 278 (2003) 21893–21900. [DOI] [PMID: 12676935]
[EC 2.4.1.65 created 1972, modified 2001, modified twice 2002]
 
 
EC 2.4.1.102     Relevance: 55%
Accepted name: β-1,3-galactosyl-O-glycosyl-glycoprotein β-1,6-N-acetylglucosaminyltransferase
Reaction: UDP-N-acetyl-α-D-glucosamine + O3-[β-D-galactosyl-(1→3)-N-acetyl-α-D-galactosaminyl]-L-seryl/threonyl-[protein] = UDP + O3-{β-D-galactosyl-(1→3)-[N-acetyl-β-D-glucosaminyl-(1→6)]-N-acetyl-α-D-galactosaminyl}-L-seryl/threonyl-[protein]
Glossary: core 1 = O3-[β-D-galactosyl-(1→3)-N-acetyl-α-D-galactosaminyl]-L-seryl/threonyl-[protein]
core 2 = O3-{β-D-galactosyl-(1→3)-[N-acetyl-β-D-glucosaminyl-(1→6)]-N-acetyl-α-D-galactosaminyl}-L-seryl/threonyl-[protein]
Other name(s): O-glycosyl-oligosaccharide-glycoprotein N-acetylglucosaminyltransferase I; β6-N-acetylglucosaminyltransferase; uridine diphosphoacetylglucosamine-mucin β-(1→6)-acetylglucosaminyltransferase; core 2 acetylglucosaminyltransferase; core 6-β-GlcNAc-transferase A; UDP-N-acetyl-D-glucosamine:O-glycosyl-glycoprotein (N-acetyl-D-glucosamine to N-acetyl-D-galactosamine of β-D-galactosyl-1,3-N-acetyl-D-galactosaminyl-R) β-1,6-N-acetyl-D-glucosaminyltransferase; GCNT1; GCNT3; UDP-N-acetyl-D-glucosamine:O-glycosyl-glycoprotein (N-acetyl-D-glucosamine to N-acetyl-D-galactosamine of β-D-galactosyl-(1→3)-N-acetyl-D-galactosaminyl-R) 6-β-N-acetyl-D-glucosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-glucosamine:O3-[β-D-galactosyl-(1→3)-N-acetyl-α-D-galactosaminyl]-glycoprotein 6-β-N-acetyl-D-glucosaminyltransferase (configuration-inverting)
Comments: The enzyme catalyses the addition of N-acetyl-α-D-glucosamine to the core 1 structure of O-glycans forming core 2.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 95978-15-7
References:
1.  Brockhausen, I., Rachaman, E.S., Matta, K.L. and Schachter, H. The separation by liquid chromatography (under elevated pressure) of phenyl, benzyl, and O-nitrophenyl glycosides of oligosaccharides. Analysis of substrates and products for four N-acetyl-D-glucosaminyl-transferases involved in mucin synthesis. Carbohydr. Res. 120 (1983) 3–16. [DOI] [PMID: 6226356]
2.  Williams, D., Longmore, G., Matta, K.L. and Schachter, H. Mucin synthesis. II. Substrate specificity and product identification studies on canine submaxillary gland UDP-GlcNAc:Gal β1-3GalNAc(GlcNAc→GalNAc) β6-N-acetylglucosaminyltransferase. J. Biol. Chem. 255 (1980) 11253–11261. [PMID: 6449508]
3.  Williams, D. and Schachter, H. Mucin synthesis. I. Detection in canine submaxillary glands of an N-acetylglucosaminyltransferase which acts on mucin substrates. J. Biol. Chem. 255 (1980) 11247–11252. [PMID: 6449507]
[EC 2.4.1.102 created 1983, modified 2018]
 
 
EC 3.2.1.46     Relevance: 54.6%
Accepted name: galactosylceramidase
Reaction: a D-galactosyl-N-acylsphingosine + H2O = D-galactose + a ceramide
Glossary: a ceramide = an N-acylsphingosine
Other name(s): cerebroside galactosidase; galactocerebroside.β-galactosidase; galactosylcerebrosidase; galactocerebrosidase; ceramide galactosidase; galactocerebroside galactosidase; galactosylceramide.β-galactosidase; cerebroside β-galactosidase; galactosylceramidase I; β-galactosylceramidase; galactocerebroside-β-D-galactosidase; lactosylceramidase I; β-galactocerebrosidase; lactosylceramidase
Systematic name: D-galactosyl-N-acylsphingosine galactohydrolase
Comments: cf. EC 3.2.1.62 glycosylceramidase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9027-89-8
References:
1.  Brady, R.O., Gal, A.E., Kanfer, J.N. and Bradley, R.M. The metabolism of glucocerebrosides. 3. Purification and properties of a glucosyl- and galactosylceramide-cleaving enzyme from rat intestinal tissue. J. Biol. Chem. 240 (1965) 3766–3770. [PMID: 5320641]
[EC 3.2.1.46 created 1972]
 
 
EC 2.4.1.92     Relevance: 54%
Accepted name: (N-acetylneuraminyl)-galactosylglucosylceramide N-acetylgalactosaminyltransferase
Reaction: UDP-N-acetyl-α-D-galactosamine + O-(N-acetyl-α-neuraminyl)-(2→3)-O-β-D-galactopyranosyl-(1→4)-β-D-glucopyranosyl-(1↔1)-ceramide = UDP + O-2-(acetylamino)-2-deoxy-β-D-galactopyranosyl-(1→4)-O-[N-acetyl-α-neuraminyl-(2→3)]-O-β-D-galactopyranosyl-(1→4)-β-D-glucopyranosyl-(1↔1)-ceramide
For diagram of ganglioside biosynthesis, click here
Glossary: ganglioside GM2 = 1-O-[O-2-(acetylamino)-2-deoxy-β-D-galactopyranosyl-(1→4)-O-[N-acetyl-α-neuraminyl-(2→3)]-O-β-D-galactopyranosyl-(1→4)-β-D-glucopyranosyl]-ceramideganglioside GM3 = 1-O-[O-(N-acetyl-α-neuraminyl)-(2→3)-O-β-D-galactopyranosyl-(1→4)-β-D-glucopyranosyl]-ceramideganglioside GD3 = 1-O-[O-(N-acetyl-α-neuraminyl)-(2→8)-O-(N-acetyl-α-neuraminyl)-(2→3)-O-β-D-galactopyranosyl-(1→4)-β-D-glucopyranosyl]-ceramide ganglioside GD2 = 1-O-[O-(N-acetyl-α-neuraminyl)-(2→8)-O-(N-acetyl-α-neuraminyl)-(2→3)-O-[2-(acetylamino)-2-deoxy-β-D-galactopyranosyl-(1→4)]-O-β-D-galactopyranosyl-(1→4)-β-D-glucopyranosyl]-ceramideganglioside SM3 = 1-O-[4-O-(3-O-sulfo-β-D-galactopyranosyl)-β-D-glucopyranosyl]-ceramideganglioside SM2 = 1-O-[O-2-(acetylamino)-2-deoxy-β-D-galactopyranosyl-(1→4)-O-3-O-sulfo-β-D-galactopyranosyl-(1→4)-β-D-glucopyranosyl]-ceramide
Other name(s): uridine diphosphoacetylgalactosamine-ganglioside GM3 acetylgalactosaminyltransferase; ganglioside GM2 synthase; ganglioside GM3 acetylgalactosaminyltransferase; GM2 synthase; UDP acetylgalactosamine-(N-acetylneuraminyl)-D-galactosyl-D-glucosylceramide acetylgalactosaminyltransferase; UDP-N-acetyl-D-galactosamine:1-O-[O-(N-acetyl-α-neuraminyl)-(2→3)-O-β-D-galactopyranosyl-(1→4)-β-D-glucopyranosyl]-ceramide 1,4-β-N-acetyl-D-galactosaminyltransferase acetylgalactosaminyltransferase; UDP-N-acetylgalactosamine GM3 N-acetylgalactosaminyltransferase; uridine diphosphoacetylgalactosamine-acetylneuraminylgalactosylglucosylceramide acetylgalactosaminyltransferase; uridine diphosphoacetylgalactosamine-hematoside acetylgalactosaminyltransferase; GM2/GD2-synthase; β-1,4N-acetylgalactosaminyltransferase; asialo-GM2 synthase; GalNAc-T; UDP-N-acetyl-D-galactosamine:(N-acetylneuraminyl)-D-galactosyl-D-glucosylceramide N-acetyl-D-galactosaminyltransferase; UDP-N-acetyl-D-galactosamine:1-O-[O-(N-acetyl-α-neuraminyl)-(2→3)-O-β-D-galactopyranosyl-(1→4)-β-D-glucopyranosyl]-ceramide 4-β-N-acetyl-D-galactosaminyltransferase
Systematic name: UDP-N-acetyl-α-D-galactosamine:O-(N-acetyl-α-neuraminyl)-(2→3)-O-β-D-galactopyranosyl-(1→4)-β-D-glucopyranosyl-(1↔1)-ceramide 4-β-N-acetyl-D-galactosaminyltransferase
Comments: This enzyme catalyses the formation of the gangliosides (i.e. sialic-acid-containing glycosphingolipids) GM2, GD2 and SM2 from GM3, GD3 and SM3, respectively. Asialo-GM3 [3] and lactosylceramide [2] are also substrates, but glycoproteins and oligosaccharides are not substrates.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 67338-98-1
References:
1.  Dicesare, J.L. and Dain, J.A. The enzymic synthesis of ganglioside. IV. UDP-N-acetylgalactosamine: (N-acetylneuraminyl)-galactosylglucosyl ceramide N-acetylgalactosaminyltransferase in rat brain. Biochim. Biophys. Acta 231 (1971) 385–393. [DOI] [PMID: 5554906]
2.  Pohlentz, G., Klein, D., Schwarzmann, G., Schmitz, D. and Sandhoff, K. Both GA2, GM2, and GD2 synthases and GM1b, GD1a, and GT1b synthases are single enzymes in Golgi vesicles from rat liver. Proc. Natl. Acad. Sci. USA 85 (1988) 7044–7048. [DOI] [PMID: 3140234]
3.  Kazuya, I.-P., Hidari, J.K., Ichikawa, S., Furukawa, K., Yamasaki, M. and Hirabayashi, Y. β1-4N-Acetylgalactosaminyltransferase can synthesize both asialoglycosphingolipid GM2 and glycosphingolipid GM2 in vitro and in vivo: isolation and characterization of a β1-4N-acetylgalactosaminyltransferase cDNA clone from rat ascites hepatoma cell line AH7974F. Biochem. J. 303 (1994) 957–965. [PMID: 7980468]
4.  Hashimoto, Y., Sekine, M., Iwasaki, K. and Suzuki, A. Purification and characterization of UDP-N-acetylgalactosamine GM3/GD3 N-acetylgalactosaminyltransferase from mouse liver. J. Biol. Chem. 268 (1993) 25857–25864. [PMID: 8245020]
5.  Nagai, K. and Ishizuka, I. Biosynthesis of monosulfogangliotriaosylceramide and GM2 by N-acetylgalactosaminyltransferase from rat brain. J. Biochem. (Tokyo) 101 (1987) 1115–1127. [PMID: 3115968]
6.  Furukawa, K., Takamiya, K. and Furukawa, K. β1,4-N-Acetylgalactosaminyltransferase—GM2/GD2 synthase: a key enzyme to control the synthesis of brain-enriched complex gangliosides. Biochim. Biophys. Acta 1573 (2002) 356–362. [DOI] [PMID: 12417418]
7.  Yamashita, T., Wu, Y.P., Sandhoff, R., Werth, N., Mizukami, H., Ellis, J.M., Dupree, J.L., Geyer, R., Sandhoff, K. and Proia, R.L. Interruption of ganglioside synthesis produces central nervous system degeneration and altered axon-glial interactions. Proc. Natl. Acad. Sci. USA 102 (2005) 2725–2730. [DOI] [PMID: 15710896]
[EC 2.4.1.92 created 1976, modified 2006]
 
 
EC 2.4.1.45      
Deleted entry: 2-hydroxyacylsphingosine 1-β-galactosyltransferase, now included with EC 2.4.1.47, N-acylsphingosine galactosyltransferase
[EC 2.4.1.45 created 1972, deleted 2016]
 
 
EC 2.4.3.4     Relevance: 52.6%
Accepted name: β-galactoside α-2,3-sialyltransferase
Reaction: CMP-N-acetylneuraminate + β-D-galactosyl-(1→3)-N-acetyl-α-D-galactosaminyl-R = CMP + α-N-acetylneuraminyl-(2→3)-β-D-galactosyl-(1→3)-N-acetyl-α-D-galactosaminyl-R
Other name(s): CMP-N-acetylneuraminate:β-D-galactoside α-2,3-N-acetylneuraminyl-transferase
Systematic name: CMP-N-acetylneuraminate:β-D-galactoside α-(2→3)-N-acetylneuraminyl-transferase
Comments: The acceptor is Galβ1,3GalNAc-R, where R is H, a threonine or serine residue in a glycoprotein, or a glycolipid. Lactose can also act as acceptor. May be identical with EC 2.4.3.2 β-D-galactosyl-(1→3)-N-acetyl-β-D-galactosaminide α-2,3-sialyltransferase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 71124-51-1
References:
1.  Rearick, J.I., Sadler, J.E., Paulson, J.C. and Hill, R.L. Enzymatic characterization of β D-galactoside α2→3 sialyltransferase from porcine submaxillary gland. J. Biol. Chem. 254 (1979) 4444–4451. [PMID: 438198]
2.  Sadler, J.E., Rearick, J.I., Paulson, J.C. and Hill, R.L. Purification to homogeneity of a β-galactoside α2→3 sialyltransferase and partial purification of an α-N-acetylgalactosaminide α2→6 sialyltransferase from porcine submaxillary glands. J. Biol. Chem. 254 (1979) 4434–4442. [PMID: 438196]
[EC 2.4.3.4 created 1984 as EC 2.4.99.4, modified 1986, transferred 2022 to EC 2.4.3.4]
 
 


Data © 2001–2022 IUBMB
Web site © 2005–2022 Andrew McDonald