Lactosylceramide 4-alpha-galactosyltransferase

lactosylceramide 4-alpha-galactosyltransferase
Identifiers
EC no.	2.4.1.228
CAS no.	52725-57-2
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Gene Ontology	AmiGO / QuickGO
Search PMC articles PubMed articles NCBI proteins

In enzymology, a lactosylceramide 4-alpha-galactosyltransferase (EC 2.4.1.228) is an enzyme that catalyzes the chemical reaction

UDP-galactose + beta-D-galactosyl-(1->4)-D-glucosylceramide ${\displaystyle \rightleftharpoons }$ UDP + alpha-D-galactosyl-(1->4)-beta-D-galactosyl-(1->4)-D- glucosylceramide

Thus, the two substrates of this enzyme are UDP-galactose and [[beta-D-galactosyl-(1->4)-D-glucosylceramide]], whereas its 3 products are UDP, [[alpha-D-galactosyl-(1->4)-beta-D-galactosyl-(1->4)-D-]], and glucosylceramide.

This enzyme belongs to the family of glycosyltransferases, specifically the hexosyltransferases. The systematic name of this enzyme class is UDP-galactose:lactosylceramide 4II-alpha-D-galactosyltransferase. Other names in common use include Galbeta1-4Glcbeta1-Cer alpha1,4-galactosyltransferase, globotriaosylceramide/CD77 synthase, and histo-blood group Pk UDP-galactose. This enzyme participates in glycosphingolipid biosynthesis - globoseries and glycan structures - biosynthesis 2.

References

• Bailly P, Piller F, Cartron JP, Leroy Y, Fournet B (1986). "Identification of UDP-galactose: lactose (lactosylceramide) alpha-4 and beta-3 galactosyltransferases in human kidney". Biochem. Biophys. Res. Commun. 141 (1): 84–91. doi:10.1016/S0006-291X(86)80338-2. PMID 3099784.
• Nilsson Sojka B, Bennett EP, Jersild C, Clausen H (2000). "Cloning and expression of the histo-blood group Pk UDP-galactose: Ga1beta-4G1cbeta1-cer alpha1, 4-galactosyltransferase. Molecular genetic basis of the p phenotype". J. Biol. Chem. 275 (22): 16723–9. doi:10.1074/jbc.M000728200. PMID 10747952.
• Suzuki Y, Urano T, Ohta M, Furukawa K (2000). "Molecular cloning of globotriaosylceramide/CD77 synthase, a glycosyltransferase that initiates the synthesis of globo series glycosphingolipids". J. Biol. Chem. 275 (20): 15152–6. doi:10.1074/jbc.M909620199. PMID 10748143.