(N-acetylneuraminyl)-galactosylglucosylceramide N-acetylgalactosaminyltransferase (EC2.4.1.92, 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-alpha-neuraminyl)-(2->3)-O-beta-D-galactopyranosyl-(1->4)-beta-D-glucopyranosyl]-ceramide 1,4-beta-N-acetyl-D-galactosaminyltransferase acetylgalactosaminyltransferase, UDP-N-acetylgalactosamine GM3 N-acetylgalactosaminyltransferase, uridine diphosphoacetylgalactosamine-acetylneuraminylgalactosylglucosylceramide acetylgalactosaminyltransferase, uridine diphosphoacetylgalactosamine-hematoside acetylgalactosaminyltransferase, GM2/GD2-synthase, beta-1,4N-aetylgalactosaminyltransferase, asialo-GM2 synthase, GalNAc-T, UDP-N-acetyl-D-galactosamine:(N-acetylneuraminyl)-D-galactosyl-D-glucosylceramide N-acetyl-D-galactosaminyltransferase) is an enzyme with systematic nameUDP-N-acetyl-D-galactosamine:1-O-(O-(N-acetyl-alpha-neuraminyl)-(2->3)-O-beta-D-galactopyranosyl-(1->4)-beta-D-glucopyranosyl)-ceramide 4-beta-N-acetyl-D-galactosaminyltransferase.[1][2][3][4][5][6][7] This enzyme catalyses the following chemical reaction:
UDP-N-acetyl-D-galactosamine + 1-O-[O-(N-acetyl-alpha-neuraminyl)-(2->3)-O-beta-D-galactopyranosyl-(1->4)-beta-D-glucopyranosyl]-ceramide UDP + 1-O-[O-2-(acetylamino)-2-deoxy-beta-D-galactopyranosyl-(1->4)-O-[N-acetyl-alpha-neuraminyl-(2->3)]-O-beta-D-galactopyranosyl-(1->4)-beta-D-glucopyranosyl]-ceramide
This enzyme catalyses the formation of the gangliosides (i.e. sialic-acid-containing glycosphingolipids) GM2, GD2 and SM2 from GM3, GD3 and SM3, respectively.
References
↑Dicesare JL, Dain JA (March 1971). "The enzymic synthesis of ganglioside. IV. UDP-N-acetylgalactosamine: (N-acetylneuraminyl)-galactosylglucosyl ceramide N-acetylgalactosaminyltransferase in rat brain". Biochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism. 231 (2): 385–93. doi:10.1016/0005-2760(71)90151-2. PMID5554906.
↑Nagai K, Ishizuka I (May 1987). "Biosynthesis of monosulfogangliotriaosylceramide and GM2 by N-acetylgalactosaminyltransferase from rat brain". Journal of Biochemistry. 101 (5): 1115–27. doi:10.1093/oxfordjournals.jbchem.a121976. PMID3115968.
↑Furukawa K, Takamiya K, Furukawa K (December 2002). "Beta1,4-N-acetylgalactosaminyltransferase--GM2/GD2 synthase: a key enzyme to control the synthesis of brain-enriched complex gangliosides". Biochimica et Biophysica Acta (BBA) - General Subjects. 1573 (3): 356–62. doi:10.1016/s0304-4165(02)00403-8. PMID12417418.