The c-series gangliosides GT3, GT2 and GP1c are formed in rat liver Golgi by the same set of glycosyltransferases that catalyse the biosynthesis of asialo-, a- and b-series gangliosides.
Biosynthesis of the c-series gangliosides GT3, GT2 and GP1c was studied in Golgi derived from rat liver. Competition experiments show that the synthesis of ganglioside GT2 (GalNAc beta 1----4-(NeuAc alpha 2----8NeuAc alpha 2----8NeuAc alpha 2----3)Gal- beta 1----4Glc beta 1----1Cer) from GT3 (NeuAc alpha 2----8NeuAc alpha 2----8-NeuAc alpha 2----3Gal beta 1----4Glc beta 1----1Cer) seems to be catalysed by the same N-acetylgalactosaminyl-transferase (GalNAc-T), which converts GM3 (NeuAc alpha 2----3Gal beta 1----4Glc beta 1----1Cer) to GM2 (GalNAc beta 1----4(NeuAc alpha 2----3)Gal beta 1----4Glc beta 1----1Cer). Similar competition experiments suggest moreover that the sialytransferase V (SAT V), which catalyses the synthesis of GT1a (NeuAc alpha 2----8NeuAc alpha 2----3Gal beta 1----3GalNAc beta 1----4- (NeuAc alpha 2----3)-Gal beta 1----4Glc beta 1----1Cer) from GD1a (NeuAc alpha-2----3Gal beta 1----3GalNAc beta 1----4(NeuAc alpha 2----3)Gal beta 1----4Glc beta 1----1-Cer) appears to be identical to the enzyme that catalyses the synthesis of GP1c (NeuAc alpha 2----8NeuAc alpha 2----3Gal beta 1----3-GalNAc beta 1----4(NeuAc alpha 2----8-NeuAc alpha 2----8NeuAc alpha 2----3)Gal beta-1----4Glc beta 1----4Glc beta 1----1Cer) from GQ1c (NeuAc alpha 2----3Gal beta 1----3Gal-NAc beta 1----4 (NeuAc alpha 2----8NeuAc alpha 2----8NeuAc alpha 2----3)Gal beta 1----4-Glc beta 1----1Cer).(ABSTRACT TRUNCATED AT 250 WORDS)
Iber
H
H
Institut für Organische Chemie und Biochemie, Universität Bonn, FRG.
Zacharias
C
C
Sandhoff
K
K
D000818:Animals; D001667:Binding, Competitive; D002384:Catalysis; D005732:Gangliosides / Q000096:biosynthesis*; D006028:Glycosphingolipids / Q000096:biosynthesis*; D016695:Glycosyltransferases / Q000037:antagonists & inhibitors / Q000737:chemistry*; D006056:Golgi Apparatus / Q000201:enzymology*; D008099:Liver / Q000201:enzymology*; D051381:Rats; D012799:Sialyltransferases / Q000037:antagonists & inhibitors / Q000737:chemistry; D013379:Substrate Specificity; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase
D005732:Gangliosides; D006028:Glycosphingolipids; D016695:Glycosyltransferases; D012799:Sialyltransferases; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase