Figure 4
From: Tumour-associated carbohydrate antigens in breast cancer
Biosynthesis of gangliosides. The action of ST3Gal V (GM3 synthase), ST8Sia I (GD3 synthase) and ST8Sia V (GT3 synthase) leads to the biosynthesis of the precursor of a-series, b-series and c-series gangliosides, respectively. The o-series gangliosides are directly synthesized from lactosylceramide (LacCer). Elongation of complex gangliosides is performed by the sequential action of N-acetyl-galactosaminyltransferase (β4-GalNAc T1), galactosyltransferase (β3-GalT4) and sialyltransferases (ST3Gal I, ST3Gal II and ST8Sia V).