Ganglioside

Ganglioside is a compound composed of a glycosphingolipid (ceramide and oligosaccharide) with one or more sialic acids (AKA n-acetylneuraminic acid) linked on the sugar chain. The 40+ known gangliosides differ mainly in the position and number of NANA residues.

It is a component of the cell plasma membrane which modulates cell signal transduction events. It appears they concentrate in lipid rafts

They have recently been found to be highly important in immunology. Natural and semisynthetic gangliosides are considered possible therapeutics for neurodegenerative disorders.

Haemagglutinin of Influenza virus exploits certain gangliosides to enter and infect the cells expressing them

Common gangliosides

 * GD1a
 * GD1b
 * GD2
 * GD3
 * GM1
 * GM2
 * GM3
 * GT1b

structures of the common gangliosides:

GM2-1 =  aNeu5Ac(2-3)bDGalp(1-?)bDGalNAc(1-?)bDGalNAc(1-?)bDGlcp(1-1)Cer

GM3 =  aNeu5Ac(2-3)bDGalp(1-4)bDGlcp(1-1)Cer

GM2,GM2a(?) =  bDGalpNAc(1-4)[aNeu5Ac(2-3)]bDGalp(1-4)bDGlcp(1-1)Cer

GM2b(?) =  aNeu5Ac(2-8)aNeu5Ac(2-3)bDGalp(1-4)bDGlcp(1-1)Cer

GM1,GM1a =  bDGalp(1-3)bDGalNAc[aNeu5Ac(2-3)]bDGalp(1-4)bDGlcp(1-1)Cer

asialo-GM1,GA1 =  bDGalp(1-3)bDGalpNAc(1-4)bDGalp(1-4)bDGlcp(1-1)Cer

asialo-GM2,GA2 =  bDGalpNAc(1-4)bDGalp(1-4)bDGlcp(1-1)Cer GM1b =  aNeu5Ac(2-3)bDGalp(1-3)bDGalNAc(1-4)bDGalp(1-4)bDGlcp(1-1)Cer

GD3 =  aNeu5Ac(2-8)aNeu5Ac(2-3)bDGalp(1-4)bDGlcp(1-1)Cer

GD2 =  bDGalpNAc(1-4)[aNeu5Ac(2-8)aNeu5Ac(2-3)]bDGalp(1-4)bDGlcp(1-1)Cer

GD1a =  aNeu5Ac(2-3)bDGalp(1-3)bDGalNAc(1-4)[aNeu5Ac(2-3)]bDGalp(1-4)bDGlcp(1-1)Cer

GD1alpha =  aNeu5Ac(2-3)bDGalp(1-3)bDGalNAc(1-4)[aNeu5Ac(2-6)]bDGalp(1-4)bDGlcp(1-1)Cer

GD1b =  bDGalp(1-3)bDGalNAc(1-4)[aNeu5Ac(2-8)aNeu5Ac(2-3)]bDGalp(1-4)bDGlcp(1-1)Cer

GT1a =  aNeu5Ac(2-8)aNeu5Ac(2-3)bDGalp(1-3)bDGalNAc(1-4)[aNeu5Ac(2-3)]bDGalp(1-4)bDGlcp(1-1)Cer

GT1,GT1b =  aNeu5Ac(2-3)bDGalp(1-3)bDGalNAc(1-4)[aNeu5Ac(2-8)aNeu5Ac(2-3)]bDGalp(1-4)bDGlcp(1-1)Cer

OAc-GT1b =  aNeu5Ac(2-3)bDGalp(1-3)bDGalNAc(1-4)aXNeu5Ac9Ac(2-8)aNeu5Ac(2-3)]bDGalp(1-4)bDGlcp(1-1)Cer

GT1c =  bDGalp(1-3)bDGalNAc(1-4)[aNeu5Ac(2-8)aNeu5Ac(2-8)aNeu5Ac(2-3)]bDGalp(1-4)bDGlcp(1-1)Cer

GT3 =  aNeu5Ac(2-8)aNeu5Ac(2-8)aNeu5Ac(2-3)bDGal(1-4)bDGlc(1-1)Cer

GQ1b =  aNeu5Ac(2-8)aNeu5Ac(2-3)bDGalp(1-3)bDGalNAc(1-4)[aNeu5Ac(2-8)aNeu5Ac(2-3)]bDGalp(1-4)bDGlcp(1-1)Cer

GGal =  aNeu5Ac(2-3)bDGalp(1-1)Cer

where

aNeu5Ac = 5-acetyl-alpha-neuraminic acid

aNeu5Ac9Ac = 5,9-diacetyl-alpha-neuraminic acid

bDGalp = beta-D-galactopyranose

bDGalpNAc = N-acetyl-beta-D-galactopyranose

bDGlcp = beta-D-glucopyranose

Cer = ceramide (general N-acylated sphingoid)