gangliosides

Lipids > sphingolipids > glycosphingolipids > gangliosides

Definition: Gangliosides are glycosylated sphingolipids enriched in membranes of the nervous system. They are mainly found in the outer leaflet of mammalian plasma membranes.

The major groups of gangliosides found in mammalian brains are GM1, GD1a, GT1b and GD1b.

Sphingolipids

There are three main types of sphingolipids: ceramides, sphingomyelins, and glycosphingolipids, which differ in the substituents on their head group.

Glycosphingolipids are ceramides with one or more sugar residues joined in a β-glycosidic linkage at the 1-hydroxyl position. Glycosphingolipids may be further subdivided into cerebrosides and gangliosides.

Cerebrosides have a single glucose or galactose at the 1-hydroxy position, while gangliosides have at least three sugars, one of which must be sialic acid.

Pathology

 Alzheimer disease

In AD patients, elevated GM1 and increased sialidase activity have been observed. Further studies pointed out that in AD brain tissue the total ganglioside pattern is significantly altered, which emphasizes the importance of glycosphingolipids in AD.

Micropathological analysis of amyloid plaques has revealed that GM1, like cholesterol, binds to Aβ and it was suggested that the GM1/Aβ complex might initiate amyloid fibril formation.

See also

 glycolipids

• glycosphingolipids ( amino alcohol sphingosine )
  • cerebrosides
  • gangliosides
  • globosides