Ganglioside

NeuNAc, an acetylated derivative of the carbohydrate sialic acid, makes the head groups of gangliosides anionic at pH 7, which distinguishes them from globosides.

The name ganglioside was first applied by the German scientist Ernst Klenk in 1942 to lipids newly isolated from ganglion cells of the brain.

They are degraded to ceramides by sequential removal of sugar units in the oligosaccharide group, catalyzed by a set of highly specific lysosomal enzymes.

Mutations in genes coding for these enzymes leads to the accumulation of partially broken down gangliosides in lysosomes, which results in a group of diseases called gangliosidosis.

For example, the fatal Tay–Sachs disease arises as a genetic defect which leads to no functional hexosaminidase A produced, causing GM2 to accumulate in lysosomes.