Glycosphingolipids ceramide

Sphingoglycolipid Glycosphingolipid Ceramide Sphingosine Dihydrosphingosine Phytoshingosine Sialic acid Glycosylation Sialylation DSLe Cerebroside Plakoside... 

The glycosphingolipids (GSLs) are sugar-containing lipids built on a backbone of ceramide they include galactosyl- and glucosylceramide (cerebrosides) and the gangliosides. Their structures are described in Chapter 14. They are mainly located in the plasma membranes of cells. 

Figure 52-6. Diagrammatic representation of the structures of the H, A,and B blood group substances. R represents a long complex oligosaccharide chain, joined either to ceramide where the substances are glycosphingolipids, or to the polypeptide backbone of a protein via a serine or threonine residue where the substances are glycoproteins. Note that the blood group substances are biantenna ry ie, they have two arms, formed at a branch point (not indicated) between the GIcNAc—R, and only one arm of the branch is shown. Thus, the H, A,and B substances each contain two of their respective short oligosaccharide chains shown above. The AB substance contains one type A chain and one type B chain.

Lavie, Y., Cao, H-t., Volner, A., Lucci, A., Han, T. Y., Geffen, V., Giuhano, A. E., and Cabot, M. C., 1997, Agents that reverse multidrug resistance, tamoxifen, verapamil, and cyclosporin A, block glycosphingolipid metabohsm by inhibiting ceramide glycosylation in human cancer cells. J. Biol. Chem. 272 1682-1687. 

Gangliosides are a class of glycosphingolipid characterized by the presence of one or more sialic acid residues. They are located in the cell membranes, particularly in the plasma membrane, of almost all cell types. They are anchored in the membranes through their ceramide moiety and have the polar sugar-containing group in the extracytoplasmic side. They are particularly abundant in the nervous system where their expression pattern is modulated during development. 

Glycolipids (5,14) are primarily glycosphingolipids, molecules that have oligosaccharide groups attached to ceramide [104404-17-3]. They are present, at least in small amounts, in the membranes of most, if not all, tissues. They too, like cell-membrane glycoproteins, are recognition determinants. 

The glycosphingolipids differ from sphingomyelin in that they do nflt contain phosphate, and the polar head function is provided by a monosaccharide or oligosaccharide attached directly to the ceramide by... 

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