Family Glycolipids

FIGURE 4. Proposed biosynthetic steps for sialyl-Le glycolipid. 

FIGURE 5. A proposed model for CARS and HY-CARS glycosyltransferases (GLTs). STD, short terminal domain TMD, transmembrane domain PCD, protease cleavable domain, CRD, carbohydrate moiety recognition domain. 

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Bacteria also contain a very rich variety of glycolipids with unusual structures. Lipid A13 is the site of attachement of the 0-specific chain of Gram (-) bacteria, which constitutes the antigenic lipopolysaccharide [87]. Other members of this family can be quoted, for example glycosyl glycerophospholipids in which the carbohydrate and glycerol moieties are linked by a phosphodiester bond (e.g. GPI anchor 14) [88] or carbohydrate esters (e.g. cord-factor of mycobacteria 15). 

N-Acetylneuraminic acid N-Acetylneuraminic acid (NANA) is a member of the family of sialic acids, each of which is acylated at a different site. These compounds are usually found as terminal carbohydrate residues of oligosaccharide side chains of glycoproteins, glycolipids, or, less frequently, of glycosaminoglycans. The]... 

Sialic acids are a family of 3-deoxy-2-ulosonic acids found most frequently as a-glycosidically linked terminal residues of glycoproteins and glycolipids. The most abundant sialic acid is N-acetylneuraminic acid (5-acetamido-3,5-di-deoxy-D-glycero-D-galacto-nonu osonic acid, NeuSAc, 1), which was first isolated in the 1930s. To date, 36 sialic acids have been isolated, many of which are 0-acetylated derivatives of N-acylated neuraminic acid [1]. 

Unique glycolipids produced by plants are the resin glycosides for which the first synthesis was based on the trichloroacetimidate method [293,294]. Other members of this family have been... 

Glycosylphosphatidylinositol (GPI) membrane anchors constitute a class of glycolipids that covalently link certain proteins to cell and virion surfaces [122,123]. A boost in their chemistry occurred in 1988 when Ferguson et al. reported the first covalent structure of a member of this family [124,125]. The first synthesis of a fully phosphorylated GPI, compound 246 (O Fig. 5), was accomplished by Fraser-Reid s group based entirely on NPG chemistry [126,127,128,129,130]. 

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