Glycosylation and oligosaccharide

Egusa, K, Fukase, K, Nakai, Y, Kusumoto, S, Stereoselective glycosylation and oligosaccharide synthesis on solid support using a 4-azido-3-chlorobenzyl group for temporary protection, Synlett, 27-32, 2000. 

Glycosylation and oligosaccharide processing play an indispensable role in the sorting/ targeting/transport of proteins to their proper cellular locations and functions. Cell surface... 

There are two established methods in use for citing locants either in parentheses between the glycosyl and glycose terms, or in front of the glycosyl prefix, as in the names of glycosides. The former (preferred) method is derived from that used to designate residues in oligosaccharides (see 2-Carb-37 and -38). 

Lysosomal enzymes are glycosylated and modified in a characteristic way. Most importantly, when they arrive in the Golgi apparatus, specific mannose residues in their oligosaccharide chains are phosphorylated. This phosphorylation is the critical event that removes them Corn the secretion pathway and directs them to lysosomes. Genetic defects affecting this phosphorylation produce I-ceU disease in which lysosomal enzymes are released into the ejctracellular space, and inclusion bodies accumulate in the cell, compromising its function. 

These proteins are glycosylated and then the oligosaccharides are modified, including addition of Man-6-P, as they pass through the Golgi apparatus. 

Various techniques have been utilized for sequencing the glycosyl residues of polysaccharides and oligosaccharides. These techniques are elaborations of the commonplace procedure of converting polysaccharides, by partial hydrolysis, into structurally analyzable oligosaccharides. This conversion is generally achieved by partial hydrolysis with acid, by acetolysis,131 or by formolysis.62 These reagents may differ in the... 

The facile and highly versatile approach, combining the selective glycosyl donors, such as 11—13, 26, 27, and 34—36, with the suitably protected mono- and oligosaccharides as glycosyl acceptors, has been extensively applied to the synthesis of numerous gangliosides,... 

---