Polysaccharide asparagine-linked

Figure 1.35 The complex structure of an asparagine-linked polysaccharide. Note the branched nature of polymer with terminal sialic acid residues on each chain. 

Swainsonine (1) is of great biochemical interest since it is a potent and specific inhibitor of both lysosomal a-mannosidase and mannosidase II, which are involved in the cellular degradation of polysaccharides and in the processing of asparagine-linked glycoproteins, respectively [1]. 

Figure 4. Structures of the carbohydrate chains linked to protein in Saccharo-myces cerevisiae X2180 mannoprotein. Four types of mannose units are linked to serine (Ser) and threonine (Thr whereas a more complex polysaccharide chain is attached to asparagine (Asn). All anomeric linkages are a, except for the trisaccharide unit l3Man-> fiGNAc- ffGNAc- by which the polysaccharide is linked to asparagine.

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