Glycosyl-linkage composition analysis

Uronosyl residues of the polysaccharides offer the same problems for glycosyl linkage analysis as they do for glycosyl composition analysis. Before the linkages to the uronosyl residues can be ascertained, the uronosyl residues must be reduced by the carbodiimide method (124) to their corresponding deuterium-labeled alditols. 

The partially methylated alditol acetate glycosyl-linkage analysis method is summarized in Fig. 3. 

6-tri-o-methyl-j -4-linked galactosyl residue a permethylated glycosyl residue 

6-tri-o-methyl 1,4,5-tri-o-acetyl-1 -deutero dulcitol a deuterium labeled partially methylated alditol acetate 

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Mass spectrometric analysis of glycoproteins has three objectives identify the protein substrate, determine the site of glycosylation, and characterize the structure (i.e composition, sequence, and linkage) of the glycans. 

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