Selective Cleavage of Heparin and Heparan Sulfate

Selective Cleavage of Heparin and Heparan Sulfate 

Although the glycosidic bonds of uronic acid residues are usually more resistant to acid hydrolysis than those of neutral polysaccharides,218 these linkages in heparin are more readily cleavable then those between the hexosamine and the uronic acid residues. Disaccharides obtained by exhaustive hydrolysis of heparin with 0.5 MHC1 at 80° contained hexu- 

Alkali-catalyzed cleavage of glycosidic bonds of glycosaminoglycur-onates occurs by way of -elimination.223 By proper choice of the experimental conditions, it seems possible to achieve a controlled degradation of heparin by -elimination, producing fragments apparently preserving 

The scope of the deamination reaction was extended to the characterization of heparin segments containing 2-acetamido-2-deoxy-D-glucosyl residues by removing (by hydrazinolysis) the N-acetyl groups and cleaving with nitrous acid (at pH 4) the otherwise resistant segments.113,232 

Major Fragments from Exhaustive Depolymerization of Heparin with Nitrous Acid (A) and Heparinase (B) 

Substantial quantities of (supposedly N-desulfated) oligosaccharide fragments were obtained by partial hydrolysis of heparin °43s cid. 

Sulfoamino groups (and, probably, some of the sulfuric ester groups) may be restored in this kind of oligosaccharide by treatment with pyridine -SOs or other sulfating agent (see Section IX). 

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VIII. Selective Cleavage of Heparin and Heparan Sulfate. 84... 

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