PURITY OF GLYCOSAMINOGLYCAN-RELATED COMPOUNDS USING CAPILLARY ELECTROPHORESIS

High performance capillary electrophoresis was used to determine impur ities in glycosaminoglycans. The counterion of glycosaminoglycans was analyzed with indirect UV-detection using a 40 mM 4-aminopyridine buff er. Calcium, lithium, potassium and sodium could be resolved. A linear correlation between the area under the curve and the concentration of sodium (r(2) = 0.98) and calcium (r(2) = 0.99) was found. Using enzym atic depolymerization, chondroitin sulfates were cleaved to disacchari des. The resulting disaccharides, with the structure 4-deoxy-alpha-L-t hreo-hex-4-enopyranosyl uronic acid (Delta UA) 2 X (1 --> 3)-D-GalNY6X (X = H, sulfate and Y = acetyl, sulfate) for dermatan sulfate, were d etected selectively at 230 nm using capillary electrophoresis. Dermata n sulfate disaccharides were analyzed using a 50 cm long fused silica capillary (75 mu m ID). The buffer used was 10 mM sodium tetraborate a nd 50 mM SDS, pH 8.8. The detection was at 230 nm. Using the main peak Delta UA (1 --> 3)-D-GalNAc4S as standard, between 1 and 80% dermatan sulfate in heparin preparations were analyzed. The disaccharide showe d a linear correlation of the peak area versus the concentration with a correlation coefficient r(2) = 0.98. The methods are useful in chara cterizing the identity and concentration of the counterion of glycosam inoglycans after chondroitinase degradation.