Chromatography of glycosaminoglycans on hydrophobic gel. Correlation between chromatographic behavior of glycosaminoglycans on Phenyl-Sepharose CL-4B and their solubility in the presence of high concentrations of ammonium sulfate.
The effect of bound sulfate groups and uronic acid residues of glycosaminoglycans on their behavior in chromatography on hydrophobic gel was examined by the use of several pairs of depolymerized chondroitin, chondroitin 4- or 6-sulfate, and dermatan sulfate having comparable degree of polymerization. Chromatography on Phenyl-Sepharose CL-4B in 4.0-2.0 M ammonium sulfate containing 10mM hydrochloric acid showed that: The retention of depolymerized chondroitin 4- or 6-sulfate on the gel varies with the temperature, whereas the depolymerized samples of chondroitin and dermatan sulfate does not show a temperature dependence (this is not the case for hyaluronic acid or dextrans). Among depolymerized samples of chondroitin and chondroitin 4- and 6-sulfate that have a similar degree of polymerization, chondroitin 4- and 6-sulfate showed the highest retention. The retention on the gel of chondroitin 6-sulfate, chondroitin 4-sulfate, and dermatan sulfate decreased in this order. The solubility in ammonium sulfate solution of the polysaccharides agreed well with the chromatographic behavior, suggesting that the fractionation by the hydrophobic gel largely depends on the ability to precipitate on the gel rather than on the hydrophobic interaction between gel and polysaccharide.