Study of sulfated glycosaminoglycans from porcine skeletal muscle epimysium including analysis of iduronosyl and glucuronosyl residues in galactosaminoglycan fractions

A sulfated glycosaminoglycan fraction was isolated from porcine longissimus dorsi epimysium. It contained galactosaminoglycans with high iduronic acid content (78% of total uronic acid). Galactosaminoglycans were fractionated by precipitation with different concentrations (18, 25, 40, 50, and 75%) of ethanol to obtain five fractions (I-V). Fractions I-III, which accounted for 91% of total uronic acid recovered, were dermatan sulfates with varying proportions of iduronic acid (42-87% of total uronic acid). Fractions IV and V were galactosaminoglycans with high glucuronic acid contents. These results were supported by those from ELISA and immunohistochemical studies. Digestion with chondroitinase B or chondroitinase AC II showed that at least 70% of the epimysial galactosaminoglycans are copolymeric chains containing both iduronosyl and glucuronosyl residues. The composition of the remaining galactosaminoglycans, resistant to both enzymes is less certain.