DECORIN AND A LARGE DERMATAN SULFATE PROTEOGLYCAN IN BOVINE STRIATED-MUSCLE

Proteoglycans were extracted and isolated from adult bovine muscle tis sue by dissociative extraction followed by density gradient centrifuga tion, gel chromatography and ion-exchange chromatography. Two proteogl ycans were characterized; one of large molecular size (PG-L) and one o f small molecular size (PG-S). The recovery of PG-L and PG-S was 33% a nd 67%, respectively. By cellulose acetate electrophoresis before and after treatment with chondroitinase AC and ABC both samples were shown to carry predominantly dermatan sulfate chains. The large proteoglyca n was recognized with an antibody against a large dermatan sulfate pro teoglycan from bovine sclera, whereas the small was recognized by an a ntibody against decorin from bovine sclera. Chondroitinase ABC treatme nt of PG-S followed by SDS-PAGE showed a core protein with a molecular weight of 45 kDa, which also reacted with the decorin antibody. Amino -acid analysis of both PG-L and PG-S revealed an amino-acid compositio n closely similar, although not identical, to the large dermatan sulfa te proteoglycan from bovine sclera and decorin, respectively. Immunohi stochemical analyses of muscle tissue sections showed that decorin and the large dermatan sulfate proteoglycan are present in the perimysium layers of muscle tissue, although with a somewhat different pattern o f distribution. Decorin was, in addition, found in the endomysium.