Link-proteins and non-collagenous proteins from normal and chondrodysplastic cartilages

Abstract
Baboon and human articular and growth cartilage was extracted with 4M guanidinium chloride in the presence of proteolysis inhibitors. After dialysis against 8 M urea pH 6.8 the proteins were separated from proteoglycans by ion-exchange chromatography. The concentrated and reduced protein fractions was analyzed by SDS-PAGE. Bands corresponding to collagen and to 6 major non-collegenous proteins were found. Two of the latter were identified with the link-proteins. By using small columns and microconcentration procedures, a gel-electrophoretic analysis of link-proteins extracted from small pieces of cartilage was performed and ten cases of osteochondrodysplasias were studied. No abnormalities were detected in the following syndromes: achondroplasia, diastrophic dwarfism, thanatophoric dwarfism, Jeune disease, spondyloepiphyseal dysplasia congenita, Kozlowski syndrome, osteogenesis imperfecta, polyepiphyseal dysplasia with diabetes mellitus.