Porcine Costal Cartilage Research Articles

The protein-polysaccharides of articular, epiphyseal plate and costal cartilages

1. 1. The yields of protein-polysaccharides obtained from bovine fetal articular, epiphyseal plate and porcine costal cartilage and their content of uronic acid, hexosamine, sialic acid, protein hydroxyproline were determined. The ability of the protein-polysaccharides to inhibit the precipitation of calcium phosphate in vitro was also studied, both before and after degradation of the protein-polysaccharides by enzymes extracts of epiphyseal plate cartilage. 2. 2. Yields and compositions of protein-polysaccharides from the diverse hyaline cartilages were similar, indicating that there are, in the narrow age range studied, in the different cartilages and in the different species of animals, remarkable similarities in the chemical nature of the hyaline cartilages with respect to their content of protein-polysaccharides. Differences in composition are manifest, however, when compared with calf nasal cartilages or nucleus pulosus. 3. 3. Most of the protein-polysaccharides inhibited the precipitation of calcium phosphate from solution. If the protein-polysaccharides are first degraded by enzyme extracts obtained from cartilage, the inhibitory activity of the protein-polysaccharides is abolished in the range of concentrations studied. These phenomena are discussed in relation to calcification of cartilage.

Studies on porcine costal cartilage protein-polysaccharide complex: II. Chemical studies

Direct alkali treatment of porcine costal cartilage protein-polysaccharide complex followed by fractionation on Sephadex G-100 yields two clearly resolved uronic acid-containing fractions. The latter, which is the major component, contains 70–85% of the total uronic acid, is homogenous on rechromatography on DEAE-Sephadex and is completely free of amino acid, as well as of glucosamine. The former peak contains 4–6% polypeptide, 5–10% glucosamine, and shows a higher specific radioactivity than does the latter peak. Hydrazinolysis of this fraction and reisolation of the polysaccharide, shows glutamic acid as the major residual amino acid. This suggests that a portion of these chains is linked to peptide via presumably the γ-carboxyl of glutamic acid. Analytical data for both polysaccharide fractions show agreement with the composition expected for chondroitin sulphate, and infrared spectra, optical rotation, and rotatory dispersion indicate that both polymers are chondroitin sulphate A. Sedimentation velocity analyses of the polysaccharide are presented.