Mucopolysaccharide and protein--polysaccharide of a transplantable rat chondrosarcoma

Two mucopolysaccharides, chondroitin 4-sulfate (97.8%) and hyaluronic acid (1.2%), were isolated after exhaustive proteolysis of a transplantable chondrosarcoma of the rat. The chondroitin 4-sulfate was fractionated into three fractions of varying degrees of sulfation and chain length. Keratan sulfate and chondroitin 6-sulfate were absent. Extraction of the fresh tumor gave two protein-polysaccharides of similar carbohydrate composition, one soluble in 0.5 M NaCl, the other insoluble. The latter was solubilized in 4 M guanidine.HCl. A dialyzable fraction from the 4 M guanidine solution may be responsible for the insolubility. Both protein-polysaccharides were antigenic and cross-reacted with similar fractions of bovine and human cartilage.