Desulfation and Depolymerization of Chondroitin 4-Sulfate and Its Degradation Products by Rat Stomach, Liver and Small Intestine 1

Summary Stomach, small intestine, and liver contain sulfatases which liberate sulfate from chondroitin 4-sulfate. Sulfatase activity is greater in 1-mo than in 4-mo old rats. For each of the 3 tissue extracts, de-sulfation occurs more rapidly -and extensively with chondroitin 4-sulfate as substrate than with the sulfated products obtained by degradation of chondroitin sulfate with gastric enzymes, hyaluronidase or chondroitinase ABC. Stomach and small intestine liberate organic sulfate in addition to inorganic sulfate, and the ratio of the former to the latter may exceed 1 (in terms of sulfate). The rate of liberation of inorganic sulfate exceeds that of organic sulfate during the early stages of incubation and the reverse occurs in the later stages. Sulfate ion inhibits the liberation of inorganic and to a lesser extent organic sulfate. These results suggest, but do not conclusively prove, that desulfation precedes depolymerization. Liver liberates chiefly inorganic sulfate and little organic sulfate. Electrophoretic analysis indicates that liver extracts form a transient complex with chondroitin 4-sulfate during the early stages of incubation.