Comparative study of carbohydrate-protein complexes. III. Peptide structures of the linkage region in proteoglycans of human, porcine and shark cartilages.

Chondroitin sulfite peptidoglycans were prepared by the pronase digestion of cartilages from human knee joints, porcine tracheae, and shark crania. The beta-elimination and sulfite addition reaction of these peptidoglycans yielded cysteic acid-containing peptides, and the amino acid sequences of some of them were determined. The finding that human and porcine peptidoglycans have the same sequence in the linkage region as that of the bovine peptidoglycan reported previously suggested that there is a common structural feature in the core proteins of these mammalian cartilage proteoglycans. The results also support the view that -Ser-Gly- is the minimum requisite for the formation of the xylosylserine linkage of proteochondroitin sulfates.