title: Collagen type IX: evidence for covalent linkages to type II collagen in cartilage.
abstract: A major site of pyridinoline cross-linking in bovine type IX collagen was traced to a tryptic peptide derived from one of the molecule's HMW chains. This peptide gave two amino acid sequences (in 2/1 ratio) consistent with it being a three-chained structure. The major sequence matched exactly that of the C-telopeptide of type II collagen from the same tissue. A second HMW chain that contained pyridinoline cross-links also gave two amino-terminal sequences, one from its own amino terminus, the other matching exactly the N-telopeptide cross-linking sequence of type II collagen. We conclude that type IX collagen molecules are covalently cross-linked in cartilage to molecules of type II collagen, probably at fibril surfaces.
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000648:ultrastructure*; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D003094:Collagen / Q000378:metabolism; D003432:Cross-Linking Reagents; D010446:Peptide Fragments / Q000032:analysis; D010449:Peptide Mapping; D011487:Protein Conformation; D011726:Pyridinium Compounds
chemical_list: D003432:Cross-Linking Reagents; D010446:Peptide Fragments; D011726:Pyridinium Compounds; D003094:Collagen