![Sample our Bioscience journals, sign in here to start your access, Latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5925/TOC-Subject-Sample-2021-Bioscience.jpg"})
Abstract
The cross-linking of type IX collagen in fetal bovine cartilage was investigated. The main cross-link was dihydroxylysinonorleucine (borohydride-reduced) with a lesser amount of the mature cross-link, pyridinoline. Dihydroxylysinonorleucine was present in all three chains of the COL2 domain of the type IX molecule, but only two of them contained pyridinoline even in mature cartilage. Amino acid squence analysis of individual tryptic peptides that contained 3H-labeled cross-links showed that they had derived from sites of covalent interaction between type IX collagen and the telopeptide sequences of type II collagen. One two-chained peptide was a helical sequence of α2(IX) COL2 linked to an α1 (II) N-telopeptide. A second peptide was a different helical sequence from another type IX chain linked to an α1(II) C-telopeptide. This latter helical sequence was also the principal site of pyridinoline cross-linking in type IX collagen.