The covalent structure of cartilage collagen. Amino acid sequence of the amino-terminal helical portion of the α1(II) chain

Abstract

The amino acid sequence of 162 residues from the NH2-terminal region of bovine .alpha.1(II) is reported. Automated sequence analysis of chains from pepsin-treated type II collagen indicated the sequence and order of 2 CNBr peptides, .alpha.1(II)-CB2 and .alpha.1(II)-CB3, at the beginning of the repetitive triplet sequence of .alpha.1(II). The sequences of .alpha.1(II)-CB6, .alpha.1(II)-CB12 and 39 residues of .alpha.1(II)-CB11 were determined largely by automated Edman degradation. Comparative sequence data are reported which indicate that the level of homology between .alpha.1(I) and .alpha.1(II) chains in the NH2-terminal region is about 80%. A similar level of homology was reported by Butler et al. for the central portions of these chains (Biochem. Biophys. Res. Commun. 57, 190). The degree of intraspecies variability between chain types is thus greater than the interspecies variability for a single chain type. Within the sequence reported here, the .alpha.1(II) chain contains glucosylgalactosylhydroxylysine at 3 positions. The corresponding sequence of .alpha.1(I) contains only 1 glycosylated hydroxylysine with the other 2 positions occupied by lysyl residues.