The covalent structure of cartilage collagen. Amino acid sequence of the NH2-terminal helical portion of the alpha 1 (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 two 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 for the central portions of these chains (Butler, W.T., Miller, E.J., Finch, J.E., Jr., and Inagami, T. (1974), 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 three positions. The corresponding sequence of alpha 1 (I) contains only one clycosylated hydroxylysine with the other two positions occupied by lysyl residues.