The chemistry of the collagen cross-links. Purification and characterization of cross-linked polymeric peptide material from mature collagen containing unknown amino acids

Abstract

A polymeric form of the .alpha.1-chain C-terminal peptide .alpha.1CB6 (poly-.alpha.1CB6) was purified from CNBr digests of insoluble bovine achilles tendon type-I collagen by gel filtration and ion-exchange chromatography. The purified material had a MW of 1.5 .times. 106-5 .times. 106 on gel filtration and an amino acid content virtually identical with that of monomeric peptide .alpha.1CB6. The material could be adsorbed on affinity gels containing immobilized anti-(.alpha.1CB6-peptide non-helical region) antibodies and was an inhibitor of hemagglutination by the same antibodies of .alpha.1CB6-peptide-coated sheep erythrocytes. Periodate treatment of the material had no effect. Alkali hydrolysates contained 2 unknown amino acids, which were purified by gel filtration and ion-exchange chromatography in volatile buffers and are apparently components of the mature cross-link of collagen.