Further Characterization of the Three Polypeptide Chains of Bovine and Human Short‐Chain Collagen (Intima Collagen)

Abstract

Short-chain collagen was isolated from bovine and from human placenta after limited pepsin digestion. By reductive cleavage of disulfide bonds under non-denaturing conditions, mainly non-collagenous domains were cleaved off yielding a uniform component composed of 3 polypeptide chains with molecular masses between 37 kDa [kilodalton] and 48 kDa in a nearly equimolar ratio. The chains (SC1, SC2 and SC3) were isolated and characterized. By comparison of peptide patterns obtained after various cleavage procedures, they could be identified as more or less shortened forms of SC1, SC2 and SC3, the isolation of which from bovine short-chain collagen has been described. The peptide patterns, as well as N-terminal sequence determination, give evidence for the genetic individuality of the 3 chains; the data so far available suggest that together they form 1 triple-helical structure which represents the collagenous domain of the basic molecular unit of short-chain collagen.