The primary structure of a triple-helical domain of collagen type VIII from bovine Descemet's membrane

We have isolated and sequenced a fragment of 469 amino acid residues from bovine type VIII collagen. The sequence was composed of a series of Gly-X-Y repeats which was interrupted 8 times by short imperfections. The number and relative location of these interruptions were similar to those of chicken α1(X) and rabbit αl(VIII) chain triple-helical domains. Comparison to published N-terminal sequences to two triple-helical fragments of bovine type VIII collagen and to the cDNA derived sequence of the rabbit αl(VIII) chain showed that this fragment was the triple-helical domain of a second type VIII collagen chain which we designate α2(VIII).