ISOLATION OF THE ALPHA-3-CHAIN OF HUMAN TYPE-V COLLAGEN AND CHARACTERIZATION BY PARTIAL SEQUENCING

The alpha-1-alpha-2-alpha-3-chain form of human type V collagen was solubilized from placenta by pepsin treatment and isolated by ion-exchange chromatography. The alpha-3-chain was further separated after denaturation of the triple helix also by ion-exchange chromatography, cleaved with lysyl endopeptidase and the fragments separated by size-exclusion chromatography and reversed phase HPLC. N-Terminal sequence analysis of the fragments and comparison to sequences contained in a database indicated a relatively high similarity of the alpha-3(V)-chain to alpha-1(V) and alpha-1(XI) with an identity of approximately 73%.