Isolation and Characterisation of the Peptides Derived from the α₁‐Chain of Calf Skin Collagen after Hydroxylamine Cleavage

The α 1 ‐chain of acid soluble calf skin collagen was cleaved with hydroxylamine and the resulting peptides were separated and purified by ion exchange and molecular sieve chromatography. Four fragments were isolated, representing molecular weights of 20 000, 31 000, 45 000, and 48 000; also intact or probably slightly modified α 1 ‐chains could be found. The peptides were renatured and precipitated as long spacing segment fragments using ATP; their order in the intact molecule was determined, using the electron microscopy, by their cross‐striation patterns. The different fragments are derived from the B‐end of the α 1 ‐chain, only the shortest peptide derives from a middle region of the molecule. The content of the hydroxamic acids of the fragments varies from 0.59 to 1.18, the modified α 1 ‐chain shows 2 groups of hydroxamic acid. In four of the five isolated fractions glycine could be determined as N‐terminal.