Isolation and characterization of cross-linked peptides from elastin.

Two peptides containing the desmosine cross-link were isolated and purified from a subtilisin digest of oxalic acidsolubilized elastin. Molecular weights averaged approximately 6000. Automated sequence data suggest that the desmosines cross-link two polypeptide chains and that both desmosine and isodesmosine are present in the same primary sequence approximately equally substituted. The primary sequence of the peptides is in good agreement with sequence data obtained on the soluble elastin precursor tropoelastin.