Isolation and characterization of salt-soluble cross-linked elastin from vascular tissue.

Fibrous elastin, a stable and important constituent of vascular tissue undergoes degenerative changes including fragmentation in atherosclerosis. The nature of the protein fragments produced during the in vivo degradation of elastin is largely unknown. From salt extracts of haemodynamically stressed tissue in sheep, polypeptides were isolated by hydrophobic interaction chromatography. These polypeptides coacervated and had amino acid compositions similar to those of in vitro solubilized elastins. The presence of the cross-links, desmosine and isodesmosine, in the isolated material indicates that the fragments originated from fibrous elastin and that cleavage of cross-links is not necessary for the solubilization of the fibre.