Partial characterization of peptide fragment purified by isoelectrofocusing after organo alkaline hydrolysis of bovine ligamentum nuchae elastin.

Highly purified elastin from bovine ligamentum nuchae was submitted to partial alkaline hydrolysis (37 degree C, 72 H, 1 N KOH in 80 p. 100 aqueous ethanol). The non-coacervable fractions were submitted to isoelectrofocusing and five kappa-elastin fractions were obtained. The amino-acid compositions, the N-terminal amino-acids, the molecular weights and the thermolysin digests of each fraction were determined by various techniques. The average MW was about 14,500 (150 - 166 amino-acids). These results suggest that the distribution of cross-linking agents in fibrous elastin may not be uniform. The results also show that in certain cross-linked regions of similar molecular weight and size appearing to be composed of different polypeptides sequences containing different amounts of cross-links.