ABSTRACT
Elastin is not amenable to classical methods of protein sequence analysis because of its high degree of cross-linking and its resulting insolubility in nonhydrolytic solvents. A soluble precursor of elastin, called tropoelastin, can be isolated by inhibiting the formation of crosslinks and the amino acid sequences of most of the tryptic peptides of porcine tropoelastin have been reported. 1 However, it has not been possible to order these tryptic peptides. Amino acid sequences carboxyl-terminal to the desmosine cross-links in elastolytic desmosine- and isodesmosine-containing peptides from porcine, bovine, and human elastin have also been determined. 2 , 3 These sequences identify the lysines which form desmosine and isodesmosine cross-links. In order to understand the structure-function relationships in elastin, it is essential to elucidate the complete primary structure of this protein.
