Structural Studies on Cross-Linked Regions of Elastin

acid sequences, the cross-linked chains must be resolved into single chain peptides.The present paper describes an approach which permits the determination of sequences COOH-terminal to the desmosine and isodesmosine cross-links of elastin; seven such peptides were isolated and sequenced from bovine ligamenturn nuchae elastin and five from porcine aortic elastin.It was found that some of these were identical with the sequences reported (1) for the NH&erminal regions of the tryptic peptides of tropoelastin.This evidence identifies some of the regions in tropoelastin which take part in the actual cross-linking.Furthermore, a model which takes into account all available data for elastin and tropoelastin is proposed.