Digestion of elastin by porcine pancreatic elastase I and elastase II.
Elastin was fully solubilized by digestion with elastase I or elastase II. Each digest was separated into high-molecular weight and low-molecular weight fractions that were characterized by the correspondence to their amino acid content, N-terminal sequence and C-terminal amino acids. It was found that although the relative amount of amino acids in the low-molecular weight fraction obtained by digestion with elastase I was lower than in digestion with elastase II, no major difference in the type of bonds cleaved in the low- or high-molecular weight fractions of each digest could be seen. There is, however, a remarkable difference in the type of bond cleaved by the two enzymes. While elastase I cleaves mostly Ala-Ala and also Ala-Gly bonds, elastase II hydrolyzes Leu-Ala, Leu-Gly, Phe-Ala, Phe-Gly and Tyr-Ala, Tyr-Gly bonds. Theoretical calculations led us to suggest both digests are composed of cross-linked peptides that vary not only in the molecular size but also in the number of cross-links found in peptides of the same size.
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D004549:Elastin / Q000302:isolation & purification*; D008970:Molecular Weight; D010196:Pancreatic Elastase; D012995:Solubility; D013379:Substrate Specificity; D013552:Swine
D004549:Elastin; D010196:Pancreatic Elastase