Acts upon elastin. Hydrolysis of proteins, including elastin. Preferential cleavage: Ala-|-Xaa. Binds 1 Ca(2+) ion per subunit. Optimum pH is 8.1 at 22 degrees Celsius with Suc-AAA-pNA as the substrate. Pancreas. Belongs to the peptidase S1 family. Elastase subfamily.