Studies on the elastolytic activity of chymotrypsin.

Chymotrypsin can completely solubilize insoluble [3H]-labeled ligamentum nuchae elastin. At similar enzyme levels, trypsin solubilizes only 5% of the elastin substrate whereas pancreatic elastase completely solubilizes the elastin at one-tenth the concentration required for chymotrypsin solubilization. The elastolytic activity of chymotrypsin is dependent on Ca+2, is enhanced by SDS, and is inhibited by NaCl at concentrations above 10 mM. The elastolytic activity of chymotrypsin is also inhibited by TPCK, a chymotrypsin specific inhibitor, but not by TLCK, a trypsin specific inhibitor. Neither TPCK nor TLCK abolish the elastolytic activity of pancreatic elastase. The sizes of [3H]elastin fragments produced by the elastolytic activity of chymotrypsin are similar to those produced by pancreatic elastase, and larger than those produced by trypsin.