One unit will hydrolyze 1 µmole of N-benzoyl-L-tyrosine ethyl ester per minute at pH 7.8 and 25 °C. Produced from 3× crystallized chymotrypsinogen.

Inhibitors: The enzyme is inhibited by heavy metals, the natural trypsin inhibitors to various degrees, an inhibitor from potato, and organophosphorus compounds. Also inhibited by AEBSF, α-1-antitrypsin, Aprotinin, DFP, PMSF, TPCK and α-2-Macroglobulin.

Chymotrypsin preferentially catalyzes the hydrolysis of peptide bonds involving L-isomers of tyrosine, phenylalanine, and tryptophan. It also readily acts upon amides and esters of susceptible amino acids. In addition to bonds involving aromatic amino acids, chymotrypsin catalyzes at a high rate the hydrolysis of bonds of leucyl, methionyl, asparaginyl, and glutamyl residues. a-Chymotrypsin is a protein consisting of 241 amino acid residues. The molecule has three peptide chains: an A chain of 13 residues, a B chain of 131 residues, and a C chain of 97 residues.

α-Chymotrypsin is used for treating pancreatic insufficiency and in traumatology.

A serine protease that hydrolyzes peptide bonds with aromatic or large hydrophobic side chains (Tyr, Trp, Phe, Met, Leu) on the carboxyl end of the bond.