Chymotrypsin is a digestive enzyme that can perform proteolysis. Chymotrypsin preferentially cleaves peptide amide bonds where the carboxyl side of the amide bond (the P1 position) is a tyrosine, tryptophan, or phenylalanine. Increased concentrations of this enzyme and/or its zymogen have been found in patients with cystic fibrosis. Description: Human pancreas.