Chymotrypsin

Chymotrypsin (bovine γ chymotrypsin: PDB 1AB9, EC 3.4.21.1) is a digestive enzyme that can perform proteolysis.

Activation of chymotrypsin

Chymotrypsin is synthesized by protein biosynthesis as a precursor called chymotrypsinogen that is enzymatically inactive. On cleavage by trypsin into two parts that are still connected via an S-S bond, cleaved chymotrypsinogen molecules can activate each other by removing two small peptides in a trans-proteolysis. The resulting molecule is chymotrypsin, three polypeptides interconnected via S-S bonds.