Chymotrypsin (bovine γ chymotrypsin:
PDB 1AB9 (
http://www.rcsb.org/pdb/cgi/explore.cgi?pid=217921034360664&page=0&pdbId=1AB9), EC 3.4.21.1) is a digestive enzyme that can perform
proteolysis.
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.