6GCH:
reference: Structure of chymotrypsin-trifluoromethyl ketone inhibitor complexes: comparison of slowly and rapidly equilibrating inhibitors., Brady K, Wei AZ, Ringe D, Abeles RH, Biochemistry 1990 Aug 21;29(33):7600-7. PMID: 2271520

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).