1CHG:
reference: Chymotrypsinogen: 2.5-angstrom crystal structure, comparison with alpha-chymotrypsin, and implications for zymogen activation., Freer ST, Kraut J, Robertus JD, Wright HT, Xuong NH, Biochemistry 1970 Apr 28;9(9):1997-2009. PMID: 5442169

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