4H4F:
reference: Long-range Electrostatic Complementarity Governs Substrate Recognition by Human Chymotrypsin C, a Key Regulator of Digestive Enzyme Activation., Batra J, Szabo A, Caulfield TR, Soares AS, Sahin-Toth M, Radisky ES, J Biol Chem. 2013 Apr 5;288(14):9848-59. doi: 10.1074/jbc.M113.457382. Epub 2013 , Feb 19. PMID: 23430245

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