5PTI:
reference: Structure of bovine pancreatic trypsin inhibitor. Results of joint neutron and X-ray refinement of crystal form II., Wlodawer A, Walter J, Huber R, Sjolin L, J Mol Biol 1984 Dec 5;180(2):301-29. PMID: 6210373

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