2FTL:
reference: Rigidification of a flexible protease inhibitor variant upon binding to trypsin., Hanson WM, Domek GJ, Horvath MP, Goldenberg DP, J Mol Biol. 2007 Feb 9;366(1):230-43. Epub 2006 Nov 7. PMID: 17157870

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