| 1KHP: reference: Two polymorphs of a covalent complex between papain and a diazomethylketone inhibitor., Janowski R, Kozak M, Jankowska E, Grzonka Z, Jaskolski M, J Pept Res 2004 Oct;64(4):141-50. PMID: 15357669 |
This OCA 
Structure page
uses Jmol,
developed by the Jmol Development Team
(documentation).