6CJ7:
reference: Manduca sexta serpin-12 controls the prophenoloxidase activation system in larval hemolymph., Yang F, Wang Y, Sumathipala N, Cao X, Kanost MR, Jiang H, Insect Biochem Mol Biol. 2018 Aug;99:27-36. doi: 10.1016/j.ibmb.2018.05.004. Epub, 2018 May 23. PMID: 29800677

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