2XDW:
reference: Inhibition of prolyl oligopeptidase with a synthetic unnatural dipeptide., Racys DT, Rea D, Fulop V, Wills M, Bioorg Med Chem. 2010 Jul 1;18(13):4775-82. Epub 2010 May 31. PMID: 20627594

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