Figure 5. Superimposition of Gly-Phe-CH₂–hDPPI (dark grey) and cathepsin K in complex on the non-covalently bound inhibitor t-butyl(1S)-1-cyclohexyl-2-oxoethylcarbamate (light grey) (PDB code 1Q6K) [31].

The inhibitors are shown in ball-and-stick representation, and the enzymes are shown as sticks. The exclusion domain of hDPPI is indicated by a transparent surface.