Codes for DPP-IV structures currently available at PDB.

Some PDB structures were discarded for the following reasons: (a) the structures were of apo forms without inhibitor, (b) inhibitors were covalently linked with Ser630, (c) inhibitors were of oligopeptide nature, (d) there were no structural factors available in the PDB or (e) the scripts in the EDS failed to produce the map from the structural factors. PDB structures marked with an asterisk (*) have mutations in the enzyme to modify the activity. Only the PDB files from the “Valid PDB Structures” section with IC50 values ≤10 nM (in bold) were used to derive the corresponding structure-based common pharmacophore for DPP-IV inhibition (see Figure 1).