Fig. 5

Superposition of DPP4 inhibitors highlights the important binding interactions to some residues. When the inhibitor-bound units were superimposed so that the RMSD targeting Cα atoms in DPP-4 (residue numbers 41–764) would be minimized based on 4PNZ_A, 68 types of inhibitors were simultaneously superimposed. The carbon skeleton of inhibitors is indicated by green line. O, N and halogen atoms are colored red, blue and pale cyan, respectively. a Binding modes between Glu205, Glu206 or Tyr662 and inhibitors. The distances between a primary or secondary amino N atom of inhibitor and the Glu205 Oε atom (<4 Å, yellow), the Glu206 Oε atom (<4 Å, cyan), or the Tyr662 Oη atom (<5 Å, magenta) are shown with dashed lines. b Binding modes between Arg125 or Asn710 and inhibitors. The distances between an O, N or halogen atom of inhibitor and the Arg125 Nη atom (<4 Å, yellow) or the Asn710 Oδ/Nδ atom (<4 Å, magenta) are shown with dashed lines