Figure 7.
Structures referred to as NH···π interactions in the literature. (a) Chk1 kinase ligands. The orange structure has a Ki of 8.5 μM (PDB code 2c3l), and the green structure has a Ki of 0.026 μM (PDB code 2c3k).(122) The additional phenyl ring displaces several water molecules, one of which was coordinated to the backbone NH below. The shortest NH···phenyl distance in the green structure is 3.4 Å. (b) A PDE10 complex structure with a reported NH···π contact(123) where in reality the glutamine side chain forms two classical hydrogen bonds to water and a tyrosine. Distances are in Å.