Figure 1.

Schematic representation of the pharmacophore expansion of a ligand‐binding site of a protein. The interaction between the ligand and protein pharmacophores gives the binding energy. a: Example of pharmacophore of the ligand pharmacophore. The dotted circles represent the pharmacophore features. b: Example of pharmacophores. HH, HA, and HD indicate hydrophobic, hydrogen‐bond acceptor, and hydrogen‐bond donor sites, shown by open, grey and black circles, respectively. Only three pharmacophores (φ₁, φ₂, and φ₃) are depicted. The lines represent the specific distances between pharmacophore features of each pharmacophore. c: Example of pharmacophore expansion of the receptor pharmacophore following eqs. 2 and 3.