Fig. 19.

a Schematic representation of NAM NPS-2143 bound to CaSR (PDB: 7M3E). b Detailed binding modes of CaSR bound to NPS-2143. Hydrogen bond is presented as orange dashes and π–π stacking is presented as gray dashes. c 2D structure of small-molecule allosteric ligand NPS-2143 provided for clarity. d Superimposed views of highlighted residues on CaSR–Cinacalcet–Ca²⁺–Trp (blue cartoon, blue sticks; PDB: 7M3F), CaSR–Ca²⁺–Trp (pink cartoon, pink sticks; PDB: 7DD6), and CaSR–NPS-2143–Ca²⁺–Trp (purple cartoon, purple sticks; PDB: 7M3E) structures. e Workflow of discovery of novel CaSR PAMs utilizing structural information