Funding Organization(s): Japan Science and Technology, Ministry of Education, Culture, Sports, Science and Technology (Japan), Japan Society for the Promotion of Science, Japan Agency for Medical Research and Development (AMED), National Institutes of Health/National Human Genome Research Institute (NIH/NHGRI)
Human muscarinic receptor M 2 is one of the five subtypes of muscarinic receptors belonging to the family of G-protein-coupled receptors. Muscarinic receptors are targets for multiple neurodegenerative diseases. The challenge has been designing subtype-selective ligands against one of the five muscarinic receptors ...
Human muscarinic receptor M 2 is one of the five subtypes of muscarinic receptors belonging to the family of G-protein-coupled receptors. Muscarinic receptors are targets for multiple neurodegenerative diseases. The challenge has been designing subtype-selective ligands against one of the five muscarinic receptors. We report high-resolution structures of a thermostabilized mutant M 2 receptor bound to a subtype-selective antagonist AF-DX 384 and a nonselective antagonist NMS. The thermostabilizing mutation S110R in M 2 was predicted using a theoretical strategy previously developed in our group. Comparison of the crystal structures and pharmacological properties of the M 2 receptor shows that the Arg in the S110R mutant mimics the stabilizing role of the sodium cation, which is known to allosterically stabilize inactive state(s) of class A GPCRs. Molecular dynamics simulations reveal that tightening of the ligand-residue contacts in M 2 receptors compared to M 3 receptors leads to subtype selectivity of AF-DX 384.
Organizational Affiliation: 
Japan Science and Technology Agency (JST) and Japan Agency for Medical Research and Development (AMED), Core Research for Evolutional Science and Technology (CREST), Konoe-cho, Yoshida, Sakyo-ku, Kyoto, Japan. kobayashi.takuya.4r@kyoto-u.ac.jp.