In Silico Finding of Key Interaction Mediated α3β4 and α7 Nicotinic Acetylcholine Receptor Ligand Selectivity of Quinuclidine-Triazole Chemotype.
The selective binding of six (S)-quinuclidine-triazoles and their (R)-enantiomers to nicotinic acetylcholine receptor (nAChR) subtypes α3β4 and α7, respectively, were analyzed by in silico docking to provide the insight into the molecular basis for the observed stereospecific subtype discrimination. Homology modeling followed by molecular docking and molecular dynamics (MD) simulations revealed that unique amino acid residues in the complementary subunits of the nAChR subtypes are involved in subtype-specific selectivity profiles. In the complementary β4-subunit of the α3β4 nAChR binding pocket, non-conserved AspB173 through a salt bridge was found to be the key determinant for the α3β4 selectivity of the quinuclidine-triazole chemotype, explaining the 47-327-fold affinity of the (S)-enantiomers as compared to their (R)-enantiomer counterparts. Regarding the α7 nAChR subtype, the amino acids promoting a however significantly lower preference for the (R)-enantiomers were the conserved TyrA93, TrpA149 and TrpB55 residues. The non-conserved amino acid residue in the complementary subunit of nAChR subtypes appeared to play a significant role for the nAChR subtype-selective binding, particularly at the heteropentameric subtype, whereas the conserved amino acid residues in both principal and complementary subunits are essential for ligand potency and efficacy.
['Arunrungvichian|Kuntarat|K|0000-0003-1183-9357', 'Chongruchiroj|Sumet|S|', 'Sarasamkan|Jiradanai|J|0000-0002-7484-0067', 'Schüürmann|Gerrit|G|0000-0002-3789-1703', 'Brust|Peter|P|0000-0001-5555-7058', 'Vajragupta|Opa|O|0000-0003-3313-0621']
D020816:Amino Acid Motifs D001665:Binding Sites D003198:Computer Simulation D008958:Models, Molecular D062105:Molecular Docking Simulation D056004:Molecular Dynamics Simulation D015394:Molecular Structure D011487:Protein Conformation D011812:Quinuclidines D011978:Receptors, Nicotinic D014230:Triazoles D064569:alpha7 Nicotinic Acetylcholine Receptor
α3β4 nAChR α7 nAChR anti-1,2,3-triazole quinuclidine stereoselectivity