Homology Modeling of the Serotonin 5-HT_(1A) Receptor Using Automated Docking of Bioactive Compounds with Defined Geometry

摘要

This paper describes a rhodopsin-based model of 5-HT_(1A) serotonin receptor.The flexibility of the receptor was considered by using large number of models for ligand dockings.Rearrangements of the heptahelical bundle were introduced,which resulted in the improvement of correlation between computational results and experimental data.The model was validated by automated docking of conformationally restricted arylpiperazines.Specific interactions,responsible for the recognition of arylpiperazine derivatives,were identified.An ionic bond was formed between the protonated amine of ligands and Asp3.32.The aromatic moiety and its substituents specifically interacted with Phe6.52 and Ser5.42,respectively,while the carbonyl groups of imide part of ligands formed hydrogen bonds with Asn7.39 and Tyr7.43.The model reproduced the binding affinity of the test group of ligands (correlation r=0.8 between pK_i and docking score).It also gave the enrichment in virtual screening-like experiment (100 compounds),in which 34 high-affinity compounds were found among 50 top-scored ligands.