title: Diazepam-bound GABAA receptor models identify new benzodiazepine binding-site ligands.
abstract: Benzodiazepines exert their anxiolytic, anticonvulsant, muscle-relaxant and sedative-hypnotic properties by allosterically enhancing the action of GABA at GABA(A) receptors via their benzodiazepine-binding site. Although these drugs have been used clinically since 1960, the molecular basis of this interaction is still not known. By using multiple homology models and an unbiased docking protocol, we identified a binding hypothesis for the diazepam-bound structure of the benzodiazepine site, which was confirmed by experimental evidence. Moreover, two independent virtual screening approaches based on this structure identified known benzodiazepine-site ligands from different structural classes and predicted potential new ligands for this site. Receptor-binding assays and electrophysiological studies on recombinant receptors confirmed these predictions and thus identified new chemotypes for the benzodiazepine-binding site. Our results support the validity of the diazepam-bound structure of the benzodiazepine-binding pocket, demonstrate its suitability for drug discovery and pave the way for structure-based drug design.
authors.affiliation: Department of Medicinal Chemistry, University of Vienna, Vienna, Austria.
authors.forename: Lars
authors.initials: L
authors.lastname: Richter
authors.forename: Chris
authors.initials: C
authors.lastname: de Graaf
authors.forename: Werner
authors.initials: W
authors.lastname: Sieghart
authors.forename: Zdravko
authors.initials: Z
authors.lastname: Varagic
authors.forename: Martina
authors.initials: M
authors.lastname: Mörzinger
authors.forename: Iwan J P
authors.initials: IJ
authors.lastname: de Esch
authors.forename: Gerhard F
authors.initials: GF
authors.lastname: Ecker
authors.forename: Margot
authors.initials: M
authors.lastname: Ernst
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D014151:Anti-Anxiety Agents / Q000737:chemistry* / Q000494:pharmacology; D001665:Binding Sites; D002531:Cerebellum / Q000187:drug effects / Q000502:physiology; D003198:Computer Simulation; D003975:Diazepam / Q000737:chemistry* / Q000494:pharmacology; D015195:Drug Design; D055724:Electrophysiological Phenomena / Q000187:drug effects; D058785:GABA-A Receptor Agonists / Q000737:chemistry* / Q000494:pharmacology; D051379:Mice; D008956:Models, Chemical; D008969:Molecular Sequence Data; D011963:Receptors, GABA-A / Q000737:chemistry*; D013329:Structure-Activity Relationship
chemical_list: D014151:Anti-Anxiety Agents; D058785:GABA-A Receptor Agonists; D011963:Receptors, GABA-A; D003975:Diazepam