title: A combined ligand-based and target-based drug design approach for G-protein coupled receptors: application to salvinorin A, a selective kappa opioid receptor agonist.
abstract: Combined ligand-based and target-based drug design approaches provide a synergistic advantage over either method individually. Therefore, we set out to develop a powerful virtual screening model to identify novel molecular scaffolds as potential leads for the human KOP (hKOP) receptor employing a combined approach. Utilizing a set of recently reported derivatives of salvinorin A, a structurally unique KOP receptor agonist, a pharmacophore model was developed that consisted of two hydrogen bond acceptor and three hydrophobic features. The model was cross-validated by randomizing the data using the CatScramble technique. Further validation was carried out using a test set that performed well in classifying active and inactive molecules correctly. Simultaneously, a bovine rhodopsin based "agonist-bound" hKOP receptor model was also generated. The model provided more accurate information about the putative binding site of salvinorin A based ligands. Several protein structure-checking programs were used to validate the model. In addition, this model was in agreement with the mutation experiments carried out on KOP receptor. The predictive ability of the model was evaluated by docking a set of known KOP receptor agonists into the active site of this model. The docked scores correlated reasonably well with experimental pK (i) values. It is hypothesized that the integration of these two independently generated models would enable a swift and reliable identification of new lead compounds that could reduce time and cost of hit finding within the drug discovery and development process, particularly in the case of GPCRs.
authors.affiliation: Department of Medicinal Chemistry and Laboratory for Applied Drug Design and Synthesis, The University of Mississippi, University, MS 38677, USA.
authors.forename: Nidhi
authors.initials: N
authors.lastname: Singh
authors.forename: Gwénaël
authors.initials: G
authors.lastname: Chevé
authors.forename: David M
authors.initials: DM
authors.lastname: Ferguson
authors.forename: Christopher R
authors.initials: CR
authors.lastname: McCurdy
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D018360:Crystallography, X-Ray; D004224:Diterpenes / Q000737:chemistry / Q000494:pharmacology*; D045785:Diterpenes, Clerodane; D015195:Drug Design; D006801:Humans; D008024:Ligands; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017473:Receptors, Opioid, kappa / Q000819:agonists* / Q000737:chemistry; D015203:Reproducibility of Results; D016415:Sequence Alignment; D012984:Software
chemical_list: D004224:Diterpenes; D045785:Diterpenes, Clerodane; D008024:Ligands; D017473:Receptors, Opioid, kappa; C090499:salvinorin A