title: Binding modes of dihydroquinoxalinones in a homology model of bradykinin receptor 1.
abstract: We report the first homology model of human bradykinin receptor B1 generated from the crystal structure of bovine rhodopsin as a template. Using an automated docking procedure, two B1 receptor antagonists of the dihydroquinoxalinone structural class were docked into the receptor model. Site-directed mutagenesis data of the amino acid residues in TM1, TM3, TM6, and TM7 were incorporated to place the compounds in the binding site of the homology model of the human B1 bradykinin receptor. The best pose in agreement with the mutation data was selected for detailed study of the receptor-antagonist interaction. To test the model, the calculated antagonist-receptor binding energy was correlated with the experimentally measured binding affinity (K(i)) for nine dihydroquinoxalinone analogs. The model was used to gain insight into the molecular mechanism for receptor function and to optimize the dihydroquinoxalinone analogs.
authors.affiliation: Basic Chemistry, Merck Research Laboratories, P.O. Box 2000, Rahway, NJ 07065, USA. sookhee_ha@merck.com <sookhee_ha@merck.com>
authors.forename: Sookhee N
authors.initials: SN
authors.lastname: Ha
authors.forename: Pat J
authors.initials: PJ
authors.lastname: Hey
authors.forename: Rick W
authors.initials: RW
authors.lastname: Ransom
authors.forename: C Meacham
authors.initials: CM
authors.lastname: Harrell
authors.forename: Kathryn L
authors.initials: KL
authors.lastname: Murphy
authors.forename: Ray
authors.initials: R
authors.lastname: Chang
authors.forename: Tsing-Bau
authors.initials: TB
authors.lastname: Chen
authors.forename: Dai-Shi
authors.initials: DS
authors.lastname: Su
authors.forename: M Kristine
authors.initials: MK
authors.lastname: Markowitz
authors.forename: Mark G
authors.initials: MG
authors.lastname: Bock
authors.forename: Roger M
authors.initials: RM
authors.lastname: Freidinger
authors.forename: Fred J
authors.initials: FJ
authors.lastname: Hess
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D017433:Protein Structure, Secondary; D011810:Quinoxalines / Q000737:chemistry*; D043783:Receptor, Bradykinin B1 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D012243:Rhodopsin / Q000737:chemistry; D016415:Sequence Alignment; D040681:Structural Homology, Protein
chemical_list: D011810:Quinoxalines; D043783:Receptor, Bradykinin B1; D012243:Rhodopsin