title: Identification of the critical residues of bradykinin receptor B1 for interaction with the kinins guided by site-directed mutagenesis and molecular modeling.
abstract: We report the critical residues for the interaction of the kinins with human bradykinin receptor 1 (B1) using site-directed mutagenesis in conjunction with molecular modeling of the binding modes of the kinins in the homology model of the B1 receptor. Mutation of Lys118 in transmembrane (TM) helix 3, Ala270 in TM6, and Leu294 in TM7 causes a significant decrease in the affinity for the peptide agonists des-Arg10kallidin (KD) and des-Arg9BK but not the peptide antagonist des-Arg10Leu9KD. In contrast, mutations in TM2, TM3, TM6, and TM7 cause a significant decrease in the affinity for both the peptide agonists and the antagonist. These data indicate that the B1 bradykinin binding pocket for agonists and antagonists is similar, but the manners in which they interact with the receptor do not completely overlap. Therefore, there is a potential to influence the receptor's ligand selectivity.
authors.affiliation: Basic Chemistry, Merck Research Laboratories, P.O. Box 2000, Rahway, New Jersey 07065, USA. 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: Mark G
authors.initials: MG
authors.lastname: Bock
authors.forename: Dai-Shi
authors.initials: DS
authors.lastname: Su
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: Douglas
authors.initials: D
authors.lastname: Pettibone
authors.forename: J Fred
authors.initials: JF
authors.lastname: Hess
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D017124:Conserved Sequence; D006801:Humans; D007705:Kinins / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation / Q000235:genetics; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D043783:Receptor, Bradykinin B1 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment
chemical_list: D007705:Kinins; D043783:Receptor, Bradykinin B1