Identification of the critical residues of bradykinin receptor B1 for interaction with the kinins guided by site-directed mutagenesis and molecular modeling.
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.
Ha
Sookhee N
SN
Basic Chemistry, Merck Research Laboratories, P.O. Box 2000, Rahway, New Jersey 07065, USA. sookhee_ha@merck.com
Hey
Pat J
PJ
Ransom
Rick W
RW
Bock
Mark G
MG
Su
Dai-Shi
DS
Murphy
Kathryn L
KL
Chang
Ray
R
Chen
Tsing-Bau
TB
Pettibone
Douglas
D
Hess
J Fred
JF
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
D007705:Kinins; D043783:Receptor, Bradykinin B1