The agonist selectivity of a mouse B-1 bradykinin receptor differs from human and rabbit B-1 receptors

A genomic clone encoding the mouse B-1 receptor was isolated by homology to the human B-1 receptor cDNA. The deduced amino acid sequence of the mouse B-1 receptor is 72% identical to the human B-1 receptor and 73% identical to the rabbit B-1 receptor. Ligand binding studies of the mouse B-1 receptor expressed in COS cells indicate that it has the pharmacological properties associated with the B-1 receptor subtype. However, the pharmacology of the mouse receptor is unique in that it possesses a 2-3-fold selectivity for the 'classical' B-1 agonist des-Arg(9)BK over the agonist des-Arg(10)kallidin. In contrast, the human and rabbit B-1 receptors exhibit an approx. 2000- and 150-fold selectivity, respectively, for des-Arg(10)kallidin over des-Arg(9)BK. Thus relative to the human and rabbit B-1 receptors the mouse B-1 receptor has the opposite selectivity for kinin agonists. The DNA sequence of the region encoding bradykinin was determined for two different mouse kininogen cDNA clones, both encode the sequence Arg-BK. Antipeptide antibodies directed against a C-terminal peptide of the human B-1 receptor were produced. Initial characterization of this antibody indicates that it detects specific bands by Western blot analyses that are present in membranes prepared from COS cells transfected with the human B-1 receptor cDNA but not from mock transfected COS cells.