Characterization of metabotropic glutamate receptors coupled to a pertussis toxin sensitive G-protein in bovine brain coated vesicles.
Glutamate metabotropic receptors (mGluRs) in bovine brain coated vesicles have been characterized by pharmacological and kinetic binding experiments. Saturation experiments revealed a single binding site with a Kd = 607.9 +/- 78.5 nM and a Bmax = 6.45 +/- 0.88 pmol/mg protein. The specific binding of L-[3H]glutamate to mGluRs is regulated by guanine nucleotides. Guanosine-5'-triphosphate (GTP; 100 microM) shifts the agonist competition curves to the right, increasing the IC50 values. Pertussis toxin treatment produces a pharmacological binding profile for quisqualate similar to that obtained in the presence of 100 microM GTP. These results indicate the presence of metabotropic glutamate receptors in coated vesicles and its coupling to a pertussis toxin sensitive G-protein.
Martín
M
M
Departamento de Inorgánica, Orgánica y Bioquímica, Facultad de Químicas, Universidad de Castilla-La Mancha, Ciudad Real, Spain.
Sanz
J M
JM
Cubero
A
A
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002417:Cattle; D003034:Coated Pits, Cell-Membrane / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000378:metabolism; D037342:Pertussis Toxin; D011869:Radioligand Assay; D017470:Receptors, Glutamate / Q000378:metabolism*; D010566:Virulence Factors, Bordetella / Q000378:metabolism*
D017470:Receptors, Glutamate; D010566:Virulence Factors, Bordetella; D006160:Guanosine Triphosphate; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins