Useful pharmacological parameters for G-protein-coupled receptor homodimers obtained from competition experiments. Agonist-antagonist binding modulation

Many G-protein-coupled receptors (GPCRs) are expressed on the plasma membrane as dimers. Since drug binding data are currently fitted using equations developed for monomeric receptors, the interpretation of the pharmacological data are equivocal in many cases. As reported here, GPCR dimer models acc...

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Bibliographic Details
Authors: Casadó, Vicent, Ferrada, Carla, Bonaventura, Jordi, Gracia, Eduard, Mallol Montero, Josefa, Canela Campos, Enric I. (Enric Isidre), 1949-, Lluís i Biset, Carme, Cortés Tejedor, Antonio, Franco Fernández, Rafael
Format: article
Status:Versión aceptada para publicación
Publication Date:2009
Country:España
Institution:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repository:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:2445/127978
Online Access:https://hdl.handle.net/2445/127978
Access Level:Open access
Keyword:Bioquímica
Biologia molecular
Interacció cel·lular
Biochemistry
Molecular biology
Cell interaction
Description
Summary:Many G-protein-coupled receptors (GPCRs) are expressed on the plasma membrane as dimers. Since drug binding data are currently fitted using equations developed for monomeric receptors, the interpretation of the pharmacological data are equivocal in many cases. As reported here, GPCR dimer models account for changes in competition curve shape as a function of the radioligand concentration used, something that cannot be explained by monomeric receptor models. Macroscopic equilibrium dissociation constants for the agonist and homotropic cooperativity index reflecting the intramolecular communication within the dopamine D1 or adenosine A2A receptor homodimer as well as hybrid equilibrium dissociation constant, which reflects the antagonist/agonist modulation may be calculated by fitting binding data from antagonist/agonist competition experiments to equations developed from dimer receptor models. Comparing fitting the data by assuming a classical monomeric receptor model or a dimer model, it is shown that dimer receptor models provide more clues useful in drug discovery than monomer-based models.