RT Journal Article
SR Electronic
T1 A new molecular mechanism to engineer protean agonism at a G protein-coupled receptor
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP mol.116.107276
DO 10.1124/mol.116.107276
A1 Anna De Min
A1 Carlo Matera
A1 Andreas Bock
A1 Janine Holze
A1 Jessica Kloeckner
A1 Mathias Muth
A1 Christian Traenkle
A1 Marco De Amici
A1 Terry Kenakin
A1 Ulrike Holzgrabe
A1 Clelia Dallanoce
A1 Evi Kostenis
A1 Klaus Mohr
A1 Ramona Schrage
YR 2017
UL http://molpharm.aspetjournals.org/content/early/2017/02/06/mol.116.107276.abstract
AB Protean agonists are of great pharmacological interest as their behavior may change in magnitude and direction depending on the constitutive activity of a receptor. Yet, this intriguing phenomenon has been poorly described and understood, due to the lack of stable experimental systems and design strategies. Here, we overcome both limitations: First, we demonstrate that modulation of the ionic strength in a defined experimental set-up allows for analysis of GPCR activation in the absence and presence of a specific amount of spontaneous receptor activity using the muscarinic M2 acetylcholine receptor as a model. Second, we employ this assay system to show that a dualsteric design principle, i.e. molecular probes, carrying two pharmacophores to simultaneously adopt orthosteric and allosteric topography within a G protein-coupled receptor, may represent a novel approach to achieve protean agonism. We pinpoint three molecular requirements within dualsteric compounds that elicit protean agonism at the muscarinic M2 acetylcholine receptor. Using radioligand binding and functional assays we posit that dynamic ligand binding may be the mechanism underlying protean agonism of dualsteric ligands. Our findings provide both new mechanistic insights into the still enigmatic phenomenon of protean agonism and a rationale for the design of such compounds for a G protein-coupled receptor.