Photoswitchable antagonists for a precise spatiotemporal control of ß 2-adrenoceptors

Abstract

beta(2)-Adrenoceptors (beta(2)-AR) are prototypical G-protein-coupled receptors and important pharmacological targets with relevant roles in physiological processes and diseases. Herein, we introduce Photoazolol-1-3, a series of photoswitchable azobenzene beta(2)-AR antagonists that can be reversibly controlled with light. These new photochromic ligands are designed following the azologization strategy, with a p-acetamido azobenzene substituting the hydrophobic moiety present in many beta(2)-AR antagonists. Using a fluorescence resonance energy transfer (FRET) biosensor-based assay, a variety of photopharmacological properties are identified. Two of the light-regulated molecules show potent beta(2)-AR antagonism and enable a reversible and dynamic control of cellular receptor activity with light. Their photopharmacological properties are opposite, with Photoazolol-1 being more active in the dark and Photoazolol-2 demonstrating higher antagonism upon illumination. In addition, we provide a molecular rationale for the interaction of the different photoisomers with the receptor. Overall, we present innovative tools and a proof of concept for the precise control of beta(2)-AR by means of light.