Photoswitchable Antagonists for a Precise Spatiotemporal Control of β2-Adrenoceptors

β2-Adrenoceptors (β2-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 β2-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 β2-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 β2-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 β2-AR by means of light.We thank Montserrat Masoliver (UVic-UCC, Vic, Spain), Joan Bertrán (UVic-UCC, Vic, Spain), Jordi Serra (UVic-UCC, Vic, Spain), Lourdes Muñoz (SiMChem, IQAC-CSIC, Barcelona), Maria José Bleda (IQAC-CSIC, Barcelona), Ignacio Pérez (IQAC-CSIC, Barcelona), Yolanda Pérez (IQAC-CSIC, Barcelona) and Carme Serra (SiMChem, IQAC-CSIC, Barcelona) for technical support. We thank Dr. Kees Jalink (The Netherlands Cancer Institute, Amsterdam, the Netherlands) for providing the plasmids encoding for the Epac-SH188 biosensor. We thank the Cisbio Bioassays for their support and technical discussion, as well as for providing plasmids in the preliminary optimization of the biological assays. The project that gave rise to these results received the support of a fellowship from “la Caixa” Foundation (ID 100010434). The fellowship code is (LCF/BQ/DE18/11670012). This work was supported by FEDER/Ministerio de Ciencia, Innovación y Universidades–Agencia Estatal de Investigación (CTQ2017-89222-R), the Catalan government (2017SGR1604), PO FEDER of Catalonia 2014-2020 (project PECT Osona Transformació Social, Ref. 001-P-000382) and the Spanish Ministry of Economy, Industry and Competitiveness (SAF2015-74132-JIN).Peer reviewe