A fine-tuned azobenzene for enhanced photopharmacology in vivo

Cell Chem Biol. 2021 Nov 18;28(11):1648-1663.e16. doi: 10.1016/j.chembiol.2021.02.020. Epub 2021 Mar 17.

Abstract

Despite the power of photopharmacology for interrogating signaling proteins, many photopharmacological systems are limited by their efficiency, speed, or spectral properties. Here, we screen a library of azobenzene photoswitches and identify a urea-substituted "azobenzene-400" core that offers bistable switching between cis and trans with improved kinetics, light sensitivity, and a red-shift. We then focus on the metabotropic glutamate receptors (mGluRs), neuromodulatory receptors that are major pharmacological targets. Synthesis of "BGAG12,400," a photoswitchable orthogonal, remotely tethered ligand (PORTL), enables highly efficient, rapid optical agonism following conjugation to SNAP-tagged mGluR2 and permits robust optical control of mGluR1 and mGluR5 signaling. We then produce fluorophore-conjugated branched PORTLs to enable dual imaging and manipulation of mGluRs and highlight their power in ex vivo slice and in vivo behavioral experiments in the mouse prefrontal cortex. Finally, we demonstrate the generalizability of our strategy by developing an improved soluble, photoswitchable pore blocker for potassium channels.

Keywords: G protein-coupled receptor; PORTL; azobenzene; calcium signaling; dorsal root ganglia; metabotropic glutamate receptor; optogenetics; photopharmacology; potassium channel; prefrontal cortex; working memory.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Azo Compounds / chemistry
  • Azo Compounds / pharmacology*
  • Cells, Cultured
  • Female
  • Humans
  • Ligands
  • Mice
  • Photochemical Processes
  • Potassium Channels / metabolism*
  • Receptors, Metabotropic Glutamate / antagonists & inhibitors*
  • Receptors, Metabotropic Glutamate / metabolism
  • Signal Transduction / drug effects

Substances

  • Azo Compounds
  • Ligands
  • Potassium Channels
  • Receptors, Metabotropic Glutamate
  • azobenzene