A Red-Shifted, Fast-Relaxing Azobenzene Photoswitch for Visible Light Control of an Ionotropic Glutamate Receptor

Journal of the American Chemical Society (Impact Factor: 11.44). 10/2013; 135(47). DOI: 10.1021/ja408104w
Source: PubMed

ABSTRACT Azobenzene photoswitches have become a dependable method for rapid and exact modulation of biological processes and material science systems. The requirement of ultraviolet (UV) light for azobenzene isomerization is not ideal for biological systems due to poor tissue penetration and potentially damaging effects. While modified azo-benzene cores with a red-shifted cis to trans isomerization have been previously described, they have not yet been incorporated into a powerful method to control protein function: the photoswitchable tethered ligand (PTL) approach. We report the synthesis and characterization of a red-shifted PTL, L-MAG0460, for the light-gated ionotropic glutamate receptor LiGluR. In cultured mammalian cells, the LiGluR+L-MAG0460 system is activated rapidly by illumination with 400-520 nm light to generate a large ionic current. The current rapidly turns off in the dark as the PTL relaxes thermally back to trans. The visible light excitation and single wavelength behavior considerably simplifies use and should improve utilization in tissue.

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