Nanoengineered Light-Harvested Proteins for Optogenetics and Photopharmacology

Chemical modification with nanometer precision can be used to probe and to improve the function of complex molecular entities, from organic materials to proteins and their assemblies. Using the pigment arrangement in photosynthetic light-harvesting as inspiration, we show that molecular photosensitizers can be located at well-defined distances from photoisomerizable units in proteins in order to enhance and spectrally shift their photoresponses. The approach is demonstrated in Channelrhodopsin-2 (ChR2) and in the light-gated ionotropic glutamate receptor (LiGluR), two archetypical actuators in optogenetics and photopharmacology that have been used both for fundamental and therapeutic purposes. These proof-of-concept experiments together with theoretical simulations predict that the photosensitivity can be increased several orders of magnitude using these means, thus providing a unique methodology to boost the performance of current optogenetic and photopharmacological toolboxes.