Light-induced conformational changes of two different Channelrhodopsin mutants probed by difference mid-Infrared microspectroscopy with Synchrotron radiation

We apply mid-Infrared (mid-IR) microspectroscopy performed with Synchrotron radiation in order to investigate the functional conformational changes of two different mutants of the light-sensitive transmembrane protein Channelrhodopsin (ChR), a microbial rhodopsin widely used in optogenetic applications. Our results serve as a promising preliminary step towards the investigation of light-sensitive ChR proteins at the nanoscale by means of mid-IR nanospectroscopic techniques based on the use of an atomic force microscope.