Ultrafast Photoinduced Deactivation Dynamics of Proteorhodopsin

We report femtosecond time-resolved absorption change measurements of the photoinduced deactivation dynamics of a microbial rhodopsin in the ultraviolet–visible and mid-infrared range. The blue light quenching process is recorded in green proteorhodopsin’s (GPR) primary proton donor mutant E108Q from the deprotonated 13-cis photointermediate. The return of GPR to the dark state occurs in two steps, starting with the photoinduced 13-cis to...