Abstract:
Retinal proteins are small transmembrane proteins working as photosensors - the visual protein rhodopsin is the most prominent example - or as photo-activated ion pumps in bacteria. According to textbooks the primary photo-reaction in retinal proteins is isomerization of retinal.
But the most recent results from different groups show that faster intra- and inter-molecular processes are also operative. In particular, it is of general importance to understand how the protein controls the bond selectivity and the speed of isomerization. We will report on femtosecond experiments, which reveal new physics regarding the protonated retinal Schiff base in solvents and in the protein matrix.