Protein-promoted chromophore excited-state decay modulation

Abstract:

In natural photosynthesis, sunlight harvested energy transfers through a dynamic protein-chromophore network with a remarkable near-unity quantum efficiency. Local fluctuations in the protein structures and conformational changes are essential for nature's efficient light conversion, but their design principles remain to be elucidated.

In our lab, we develop simplified hybrid systems linking chromophores to engineered proteins. This strategy allows us to rationally modify the protein-chromophore interaction's nature and strength, evaluated as bio-exciton coupling. We study excited-state dynamics using time-resolved spectroscopy and correlate decay kinetics with engineered bio-exciton coupling. Small changes in the protein sequence make chromophore excitation follow a preferential decay pathway. Our studies set the basis to use a controlled modification of the chromophore environment to improve light energy conversion efficiency in engineered photosystems.