Peculiarities of light-induced slow protein dynamics in the photosynthetic reaction center

A series of distinctive peaks of the relaxation time spectrum is revealed in dispersive kinetics of recombination of the photogenerated radical pair in the photosynthetic reaction center (RC). They reflect the formation of ‘taxonomic’ conformational states of the RC under continuous pre-illumination. With the longer exposure, the positions of the peak maxima shift linearly to longer times. Subsequent recombination kinetics in these states follow the same fractional power law, clearly pronounced even at room temperatures and in the absence of agents constraining conformational lability.