STRUCTURAL DYNAMICS OF PURPLE BACTERIA RE ACTION CENTERS AFFECTS STABILIZATION OF PHOTOMOBILIZED ELECTRON ON QUINONE ACCEPTORS

Background illumination of reaction centers of purple bacteria leads t o stationary oxidation of some reaction centers and can also increase the rate of reduction of photooxidized bacteriochlorophyll by quinone accepters. The latter can be explained by the time distribution of rel axation processes in the reaction centers accompanied by changes in ch arge of the electron carriers. Accelerated cooling (15 degrees C/s and more) of samples adapted to the activation light fixes low temperatur e distribution of conformation states; the indices of the pigment-acce ptor interaction differ from those seen under conditions of slow cooli ng (similar to 0.1 degrees C/s). The observed variability reflects the diversity of structural dynamics of the reaction centers.