Olenchuk M. Investigation of photoinduced electron transfer in photosynthetic bacterial reaction centers

The interaction between light and photoactive biological macromolecules, photosynthetic bacterial reaction centers (RC), which are capable to stay in charge separated states for a long time (second and more) has been investigated and sys-temized. The conditions for uniform distribution of exciting light along its optical way were defined. To analyze the ex-perimental data the new computational technique which tak-ing into account the nonlinearity of molecular absorptions was developed. Experimental results of photodonor oxidation kinetic revealed that short light excitation (< 5s, intensity < 2mW/cm2 ) does not lead to any substantial conformational changes but in-crease of photoactivation time (up to hundreds seconds) de-creases the decay rate of charge separated states in order of several magnitudes. The decay rate also depends on light in-tensity, temperature and type of detergent. The research data confirmed the appearance of new conformational sub-states in RC macromolecules. These new sub-states depends on condi-tion of photoactivation, namely, intensity and duration of light excitation. The rate constant of electron recombination from charge separated states were analyzed for different type of RC.