0372-400Х (Edition in Ukrainian)
2071-0186 (Edition in English)
2071-0194 (in electronic form)
Abbreviated key title: Ukr. J. Phys.
Barabash Y.M., Drapikovskyi M.A., Zabolotny M.A., Kulish M.P., Dmytrenko O.P.
Taras Shevchenko National University of Kyiv
(2, Prosp. Academician Glushkov, Kyiv 03022, Ukraine)
Investigation of the Kinetics of Photoinduced Electronic Transitions in Nanostructures of Bacterial Reaction Centers
Original Author's Text: English
Abstract: We have studied the slow dynamics of isolated complexes of chlorophyll-containing membrane proteins of photosynthetic reaction centers (RCs) of Rb. sphaeroides R-26 induced by light fluxes. The analysis of a variation of the absorption of a solution of RCs in the frame of the three-level model is carried out. The equation defining the ratio of the populations of the electron levels of the primary and secondary quinones is deduced. The solution of this equation has non-Boltzmann character even in the stationary case and depends on the exciting light intensity. A model of the dynamics of levels of RC, which accounts for the presence of polarization processes in a vicinity of the secondary quinone acceptor (QB) is proposed. It is assumed that all RCs have the same structure, but can be in different states, whose characteristics depend on both the time interval having passed after the absorption of a light quantum and the local viscosity and elasticity of the environment of QB. The presence of deformational properties of the environment of QB yields the possibility for a configuration of RC to be changed, which agrees with the experimental data.
Key words: biophysics, bacterial reaction centers, electron kinetics, models.