[The analysis of kinetics of recombination of photodivided charges in the Rhodobacter sphaeroides photosynthetic reaction centers using relaxation time constant distribution method].

The kinetics of dark recombination of charges photodivided between the bacteriochlorophyll dimer (P) and the quinone acceptors of the photosynthetic reaction centers (RCs) of Rhodobacter sphaeroides has been studied. The electron transfer between P and the quinone acceptors of times of light activation from 1 to 60 s was investigated. The relaxation time constant distribution was computed from experimental kinetic curves of charge recombination using an original method developed by the authors.

[Slow photoinduced changes in reaction centers of Rhodobacter sphaeroides R-26 by holographic interferometry].

Using the on-line holographic interferometry, changes in the refraction index of illuminated solutions containing the Rhodobacter sphaeroides R-26 reaction centers isolated from membranes by detergents of ionic and nonionic nature were registered. Factors affecting the refraction index of these solutions were analyzed. It was shown that the photoinduced changes in this parameter are due to structural changes in the molecular complex of reaction centers.

[A new phenomenon induced by ion conformational interaction in biomembrane channels].

In several experimental studies it has been observed that when the ion flow approaches zero one of the conduction sublevels disappears irrespective of how the controlling parameters are changed. It is explained by the fact that the bistable regime in the ion channel appears only when the difference of the electrochemical potentials exceeds the threshold level, and such systems can function only in strongly now-equilibrium conditions. We describe the conformational mobility of the ion channel structure in terms of stochastic differential equations.

[Electron-conformation transitions in the complex of bacterial photosynthetic reaction centers with cytochromes].

A theoretical model of conformation--regulated electron transfer from multihaem cytochrome c to bacteriochlorophyll of the reaction centre (RC) is considered. The theoretical data are compared with the experimental ones on the basis of temperature dependence of laser-induced electron transfer from high-potential cytochrome Ch bacheriochlorophyll of RC in Ectothiohodospira shaposhnikovii chromatophores. From this comparison there were calculated the thermodynamic characteristics of cytochrome Ch transfer from the configuration without electron transfer to RC bacteriochlorophyll into the coordinated configuration with an effective transfer.