Nonlinear Dynamic Processes in an Ensemble of Photosynthetic Reaction Centers. Theory and Experiment

Goushcha, Alexander O.; Kapoustina, M. T.; Kharkyanen, and Valery N.; Holzwarth, Alfred R.

doi:10.1021/jp970868k

Cited by 17 publications

(13 citation statements)

References 38 publications

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“…For a set of given values of the rate constants the kinetics of ET is described by a system of balance equations (see e.g. [15][16][17]24]) that corresponds to Scheme (s1). The solution of such equations for the case of Rb.…”

Section: Structural Self-regulation In Rcmentioning

confidence: 99%

“…The latter implies certain nonlinear phenomena (characterized e.g. by hysteresis and bifurcations in the system transport properties) emerging due to the feedback between the flow of transferred charges and structural variables, see also [15][16][17]21]. Experimental studies revealed the hysteresis behavior of the absorbance of RCs from Rb.…”

Section: Introductionmentioning

confidence: 99%

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Abgaryan

Christophorov

Goushcha

et al. 1998

Journal of Biological Physics

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We describe the phenomenon of light-induced structural transformations in the reaction centers (RC) of photosynthetic bacteria which makes self-regulation of the RC charge separation efficiency possible. The nature of the effect is that the light-driven electron transfer (ET) between the RC redox-cofactors causes structural changes in the protein-cofactors system and this in turn affects the ET kinetics. If the electron-conformation interaction is strong enough, then such self-regulation gives birth to a new RC conformational state of enhanced charge separation efficiency. We show experimental results of stationary and kinetic absorbance change characteristics under different photoexcitation conditions, indicating structural rearrangements on a rather long (minutes) time scale, mainly within the secondary acceptor binding pocket. To simplify the description, in constructing a theory of structure-function reorganization in the RC we employ the adiabatic approach. Final expressions enable us to make qualitative comparison with experimentally observed kinetics of the fast and slow stages of 'free' and 'structurally controlled' electron relaxation, respectively.

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Section: Structural Self-regulation In Rcmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Untitled

Abgaryan

Christophorov

Goushcha

et al. 1998

Journal of Biological Physics

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“…In this case, the coefficient 21 should be determined with the help of Eq. (8). We also additionally assumed [5,7] that the coefficient of extinction does not depend on time.…”

Section: The Three-level Model Of the Dynamics Of An Electron In Rcmentioning

confidence: 99%

“…Let the potential energy ( ) of quinone Q attain the minimum at the point = 0. For simplicity, we assume that the function ( ) has[2,5,8] parabolic character:…”

mentioning

confidence: 99%

Investigation of the Kinetics of Photoinduced Electronic Transitions in Nanostructures of Bacterial Reaction Centers

et al. 2016

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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 (Q) 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 Q. The presence of deformational properties of the environment of Q yields the possibility for a configuration of RC to be changed, which agrees with the experimental data.

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“…If the electron overcomes the barrier by the tunneling mechanism, relation (29) should be replaced by the relevant one from work [9]. The value of k АВ is determined by the relation analogous to (29):…”

Section: Model For K 21 (T) In the Dark Statementioning

confidence: 99%

A Model of Light-Activated Changes in Reaction Centers of Purple Bacteria

Barabash¹

2015

J Bioprocess Biotech

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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 the presence of polarization processes in the vicinity of the secondary quinone acceptor (Q B ) 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 Q B . The presence of deformational properties of the environment of Q B yields the possibility for a configuration of RC to be changed, which agrees with the experimental data.

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Nonlinear Dynamic Processes in an Ensemble of Photosynthetic Reaction Centers. Theory and Experiment

Cited by 17 publications

References 38 publications

Untitled

Untitled

Investigation of the Kinetics of Photoinduced Electronic Transitions in Nanostructures of Bacterial Reaction Centers

A Model of Light-Activated Changes in Reaction Centers of Purple Bacteria

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