Light Harvesting in a Fluctuating Antenna
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- 作者：Jevgenij Chmeliov ; Gediminas Trinkunas ; Herbert van Amerongen ; Leonas Valkunas
- 刊名：Journal of the American Chemical Society
- 出版年：2014
- 出版时间：June 25, 2014
- 年：2014
- 卷：136
- 期：25
- 页码：8963-8972
- 全文大小：530K
- ISSN：1520-5126
文摘
One of the major players in oxygenic photosynthesis, photosystem II (PSII), exhibits complex multiexponential fluorescence decay kinetics that for decades has been ascribed to reversible charge separation taking place in the reaction center (RC). However, in this description the protein dynamics is not taken into consideration. The intrinsic dynamic disorder of the light-harvesting proteins along with their fluctuating dislocations within the antenna inevitably result in varying connectivity between pigment鈥損rotein complexes and therefore can also lead to nonexponential excitation decay kinetics. On the basis of this presumption, we propose a simple conceptual model describing excitation diffusion in a continuous medium and accounting for possible variations of the excitation transfer rates. Recently observed fluorescence kinetics of PSII of different sizes are perfectly reproduced with only two adjustable parameters instead of the many decay times and amplitudes required in standard analysis procedures; no charge recombination in the RC is required. The model is also able to provide valuable information about the structural and functional organization of the photosynthetic antenna and in a straightforward way solves various contradictions currently existing in the literature.