Elementary Energy Transfer Pathways in Allochromatium vinosum Photosynthetic Membranes.
Elementary Energy Transfer Pathways in Allochromatium vinosum Photosynthetic Membranes.
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Allochromatium vinosum 光合膜中的基本能量传递途径。
DOI：
10.1016/j.bpj.2015.09.008
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发表时间：
2015
影响因子：
3.4
通讯作者：
Lüer L
中科院分区：
文献类型：
--
作者：
Lüer L
已知葡萄异色菌（Allochromatium vinosum）紫色细菌在生长期间根据环境因素（例如温度和平均光强度）来调整其光捕获策略。在低光照或低环境温度条件下，光合膜中的大多数LH 2复合物形成B820激子，其与LH 1的光谱重叠减少。为了阐明LH2电子结构的这种光和温度适应的原因，我们在A. vinosummembrane中进行了宽带飞秒瞬态吸收光谱作为激发波长的函数。所获得的数据的目标分析产生的所有相关的基本能量转移（ET）过程的个别速率常数。我们发现，在高光生长膜的ET动力学是很好地描述了一个均匀的模型，向前和向后的速率常数独立的泵浦波长。因此，整个B800→B850→B890→反应中心ET级联反应可以用简单的三指数动力学很好地描述。在低光生长的膜中，我们发现，从B890到B820的基本反向传输速率常数与高光生长的样品中从B890到B850的相应常数相比大大降低。低光生长膜的ET动力学强烈依赖于泵浦波长，清楚地表明，激发记忆在整个激子寿命中不会丢失。所观察到的前向和后向ET速率常数的泵浦能量依赖性表明激子通过B850→ B850转移步骤扩散，使得整体ET动力学非指数。我们的研究结果表明，紊乱在我们理解低光适应中起着至关重要的作用。
Allochromatium vinosum(formerlyChromatium vinosum) purple bacteria are known to adapt their light-harvesting strategy during growth according to environmental factors such as temperature and average light intensity. Under low light illumination or low ambient temperature conditions, most of the LH2 complexes in the photosynthetic membranes form a B820 exciton with reduced spectral overlap with LH1. To elucidate the reason for this light and temperature adaptation of the LH2 electronic structure, we performed broadband femtosecond transient absorption spectroscopy as a function of excitation wavelength inA. vinosummembranes. A target analysis of the acquired data yielded individual rate constants for all relevant elementary energy transfer (ET) processes. We found that the ET dynamics in high-light-grown membranes was well described by a homogeneous model, with forward and backward rate constants independent of the pump wavelength. Thus, the overall B800→B850→B890→ Reaction Center ET cascade is well described by simple triexponential kinetics. In the low-light-grown membranes, we found that the elementary backward transfer rate constant from B890 to B820 was strongly reduced compared with the corresponding constant from B890 to B850 in high-light-grown samples. The ET dynamics of low-light-grown membranes was strongly dependent on the pump wavelength, clearly showing that the excitation memory is not lost throughout the exciton lifetime. The observed pump energy dependence of the forward and backward ET rate constants suggests exciton diffusion via B850→ B850 transfer steps, making the overall ET dynamics nonexponential. Our results show that disorder plays a crucial role in our understanding of low-light adaptation inA. vinosum.
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影响因子：
4.3
作者：
de Rivoyre, Matthieu;Ginet, Nicolas;Lavergne, Jerome
通讯作者：
Lavergne, Jerome
影响因子：
2.9
作者：
Nagarajan, V;Parson, WW
通讯作者：
Parson, WW
影响因子：
4.3
作者：
Carey, Anne-Marie;Hacking, Kirsty;Cogdell, Richard J.
通讯作者：
Cogdell, Richard J.
John T.M.Kennis 等人：“光合紫色硫细菌 Chromatium tepidum 的分离 B800-850 复合物中的能量转移和激子耦合。
DOI：
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发表时间：
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影响因子：
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作者：
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分子聚集体的三阶光学响应。
DOI：
--
发表时间：
1993
期刊：
影响因子：
--
作者：
J. Knoester
通讯作者：
J. Knoester