Electronic Structure Effects Related to the Origin of the Remarkable Near-Infrared Absorption of Blastochloris viridis' Light Harvesting 1-Reaction Center Complex.
Electronic Structure Effects Related to the Origin of the Remarkable Near-Infrared Absorption of Blastochloris viridis' Light Harvesting 1-Reaction Center Complex.
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与Blastochloris viridis光捕获1-反应中心复合物显著近红外吸收起源相关的电子结构效应。
DOI：
10.1021/acs.jctc.2c00497
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发表时间：
2022-07-12
影响因子：
5.5
通讯作者：
Barroso-Flores, Joaquin
中科院分区：
文献类型：
--
作者：
Mondragon-Solorzano, Gustavo;Sandoval-Lira, Jacinto;Nochebuena, Jorge;Cisneros, G. Andres;Barroso-Flores, Joaquin
各种光合作用生物已经进化到吸收可见光光谱不同区域的光，从而适应地球上各种可用的照明条件。虽然这些自养生物大多在700-800 nm附近吸收波长，但也有一些能够在此范围以上红移吸收，但没有绿色布拉德绿那么显著，其主要吸收在1015 nm，比其主要成分色素BCHL-b低约220 nm(0.34 eV)，其主要吸收在795 nm。它的捕光1-反应中心的结构最近被冷冻-EM阐明；然而，这种红移吸收背后的电子结构细节仍然没有得到关注。我们使用混合量子力学/分子力学(QM/MM)计算优化了其中一个活性中心，并进行了经典分子动力学(MD)模拟来采样优化结构以外的构象。我们用含时密度泛函方法在CAM-B3LYP/cc-pVDZ水平上进行了激发态计算。我们通过使用计算的MD系综中的代表性结构顺序地修改我们系统中涉及的组件的数量来重现近红外吸收。自然跃迁轨道分析揭示了BCHL-b片段参与了天然结构和由QM/MM和MD模拟得到的结构中的主要跃迁。氢键色素与蛋白质之间的相互作用对分子的构象稳定和定向起作用，而细菌氯素环构象和激子离域是造成红移现象的最主要因素。
Various photosynthetic organisms have evolved to absorb light in different regions of the visible light spectrum, thus adapting to the various lighting conditions available on Earth. While most of these autotrophic organisms absorb wavelengths around the 700–800 nm region, some are capable of red-shifted absorptions above this range, but none as remarkably as Blastochloris viridis whose main absorption is observed at 1015 nm, approximately 220 nm (0.34 eV) lower in energy than their main constituent pigments, BChl-b, whose main absorption is observed at 795 nm. The structure of its light harvesting 1-reaction center was recently elucidated by cryo-EM; however, the electronic structure details behind this red-shifted absorption remain unattended. We used hybrid quantum mechanics/molecular mechanics (QM/MM) calculations to optimize one of the active centers and performed classical molecular dynamics (MD) simulations to sample conformations beyond the optimized structure. We did excited state calculations with the time-dependent density functional theory method at the CAM-B3LYP/cc-pVDZ level of theory. We reproduced the near IR absorption by sequentially modifying the number of components involved in our systems using representative structures from the calculated MD ensemble. Natural transition orbital analysis reveals the participation of the BChl-b fragments to the main transition in the native structure and the structures obtained from the QM/MM and MD simulations. H-bonding pigment–protein interactions play a role on the conformation stabilization and orientation; however, the bacteriochlorin ring conformations and the exciton delocalization are the most relevant factors to explain the red-shifting phenomenon.
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阐明生命的起源：生物分子非生物合成中的紫外光化学。
影响因子：
15
作者：
Green NJ;Xu J;Sutherland JD
通讯作者：
Sutherland JD
DOI：
10.1107/s0907444904019158
发表时间：
2004-12-01
影响因子：
2.2
作者：
Emsley, P;Cowtan, K
通讯作者：
Cowtan, K
影响因子：
4.3
作者：
Llansola-Portoles, Manuel J.;Li, Fei;Robert, Bruno
通讯作者：
Robert, Bruno
影响因子：
2.2
作者：
EDWARDS, WD;ZERNER, MC
通讯作者：
ZERNER, MC
影响因子：
3.7
作者：
Fujita, Takatoshi;Huh, Joonsuk;Aspuru-Guzik, Alan
通讯作者：
Aspuru-Guzik, Alan