Theoretical Model of the Far-Red-Light-Adapted Photosystem I Reaction Center of Cyanobacterium <i>Acaryochloris marina</i> Using Chlorophyll <i>d</i> and the Effect of Chlorophyll Exchange
Theoretical Model of the Far-Red-Light-Adapted Photosystem I Reaction Center of Cyanobacterium <i>Acaryochloris marina</i> Using Chlorophyll <i>d</i> and the Effect of Chlorophyll Exchange
复制标题
利用叶绿素<i>d</i>构建蓝藻<i>Acaryocholis marina</i>远红光适应光系统I反应中心的理论模型及叶绿素交换效应
DOI：
10.1021/acs.jpcb.2c00869
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Itoh Shigeru
中科院分区：
文献类型：
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作者：
Kimura Akihiro;Kitoh-Nishioka Hirotaka;Aota Toshimichi;Hamaguchi Tasuku;Yonekura Koji;Kawakami Keisuke;Shinzawa-Itoh Kyoko;Inoue-Kashino Natsuko;Ifuku Kentaro;Yamashita Eiki;Kashino Yasuhiro;Itoh Shigeru
基于激子理论和Hamaguchiet al.最近鉴定的AmPSI分子结构，构建了蓝藻Acaryochlorismarina（AmPSI）远红光适应光系统I（PSI）反应中心（RC）复合体的理论模型。(Nat.通信：2021，12，2333）。marina在可见光至远红光（400-750 nm）下进行光合作用，其被叶绿素（Chl-d）吸收。这是在相反的情况下，所有其他的光合作用过程的蓝藻和植物，其中含有叶绿素（Chl-a），只吸收400-700 nm的可见光。AmPSI含有70个Chl-d、1个Chl-d′、2个Pheo-a和12个类胡萝卜素。一对Chl-d/Chl-d′作为电子供体（P740），两个Pheo-a作为初级电子受体A0，分别作为P700和Chl-a的电子供体。利用Poisson-TrESP（P-TrESP）和电荷密度耦合（CDC）方法，考虑了AmPSI的激子耦合强度和各色素的位能位移，构建了AmPSI的激子哈密顿量.该模型的构建，以适应实验测量的吸收光谱和圆二色性（CD）光谱在下坡/上坡激发能量转移过程中。进一步将所构建的AmPSI理论模型与细长热聚球藻（Thermosynechococcuselongatus，TePSI）的Chl-a-型PSI（仅含Chl-a和Chl-a′）进行了比较。通过Chl-d对AmPSI和TePSI的交换反应进一步考察了AmPSI和TePSI的功能特性。
A theoretical model of the far-red-light-adapted photosystem I (PSI) reaction center (RC) complex of a cyanobacterium,Acaryochloris marina(AmPSI), was constructed based on the exciton theory and the recently identified molecular structure of AmPSI by Hamaguchiet al.(Nat. Commun.,2021,12, 2333).A. marinaperforms photosynthesis under the visible to far-red light (400–750 nm), which is absorbed by chlorophylld(Chl-d). It is in contrast to the situation of all the other oxygenic photosynthetic processes of cyanobacteria and plants, which contains chlorophylla(Chl-a) that absorbs only 400–700 nm visible light. AmPSI contains 70 Chl-d, 1 Chl-d′, 2 pheophytina(Pheo-a), and 12 carotenoids in the currently available structure. A special pair of Chl-d/Chl-d′acts as the electron donor (P740) and two Pheo-aact as the primary electron acceptor A0as the counterparts of P700 and Chl-a, respectively, of Chl-a-type PSIs. The exciton Hamiltonian of AmPSI was constructed considering the excitonic coupling strength and site energy shift of individual pigments using the Poisson-TrESP (P-TrESP) and charge density coupling (CDC) methods. The model was constructed to fit the experimentally measured spectra of absorption and circular dichroism (CD) spectra during downhill/uphill excitation energy transfer processes. The constructed theoretical model of AmPSI was further compared with the Chl-a-type PSI ofThermosynechococcus elongatus(TePSI), which contains only Chl-aand Chl-a′. The functional properties of AmPSI and TePSI were further examined by thein silicoexchange of Chl-dby Chl-ain the models.