β-Carotene Probes the Energy Transfer Pathway in the Photosystem II Core Complex
β-Carotene Probes the Energy Transfer Pathway in the Photosystem II Core Complex
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β-胡萝卜素探索光系统 II 核心复合体中的能量传递途径
DOI：
10.1021/acs.jpclett.9b01072
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Miyasaka Hiroshi
中科院分区：
文献类型：
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作者：
Yoneda Yusuke;Nagasawa Yutaka;Umena Yasufumi;Miyasaka Hiroshi
完整的光系统II核心复合体(PSII-CC)的动力学已被广泛研究，以阐明其优异的光功能。然而，由于核心复合体中的大量叶绿素(Chl)具有相似的光谱特征，因此很难观察到PSII-CC的初级光合作用过程。本文比较了不同激发波长下，β-胡萝卜素(Bcr)在完整的PSⅡ-CC中的能量转移(ET)和反应中心电荷分离(CS)的动力学。当激发波长为510 nm，选择性激发D1D2RC内的Bcr(Bcr651)时，叶绿素阴离子吸收带出现在9.6ps内。另一方面，当激发波长为490 nm时，主要激发天线复合体中的未知BCR，在20ps后出现阴离子带。这些激发波长依赖的实验揭示了PSII-CC的一条新的ET途径，这表明PSII-CC的初始CS受到ET对RC的限制。
The dynamics of the intact photosystem II core complex (PSII-CC) has been investigated extensively to elucidate its excellent photofunction. However, it is significantly difficult to observe the primary photosynthetic processes in PSII-CC because a vast number of chlorophylls (Chl) in the core complex show similar spectral features. In the present work, the dynamics of the energy transfer (ET) from β-carotene (Bcr) in intact PSII-CC followed by charge separation (CS) at the reaction center (RC) with different excitation wavelengths were compared. Upon excitation at 510 nm, which selectively excites Bcr (Bcr651) inside of the D1-D2 RC, the pheophytin anion absorption band appeared within 9.6 ps. On the other hand, upon excitation at 490 nm, mainly exciting unspecified Bcr in the antenna complex, the anion band appeared after 20 ps. These excitation wavelength dependence experiments revealed a new ET pathway of PSII-CC, which indicates that the initial CS of PSII-CC is limited by ET to the RC.