Mechanism of LaCl3 on Increasing Photosystem II Activity of Spinach
Mechanism of LaCl3 on Increasing Photosystem II Activity of Spinach
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DOI：
10.1002/cjoc.200590617
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发表时间：
2005-05
影响因子：
5.4
通讯作者：
H. Fa-shui;W. Ling;Tao Ye
中科院分区：
文献类型：
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作者：
H. Fa-shui;W. Ling;Tao Ye
研究了LaCl3对菠菜PSII颗粒中K3Fe(CN)6 （FeCy）还原速率和出氧速率的影响，以及由菠菜中3个多肽组成的PSII反应中心复合物D1/D2/Cytb559的光谱表征。实验结果表明，LaCl3能显著加速菠菜PSII光能向电能的转化、电子传递、水光解和析氧，这与D1/D2/Cytb559配合物的光谱表征有关。D1/D2/Cytb559复合物紫外-可见光谱中Chl-a的sot波段和Q波段发生蓝移，与对照相比，LaCl3处理的菠菜荧光发射峰发生蓝移。扩展x射线吸收精细结构光谱（EXAFS）表明，在D1/D2/Cytb559配合物中，La3+在第一个配位壳层与8个氮或氧原子配位，键长为0.254 nm；在第二个配位壳层与6个氮或氧原子配位，键长为0.321 nm。结果表明，LaCl3对D1/D2/Cytb559复合体的二级结构影响不大。
The effect of LaCl3 on the K3Fe(CN)6 (FeCy) reduction rate and the oxygen-evolving rate of PSII particles of spinach, and the spectral characterization of the D1/D2/Cytb559 of a PSII reaction center complex consisting of three polypeptides from spinach were studied. The experimental results showed that LaCl3 could significantly accelerate the transformation from light energy to electric energy, the electron transport, water photolysis and oxygen evolution of PSII of spinach, which was related to the spectral characterization of the D1/D2/Cytb559 complex. Soret band and Q band of Chl-a of UV-vis spectrum of D1/D2/Cytb559 complex were blue shifted, and the fluorescence emission peak was blue shifted in LaCl3 treated spinach compared with that in the control. The EXAFS (extended X-ray absorption fine structure spectroscopy) revealed that La3+ was coordinated with 8 nitrogen or oxygen atoms in the first coordination shell with LaN or LaO bond length of 0.254 nm, and with 6 nitrogen or oxygen atoms in the second coordination shell with LaN or LaO bond length of 0.321 nm in the D1/D2/Cytb559 complex. The CD suggested that the secondary structure of D1/D2/Cytb559 complex have been little affected by the treatment of LaCl3.