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Reconstitution of lypophilic components in Photosystem I complex which had been extracted with diethyl ether

用乙醚萃取的光系统 I 复合物中亲脂性成分的重构

基本信息

批准号：
15570040
负责人：
IKEGAMI Isamu
金额：
$ 2.5万
依托单位：
Teikyo University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15570040/
关键词：
Photosynthesis Photosystem I Photosynthetic Reaction center Chlorophyll P700

项目摘要

1.Chlorophylls, such as Chl b, Chl a epimer and Phe a, all which do not act as intrinsic antenna in the PSI RC complex, were added with phosphatidylglycerol to the antenna-depleted PSI complex that had a Chl a/P700 ratio of 12. We found that the Chl a-binding site allows to receive Chl b with the same affinity as Chl a, but Chl a epimer with the affinity half of Chl a. The bound Chl b and Chl a epimer act as efficient antenna as Chl a. Phe a binds the antenna-depleted PSI complex, but without any efficient transfer of light energy to P700. We conclude that Chl a-binding site is tolerable to Chl with a side-chain different from Chl a, showing lower affinity with a large structural difference, and that Mg is essential to bind the site.2.Chlorella, when grown in the dark with an extremely high concentration of Zn, formed Zn-Chl a in amount of about 30% of Chl a. We found that the Zn-Chl a binds to PSI and PSII RC complexes and acts as efficient antenna as Mg-Chl a.3.PSI complex isolated from phylloquinone-depleted mutant of Arabidopsis, had no P700 but emitted the far red fluorescence at 77K which is characteristic to PSI antenna. We suggest that it had a PSI complex with antenna Chl a but without PSI electron carriers such as P700 and A_0.

1.将叶绿素（如Chl b、Chl a外映体和Phe a）加入到Chl a/P700比值为12的无天线PSI - RC复合物中，这些叶绿素在PSI - RC复合物中不充当本振天线。我们发现Chl - a结合位点允许接收与Chl - a具有相同亲和力的Chl -b，但Chl - a的亲和力只有Chl - a的一半。结合的Chl -b和Chl - a表映体作为Chl - a的有效天线。Phe a结合了天线消耗的PSI复合物，但没有任何有效的光能转移到P700。我们得出结论，Chl - a结合位点与Chl - a的侧链不同，Chl - a可以耐受，其亲和力较低，结构差异大，Mg是结合该位点所必需的。当小球藻在极高浓度Zn的黑暗环境中生长时，形成约30% Chl a的Zn-Chl a。我们发现Zn-Chl a与PSI和PSII RC配合物结合，并作为Mg-Chl a的有效天线。从拟南芥叶绿醌缺失突变体中分离得到的PSI配合物不含P700，但在77K下发出PSI天线特有的远红色荧光。我们认为它具有具有天线Chl a的PSI配合物，但没有P700和A_0等PSI电子载流子。