Self-Assembly of Light-Harvesting Complex for An Artificial Photosynthetic Antenna System and Its Functional Analysis

人工光合天线系统集光复合体的自组装及其功能分析

基本信息

批准号：
13480186
负责人：
NANGO Mamoru
金额：
$ 9.28万
依托单位：
Nagoya Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13480186/
关键词：
Photosynthetic light-harvesting Self assembly lipid bilayers electrode Photocurrent 光合成細菌人口光合成

项目摘要

The light reactions occur in closely coupled pigment systems of the light-harvesting (LH) -α and -β polypeptides and reaction center (RC) complexes in photosynthetic bacteria ; light energy is absorbed by excitonically coupled antenna pigments bound to the LH polypeptides, and the excitation energy is efficiently transported to RC. Thus, the construction of the LH 1 complex with the excitonically coupled pigments will be useful for studying the structure and the energy transfer via individual pigments.We now report molecular assemblies of bacteriochlorophylls (BChl a &Zn-BChl a) using LH polypeptides separately isolated from photosynthetic bacteria on electrodes. The LH polypeptides organized Zn-BChl a complex on electrodes as well as BChl a complex, where polar amino acids at N-or C-terminal of the LH polypeptides performed a crucial role on the complex-formation. The stability of the complexes depended upon the structure of lipid bilayers. The proof of the complex-forming on electrod … More es was noted by monitoring the Qy absorption band-shift of BChl a or Zn-BChl a, where the Qy band was red-shifted. The Zn-BChl a complex in lipid bilayers was more stable than BChl a complex. UV-vis., CD and AFM data of these pigment complexes assembled with the LH polypeptides in lipid bilayers were analogous to those of the LH1-type complex of these photosynthetic bacterias.Further, successful immobilizations of reconstituted light-harvesting 1 (LH1) complexes onto amino terminated ITO electrode (APS-ITO) as well as the LH1-RC 'core' complex were studied. Our recent work extends this approach to using the combination of the LH-α and -β polypeptides and bacteriochlorophylls as the native LH and RC complexes. These complexes were immobilized onto the electrode. The assembly of the complexes on the electrode was confirmed by Near-IR absorption spectroscopy. These data showed that the LH1-type complex consisting of the LH -α and -β polypeptides with BCH a or Zn-BChl a was stably assembled on the electrode at room temperature as well as on a GC and an ITO modified with lipid bilayers. These absorption spectra were usefull to demonstrate the photocurrent response induced by illumination at 880 nm, showing electron transfer between bacteriochlorophylls and these electrodes. Interestingly, the photoelectric current on these electrodes depended on the structures of the LH complexes and the wavelength of the light, and the structure of lipid bilayers. The action spectra revealed a maximum at the wavelength corresponding to the absorption band of the complexes. Less

光反应发生在光合细菌中光收获（LH）-α和-β多肽和反应中心（RC）复合物的近耦合猪系统中。光能通过与LH多肽结合的激偶联天线色素吸收，而刺激能有效地运输到RC。这是，使用兴奋的耦合色素的LH 1复合物的构造将有助于研究通过各个色素的结构和能量转移。现在，我们报告使用与光合细菌在电动机上分离的LH多肽分别分离出细菌叶绿素（BCHL A＆ZN-BCHL A）的分子组件（BCHL A＆ZN-BCHL A）。 LH多肽在电极和BCHL A上组织了Zn-BCHL A复合物，其中LH多肽的N或C末端的极性氨基酸在复合形成中起着至关重要的作用。复合物的稳定性取决于脂质双层的结构。通过监视BCHL A或Zn-BCHL A的QY抽象带换档，在电极上进行复合形成的证明，其中QY带被红色换。脂质双层中的Zn-BCHL A复合物比BCHL A复合物更稳定。这些色素双层中与LH多肽组装的这些色素复合物的UV-VIS，CD和AFM数据类似于这些光合细菌的LH1型型复合物的含量类似。研究了“核心”复合物。我们最近的工作将这种方法扩展到使用LH -α和-β多肽和细菌氯酚类作为天然LH和RC复合物的组合。这些络合物被固定在电极上。通过近红外抽象光谱证实了复合物在电极上的组装。这些数据表明，由LH-α和-β多肽与BCH A或Zn-BCHL A组成的LH1型复合物在室温下以及在GC上稳定地组装在电极上，并在GC上和ITO修饰了脂质双层。这些抽象光谱可用于证明在880 nm处照明引起的光电流响应，显示细菌氯栖omlodriophiarylohlophylls和这些电子之间的电子转移。有趣的是，这些电子上的光电电流取决于LH复合物的结构和光的波长以及脂质双层的结构。动作光谱在与复合物的抽象带相对应的波长处揭示了最大值。较少的