通过反散干扰测量检测光系统I:铁素复合物的检测
Pierre Sétif1, Nathan Harris, Bernard Lagoutte
1iBiTec-S, URA CNRS 2096, CEA Saclay, 91191 Gif sur Yvette, France. pierre.setif@cea.fr
Journal of the American Chemical Society
|August 5, 2010
概括
研究人员使用反向散射干扰测量测量了光系统I (PSI):ferredoxin复合体的结合亲和力. 在PsaE亚单元中的一个关键突变显著减少了结合,突出了阿尔金因39的存在.
科学领域:
- 光合作用研究研究光合作用.
- 蛋白质与蛋白质的相互作用
- 生物物理化学 生物物理化学
背景情况:
- 光系统I (PSI) 对于光合作用中的光依赖反应至关重要.
- 铁素在光合作用生物中充当电子载体.
- 了解PSI:ferredoxin相互作用是阐明电子转移通路的关键.
研究的目的:
- 量化测量蓝色细菌PSI:ferredoxin复合物的解离常数 (K(d)).
- 调查PsaE子单元,特别是阿尔金因39在铁素与PSI结合中的作用.
- 根据现有的功能数据验证生物物理测量.
主要方法:
- 使用反向散射干扰测量 (BSI) 来监测复杂的形成.
- 对PSI进行了费雷多克辛度的定位.
- 对干扰边缘移位的分析,以确定折射率的变化.
主要成果:
- 对于野生类型的PSI,确定了0.140.38微米之间的解离常数 (K(d)).
- 在PsaE子单元中没有观察到可检测的复合体形成与PSI突变 (R39Q).
- 结果与之前关于电子转移的功能研究量化一致.
结论:
- 铁素和PSI之间的主要结合相互作用是由PsaE亚单元的特定区域调解的,包括阿尔金宁39.
- 这一发现支持了PSI上ferredoxin单一高亲和结合点的模型.
- 这项研究没有提供证据证明可能逃避功能检测的二次结合部位.
相关概念视频
Photosystem I
Although structurally similar to photosystem II (PSII), photosystem I (PSI) is has a different electron supplier and electron acceptor.
Both these photosystems work in concert. An excited electron from PSII is relayed to PSI via an electron transport chain in the thylakoid membrane of the chloroplast, which is comprised of the carrier molecule plastoquinone, the dual-protein cytochrome complex, and plastocyanin. As electrons move between PSII and PSI, they lose energy and must be re-energized...
Both these photosystems work in concert. An excited electron from PSII is relayed to PSI via an electron transport chain in the thylakoid membrane of the chloroplast, which is comprised of the carrier molecule plastoquinone, the dual-protein cytochrome complex, and plastocyanin. As electrons move between PSII and PSI, they lose energy and must be re-energized...
Photosystem II
The multi-protein complex photosystem II (PS II) harvests photons and transfers their energy through its bound pigments to its reaction center, and ultimately to photosystem I (PSI) through the electron transport chain. The pigments responsible for caputirng the light energy in photosystems include chlorophyll a, chlorophyll b, and carotenoids.
The pigment molecules are arranged across two photosystem domains — the antenna complex and the reaction center. The main aim of the pigment molecules...
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The Photochemical Reaction Center
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Photosystems contain many pigment molecules, such as chlorophylls and carotenoids, arranged in a particular organization across two domains — the antenna complex and the reaction center. The main aim of the pigment molecules...
The Antenna Complex
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There are two main infrared (IR) spectrophotometers: dispersive IR spectrometers and Fourier transform infrared (FTIR) spectrometers. In a dispersive IR spectrometer, a beam of infrared radiation produced by a hot wire is divided into two parallel equal-intensity beams using mirrors. One beam passes through the sample, while another is a reference beam. The beams then move through the monochromator, which separates the radiations into a continuous spectrum of different frequencies. The...

