通过单分子刺激发射光谱学访问光系统I的天线系统
Xianjun Zhang1,2, Rin Taniguchi1, Ryo Nagao3
1Department of Chemistry, Graduate School of Sciences, Tohoku University, Sendai 980-8578, Japan.
The journal of physical chemistry. B
|March 8, 2024
概括
单分子激发发射谱学 (SMEES) 揭示了光系I中的可变能量转移. 这种技术同时跟踪激发和发射光谱,为光合作用提供了新的见解.
科学领域:
- 生物物理学的生物物理.
- 光合作用研究研究 光合作用研究
- 频谱学是一种光谱学.
背景情况:
- 单分子光谱学与同时激发和发射检测作斗争.
- 光系统I (PSI) 对于光合作用中的电子转移至关重要.
- PSI含有红移色 (Chls) 具有较低的激发能.
研究的目的:
- 为光系统I (PSI) 实施单分子激发发射谱学 (SMEES).
- 在PSI中调查激发能量转移 (EET) 的变化.
- 描述天线系统在EET中的作用.
主要方法:
- 开发了一种与冷相容的直线聚焦激发光谱显微镜.
- 应用单分子激发-发射光谱 (SMEES) 对孤立的PSI粒子.
- 分析了随着时间的推移倾斜的2D激发发射矩阵 (2D-EEMs).
主要成果:
- 从*Thermosynechococcus vestitus*获得PSI的倾斜2D-EEM,在80K左右.
- 观察到红移Chl池的激发光谱的突出变化.
- 证明了与辐射相关的波长依赖激发光谱.
结论:
- 中小企业提供有关PSI天线系统的直接信息.
- 在PSI中确定了从天线到终端发射器的可变EET路径.
- 强调中小企业在研究色素-蛋白质复合体方面的实用性.
更多相关视频
11:55In Vitro Reconstitution of Light-harvesting Complexes of Plants and Green Algae
Published on: October 10, 2014
18.2K
08:40Separation of Spinach Thylakoid Protein Complexes by Native Green Gel Electrophoresis and Band Characterization using Time-Correlated Single Photon Counting
Published on: February 14, 2019
8.3K
相关概念视频
The Antenna Complex
6.0K
Plants and other photosynthetic organisms comprise pigments capable of absorption of direct sunlight. These pigments are present in the reaction center - the main site of photochemical reactions as well as in the antenna complex. Under average light conditions, the rate at which reaction center pigments absorb light is far below the electron transport chain's capacity. As a result, the reaction center alone cannot provide enough energy to drive photosynthesis. The photosynthetic efficiency...
6.0K
Photosystem II
70.3K
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...
The pigment molecules are arranged across two photosystem domains — the antenna complex and the reaction center. The main aim of the pigment...
70.3K
The Photochemical Reaction Center
4.1K
Reaction centers are pigment-protein complexes that initiate energy conversion from photons to chemical entities. Therefore, photochemical reaction center is a more appropriate term that describes these complexes. The Nobel laureates Robert Emerson and William Arnold provided the first experimental evidence of photochemical reaction centers by demonstrating the participation of nearly 2,500 chlorophyll molecules for the release of just one molecule of oxygen. Despite thousands of photosynthetic...
4.1K
Photochemical Electrocyclic Reactions: Stereochemistry
1.8K
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
1.8K
The Z-Scheme of Electron Transport in Photosynthesis
10.1K
The light reactions of photosynthesis assume a linear flow of electrons from water to NADP+. During this process, light energy drives the splitting of water molecules to produce oxygen. However, oxidation of water molecules is a thermodynamically unfavorable reaction and requires a strong oxidizing agent. This is accomplished by the first product of light reactions: oxidized P680 (or P680+), the most powerful oxidizing agent known in biology. The oxidized P680 that acquires an electron from the...
10.1K
UV–Vis Spectroscopy of Conjugated Systems
7.0K
Organic compounds with conjugated double bonds show strong absorption features in the UV–visible region of the electromagnetic spectrum attributed to π → π* electronic excitations. Generally, a UV–vis absorption spectrum is recorded as a plot of absorbance vs wavelength. The wavelength of maximum absorbance, which manifests as a peak in the absorption spectrum, is denoted as λmax.
One of the factors influencing λmax is the extent...
One of the factors influencing λmax is the extent...
7.0K
