绿色mEos4b的机械研究揭示了一个动态的长期黑暗状态
Elke De Zitter1, Jacqueline Ridard2, Daniel Thédié3
1Department of Chemistry, KU Leuven, Heverlee 3001, Belgium.
Journal of the American Chemical Society
|May 29, 2020
概括
由于染色体异构化,绿色到红色可变光蛋白 (PCFP) 呈现出动态的暗色状态. 这影响了显微镜数据的质量,H结合模式影响了PCFP和可逆切换光蛋白 (RSFP) 的切换效率.
科学领域:
- 生物物理
- 显微镜
- 结构生物学
背景情况:
- 绿色转换为红色的光蛋白 (PCFP) 对于光激活局部化显微镜 (PALM) 等先进的显微镜技术至关重要.
- 虽然它们的光转换和红色状态属性得到了很好的研究,但它们的绿色状态的光物理行为,包括黑暗状态的形成,不太清楚.
- 绿态暗态可以显著影响PALM数据质量,并用于设计可逆切换光蛋白 (RSFP).
研究的目的:
- 研究PCFP中绿色状态的光物理行为,特别关注黑暗状态的形成和动态.
- 阐明PCFP和RSFP光交换效率和对比度的分子机制.
- 使用结构和光谱方法比较不同PCFP的暗状态,例如mEos4b和IrisFP.
主要方法:
- 运动晶体学
- 分子动力学模拟
- 拉曼光谱学
- 射线晶体学
- 光谱分析
主要成果:
- 绿色mEos4b通过染色体的cis-trans异构化过渡到长期存在的暗色状态,类似于其他RSFP.
- 绿色的mEos4b的暗态比绿色的IrisFP更为动态,其特征在于染色体周围的键较少.
- 染色体周围的H结合模式对于控制PCFP和RSFP的光交换量子产量至关重要.
- 与IrisFP相比,mEos4b黑暗状态的动态性有助于其更低的切换对比度.
结论:
- PCFP和RSFP的光物理是复杂的,暗态动态在它们的性能中起着关键作用.
- 这些光蛋白的光交换特性是理解和设计的基础.
- 这项研究提供了对PCFP光物理学的全面了解,有助于开发用于超分辨率显微镜的改进光探针.
相关概念视频
03:02Colors and Magnetism
13.6K
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
13.6K
02:42Valence Bond Theory
10.8K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
10.8K
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
2.8K
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
2.8K
02:13Energy Diagrams, Transition States, and Intermediates
19.5K
Free-energy diagrams, or reaction coordinate diagrams, are graphs showing the energy changes that occur during a chemical reaction. The reaction coordinate represented on the horizontal axis shows how far the reaction has progressed structurally. Positions along the x-axis close to the reactants have structures resembling the reactants, while positions close to the products resemble the products. Peaks on the energy diagram represent stable structures with measurable lifetimes, while...
19.5K