通过操纵电子分区函数来调整蛋白质氧化中心的氧化/热性参数
Damian Alvarez-Paggi1, Ulises A Zitare1, Jonathan Szuster1
1Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE), Departamento de Química Inorgánica, Analítica y Química Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and CONICET ,1428 Buenos Aires, Argentina.
Journal of the American Chemical Society
|July 1, 2017
概括
研究人员调整了细胞染色体c氧化酶中的铜-A (CuA) 氧化还原中心的分离函数 (Q). 这种调整通过改变电子状态和静电环境来调节氧化还原潜力,揭示了关键的热力学相关性.
科学领域:
- 生物化学
- 生物物理化学
- 结构生物学
背景情况:
- 细胞染色体c氧化酶是细胞呼吸中的关键酶.
- 这种酶中的铜-A (CuA) 中心在电子转移中起着至关重要的作用.
- 了解影响CuA的氧化还原潜力的因素对于阐明酶功能至关重要.
研究的目的:
- 研究CuA氧化还原中心的分区函数 (Q) 的操作方法.
- 探索改变电子状态和静电电位对CuA氧化还原特性的影响.
- 建立热力学贡献与CuA中心及其配体的特性之间的相关性.
主要方法:
- 使用点突变和循环工程来修改CuA中心周围的蛋白质结构.
- 改变pH以改变质子状态和静电环境.
- 对氧化还原潜力变化的和贡献进行分析.
- 研究弱轴联体的身份和疏水性的作用.
主要成果:
- 通过蛋白质工程和环境变化成功操纵CuA分区功能 (Q).
- 建立了分区函数 (Q) 和对氧化还原潜力的热贡献之间的明确相关性.
- 发现了对氧化还原潜力和弱轴联体的同一性/疏水性之间的显著关系.
- 展示了电子结构,静电学和氧化还原热力学之间的相互作用.
结论:
- CuA氧化还原中心的分区函数 (Q) 是其氧化还原特性的一个关键决定因素.
- 蛋白质工程和环境因素提供了有效的调整酶氧化还原潜力的手段.
- 轴联体的性质显著影响了对氧化还原潜力的体贡献,突出显示了联体与蛋白的相互作用.
![Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F55858.jpg&w=3840&q=50)
相关概念视频
01:23Redox Equilibria: Overview
1.7K
A reduction-oxidation reaction is commonly called a redox reaction. In a redox reaction, electrons are transferred from one species to another rather than being shared between or among atoms. The reducing agent or reductant is the species that loses electrons and gets oxidized in the process. The species that gains electrons and gets reduced in the process is the oxidizing agent or oxidant. Redox reactions are represented as two separate equations called half-reactions, where one equation...
1.7K
02:04Covalently Linked Protein Regulators
9.8K
Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein....
These groups modify specific amino acids in a protein....
9.8K
01:30Ladder Diagrams: Redox Equilibria
828
Ladder diagrams are useful tools for understanding redox equilibrium reactions, especially the effects of concentration changes on the electrochemical potential of the reaction. The vertical axis in the redox ladder diagrams represents the electrochemical potential, E. The area of predominance is demarcated using the Nernst equation.
Consider the Fe3+/Fe2+ half-reaction, which has a standard-state potential of +0.771 V. At potentials more positive than +0.771 V, Fe3+ predominates, whereas Fe2+...
Consider the Fe3+/Fe2+ half-reaction, which has a standard-state potential of +0.771 V. At potentials more positive than +0.771 V, Fe3+ predominates, whereas Fe2+...
828
01:19Protein Dynamics in Living Cells
2.8K
Different fluorescence-based techniques are used to study the protein dynamics in living cells. These techniques include FRAP, FRET, and PET.
Fluorescent recovery after photobleaching (FRAP) is a fluorescent-protein-based detection technique used to quantify protein movement rates within the cell. This method exposes a small portion of the cell to an intense laser beam. The laser beam causes permanent photobleaching of the fluorophore-tagged proteins in the exposed region. As the bleached...
Fluorescent recovery after photobleaching (FRAP) is a fluorescent-protein-based detection technique used to quantify protein movement rates within the cell. This method exposes a small portion of the cell to an intense laser beam. The laser beam causes permanent photobleaching of the fluorophore-tagged proteins in the exposed region. As the bleached...
2.8K
01:26Protein Modifications in the RER
7.3K
Modification of secretory and transmembrane proteins entering the rough ER begins in the ER lumen. These modifications aid in protein folding and stabilize the acquired tertiary structure. Protein modifications in the rough ER co-occur at different stages of protein folding.
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal...
Broadly, these modifications can be categorized into four main categories — glycosylation, formation of disulfide bonds, assembly of protein subunits, and specific proteolytic cleavages like removal of signal...
7.3K
02:59The Nernst Equation
47.7K
Nonstandard Reaction Conditions
The interconnection between standard cell potentials and various thermodynamic parameters such as the standard free energy change ΔG° and equilibrium constant K has been previously explored. For example, a redox reaction involving zinc(II) and tin(II) ions at 1 M concentration with Eºcell = +0.291 V and ΔG° = −56.2 kJ is spontaneous.
The interconnection between standard cell potentials and various thermodynamic parameters such as the standard free energy change ΔG° and equilibrium constant K has been previously explored. For example, a redox reaction involving zinc(II) and tin(II) ions at 1 M concentration with Eºcell = +0.291 V and ΔG° = −56.2 kJ is spontaneous.
47.7K