空间有限的复合体之间的氧化伙伴交换控制了细胞染色体b5对P450CYP3A4的合效应
Philippe Urban1, Alain Perret2, Denis Pompon3
1TBI, CNRS, INRA, INSA, Université de Toulouse, Toulouse, France. urban@insa-toulouse.fr.
Scientific reports
|July 8, 2025
概括
细胞染色体b5通过氧化还原机制增强CYP3A4的活性,作为电子捐赠者和受体. 这项研究阐明了激活过程,支持了细胞染色体P450功能的氧化还原模型.
科学领域:
- 生物化学 生化学
- 分子生物学分子生物学
- 酶学 是一种酶学.
背景情况:
- 已知细胞染色体b5 (b5) 增强了细胞染色体P450酶的活性,特别是CYP3A4.4.
- 这种增强的确切机制一直在争论中,提出的模型包括构造变化或基于氧化还原的相互作用.
研究的目的:
- 阐明细胞染色体b5激活CYP3A4.4的机制.
- 区分拟议的构造型和基于氧化还原的激活模型.
主要方法:
- 使用了一种半合成系统,包括CYP3A4,其减少酶 (CPR) 和ER结合的b5.
- 采用了具有修改的氧化还原特性的b5类似物,快速运动实验,活动测试和结构预测 (AlphaFold,分子动力学).
主要成果:
- 结果强烈支持由b5.5对CYP3A4的基氧还原激活机制.
- b5既是电子受体又是电子供体,在催化循环期间与CYP3A4保持关联.
- 结构建模表明相互排斥的二进制复合体 (CPR-P450和b5-P450) 的形成具有电子转移能力,并建议潜在的三进制复合体.
结论:
- 细胞染色体b5主要通过基于氧化还原的机制激活CYP3A4.
- 相互作用涉及特定的二进制复合体和潜在的三进制复合体,促进电子交换.
- 结构模型提供了对CYP3A4激活的氧化还原和潜在非氧化还原贡献的见解.
相关概念视频
Redox Reactions
202
Redox reactions are vital biochemical processes that underpin energy metabolism in cells. These reactions involve the transfer of electrons between molecules, occurring in tandem as oxidation and reduction. Oxidation refers to the loss of electrons, while reduction denotes their gain. This coupling ensures the seamless flow of electrons through metabolic pathways. For example, in bacterial metabolism, glucose undergoes oxidation to carbon dioxide, while oxygen is simultaneously reduced to...
202
Redox Equilibria: Overview
1.1K
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...
1.1K
Oxidation of Phenols to Quinones
3.5K
In the presence of oxidizing agents, phenols are oxidized to quinones. Quinones can be easily reduced back to phenols using mild reducing agents. The electron-donating hydroxyl group enhances the reactivity of the aromatic ring, enabling oxidation of the ring even in the absence of an α hydrogen.
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox...
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox...
3.5K
Electron Transport Chain: Complex III and IV
8.1K
During the electron transport chain, electrons from NADH and FADH2 are first transferred to complexes I and II, respectively. These two complexes then transfer the electrons to ubiquinol, which carries them further to complex III. Complex III passes the electrons across the intermembrane space to Cyt c, which carries them further to complex IV. Complex IV donates electrons to oxygen and reduces it to water. As electrons pass through complexes I, III, and IV, the energy released aids the pumping...
8.1K
Drug Metabolism: Phase I Reactions
3.7K
A phase I reaction is a biochemical process that introduces a functionally reactive polar group to a substance. This transformation predominantly occurs in the liver, facilitated by the cytochrome P450 system of hemoproteins situated in the lipophilic endoplasmic reticulum of cells. The metabolite generated through this process can have varying polarities. If it is sufficiently polar, it can be easily excreted in the urine due to its water compatibility. However, if the metabolite is nonpolar,...
3.7K
Redox Titration: Other Oxidizing and Reducing Agents
403
Besides iodine, other oxidizing or reducing agents can serve as titrants in redox titrations. Common oxidizing titrants include KMnO4, cerium(IV), and K2Cr2O7. The choice of oxidizing titrants depends on factors like stability, cost, analyte strength, and reaction rate between the analyte and titrant. KMnO4 is a strong oxidizing titrant that reduces from Mn(VII) to Mn(II) in a highly acidic solution, simultaneously oxidizing the analyte to a higher oxidation state. In this case, KMnO4 acts as a...
403

![[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59739.jpg&w=3840&q=50)
