通过Streptomyces coelicolor 细胞染色体 P450 154A1 循环生成细胞的双氨,没有氧化/还原
Qian Cheng1, David C Lamb, Steven L Kelly
1Department of Biochemistry and Center in Molecular Toxicology, Vanderbilt University, School of Medicine, Nashville Tennessee 37232-0146, USA.
Journal of the American Chemical Society
|October 29, 2010
概括
斯特雷普托米塞斯 (Streptomyces coelicolor) 细胞染色体P450 154A1对于子的稳定性至关重要. 这种酶催化了一种新型的双氨基基质的异常分子内循环,形成一种类似帕特诺-布希的产物.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 微生物学 微生物学
背景情况:
- 斯特雷普托米切斯 (Streptomyces coelicolor) 含有P450 (P450) 154A1细胞染色体,因其独特的血方向而闻名.
- P450 154A1基因的功能,特别是与细菌子稳定性相关的功能,仍然在很大程度上未被探索.
研究的目的:
- 为了研究Streptomyces coelicolor P450 154A1.1.的催化特性和生物作用.
- 为了确定内源基质,并描述P450 154A1.1.的生物转化产品.
主要方法:
- 涉及基因删除的遗传分析.
- 代谢分析,以识别基质.
- 生物化学测试用于研究酶活性.
- 结晶学是为了理解血红素的方向.
主要成果:
- 删除P450 154A1基因损害了长期的细菌子稳定性.
- 一种新型,高度结合的dipentaenone被确定为内源基质.
- P450 154A1调解了一种意想不到的Dipentaenone的分子内循环转化到一种类似帕特诺-布奇的产品,特别是在没有氧化或减少的情况下.
结论:
- P450 154A1 在Streptomyces coelicolor子的长期稳定性中起着重要作用.
- 该酶表现出独特的催化活性,通过分子内循环机制转化滴氨酸.
- 这项研究揭示了一种新的酶变化,并强调了P450s在细菌生理学中的重要性.
相关概念视频
Drug Metabolism: Phase I Reactions
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,...
Oxidation of Phenols to Quinones
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 property is crucial in...
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 property is crucial in...
Thermal and Photochemical Electrocyclic Reactions: Overview
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.
Role of Reduced Coenzymes NADH and FADH₂
The energy released from the breakdown of the chemical bonds within nutrients can be stored either through the reduction of electron carriers or in the bonds of adenosine triphosphate (ATP). In living systems, a small class of compounds functions as mobile electron carriers, molecules that bind to and shuttle high-energy electrons between compounds in pathways. The principal electron carriers that will be considered originate from the B vitamin group and are derivatives of nucleotides; they are...
Benzene to 1,4-Cyclohexadiene: Birch Reduction Mechanism
Birch reduction uses solvated electrons as reducing agents. The reaction converts benzene to 1,4-cyclohexadiene. The reaction proceeds by the transfer of a single electron to the ring to form a benzene radical anion. This anion is highly basic—it abstracts a proton from the alcohol to form a cyclohexadienyl radical. Another single electron transfer gives the cyclohexadienyl anion. A proton transfer from the alcohol forms 1,4-cyclohexadiene. Since this reduction occurs via radical anion...
Photochemical Electrocyclic Reactions: Stereochemistry
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
![Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F60786.jpg&w=3840&q=50)

