セルラー・ディペンタエノンのサイクリングは,Streptomyces coelicolor cytochrome P450 154A1によって,酸化/還元なしに行われます
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
まとめ
Streptomyces coelicolor サイトクロームP450 154A1は,胞子安定性にとって極めて重要です. この酵素は,新しいディペンタエノンの基板の異常な分子内サイクルを触媒化し,パターノ・ブーチのような製品を形成します.
科学分野:
- バイオケミストリー バイオケミストリー
- 分子生物学は分子生物学である.
- 微生物学 微生物学とは
背景:
- Streptomyces coelicolorには,特徴的なヘム方向性で知られるサイトクロームP450 (P450) 154A1が含まれています.
- P450 154A1遺伝子の機能,特にバクテリア胞子の安定性に関する機能は,ほとんど未知のままです.
研究 の 目的:
- ストレプトマイセス・セリカラーP450 154A1.1.の触媒特性と生物学的役割を調査する.
- 固有の基質を特定し,P450 154A1.1.の生物変異産物を特徴付ける.
主な方法:
- 遺伝子の削除を含む遺伝分析.
- メタボロミックプロファイリングで基板を特定する.
- 酵素活性を研究するための生化学分析.
- ヘム・オリエンテーションを理解するための結晶学.
主要な成果:
- P450 154A1遺伝子の削除は,長期間細菌胞子の安定性を損ねました.
- 新しい,高度に結合されたディペンタエノンは,内在的な基質として特定されました.
- P450 154A1は,特に酸化や還元なしに,ディペンタエノンのパターノ・ブーキのような製品への予期せぬ分子内循環を媒介した.
結論:
- P450 154A1は,Streptomyces coelicolor胞子の長期的な安定性において重要な役割を果たしています.
- この酵素はユニークな触媒活性を示し,分子内循環機構を通じてディペンタエノンを変換します.
- この研究は,新しい酵素変換を明らかにし,細菌生理学におけるP450sの重要性を強調しています.
関連する概念動画
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)

