フォーマルデヒドは,[FeFe]-水素合成による水素生成の迅速かつ可逆的阻害剤である
Annemarie F Wait1, Caterina Brandmayr, Sven T Stripp
1Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, UK.
Journal of the American Chemical Society
|January 6, 2011
まとめ
フォーマルアルデヒドは,二水素生成に不可欠な酵素である[FeFe]-ヒドロゲナーゼの活動を迅速かつ可逆的に抑制します. タンパク質膜の電気化学を用いて観察されたこの特定の阻害は,ホルムアルデヒドを強調しています.
科学分野:
- バイオケミストリー バイオケミストリー
- 酵素学 酵素学とは
- バイオ・オーガニック化学 バイオ・オーガニック化学
背景:
- [FeFe]-ヒドロゲナーゼは,二水素 (H2) 生産に不可欠なバイオカタリストです.
- 酵素阻害剤の理解は,生物触媒的プロセスを制御し,酵素機構を研究するために不可欠です.
研究 の 目的:
- フォーマルデヒドが[FeFe]-ヒドロゲネーズに及ぼす抑制効果を調査する.
- フォーマルデヒド阻害の特異性と可逆性を決定する.
- 酵素の活性部位内のホルムアルデヒドの潜在的な結合部位を解明する.
主な方法:
- タンパク質膜の電気化学を用いて,酵素の活性度を測定した.
- 抑制を確認するために,従来の溶液測定法を使用した.
- [FeFe]-ヒドロゲナーゼの異なる変種と[NiFe]-ヒドロゲナーゼを比較した研究が行われました.
主要な成果:
- フォーマルアルデヒドは[FeFe]-ヒドロゲネーゼの陽子還元活動を迅速かつ可逆的に阻害する.
- 抑制は[FeFe]-ヒドロゲネーゼに特異的であり,H2酸化への影響は弱く[NiFe]-ヒドロゲネーゼへの影響は最小限である.
- フォーマルアルデヒドはまた,一酸化炭素 (CO) と酸素 (O2) による無活性化に対する保護効果を示した.
結論:
- フォーマルアルデヒドは[FeFe]-ヒドロゲネーゼの特定の阻害剤として作用し,活性部位の近くで結合する可能性が高い.
- 保存されたライシンおよびシステイン残留を含む[FeFe]-水酸化酵素の独特の活性部位特性は,ホルムアルデヒド結合に関与しています.
- この発見は[FeFe]-ヒドロゲネーゼ触媒のメカニズムと酵素調節のための潜在的な戦略の洞察を提供します.
関連する概念動画
Hydrogen Bonds
Hydrogen BondsHydrogen bonds are weak attractions between atoms that have formed other chemical bonds. One of these atoms is electronegative, like oxygen, and has a partial negative charge. The other is a hydrogen atom that has bonded with another electronegative atom and has a partial positive charge.Hydrogen Bonds Control the World!Because hydrogen has very weak electronegativity when it binds with a strongly electronegative atom, such as oxygen or nitrogen, electrons in the bond are...
Hydrogen Bonds
A hydrogen bond is formed when a weakly positive hydrogen atom already bonded to one electronegative atom (for example, the oxygen in the water molecule) is attracted to another electronegative atom from another polar molecule, such as water (H2O), hydrogen fluoride (HF), or ammonia (NH3). The huge electronegativity difference between the H atom (2.1) and the atom to which it is bonded (4.0 for an F atom, 3.5 for an O atom, or 3.0 for an N atom), combined with the very small size of an H atom...
Reduction of Alkenes: Catalytic Hydrogenation
Alkenes undergo reduction by the addition of molecular hydrogen to give alkanes. Because the process generally occurs in the presence of a transition-metal catalyst, the reaction is called catalytic hydrogenation.
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the surface of...
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the surface of...
Enzyme Inhibition
Inhibitors are molecules that reduce enzyme activity by binding to the enzyme. In a normally functioning cell, enzymes are regulated by a variety of inhibitors. Drugs and other toxins can also inhibit enzymes. Some inhibitors bind to the enzyme’s active site, while others inhibit enzymatic activity by binding to other sites on the protein structure.
Aldehydes and Ketones with HCN: Cyanohydrin Formation Overview
Cyanohydrins are compounds that contain –CN and –OH groups on the same carbon atom. They are formed by the nucleophilic addition of the cyanide ions to the carbonyl group. Cyanide ions are highly basic and nucleophilic and can be generated from HCN under aqueous conditions. However, since HCN is a weak acid, the number of cyanide ions generated is very small. Hence, a small amount of base or KCN/NaCN is added to HCN to increase the concentration of the cyanide ions in the reaction mixture.
Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
![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)

