関連する実験動画
Updated: Jul 25, 2026

15:08
Probing and Mapping Electrode Surfaces in Solid Oxide Fuel Cells
Published on: September 20, 2012
硫化ナトリウムがNiを含む一酸化炭素を脱水化すると,硫化ナトリウムの作用
1Department of Chemistry, Texas A&M University, College Station, 77843-3255, USA.
Journal of the American Chemical Society
|July 22, 2004
まとめ
硫化物イオンは,酵素に逆転的に結合することによって,一酸化炭素脱水素酶 (CODH) の活性を阻害する.
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:
- 炭素一酸化物脱水素酵素 (CODH) は,炭素循環に不可欠です.
- 活性サイトCクラスター構造は,CODH酵素によって異なります.
- 重要な違いは,Carboxydothermus hydrogenoformans CODHにmu(2) - 硫化イオンの存在であり,Rhodospirillum rubrum (CODH(Rr)) とMoorella thermoacetica (CODH(Mt)) CODHには存在しないことです.
研究 の 目的:
- CODH活性部位における構造的,機能的差異を調査する.
- CODHの活性とスペクトル特性に対する硫化物の影響を調査する.
主な方法:
- 酵素活性アッセイ. 酵素活性アッセイ.
- 電子パラマグネティック共振 (EPR) スペクトロスコーピー.
- 阻害定数 (K ((I)) を決定するための運動分析.
主要な成果:
- 硫化物は,CODH (Rr) とCODH (Mt) のCO酸化活動を部分的に阻害し,CODH (Rr) の遅延を引き起こした.
- C (赤1) 状態でのCODH (Mt) との硫化物結合は,EPR信号を変化させ,可逆的であった.
- 運動モデルでは,C (red1) に逆転可能な硫化物結合を提案し,触媒を阻害し,還元時に解離する.
結論:
- 硫化物は,C ((red1)) 状態に結合することによって,CODHの活性を逆転的に抑制する.
- 硫化物の抑制作用は他のアニオンと類似しており,共通の結合方式を示唆しています.
- この結合には,Ni原子とC群のユニークなFe原子の橋渡しが含まれます.
関連する概念動画
Catalysis
The presence of a catalyst affects the rate of a chemical reaction. A catalyst is a substance that can increase the reaction rate without being consumed during the process. A basic comprehension of a catalysts’ role during chemical reactions can be understood from the concept of reaction mechanisms and energy diagrams.
Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.
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...
Reduction of Alkynes to trans-Alkenes: Sodium in Liquid Ammonia
Alkynes can be reduced to trans-alkenes using sodium or lithium in liquid ammonia. The reaction, known as dissolving metal reduction, proceeds with an anti addition of hydrogen across the carbon–carbon triple bond to form the trans product. Since ammonia exists as a gas (bp = −33°C) at room temperature, the reaction is carried out at low temperatures using a mixture of dry ice (sublimes at −78°C) and acetone.
When dissolved in liquid ammonia, an alkali metal, such as sodium, dissociates into a...
When dissolved in liquid ammonia, an alkali metal, such as sodium, dissociates into a...
Preparation and Reactions of Sulfides
Sulfides are the sulfur analog of ethers, just as thiols are the sulfur analog of alcohol. Like ethers, sulfides also consist of two hydrocarbon groups bonded to the central sulfur atom. Depending upon the type of groups present, sulfides can be symmetrical or asymmetrical. Symmetrical sulfides can be prepared via an SN2 reaction between 2 equivalents of an alkyl halide and one equivalent of sodium sulfide.
meta-Directing Deactivators: –NO2, –CN, –CHO, –⁠CO2R, –COR, –CO2H
All meta-directing substituents are deactivating groups. These substituents withdraw electrons from the aromatic ring, making the ring less reactive toward electrophilic substitution. For example, the nitration of nitrobenzene is 100,000 times slower than that of benzene because of the deactivating effect of the nitro group. The first step in an electrophilic aromatic substitution is the addition of an electrophile to form a resonance-stabilized carbocation. The energy diagrams for the...
![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)
