酵素ダイナミクスと水素トンネリングは,熱愛性アルコール脱水酸化酵素で
A Kohen1, R Cannio, S Bartolucci
1Department of Chemistry, University of California at Berkeley, 94720, USA.
Nature
|June 12, 1999
まとめ
水素トンネリングは,高温下でも酵素反応に大きく貢献します. この研究では,熱愛性アルコール脱水素酵素 (ADH) が65°Cでのトンネル掘削を利用し,より低い温度でのトンネル掘削が減少していることが示されています.
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
- 物理化学 物理化学
背景:
- 酵素 (生物学的触媒) は,物理的過程を通じて反応を加速する.
- 量子力学的効果である水素トンネリングは,室温での酵素触媒でますます認識されています.
- トンネル掘削の重要性は,小分子反応の温度低下に伴い,典型的には上昇する.
研究 の 目的:
- 高度の生理学的温度下における酵素における水素トンネリングの研究.
- 熱ストレス下にある熱性酵素でトンネリングが発生するかどうかを判断する.
- 生物系におけるトンネル掘削の温度依存性を調査する.
主な方法:
- 熱愛性アルコール脱水素酶 (ADH) 酵素を使用した.
- 高温 (65°C) を含む様々な温度下での運動研究を実施した.
- 水素トンネル掘削の貢献を定量化するために,反応速度を分析した.
主要な成果:
- 65°Cの熱愛性ADHで有意な水素トンネリングが実証されています.
- 温度が室温を下回るにつれてトンネル掘削の貢献度が低下することが観察されました.
- 発見は,硬い障壁を通るトンネル掘削の予測と対照的です.
結論:
- 水素トンネリングは,温度範囲の間の酵素触媒において重要な役割を果たします.
- 熱的に刺激された酵素の変動は,水素トンネリングと結合割れを調節する.
- この研究は,熱性酵素における量子効果の実験的証拠を提供する.
さらに関連する動画
08:10Fizzy Extraction of Volatile Organic Compounds Combined with Atmospheric Pressure Chemical Ionization Quadrupole Mass Spectrometry
Published on: July 14, 2017
08:31Anaerobic Protein Purification and Kinetic Analysis via Oxygen Electrode for Studying DesB Dioxygenase Activity and Inhibition
Published on: October 3, 2018
関連する概念動画
01:19Enzyme Kinetics
Enzymes speed up reactions by lowering the activation energy of the reactants. The speed at which the enzyme turns reactants into products is called the rate of reaction. Several factors impact the rate of reaction, including the number of available reactants. Enzyme kinetics is the study of how an enzyme changes the rate of a reaction.
Scientists typically study enzyme kinetics with a fixed amount of enzyme in the controlled environment of a test tube. When more reactant, or substrate, is...
Scientists typically study enzyme kinetics with a fixed amount of enzyme in the controlled environment of a test tube. When more reactant, or substrate, is...
02:50Catalysis
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.
01:27Fast Reactions
Fast reactions occurring in times shorter than the time needed to mix reactants pose a unique challenge for investigation. In a liquid-phase continuous-flow system, reactants A and B are swiftly pushed into the mixing chamber, where mixing occurs within 1 ms. The reaction mixture then flows through an observation tube, and one measures light absorption to determine species concentrations at various points of the tube. This method is most appropriate when relatively large volumes of reactants...
01:27Catalysis
Catalysis influences the rate of chemical reactions by providing an alternative reaction pathway with lower activation energy. A catalyst speeds up a reaction, but it is not consumed during the process. The fundamental principle of catalysis is the ability of a catalyst to alter the reaction mechanism, often introducing a more efficient pathway than the uncatalyzed process.In a catalyzed reaction, the catalyst participates directly in the reaction mechanism. It interacts with reactants to form...
01:28Bioreactor Controls-I
Maintaining optimal conditions within fermenters is essential for maximizing microbial productivity and ensuring process efficiency. This lesson focuses on key parameters—temperature, foam, pH, carbon dioxide, oxygen, and pressure—and their precise measurement and control strategies in fermentation systems.Temperature ControlTemperature regulation is critical due to the exothermic nature of many fermentation processes. In small laboratory fermenters, temperature is commonly monitored using...
01:18Bioreactor Controls-II
In aerobic fermentations, oxygen is vital for microbial growth and metabolite production. Since air comprises only about 20% oxygen and the gas is poorly soluble in water—just 9 ppm at 20°C—supplying sufficient oxygen becomes a critical challenge, especially in high-demand processes like yeast growth or citric acid production. Even a fully saturated broth may offer only a few seconds of oxygen availability.To address this, sterile or scrubbed air is introduced into the fermentor via a sparger...