ヴァナジウムハロペロキシダースのコファクターのペロキソ形態の反応性. DFTの調査が実施されました
Giuseppe Zampella1, Piercarlo Fantucci, Vincent L Pecoraro
1Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy.
Journal of the American Chemical Society
|January 20, 2005
まとめ
密度関数理論は,プロトネーションがバナジウムハロペロキシダゼ (VHPO) ペロキソ複合体を活性化することを明らかにする. 陽子化されていない酸素原子はオキシオ転送を促進し,Lys353は陽子活性化を模倣する.
科学分野:
- バイオケミストリー バイオケミストリー
- コンピューティング・ケミストリー
- 酵素のメカニズム
背景:
- バナジウムハロペロキシダゼ (VHPO) は,ペロキソバナジウム共因子を利用する酵素です.
- コファクターの反応性を理解することは,VHPOの触媒メカニズムを明らかにする鍵です.
研究 の 目的:
- VHPOペロキソ複合体の構造,電子,および反応性の性質を調査する.
- コファクター反応性に対するプロトネーション状態と微環境の影響を調べる.
主な方法:
- 密度関数理論 (DFT) の計算が採用されました.
- 分析はペロキソバナジウム複合体のモデルに焦点を当てた.
主要な成果:
- プロトネーションはペロキソバナジウム複合体を有意に活性化させ,実験結果と一致する.
- オキシオトランスファーステップは,アクセシブルでプロトン化されていない軸性ペロキソ酸素を含みます.
- Lys353は,ペロキソコファクターのプロトン活性化を潜在的に模倣することが判明しました.
結論:
- プロトネーションは,VHPOペロキソコファクターの活性化に不可欠です.
- 酵素の活性部位は,反応性過酸化酸素への基質のアクセスを促進する.
- Lys353のようなアミノ酸残基は,VHPOの活性を調節する役割を果たす可能性があります.
関連する概念動画
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Enzyme 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...
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Cofactors and Coenzymes
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Introduction to Mechanisms of Enzyme Catalysis
For many years, scientists thought that enzyme-substrate binding took place in a simple "lock-and-key" fashion. This model stated that the enzyme and substrate fit together perfectly in one instantaneous step. However, current research supports a more refined view scientists call induced fit. The induced-fit model expands upon the lock-and-key model by describing a more dynamic interaction between enzyme and substrate. As the enzyme and substrate come together, their interaction causes a mild...
Cofactors and Coenzymes
Enzymes are proteins made of amino acids. The functional group of each constituent amino acid catalyzes a wide variety of chemical reactions via ionic interactions or acid-base reactions. However, amino acids cannot catalyze oxidation-reduction and group transfer reactions and need to be aided by non-protein components called cofactors. Cofactors are also referred to as the chemical teeth of an enzyme.
Cofactors can be metallic ions or organic molecules called coenzymes. These types of helper...
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Factors Affecting Activity Coefficient
The extended Debye-Hückel equation indicates that the activity coefficient of an ion in an aqueous solution at 25°C depends on three partially interdependent properties: the ionic strength of the solution, the charge of the ion, and the ion size.
The activity coefficient value for an ion is close to one when the solution has almost zero ionic strength, i.e., when the solution shows close to ideal behavior. As the ionic strength of the solution increases from 0 to 0.1 mol/L, a decrease in the...
The activity coefficient value for an ion is close to one when the solution has almost zero ionic strength, i.e., when the solution shows close to ideal behavior. As the ionic strength of the solution increases from 0 to 0.1 mol/L, a decrease in the...
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