イソコリスマートピルバートリアゼ: 環状反応機構?
Michael S DeClue1, Kim K Baldridge, Dominik E Künzler
1Laboratory of Organic Chemistry, Swiss Federal Institute of Technology, ETH Hönggerberg, CH-8093 Zürich, Switzerland.
Journal of the American Chemical Society
|October 27, 2005
まとめ
Pseudomonas aeruginosaからのイソコリスマートピルバートリアゼ (IPL) は,シデロフォア生物合成の重要なステップを触媒化する. デウテリウムの標識とNMRは,C-H結合の割れが速度を制限する,ペリサイクル反応機構を明らかにした.
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
- 構造生物学 構造生物学とは
背景:
- イソコリスマートピルバートリアゼ (IPL) は,細菌のシデロフォア生物合成に不可欠です.
- IPLは,イソコリスマートのサリシラートとピルベートへの分裂を触媒化する.
研究 の 目的:
- Pseudomonas aeruginosaからのイソコリスマートピルバートリアゼの触媒機構を解明する.
- 酵素の反応経路におけるC-H結合分裂の役割を調査する.
主な方法:
- 選択的にデュテラートされたイソコリスマートを基板として利用した.
- 2H NMRスペクトロシーを用いて,反応中介物質と反応産物をモニタリングした.
- 移行状態をモデル化するためにハイブリッド密度関数理論 (HDFT) の計算を行いました.
主要な成果:
- イソコリスマートのC2からピルーバートのC9への量的なデウテリウム移転が実証された.
- kcatに対するデウテリウム運動同位体 (2.34) の有意な効果を測定し,速度を制限するC−H割れを示した.
- HDFTの計算は,実験データと一致する協調された,非同期の環周転移構造を予測した.
結論:
- イソコリスマートピルバートリアゼは,ペリサイクリック反応を触媒化し,既知の酵素の小さなクラスに追加します.
- この発見は,他の関連酵素もペリサイクルメカニズムを使用している可能性があることを示唆しています.
関連する概念動画
Allosteric Regulation
Allosteric regulation of enzymes occurs when the binding of an effector molecule to a site that is different from the active site causes a change in the enzymatic activity. This alternate site is called an allosteric site, and an enzyme can contain more than one of these sites. Allosteric regulation can either be positive or negative, resulting in an increase or decrease in enzyme activity. Most enzymes that display allosteric regulation are metabolic enzymes involved in the degradation or...
Enzymes
Inside living organisms, enzymes act as catalysts for many biochemical reactions involved in cellular metabolism. The role of enzymes is to reduce the activation energies of biochemical reactions by forming complexes with its substrates. The lowering of activation energies favor an increase in the rates of biochemical reactions.
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
Enzyme deficiencies can often translate into life-threatening diseases. For example, a genetic abnormality resulting in the deficiency of the enzyme G6PD...
Allosteric Regulation
Allosteric regulation of enzymes occurs when the binding of an effector molecule to a site that is different from the active site causes a change in the enzymatic activity. This alternate site is called an allosteric site, and an enzyme can contain more than one of these sites. Allosteric regulation can either be positive or negative, resulting in an increase or decrease in enzyme activity. Most enzymes that display allosteric regulation are metabolic enzymes involved in the degradation or...
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...
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...
Heterogeneous Catalysis
Heterogeneous catalysis involves a catalyst in a different phase from the reactants. It is a process where the catalyst and the reactants are in distinct phases, typically solid and gas or liquid.Most heterogeneous catalysts are metals, metal oxides, or acids. The list includes transition metals like iron (Fe), cobalt (Co), nickel (Ni), palladium (Pd), platinum (Pt), chromium (Cr), manganese (Mn), tungsten (W), silver (Ag), and copper (Cu). These metals possess partially vacant d orbitals that...


