コリスマートミュータゼによる速度増強に対するコンフォメーション圧縮と優先移行状態の安定化の貢献
Cristiano Ruch Werneck Guimarães1, Matthew P Repasky, Jayaraman Chandrasekhar
1Department of Chemistry, Yale University, 225 Prospect Street, New Haven, Connecticut 06520-8107, USA.
Journal of the American Chemical Society
|June 5, 2003
まとめ
コリスマートミュータゼ (CM) は,その基質を事前に組織化するのではなく,その基質の接近攻撃形状 (NAC) を圧縮することによって反応を加速します. この酵素触媒による圧縮はエンタルピー的に制御され,酵素触媒で観察された有意な速度向上を説明します.
科学分野:
- バイオケミストリー バイオケミストリー
- 酵素の動力学について
- 計算化学はコンピュータ化学である.
背景:
- コリスマートミュータゼ (CM) は,重要なクライゼン再配置を触媒化する.
- 酵素触媒による速度増強を理解することは,酵素機構の研究の鍵です.
研究 の 目的:
- コリスマートミュータゼ (CM) 触媒反応における接近攻撃形状 (NAC) の役割を調査する.
- CMによって提供されるレートの上昇の背後にあるメカニズムを明らかにする.
主な方法:
- 組み合わせた量子力学/分子力学 (QM/MM) シミュレーション.
- モンテカルロ/自由エネルギー波動 (MC/FEP) 計算.
- 溶液と活性部位における基質の形状偏好の分析.
主要な成果:
- コリスマートは,水 (82%) とCM活性部位 (100%) の両方でNAC構造に主として存在します.
- NACへの酵素前組織化は,自由エネルギーの活性化に寄与しません.
- 速度の向上は,主に酵素によるNACの構成圧縮によるもので,これはエンタルピー的に制御されるプロセスである.
結論:
- CMの主な触媒メカニズムは,近攻撃コンフォームのエンタルピー的に駆動されたコンフォーメーション圧縮を伴う.
- 優先的な移行状態の安定化は,CM触媒において二次的な役割を果たします.
- コンピューティング・メソッドは,酵素活動の実験的観測を正確に再現します.
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