エナチオセレクティブエポキシドヒドロラゼの方向進化:各進化段階におけるエナチオセレクティブ性の源を明らかにする
Manfred T Reetz1, Marco Bocola, Li-Wen Wang
1Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mulheim/Ruhr, Germany. reetz@mpi-muelheim.mpg.de
Journal of the American Chemical Society
|May 28, 2009
まとめ
誘導進化により,ラセミックグリシジルフェニルエーテルを分解する優れたエポキシドヒドロラゼ酵素変異体が生まれた. この強化された酵素は,著しく改善されたエナチオセレクティブ性を示し,キラル触媒に対するよりグリーンな代替案を提供します.
科学分野:
- バイオカタリスと酵素工学
- 有機化学 オーガニック・ケミストリー
- 構造生物学 構造生物学とは
背景:
- 誘導進化は,従来の非対称な触媒の代替手段を提供している.
- 酵素は,エナチオ選択的触媒化のために設計することができます.
- エポキシードヒドローラゼは貴重なバイオカタリストです.
研究 の 目的:
- アスペルギルス・ニジャーエポキシド・ヒドロラゼ.の誘導進化変異体における強化されたエナンチオセレクティブ性のメカニズム的根拠を解明する.
- 野生型酵素と変異型酵素の構造的,機能的な違いを理解する.
- エンジニアリングされた酵素の基質範囲とエナチオ選択性の予測を検証する.
主な方法:
- 運動分析 運動分析
- 分子ダイナミクスシミュレーション
- 分子モデリング
- 阻害アッセイは抑制アッセイである.
- 野生型および変異性酵素のX線結晶学
主要な成果:
- 変異したエポキシドヒドローラゼは,グリシジルフェニルエーテル分解の野生型 (E=4.6) に比べて,エナチオセレクティブ性が劇的に増加した (E=115).
- X線構造は,全体的な構造的類似性にもかかわらず,野生型および変異性酵素の活性部位構造の有意な違いを明らかにしました.
- 計算データと実験データは,変異体の活性部位が (S) -エナティオメアを好ましく結合し,水解のために位置づけるモデルをサポートしています.
結論:
- 変異酵素の強化されたエナチオセレクティビティは, (S) -エナチオメールの生産的な結合を促進する特定の活性部位の改変に起因する.
- 誘導進化は,バイオカタリシスにおける酵素の酵素選択性を最適化するための強力なツールです.
- この研究は,関連する基板に対する酵素性能の予測を可能にするメカニズム的理解を提供します.
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