ホーラーラディッシュペロキシダースの単点変異がエナチオセレクティビティを顕著に高める方法
Eugene Antipov1, Art E Cho, Alexander M Klibanov
1Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Journal of the American Chemical Society
|July 21, 2009
まとめ
ほとんどのヒースラディッシュペロキシダース (HRP) ミュータントは,野生のタイプとは異なり,エナチオセレクティブ性を示しています. Arg178Gluの変種は,キラルフェノールの (S) -エナティオメールに対する25倍以上の好みを示した.
科学分野:
- バイオカタリシス バイオカタリシス
- 酵素工学とは
- 有機化学 オーガニック・ケミストリー
背景:
- ホースラディッシュ過酸化酵素 (HRP) は,広く研究されている酵素です.
- 酵素反応におけるエナチオセレクティビティは,キラル化合物の合成に不可欠である.
- 酵素活性部位を改変すると,基質の特異性とエナチオセレクティブ性が変化する.
研究 の 目的:
- HRPの位置178における突然変異が,そのエナチオ選択性に対する影響を調査する.
- キラルフェノールに対する強化されたエナチオ選択性を持つHRP変種を特定する.
- 観察されたエナチオ選択性変化の背後にあるメカニズムを解明する.
主な方法:
- サイト・ディレクテッド・ミュータジェネシスは,HRPの178.位に変異がある変異種を作成するために使用されました.
- 酵素酸化アッセイは,様々なキラルフェノール基板を用いて行われました.
- 動力分析と分子モデリングは,酵素-基板相互作用と移行状態を研究するために使用されました.
主要な成果:
- ほとんどのHRP変異体は,野生型酵素とは異なり,エナチオセレクティブ性を示した.
- Arg178Gluの変種は, (S) -エナチオメアに対する25倍以上の好みを示し,最も高いエナチオ選択性を示した.
- 分子モデリングは,Glu178と (R) -エナチオメアの移行状態の間の静電抵抗がエナチオ選択性に貢献することを示しました.
結論:
- HRPの位置178の変異は,キラルフェノールに対するエナチオ選択性を大幅に高めることができます.
- Arg178Glu変異は,非対称合成のための有望な変異体を表しています.
- 静電相互作用の役割を理解することで,合理的な酵素設計の洞察が得られます.
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