選択的四次炭素結合形成のためのトリプトファン合成 TrpB の調整
Markus Dick1, Nicholas S Sarai1, Michael W Martynowycz2
1Division of Chemistry and Chemical Engineering 210-41 , California Institute of Technology , 1200 East California Boulevard , Pasadena , California 91125 , United States.
Journal of the American Chemical Society
|November 21, 2019
まとめ
研究者は,新しい非正規のアミノ酸を作成するために,トリプトファン合成酵素の変種である TrpB Pf_quat を設計しました. この酵素は選択的に全炭素四分型ステレオセンターを形成し,合成化学の能力を拡張します.
科学分野:
- 生物触媒
- 酵素工学
- 有機合成
背景:
- トリプトファン合成酵素 (TrpB) は自然にL-セリンとインドル凝縮をL-トリプトファンに触媒化する.
- 以前のエンジニアリングの努力により,TrpBは非正規のアミノ酸を合成することができました.
- 合成化学における四次性ステレオセンターの作成は依然として課題である.
研究 の 目的:
- 3-置換されたオキシンドールとのC-C結合の形成のためにTrpBを設計する.
- 新しい四次性ステレオセンターを生成できる酵素を開発する.
- 様々な非正規のアミノ酸を合成するために,エンジニアリングされたTrpBの有用性を拡張する.
主な方法:
- 6世代に渡ってTrpB酵素の進化を指揮した.
- N1保護とN1保護なしの基板として,3-置換オキシンドルを利用する.
- ステレオセンターの構成を決定するためにマイクロクリスタル電子 difraktion (MicroED) を使用します.
主要な成果:
- エンジニアリングされたTrpB変種,TrpB Pf_quatは,3-置換されたオキシンドールアルキル化で400倍以上の活性を示しています.
- 酵素は,アミノ酸産物のガンマ位置で選択的に全炭素四分型ステレオセンターを形成する.
- TrpB Pf_quatは,ラクトンとケトンの三次炭素に対する地域選択性を示しています.
- 酵素の高温安定性と発現レベル (E. coli培養で500 mg/L)
結論:
- TrpB Pf_quatは,全炭素四分型ステレオセンターで非正規のアミノ酸を構成するための効率的で持続可能なバイオ触媒プラットフォームを提供します.
- エンジニアリングされた酵素は,生物触媒のC-C結合形成の範囲を拡大します.
- マイクロEDの分析により,新たに形成されたステレオセンターのステレオ化学が確認されました.
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