エステル水解のための触媒ダイアードとオキシアニオンホールの計算設計
Florian Richter1, Rebecca Blomberg, Sagar D Khare
1Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA.
Journal of the American Chemical Society
|August 9, 2012
まとめ
人工エステラゼの計算設計は,骨幹NH群がオキシアニオンホールに不可欠であり,触媒効率を高めることを明らかにしました. しかし,高い活動率と適切なアクティブサイト形成を達成するには,依然として課題が残っています.
科学分野:
- バイオケミストリー バイオケミストリー
- コンピューティング・ケミストリー
- 酵素工学とは
背景:
- 核性触媒は水解反応を加速する.
- 自然の酵素は,基板活性化のために触媒二酸化物/三酸化物とオキシアニオンホールを利用します.
- 自然進化におけるこれらの構成要素の役割の分離は困難である.
研究 の 目的:
- エステラーゼ活性に対する最低限の要件を探求する.
- 触媒ダイアードとオクシアニオンホールを用いて人工触媒を計算的に設計する.
- 触媒モチーフの独立した貢献を調査する.
主な方法:
- 人工触媒のコンピューター設計.
- 触媒ダイアド (Cys-His) と設計されたオキシアニオン穴を用いた.
- アクティブサイト最適化と運動実験.
- 結晶学による構造分析.
主要な成果:
- 骨幹NH群から設計されたオキシアニオン穴は,より高い成功率を示した.
- 4つのアクティブ・デザインが,異なるスケーファッドで生成されました.
- 最も活発な変種は,400 M(-1) s(-1) の触媒効率 (k ((cat) / K ((M)) を達成しました.
- アクティブサイトシステインのアキレーションは効率的だったが,アキル酵素水解は遅かった.
- 設計されたCys-Hisダイアードは,結晶構造に適切に形成されていませんでした.
結論:
- バックボーンNH群は,人工エステラゼスのオキシアニオン穴の設計に有効です.
- 高い触媒効率を達成することは,ゆっくりとしたアシル酵素中間水解によって制限されます.
- コンピュータによる設計は,自然酵素の活性部位の精度を複製する上で課題に直面しています.
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