ガン性RASを活性化するためのGAPのメカニズムベースの再設計
Dénes Berta1, Sascha Gehrke1, Kinga Nyíri2,3
1Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom.
Journal of the American Chemical Society
|September 8, 2023
まとめ
Ras GTPasesは細胞の信号伝達に 重要な役割を果たしますが 変異は癌を引き起こすのです この研究は,GTPの水解機構を明らかにし,腫瘍性Rasタンパク質の機能を回復する新しいRas- GAP変異体を設計した.
科学分野:
- 生物化学
- 分子生物学
- コンピュータ化学
背景:
- Ras GTPasesは,細胞信号伝達経路の重要なレギュレータである.
- 特にGly12,Gly13,Gln61のRas遺伝子の変異は,がんにおいて頻繁に見られ,GTPaseの活性低下につながる.
- GTPの水解のメカニズムを理解することは,標的型がん治療の開発に不可欠です.
研究 の 目的:
- Ras.GAP複合体によって触媒化されたGTP水解のメカニズムを解明する.
- 腫瘍性Ras変異体 (G12D,G12C) を用いて提案されたメカニズムを検証する.
- 腫瘍性Rasに触媒活性を取り戻すRas-GAP変異体の設計のための計算戦略を開発する.
主な方法:
- 量子力学/分子力学 (QM/MM) の自由エネルギー計算と最小化が反応機構を研究するために使用された.
- アクティベーションバリアを計算して190個のRas- GAP変異体の計算スクリーニングを行いました.
- 単一および二重のRas-GAP変異の超高速スクリーニングのための機械学習モデルが開発されました.
主要な成果:
- Ras.GAPによるGTP水解の2段階メカニズムが提案され,Gln61を一時的なブロンステッド基として使用した.
- このメカニズムは,G12DとG12CのRas変異体における触媒活性喪失を正確に予測した.
- 計算によるスクリーニングにより,G12D Rasの触媒活性を取り戻すことが予測されるいくつかのRas- GAP変異が特定されました.
結論:
- この研究は,Ras GTPの水解のための検証されたメカニズムと,タンパク質触媒の設計のための計算的枠組みを提供します.
- 開発されたスクリーニングプロトコルは,加強された触媒活性を持つタンパク質配列の迅速かつ正確な設計を可能にします.
- Ras-GAPの活性をターゲットにすることで,がんにおける異常なRas誘導信号を逆転させるための潜在的な治療戦略が提供されます.
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