时间分辨率晶体学揭示了N-RAS和瘤突变G12C,G12V和Q61L的GTP水解机制
Guowu Lin1, Paola Zinser-Peniche1, Xiaohong Zhou1
1Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
bioRxiv : the preprint server for biology
|September 2, 2025
概括
研究人员可视化了RAS蛋白中的GTP水解,揭示了癌症相关突变的独特反应机制. 这种对GTPase活性的结构洞察力可以指导针对特定中间状态的新癌症药物发现.
科学领域:
- 生物化学
- 结构生物学
- 分子生物学
背景情况:
- RAS GTPases是细胞信号的关键调节者,它们充当分子开关.
- 人类癌症中RAS突变很常见,通常会损害GTP水解,导致细胞生长不受控制.
- 对于RAS无活化至关重要的GTP水解的精确机制在结构上仍然难以捉摸.
研究的目的:
- 在RAS蛋白中结构性地解决GTP水解的实时机制.
- 研究野生型RAS与主要致癌突变体之间的GTP水解机制差异.
- 根据水解反应期间的短暂结合口袋来确定潜在的药物点.
主要方法:
- 时间分辨率晶体学使用光性GTP基质.
- 在GTP水解过程中捕获和分析多种反应中间体.
- 野生型N-RAS,瘤突变物 (G12C,G12V,Q61L) 和快速水解突变物 (Y32R) 的结构比较.
主要成果:
- 捕获了57种不同的反应中间体,详细说明了GTP水解途径.
- 观察到共同的机理元素,包括初始开放状态,闭合的迈克利斯复合体和产物释放.
- 在野生型和突变RAS蛋白之间发现了反应机制和速率的显著差异.
- 在水解过程中发现了密码结合口袋,
结论:
- 这项研究首次阐明了RAS蛋白中的GTP水解机制的结构.
- 了解这些机制可以了解RAS突变在癌症中的作用.
- 已识别的依赖状态的结合口袋代表了针对RAS驱动癌症的基于结构的药物发现的有希望的目标.
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