单分子光实验确定蛋白质折叠过渡路径次数
Hoi Sung Chung1, Kevin McHale, John M Louis
1Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health (NIH), Bethesda, MD 20892-0520, USA. chunghoi@niddk.nih.gov
Science (New York, N.Y.)
|February 25, 2012
概括
蛋白质折叠速度有很大差异,但实际的折叠事件时间对于快速和慢速折叠的蛋白质来说是相似的. 这一发现有助于理解蛋白质动力学和能量格局.
科学领域:
- 生物物理学的生物物理.
- 蛋白质动力学 蛋白质动力学
- 单分子生物物理学的单分子生物物理
背景情况:
- 过渡路径代表了在跨越自由能量屏障期间的关键分子轨迹.
- 了解转变路径对于阐明蛋白质折叠机制至关重要.
- 单分子福斯特共振能量转移 (smFRET) 实验允许观察这些动态事件.
研究的目的:
- 为了研究和比较快速和缓慢折叠蛋白质的平均过渡路径时间.
- 为了确定折叠率差异是否与过渡路径持续时间相关.
- 提供对蛋白质折叠的能量景观理论的见解.
主要方法:
- 光轨迹的光子对光子分析.
- 单分子福斯特共振能量转移 (smFRET) 实验.
- 测量不同蛋白质折叠行为的平均过渡路径时间.
主要成果:
- 虽然蛋白质的折叠速率系数在蛋白质之间有1万倍的差异,但它们的平均过渡路径时间差不多不到5倍.
- 这表明,无论整体折叠速度如何,折叠发生的实际时间都非常相似.
- 结果与简化能源景观模型的预测一致.
结论:
- 过渡路径的持续时间,核心折叠事件,在不同折叠速率的蛋白质中在很大程度上保持.
- 蛋白质折叠速度主要是由过渡路径本身之外的因素决定的.
- 能源景观理论提供了一个可行的框架来解释这些在过渡路径时间观察到的相似性.
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