核酸中二级/三级结构动态的二维 (P/T) 研究:单个分子层面的压力诱导和马克斯韦关系
Hsuan-Lei Sung1,2, David J Nesbitt1,2,3
1JILA, National Institute of Standards and Technology and University of Colorado, Boulder, CO 80309, USA. djn@jila.colorado.edu.
Physical chemistry chemical physics : PCCP
|February 24, 2025
概括
了解核酸折叠需要分析不同压力和温度下的和变化. 这项研究使用单分子光共振能量转移 (smFRET) 来量化DNA和RNA折叠热力学,揭示压力诱导的不稳定性和温度依赖的效应.
科学领域:
- 热力学是一种热力学.
- 生物物理学的生物物理.
- 分子生物学分子生物学
背景情况:
- 核酸形状折叠是由体力和体力之间的平衡决定的.
- 极端环境条件,如高压和高温,显著影响这些热力学贡献.
- 在分子水平上了解这些效应对于预测核酸行为至关重要.
研究的目的:
- 量化研究DNA和RNA折叠的动力学和平衡.
- 研究压力和温度对核酸二级和三级结构的影响.
- 确定折叠的二维自由能量表面作为压力和温度的函数.
主要方法:
- 单分子光共振能量转移 (smFRET) 显微镜.
- 量化运动和平衡测量.
- 可变压力 (1-1000 bar) 和温度 (21-27 °C) 的条件.
主要成果:
- DNA和RNA结构对温度升高的反应不同:DNA稳定,而RNA则不稳定.
- 通过增加压力来破坏DNA和RNA折叠到原始状态的稳定性,这意味着体积变化为正值 (ΔV > 0).
- 与常见的预期相反,Mn2+ рибо开关在三级折叠时表现出正的变化 (ΔS > 0).
结论:
- 通过实验确定折叠的自由能量作为压力和温度的函数 (ΔG,P,T).
- 在核酸折叠的单个分子水平上,第一次实验证实了麦克斯韦关系 (∂ΔS/∂P) = - ∂ΔV/∂T.
- 这项工作为在各种环境条件下核酸折叠提供了关键的热力学见解.
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