展开蛋白质和IDP中的本地和大规模构造动力学. II. II. II. II. II. II. II. II. II. II. II. II. II. II. II. II. II. II. 温度和内部摩擦的影响
Florian Krieger1, Karin Stecher2, Christian Nyffenegger2
1Biozentrum der Universität Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland.
The journal of physical chemistry. B
|September 18, 2023
概括
蛋白质动力学受到能量障碍的控制,短循环面临重大障碍. 循环形成障碍随着大小的减少,受内部摩擦和未折叠蛋白质和内在无序蛋白质的硬质效应的影响.
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
- 聚合物物理 聚合物物理
背景情况:
- 蛋白质的内部动态对于折叠和功能至关重要.
- 展开的蛋白质和内在无序的蛋白质 (IDPs) 呈现出对细胞过程至关重要的动态.
- 在未折叠的蛋白质中运动的支配因素和能量障碍仍然是一个开放的问题.
研究的目的:
- 调查展开的多链和IDP中局部和远程循环形成的能量障碍.
- 了解内部摩擦和固体效应在蛋白质动态中的作用.
- 为了将循环形成障碍与溶剂粘度效应相关联.
主要方法:
- 三倍三倍的能量转移 (TTET) 用于研究同型多链和IDP中的循环形成.
- 确定了激活能量 (Ea) 和阿雷尼乌斯预指数因子 (A).
- 分析了循环形成对溶剂粘度的依赖.
主要成果:
- 短循环形成具有显著的能量障碍 (高达18kJ/mol) 与最小的序列依赖.
- 循环形成障碍物随着多-Gly-Ser和多链的循环大小的增加而减少,在长链中达到平原.
- 观察到Ea和溶剂粘度灵敏度 (α) 之间的负相关性,与Grote-Hynes理论保持一致.
- 在IDP序列中的远程循环形成显示了更高的Ea和A,这是由于硬质效应而不是其他相互作用.
结论:
- 内部摩擦,特别是固体效应,在未折叠的蛋白质中显著影响循环形成障碍.
- 环的大小和链条的灵活性调节内部摩擦的影响.
- 虽然在短循环中顺序独立,但在IDP中的远距离循环形成中,固态效应成为主导因素.
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