对于GNNQQNY的热力学和聚合动力学
Birgit Strodel1, Chris S Whittleston, David J Wales
1University Chemical Laboratories, Lensfield Road, Cambridge CB2 1EW, UK.
Journal of the American Chemical Society
|December 7, 2007
概括
酵母子酸GNNQQNY在单体形式迅速波动,形成稳定的二元体,包括β片结构. 滴聚物形成是快速而稳定的,相互转化比解离更有可能发生.
科学领域:
- 生物物理学的生物物理.
- 计算化学计算化学
- 蛋白质的错误折叠 蛋白质的错误折叠
背景情况:
- 像GNNQQNY这样的amyloidogenic都涉及到酵母菌的子形成.
- 了解这些的结构动态对于阐明聚合机制至关重要.
研究的目的:
- 调查GNNQQNY的单体和二元形式的自由能量格局和构造动态.
- 确定GNNQQNY单体和二元体的稳定结构和相互转换途径.
主要方法:
- 单原子电位和隐性溶剂模型用于类模拟.
- 复制品交换分子动力学来探索构造空间.
- 离散路径采样用于分析自由能量最小值之间的相互转换路径.
主要成果:
- 单体GNNQQNY快速采样四种构造,其中中间结构是最稳定的.
- GNNQQNY二元体形成了三个稳定的板结构:在注册并行,在注册之外并行和反并行.
- 反平行二元体是通过静电相互作用稳定,而注册式平行二元体则依赖于疏水性相互作用,并且具有更高的构造.
- 在室温下,从单体中形成的模量是快速且动态稳定的.
- 二元体结构之间的相互转换比二元体解离更有可能发生.
结论:
- 酸GNNQQNY在单体和二元状态下表现出复杂的结构灵活性.
- 特定的二极体结构,特别是类似于粉样蛋白β片的注册式平行形式,通过不同的相互作用得到稳定.
- GNNQQNY二元体的动力稳定性和相互转换途径为粉样蛋白形成的早期阶段提供了洞察力.
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