拥挤诱导了生物巨分子在长距离的集体水合
John T King1, Evan J Arthur, Charles L Brooks
1Department of Chemistry, University of Michigan , 930 N. University Ave., Ann Arbor, Michigan 48109, United States.
Journal of the American Chemical Society
|December 18, 2013
概括
大分子拥挤大大减缓了蛋白质水化动态,诱导了类似杂的过渡. 这种集体水合发生在特定的蛋白质距离,不同于聚合物和蛋白质 crowders.
科学领域:
- 生物物理学的生物物理.
- 化学物理 化学物理
- 频谱学是一种光谱学.
背景情况:
- 大分子拥挤显著影响蛋白质的行为和动态.
- 了解水化动态对于拥挤环境中的蛋白质功能至关重要.
- 蛋白溶酶 (HEWL) 作为研究拥挤效应的模型蛋白质.
研究的目的:
- 通过使用超快的2D-IR光谱来研究拥挤的HEWL的皮秒蛋白质和水合动态.
- 为了区分惰性聚合物 crowders (PEG) 与蛋白质 crowders (lyszyme) 对HEWL动态的影响.
- 为了确定在不同拥挤条件下水分变化的过渡点和机制.
主要方法:
- 使用超快的二维红外 (2D-IR) 光谱.
- 采用了一个金属碳烯振动探头,连接到HEWL.
- 系统地挤满了HEWL的聚乙烯糖醇 (PEG) 和多余的酶.
主要成果:
- 观察到皮秒蛋白质和水化动态中的急剧动态干扰类过渡.
- 将这种转变归因于由拥挤引起的独立到集体水合过渡.
- 与散装水相比,水化动态减缓了多达一个数量级;在30-40 Å的蛋白间距离上观察到集体水化.
结论:
- 大分子拥挤会导致蛋白质水化动态的显著减缓,导致干扰过渡.
- 这种过渡表明,蛋白质的集体水合在介面镜间距离的距离.
- 小分子 (糖醇) 和大分子 (PEG,蛋白质) 剂之间的拥挤效应从根本上有所不同.
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