用X射线衍射和非弹性X射线散射研究了水合抗冻蛋白III在180k-298k范围内的结构和集体动力学。

PubMed ID
发表日期 2016年Apr月

原始出处 化学物理学杂志
The Journal of chemical physics
作者 Yoshida  Koji  Baron  Alfred Q R  Uchiyama  Hiroshi  Tsutsui  Satoshi  Yamaguchi  Toshio 

文献标题 用X射线衍射和非弹性X射线散射研究了水合抗冻蛋白III在180k-298k范围内的结构和集体动力学。
Structure and collective dynamics of hydrated anti-freeze protein type III from 180 K to 298 K by X-ray diffraction and inelastic X-ray scattering.

文献摘要

利用X射线衍射和非弹性X射线散射(IXS)研究了水合水平h(=水质量/蛋白质质量)为0.4的水合抗冻蛋白III(AFP III)粉末在180k和298k之间的温度范围。X射线衍射数据显示,在180k和298k之间,在没有冷冻水的情况下,变化平稳,基本上是单调的。同时,在较高温度(298-220k)下,在很大程度上与温度无关之后,IXS观测到的集体动力学显示出180k时声速的强烈变化。我们用先前讨论过的动态跃迁来解释这种变化,使用的探针包括太赫兹红外吸收光谱和非相干弹性和准弹性中子散射。这一发现表明,无论是在IXS的集体动力学还是中子散射的单粒子动力学中,水合蛋白质的动态转变都可以在亚皮秒尺度以及纳米和皮秒尺度上观察到。此外,水合AFPⅢ的动态转变很可能与其水化结构没有直接关系。


We investigated hydrated antifreeze protein type III (AFP III) powder with a hydration level h (=mass of water/mass of protein) of 0.4 in the temperature range between 180 K and 298 K using X-ray diffraction and inelastic X-ray scattering (IXS). The X-ray diffraction data showed smooth, largely monotonic changes between 180 K and 298 K without freezing water. Meanwhile, the collective dynamics observed by IXS showed a strong change in the sound velocity at 180 K, after being largely temperature independent at higher temperatures (298-220 K). We interpret this change in terms of the dynamic transition previously discussed using other probes including THz IR absorption spectroscopy and incoherent elastic and quasi-elastic neutron scattering. This finding suggests that the dynamic transition of hydrated proteins is observable on the subpicosecond time scale as well as nano- and pico-second scales, both in collective dynamics from IXS and single particle dynamics from neutron scattering. Moreover, it is most likely that the dynamic transition of hydrated AFP III is not directly correlated with its hydration structure.


获取全文 10.1063/1.4944987