Hierarchical molecular dynamics of bovine serum albumin in concentrated aqueous solution below and above thermal denaturation
Hierarchical molecular dynamics of bovine serum albumin in concentrated aqueous solution below and above thermal denaturation
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DOI：
10.1039/c4cp04944f
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发表时间：
2015-01-01
影响因子：
3.3
通讯作者：
Seydel, Tilo
中科院分区：
文献类型：
--
作者：
Grimaldo, Marco;Roosen-Runge, Felix;Seydel, Tilo
蛋白质在溶液中的动力学是一个复杂的、分层次的过程，受水环境和温度的影响。我们提出了一个全面的研究纳秒时间和纳米长度尺度下，在变性温度Td和以上。我们的实验数据证据在三个不同的时间尺度上的蛋白质溶液的动力学过程。我们提出了一个一致的分层蛋白质动力学的物理图像：（i）整个蛋白质分子的自扩散被证实同意胶体理论的所有温度下，蛋白质是在其天然构象状态。在较高温度T > T-d时，自扩散被交联或缠结强烈阻碍。(ii)主干波动的幅度随着T的增加而增加，并且在T-d以上观察到其动力学的转变。(iii)移动的侧链的数量在T-d急剧增加，而它们的平均动力学仅表现出很小的变化。准弹性中子散射和所提出的分析框架相结合，提供了一个详细的微观图像的蛋白质分子动力学在溶液中，从而反映了宏观性质的变化，如簇的形成和凝胶化。
The dynamics of proteins in solution is a complex and hierarchical process, affected by the aqueous environment as well as temperature. We present a comprehensive study on nanosecond time and nanometer length scales below, at, and above the denaturation temperature T-d. Our experimental data evidence dynamical processes in protein solutions on three distinct time scales. We suggest a consistent physical picture of hierarchical protein dynamics: (i) self-diffusion of the entire protein molecule is confirmed to agree with colloid theory for all temperatures where the protein is in its native conformational state. At higher temperatures T > T-d, the self-diffusion is strongly obstructed by cross-linking or entanglement. (ii) The amplitude of backbone fluctuations grows with increasing T, and a transition in its dynamics is observed above T-d. (iii) The number of mobile side-chains increases sharply at T-d while their average dynamics exhibits only little variations. The combination of quasi-elastic neutron scattering and the presented analytical framework provides a detailed microscopic picture of the protein molecular dynamics in solution, thereby reflecting the changes of macroscopic properties such as cluster formation and gelation.