The “Protein Dynamical Transition” Does Not Require the Protein Polypeptide Chain
The “Protein Dynamical Transition” Does Not Require the Protein Polypeptide Chain
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DOI：
10.1021/jz200797g
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发表时间：
2011-08
影响因子：
5.7
通讯作者：
G. Schirò;C. Caronna;F. Natali;M. Marek Koza;A. Cupane
中科院分区：
文献类型：
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作者：
G. Schirò;C. Caronna;F. Natali;M. Marek Koza;A. Cupane
我们通过实验证明，中子散射揭示的蛋白质动力学的主要特征，即“蛋白质动力学转变”和“玻色子峰”，不需要蛋白质多肽链。我们发现，在具有肌红蛋白化学成分但缺乏多肽链的水合氨基酸混合物中，也观察到了在约 220 K 时氢原子波动的快速增加，类似于在水合肌红蛋白粉末中观察到的氢原子波动；与蛋白质的行为一致，这种转变在干燥混合物中被消除。此外，在我们的混合物中也观察到了过量的 3 meV 左右的低频振动模式（通常在蛋白粉中观察到）。我们的结果证实，动态转变是水驱动的起始，并表明它主要涉及氨基酸侧链。综合目前关于变性构象蛋白质动力学和脱水蛋白质活性的数据和最新结果，可以得出结论：...
We give experimental evidence that the main features of protein dynamics revealed by neutron scattering, i.e., the “protein dynamical transition” and the “boson peak”, do not need the protein polypeptide chain. We show that a rapid increase of hydrogen atoms fluctuations at about 220 K, analogous to the one observed in hydrated myoglobin powders, is also observed in a hydrated amino acids mixture with the chemical composition of myoglobin but lacking the polypeptide chain; in agreement with the protein behavior, the transition is abolished in the dry mixture. Further, an excess of low-frequency vibrational modes around 3 meV, typically observed in protein powders, is also observed in our mixture. Our results confirm that the dynamical transition is a water-driven onset and indicate that it mainly involves the amino acid side chains. Taking together the present data and recent results on the dynamics of a protein in denatured conformation and on the activity of dehydrated proteins, it can be concluded that...