Effect of conformational states on protein dynamical transition
Effect of conformational states on protein dynamical transition
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DOI：
10.1016/j.bbapap.2009.06.025
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发表时间：
2010-01-01
影响因子：
3.2
通讯作者：
Kataoka, Mikio
中科院分区：
文献类型：
--
作者：
Nakagawa, Hiroshi;Kamikubo, Hironari;Kataoka, Mikio
为了研究折叠蛋白的特性，用非相干弹性中子散射方法研究了金黄色葡萄球菌核酸酶野生型和缺失突变体的构象状态对蛋白质动态转变的影响。缺失C-末端13个残基的SNase缺失突变体具有致密的变性结构，可视为一种内在非结构蛋白的模型。在10~300K的不同温度下，对安装在不同温度下的In10和In13进行了非相干弹性中子散射实验，根据弹性散射强度的Q依赖关系得到了均方位移随温度的变化关系。测量是在干燥和水合的粉末样品上进行的。在水合样品中，野生型和突变体之间没有显著差异，而在干燥样品中，野生型和突变体之间存在显著差异。在140K附近观察到了干燥和水合样品的动态转变。野生型和突变体在转换前和转换后的MSD随温度变化的斜率不同，表明折叠诱导硬化。水化水在240K附近激活了进一步的转变。野生型和突变体MSD的温度依赖性行为没有区别，表明水化水动力学决定了MSD的动力学性质。(C)2009爱思唯尔B.V.保留所有权利。
In order to examine the properties specific to the folded protein, the effect of the conformational states on protein dynamical transition was studied by incoherent elastic neutron scattering for both wild type and a deletion mutant of staphylococcal nuclease. The deletion mutant of SNase which lacks C-terminal 13 residues takes a compact denatured structure, and can be regarded as a model of intrinsic unstructured protein. Incoherent elastic neutron scattering experiments were carried out at various temperature between 10 K and 300 K on IN10 and IN13 installed at ILL Temperature dependence of mean-square displacements was obtained by the q-dependence of elastic scattering intensity. The measurements were performed on dried and hydrated powder samples. No significant differences were observed between wild type and the mutant for the hydrated samples, while significant differences were observed for the dried samples. A dynamical transition at similar to 140 K observed for both dried and hydrated samples. The slopes of the temperature dependence of MSD before transition and after transition are different between wild type and the mutant, indicating the folding induces hardening. The hydration water activates a further transition at similar to 240 K. The behavior of the temperature dependence of MSD is indistinguishable for wild type and the mutant, indicating that hydration water dynamics dominate the dynamical properties. (C) 2009 Elsevier B.V. All rights reserved.