• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Applied Magnetic Resonance >Response of lysozyme internal dynamics to hydration probed by C-13 and H-1 solid-state NMR relaxation
【24h】

Response of lysozyme internal dynamics to hydration probed by C-13 and H-1 solid-state NMR relaxation

机译：C-13和H-1固态NMR弛豫探测溶菌酶内部动力学对水合的响应。

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

We have studied the hydration dependence of the internal protein dynamics of hen egg white lysozynie by naturally abundant C-13 and H-1 nuclear magnetic resonance (NMR) relaxation. NMR relaxation times T-1 off-resonance T-1p and proton-decoupled on-resonance T-1p (only for carbon experiments) were measured in the temperature range from 0 to 50degreesC. The spectral resolution in carbon cross-polarization magic angle spinning spectrum allows to treat methine. methylene and methyl carbons separately, while proton experiments provide only one integral signal from all protons at a time. The relaxation times were quantitatively analyzed by the well-established correlation function formalism and model-free approach. The whole set of the data could be adequately described by a model assuming three types of motion having correlation times around 10(-4), 10(-9) and 10(-12). The slowest process originated from correlated conformational transitions between different energy minima. the intermediate process could be identified as librations within one energy minimum, and the fastest one is a fast rotation of methyl protons around the symmetry axis of methyl groups. A comparison of the dynamic behavior of lysozyme and polylysine obtained from a previous study (A. Krushelnitsky, D. Faizullin, D. Reichert. Biopolymers 73, 1-15 2004) reveals that in the dry state both biopolymers are rigid on both fast and slow time scales. Upon hydration, lysozyme and polylysine reveal a considerable enhancement of the internal mobility, however. in different was. The side chain of polylysine are more mobile than those of lysozynte. whereas for the backbone a reversed picture is observed. This difference correlates with structural features of lysozyme and polylysine discussed in detail. Due to the presence of a fast spin diffusion. the analysis of proton relaxation data is a more difficult task. However, our data demonstrate that the correlation functions of motion obtained from carbon and proton experiments are substantially different. We explained this by the fact that these two types of NMR relaxation experiments probe the motion of different internuclear vectors. The comparison of the proton data with our previous results on proton relaxation times T-1 measured over a wide temperature range indicates that at low temperatures lysozyme undergoes structural rearrangements affecting the amplitudes and/or activation energies of motions.
机译：我们已经通过自然丰富的C-13和H-1核磁共振（NMR）弛豫研究了蛋清溶菌酶内部蛋白质动力学的水合依赖性。在0至50℃的温度范围内测量NMR弛豫时间T-1非共振T-1p和质子去耦共振T-1p（仅用于碳实验）。碳交叉极化魔角旋转光谱中的光谱分辨率允许处理次甲基。亚甲基和甲基碳分别存在，而质子实验一次只能从所有质子提供一个积分信号。通过建立完善的相关函数形式主义和无模型方法对弛豫时间进行了定量分析。假设三种类型的运动的相关时间在10（-4），10（-9）和10（-12）左右，模型可以充分描述整个数据集。最慢的过程源自不同能量最小值之间的相关构象转变。中间过程可被确定为在一个能量最小值内的释放，而最快的过程是甲基质子围绕甲基的对称轴快速旋转。从以前的研究（A. Krushelnitsky，D. Faizullin，D. Reichert。Biopolymers 73，2004年1月15日）获得的溶菌酶和聚赖氨酸的动力学行为的比较表明，在干燥状态下，两种生物聚合物在快速和快速状态下都是刚性的时间尺度慢。水合后，溶菌酶和聚赖氨酸显着提高了内部迁移率。在不同的是。聚赖氨酸的侧链比溶菌酶的侧链更易移动。而对于主干，观察到相反的图像。这种差异与详细讨论的溶菌酶和聚赖氨酸的结构特征有关。由于存在快速自旋扩散。质子弛豫数据的分析是一项更加艰巨的任务。但是，我们的数据表明，从碳和质子实验获得的运动的相关函数存在很大差异。我们通过这两种NMR弛豫实验探讨了不同核间载体的运动这一事实来对此进行解释。将质子数据与我们先前在宽温度范围内测得的质子弛豫时间T-1的结果进行比较，表明溶菌酶在低温下会发生结构重排，从而影响运动的幅度和/或激活能。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号