University of Alaska-Anchorage, Anchorage, Alaska 99508, USA.
J Phys Chem B. 2010 Dec 9;114(48):15799-807. doi: 10.1021/jp1082467. Epub 2010 Nov 15.
Quantitative dynamics of methyl groups in 9-fluorenylmethyloxycarbonyl-leucine (FMOC-leu) have been analyzed and compared with earlier studies of methyl dynamics in chicken villin headpiece subdomain protein (HP36) labeled at L69, a key hydrophobic core position. A combination of deuteron solid-state nuclear magnetic resonance experiments over the temperature range of 7-324 K and computational modeling indicated that while the two compounds show the same modes of motions, there are marked differences in the best-fit parameters of these motions. One of the main results is that the crossover observed in the dynamics of the methyl groups in the HP36 sample at 170 K is absent in FMOC-leu. A second crossover at around 95-88 K is present in both samples. The differences in the behavior of the two compounds suggest that some of the features of methyl dynamics reflect the complexity of the protein hydrophobic core and are not determined solely by local interactions.
已分析并比较了 9-芴甲氧羰基-亮氨酸（FMOC-leu）中甲基的定量动力学，与之前在鸡绒毛状蛋白头部片段亚基蛋白（HP36）中 L69 位标记的甲基动力学的研究进行了比较，L69 是一个关键的疏水性核心位置。在 7-324 K 的温度范围内，氘固态核磁共振实验与计算建模的组合表明，尽管这两种化合物表现出相同的运动模式，但这些运动的最佳拟合参数存在显著差异。主要结果之一是，在 HP36 样品中，在 170 K 时观察到的甲基动力学的交叉现象在 FMOC-leu 中不存在。在两个样品中都存在大约 95-88 K 的第二个交叉。这两种化合物行为的差异表明，一些甲基动力学的特征反映了蛋白质疏水性核心的复杂性，而不仅仅取决于局部相互作用。
