Cytosol has a small effect on protein backbone dynamics (Retracted Article. See vol 46, pg 8206, 2007)
Cytosol has a small effect on protein backbone dynamics (Retracted Article. See vol 46, pg 8206, 2007)
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DOI：
10.1021/bi060547b
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发表时间：
2006-08-22
期刊：
影响因子：
2.9
通讯作者：
Pielak, Gary J.
中科院分区：
文献类型：
--
作者：
Bryant, Julie E.;Lecomte, Juliette T. J.;Pielak, Gary J.
细胞中充满了大分子，但大多数关于蛋白质的生物物理信息都是在稀溶液中获得的。为了确定这种二分法的影响，我们使用核磁共振光谱测量了活大肠杆菌和稀释溶液中均匀富集N-15的脱辅基细胞色素B（5）的骨架N-15 T-1和T-2弛豫时间以及{H-1}-N-15核奥弗豪泽增强（nOe）。这些数据使我们能够评估这种部分折叠的蛋白质在细胞和稀溶液中的骨架动力学。通过使用无模型方法分析两个数据集。从稀溶液到胞质溶胶的转移对T-1、T-2和nOe值有定量影响。大多数的影响是由于增加的整体相关时间，所造成的增加的粘度的细胞质相比，稀释溶液。我们的主要结论是，胞质溶胶不改变模式的骨干动力学的脱辅基细胞色素b5。观察到皮秒和毫秒运动的时间尺度增加，但增加不到30%。
Cells are crowded with macromolecules, yet most biophysical information about proteins is obtained in dilute solution. To determine the impact of this dichotomy, we used nuclear magnetic resonance spectroscopy to measure the backbone N-15 T-1 and T-2 relaxation times and the {H-1}-N-15 nuclear Overhauser enhancement (nOe) of uniformly N-15-enriched apocytochrome b(5) in living Escherichia coli and in dilute solution. These data allowed us to assess the backbone dynamics of this partially folded protein in cells and in dilute solution. The two data sets were analyzed by using the model-free approach. Transfer from dilute solution to the cytosol has a quantitative effect on T-1, T-2, and nOe values. Most of the effects are attributed to an increase in the overall correlation time, caused by the increased viscosity of the cytosol compared to that of the dilute solution. Our main conclusion is that the cytosol does not alter the pattern of backbone dynamics of apocytochrome b5. Increases in the time scale of both the picosecond and millisecond motions are observed, but the increases are less than similar to 30%.