The native intracellular environment of proteins is crowded with metabolites and macromolecules. However, most biophysical information concerning proteins is acquired in dilute solution. To determine whether there are differences in dynamics, nuclear magnetic resonance spectroscopy can be used to measure 15N relaxation in uniformly 15N-enriched apocytochrome b5 inside living Escherichia coli and in dilute solution. Such data can then be used to compare the fast backbone dynamics of the partially folded protein in cells to its dynamics in dilute solution by using Lipari-Szabo analysis. It appears that the intracellular environment does not alter the protein's structure, or significantly change its fast dynamics. Specifically, the cytosol does not change the amplitude of fast backbone motions, but does increase the average timescale of these motions, most likely due to the increase in viscosity of the cytosol.

中文翻译：

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细胞内蛋白质动力学。

蛋白质的天然细胞内环境挤满了代谢产物和大分子。但是，大多数有关蛋白质的生物物理信息都是在稀溶液中获得的。为了确定动力学是否存在差异，可以使用核磁共振波谱法在活的大肠杆菌内部和稀溶液中均匀富集15N的脱细胞色素b5中测量15N弛豫。然后，通过使用Lipari-Szabo分析，可以将此类数据用于比较细胞中部分折叠的蛋白质的快速骨架动力学与其在稀溶液中的动力学。看来细胞内环境不会改变蛋白质的结构，也不会显着改变其快速动力学。具体而言，胞质溶胶不会改变快速骨干运动的幅度，