Abstract：
Natural deep eutectic solvents (NADESs) comprised of osmolytes are of interest as potential biomolecular (cryo)protectants. However, the way these solvents influence the structure and dynamics of biomolecules as well as the role of water remains poorly understood. We carried out principal component analysis of various secondary structure elements of ubiquitin in water and a betaine : glycerol : water (1 : 2 : ζ; ζ = 0, 1, 2, 5, 10, 20, 45) NADES, from molecular dynamics trajectories, to gain insight into the protein dynamics as it undergoes a transition from a highly viscous anhydrous to an aqueous environment. A crossover of the protein\'s essential dynamics at ζ ∼ 5, induced by solvent-shell coupled fluctuations, is observed, indicating that ubiquitin might (re)fold in the NADES upon water addition at ζ > ∼5. Further, in contrast to water, the anhydrous NADES preserves ubiquitin\'s essential modes at high temperatures explaining the protein\'s seemingly enhanced thermal stability.
摘要：
由渗透物组成的天然深共晶溶剂（NADES）作为潜在的生物分子（冷冻）保护剂是令人感兴趣的。然而,这些溶剂影响生物分子的结构和动力学以及水的作用的方式仍然知之甚少。我们对水中泛素的各种二级结构元素和甜菜碱：甘油：水（1：2：ζ；ζ=0、1、2、5、10、20、45）NADES进行了主成分分析，从分子动力学轨迹来看，以深入了解蛋白质动力学，因为它经历了从高粘性无水到水性环境的转变。由溶剂-壳耦合波动诱导的蛋白质在ζ~5的基本动力学交叉，被观察到，表明在ζ>~5处加水时，泛素可能(重新)在NADES中折叠。Further,与水相比，无水NADES在高温下保留了泛素的基本模式，解释了蛋白质似乎增强的热稳定性。
