论文标题
在水溶液中稳定多肽的$α-$螺旋：偶极方向或氢键？
Stabilizing $α-$helicity of polypeptide in aqueous urea: Dipole orientation or hydrogen bonding?
论文作者
论文摘要
尿素对蛋白质的强烈趋势通过尿素保留优先结合脱水而剥离蛋白质。但是，即使经过广泛的实验和计算研究，尿素对二级结构稳定性的影响仍然难以捉摸。例如，与共同的理解相反，实验研究表明，特定的多肽（例如多丙氨酸或富含丙氨酸的系统）甚至可能显示出在水溶液中形成二级结构的趋势。我们使用超过15美元的全原子模拟研究了这种看似违反直觉的行为。这些结果表明，局部偶极子方向和氢键之间的微妙平衡如何决定尿素水溶液中的多肽溶剂化。我们的工作建立了结构性关系，该关系突出了微观偶极偶极子方向/相互作用对宏观蛋白质溶剂化的操作理解的重要性。
Urea denatures proteins due to its strong tendency to dehydrate the first solvation shell via urea-residue preferential binding. However, even after extensive experimental and computational investigations, the influence of urea on the stability of secondary structures remains elusive. For example, contrary to the common understanding, experimental studies have indicated that specific polypeptides, such as poly-alanine or alanine-rich systems, may even show an improved tendency to form secondary structures in aqueous urea. We investigate this seemingly counter-intuitive behaviour using over 15$μ$s long all-atom simulations. These results show how a delicate balance between the localized dipole orientations and hydrogen bonding dictates polypeptide solvation in aqueous urea. Our work establishes a structure-property relationship that highlights the importance of microscopic dipole-dipole orientations/interactions for the operational understanding of macroscopic protein solvation.
