School of Molecular Sciences , Arizona State University , Tempe , Arizona 85287-1604 , United States.
J Phys Chem B. 2019 Jan 17;123(2):480-486. doi: 10.1021/acs.jpcb.8b12052. Epub 2019 Jan 2.
In this simulation study, we investigate the influence of biomolecular confinement on dynamical processes in water. We compare water confined in a membrane protein nanopore at room temperature to pure liquid water at low temperatures with respect to structural relaxations, intermolecular vibrations, and the propagation of collective modes. We observe distinct potential energy landscapes experienced by water molecules in the two environments, which nevertheless result in comparable hydrogen bond lifetimes and sound propagation velocities. Hence, we show that a viscoelastic argument that links slow rearrangements of the water-hydrogen bond network to ice-like collective properties applies to both, the pure liquid and biologically confined water, irrespective of differences in the microscopic structure.
在这项模拟研究中，我们研究了生物分子限制对水中动力学过程的影响。我们比较了在室温下限制在膜蛋白纳米孔中的水与低温下的纯液态水在结构弛豫、分子间振动和集体模式传播方面的差异。我们观察到水分子在两种环境中经历的明显势能景观，但这导致了类似的氢键寿命和声音传播速度。因此，我们表明，将水-氢键网络的缓慢重排与类冰集体性质联系起来的粘弹性论点适用于纯液态水和生物限制水，而与微观结构的差异无关。
