IIS, LIMMS CNRS-IIS UMI2820, The University of Tokyo, 4-6-1 Komaba, Meguro-ku Tokyo 153-8505, Japan.
Laboratoire d'Electrochimie Moléculaire, UMR 7591 CNRS, Université Paris Cité, 15 rue Jean-Antoine de Baïf, F-75205 Paris Cedex 13, France.
ACS Nano. 2023 Sep 12;17(17):17031-17040. doi: 10.1021/acsnano.3c04349. Epub 2023 Aug 24.
Theoretical treatments of polymer dynamics in liquid generally start with the basic assumption that motion at the smallest scale is heavily overdamped; therefore, inertia can be neglected. We report on the Brownian motion of tethered DNA under nanoconfinement, which was analyzed by molecular dynamics simulation and nanoelectrochemistry-based single-electron shuttle experiments. Our results show a transition into the ballistic Brownian motion regime for short DNA in sub-5 nm gaps, with quality coefficients as high as 2 for double-stranded DNA, an effect mainly attributed to a drastic increase in stiffness. The possibility for DNA to enter the underdamped regime could have profound implications on our understanding of the energetics of biomolecular engines such as the replication machinery, which operates in nanocavities that are a few nanometers wide.
聚合物在液体中的动力学的理论处理通常从一个基本假设开始，即最小尺度上的运动是严重过阻尼的；因此，可以忽略惯性。我们报告了受约束的 DNA 在纳米限制下的布朗运动，这是通过分子动力学模拟和基于纳电子化学的单电子穿梭实验进行分析的。我们的结果表明，在亚 5nm 的间隙中，短 DNA 进入弹道布朗运动状态，双链 DNA 的质量系数高达 2，这一效应主要归因于刚度的急剧增加。DNA 进入欠阻尼状态的可能性可能对我们理解生物分子发动机的能量学产生深远的影响，例如复制机械，它在几纳米宽的纳米腔中运行。
