长寿命的环形聚合物自缠结。

Long-Lived Self-Entanglements in Ring Polymers.

机构信息

Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.

Department of Physics and Biophysics, University of San Diego, San Diego, California 92110, USA.

出版信息

Phys Rev Lett. 2019 Jul 26;123(4):048002. doi: 10.1103/PhysRevLett.123.048002.

DOI:10.1103/PhysRevLett.123.048002

PMID:31491263

Abstract

The entanglement of ring polymers remains mysterious in many aspects. In this Letter, we use electric fields to induce self-entanglements in circular DNA molecules, which serve as a minimal system for studying chain entanglements. We show that self-threadings give rise to entanglements in ring polymers and can slow down polymer dynamics significantly. We find that strongly entangled circular molecules remain kinetically arrested in a compact state for very long times, thereby providing experimental evidence for the severe topological constraints imposed by threadings.

摘要

环形聚合物的缠结在许多方面仍然是神秘的。在这封信中，我们使用电场在圆形 DNA 分子中诱导自缠结，这是研究链缠结的最小系统。我们表明，自穿线会导致环形聚合物中的缠结，并会显著减慢聚合物动力学。我们发现，强缠结的圆形分子在紧凑状态下会被动力学捕获很长时间，从而为穿线施加的严重拓扑约束提供了实验证据。