Emanuel Marc, Lanzani Giovanni, Schiessel Helmut
Instituut Lorentz voor de Theoretische Natuurkunde, Universiteit Leiden, P. O. Box 9506, NL-2300 RA Leiden, The Netherlands and Institute of Complex Systems II, Forschungszentrum Jülich, Jülich 52425, Germany and Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628CJ Delft, The Netherlands.
Phys Rev E Stat Nonlin Soft Matter Phys. 2013 Aug;88(2):022706. doi: 10.1103/PhysRevE.88.022706. Epub 2013 Aug 12.
We use the wormlike chain model to study supercoiling of DNA under tension and torque. The model reproduces experimental data for a broad range of forces, salt concentrations, and contour lengths. We find a plane of first-order phase transitions ending in a smeared-out line of critical points, the multiplectoneme phase, which is characterized by a fast twist-mediated diffusion of plectonemes and a torque that rises after plectoneme formation with increasing linking number. The discovery of this phase at the same time resolves the discrepancies between existing models and experiment.
我们使用蠕虫状链模型来研究在张力和扭矩作用下DNA的超螺旋。该模型在广泛的力、盐浓度和轮廓长度范围内再现了实验数据。我们发现了一个一级相变平面，其终止于一条模糊的临界点线，即多重螺旋相，其特征是螺旋的快速扭曲介导扩散以及螺旋形成后随着连环数增加而上升的扭矩。同时，这一相的发现解决了现有模型与实验之间的差异。
