在角度和二面角限制下的高斯半柔性环

Gaussian semiflexible rings under angular and dihedral restrictions.

作者信息

Dolgushev Maxim, Guérin Thomas, Blumen Alexander, Bénichou Olivier, Voituriez Raphaël

机构信息

Theoretical Polymer Physics, University of Freiburg, Hermann-Herder-Str. 3, 79104 Freiburg, Germany.

Laboratoire de Physique Théorique de la Matière Condensée, Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, 4 Place Jussieu, 75005 Paris, France.

出版信息

J Chem Phys. 2014 Jul 7;141(1):014901. doi: 10.1063/1.4885445.

DOI:10.1063/1.4885445

PMID:25005305

Abstract

Semiflexible polymer rings whose bonds obey both angular and dihedral restrictions [M. Dolgushev and A. Blumen, J. Chem. Phys. 138, 204902 (2013)], are treated under exact closure constraints. This allows us to obtain semianalytic results for their dynamics, based on sets of Langevin equations. The dihedral restrictions clearly manifest themselves in the behavior of the mean-square monomer displacement. The determination of the equilibrium ring conformations shows that the dihedral constraints influence the ring curvature, leading to compact folded structures. The method for imposing such constraints in Gaussian systems is very general and it allows to account for heterogeneous (site-dependent) restrictions. We show it by considering rings in which one site differs from the others.

摘要

键同时服从角向和二面角限制的半柔性聚合物环[M. 多尔古舍夫和A. 布卢门，《化学物理杂志》138, 204902 (2013)]，在精确的封闭约束条件下进行处理。这使我们能够基于朗之万方程组获得其动力学的半解析结果。二面角限制在均方位移行为中清晰地表现出来。平衡环构象的确定表明，二面角约束会影响环的曲率，从而导致紧凑的折叠结构。在高斯系统中施加此类约束的方法非常通用，并且能够考虑非均匀（位点相关）限制。我们通过考虑其中一个位点与其他位点不同的环来证明这一点。