Ubbink J, Odijk T
Department of Polymer Technology, Faculty of Chemical Engineering and Materials Science, Delft University of Technology, The Netherlands.
Biophys J. 1995 Jan;68(1):54-61. doi: 10.1016/S0006-3495(95)80158-X.
A model is proposed for polymer- and salt-induced toroidal condensates of DNA, based on a recent theory of the undulation enhancement of the electrostatic interaction in the bulk hexagonal phase of semiflexible polyions. In a continuum approximation, the thermodynamic potential of a monomolecular toroid may be split up in bulk, surface, and curvature contributions. With the help of an approximate analytical minimization procedure, the optimal torus dimensions are calculated as a function of the concentrations of inert polymer and added salt. The stability of the torus is analyzed in terms of its surface tension and a bulk melting criterion. The theory should be applicable to psi-toroids that are not too thick.
基于半柔性聚离子本体六方相中静电相互作用波动增强的最新理论,提出了一种聚合物和盐诱导的DNA环形凝聚物模型。在连续介质近似中,单分子环面的热力学势可分为本体、表面和曲率贡献。借助近似解析最小化程序,计算出最佳环面尺寸作为惰性聚合物和添加盐浓度的函数。根据环面的表面张力和本体熔化判据分析其稳定性。该理论应适用于不太厚的ψ-环面。