The persistence length and length per base of single-stranded DNA obtained from fluorescence correlation spectroscopy measurements using mean field theory
The persistence length and length per base of single-stranded DNA obtained from fluorescence correlation spectroscopy measurements using mean field theory
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DOI：
10.1016/j.physa.2012.09.022
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发表时间：
2013-03-01
影响因子：
3.3
通讯作者：
Jiang, Jiahuan
中科院分区：
文献类型：
--
作者：
Chi, Qingjia;Wang, Guixue;Jiang, Jiahuan
利用动力学平均场理论预测了单链DNA的末端单体均方位移，并最终估计了两个重要参数--持续长度l（p）和每碱基长度l（d）.这两个参数都是自由的，最后通过将理论数据与Shusterman等人的实验数据拟合得到最佳值[R. Shusterman，S. Alon，T.加夫里尼奥夫岛Krichevsky，双链和单链DNA聚合物中的分子动力学，Phys. Rev. Lett. 92（2004）048303]。用蒙特卡罗方法进行了三种优化方法，即全局优化、个体优化和选择优化。所有优化方法都能忠实地再现实验数据。在2400和6700碱基ssDNA的选择优化中，获得I（p）= 2.223 nm和I（d）= 0.676 nm。理论结果表明，ssDNA的持久长度比普通的合成聚合物更大，并且所获得的每个碱基的长度大于从单分子力测量获得的报道值。从平均场理论得到的l（p）和l（d）补充了以前测量的溶液中不同盐浓度的电流数据。(c)2012爱思唯尔有限公司版权所有。
A dynamical mean field theory is used to predict the end-monomer mean square displacement of single-stranded DNA and finally estimate two important parameters- the persistence length l(p) and the length per base l(d). Both parameters are set free, and finally reach optimum values by fitting the theoretical data to the experimental data of Shusterman et al. [R. Shusterman, S. Alon, T. Gavrinyov, O. Krichevsky, Monomer dynamics in double- and single-stranded DNA polymers, Phys. Rev. Lett. 92 (2004) 048303]. Three optimization methods, global optimization, individual optimization and selected optimization are performed with the Monte Carlo method. All the optimization methods can faithfully reproduce the experimental data. In selected optimization for 2400 and 6700 bases ssDNA, l(p) = 2.223 nm and l(d) = 0.676 nm are obtained. The theoretical results show a larger persistence length for ssDNA than ordinary synthetic polymers, and the obtained length per base is larger than the reported value obtained from single molecule force measurements. The l(p) and l(d) obtained from mean field theory complement the current data previously measured for different salt concentrations in solution. (c) 2012 Elsevier B.V. All rights reserved.