QQ客服 官方微博 反馈留言

	Density-functional theory and Monte Carlo simulation study on the electric double layer around DNA in mixed-size counterion systems
	Wang, K ; Yu, YX ; Gao, GH ; Luo, GS
	2010-05-07 ; 2010-05-07
关键词	FREE-ENERGY MODEL HYPERNETTED-CHAIN APPROXIMATION POISSON-BOLTZMANN CALCULATIONS RESTRICTED-PRIMITIVE-MODEL POLY-ELECTROLYTE THEORIES HARD-SPHERE FLUID POLYELECTROLYTE SOLUTIONS COLLOIDAL PARTICLES COMPETITIVE-BINDING K+ IONS Physics, Atomic, Molecular & Chemical
中文摘要	A density-functional approach and canonical Monte Carlo simulations are presented for describing the ionic microscopic structure around the DNA molecule immersed in mixed-size counterion solutions. In the density-functional approach, the hard-sphere contribution to the Helmholtz energy functional is obtained from the modified fundamental measure theory [Y.-X. Yu and J. Z. Wu, J. Chem. Phys. 117, 10156 (2002)], and the electrostatic contribution is evaluated through a quadratic functional Taylor expansion. The new theory is suitable to the systems containing ions of arbitrary sizes and valences. In the established canonical Monte Carlo simulation, an iterative self-consistent method is used to evaluate the long-range energy, and another iterative algorithm is adopted to obtain desired bulk ionic concentrations. The ion distributions from the density-functional theory (DFT) are in good agreement with those from the corresponding Monte Carlo (MC) simulations. It is found that the ratio of the bulk concentrations of two species of counterions (cations) makes significant contribution to the ion distributions in the vicinity of DNA. Comparisons with the electrostatic potential profiles from the MC simulations show that the accuracy of the DFT becomes low when a small divalent cation exists. Both the DFT and MC simulation results illustrate that the electrostatic potential at the surface of DNA increases as the anion diameter or the total cation concentration is increased and decreases as the diameter of one cation species is increased. The calculation of electrostatic potential using real ion diameters shows that the accuracy of DFT predictions for divalent ions is also acceptable.
语种	英语 ; 英语
出版者	AMER INST PHYSICS ; MELVILLE ; CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA
内容类型	期刊论文
源URL	[http://hdl.handle.net/123456789/17230]
专题	清华大学
推荐引用方式 GB/T 7714	Wang, K,Yu, YX,Gao, GH,et al. Density-functional theory and Monte Carlo simulation study on the electric double layer around DNA in mixed-size counterion systems[J],2010, 2010.
APA	Wang, K,Yu, YX,Gao, GH,&Luo, GS.(2010).Density-functional theory and Monte Carlo simulation study on the electric double layer around DNA in mixed-size counterion systems..
MLA	Wang, K,et al."Density-functional theory and Monte Carlo simulation study on the electric double layer around DNA in mixed-size counterion systems".(2010).

个性服务

查看访问统计

相关权益政策

暂无数据

收藏/分享

除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。