An accurate and efficient empirical approach for calculating the dielectric self-energy and ion-ion pair potential in continuum models of biological ion channels
An accurate and efficient empirical approach for calculating the dielectric self-energy and ion-ion pair potential in continuum models of biological ion channels
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DOI：
10.1021/jp047438w
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发表时间：
2005-01-13
影响因子：
3.3
通讯作者：
Coalson, RD
中科院分区：
文献类型：
--
作者：
Cheng, HY;Coalson, RD
本文提出了计算圆柱形离子通道中介电自能和离子-离子对相互作用的经验公式。所提出的方法可以扩展到更复杂的通道结构，例如，（i）具有可变半径的“直”通道和（ii）具有恒定半径的“弯曲”通道。出于校准目的，我们将基于本文开发的近似有效电势获得的结果与通过Graf等人的算法获得的精确静电计算进行比较：（1，2）协议令人满意。动态晶格蒙特卡罗（DLMC）技术被用来进一步评估建议的经验电位的准确性和效率。用我们简单的经验能量公式得到的浓度分布和电流-电压曲线与用Graf等人的算法得到的数值结果非常一致，精确计算所有相关的静电力有效离子-离子势的使用大大降低了在介电不均匀环境中进行DLMC离子渗透模拟所需的计算机存储器，从而能够处理比数值精确技术所能处理的更大的系统。
This paper presents empirical formulas for calculating the dielectric self-energy and ion-ion pair interactions in cylindrical ion channels. The proposed approach can be extended to more complex channel structures, for example, (i) a "straight" channel with variable radius and (ii) a "curved" channel with constant radius. For calibration purposes, we compare results obtained based on the approximate effective potentials developed herein to exact electrostatic calculations obtained via the algorithm of Graf et al.: (1,2) the agreement is satisfactory. A dynamic lattice Monte Carlo (DLMC) technique is used to further assess the accuracy and efficiency of the proposed empirical potentials. The concentration profiles and current-voltage curves produced with our simple empirical energy formulas are in excellent agreement with numerical results obtained using the algorithm of Graf et al., which calculates all relevant electrostatic forces exactly. The use of effective ion-ion potentials greatly reduces the computer memory required to perform DLMC ion permeation simulations in dielectrically inhomogeneous environments, thus enabling treatment of larger systems than can be handled by numerically exact techniques.