Dielectric self-energy in Poisson-Boltzmann and Poisson-Nernst-Planck models of ion channels
Dielectric self-energy in Poisson-Boltzmann and Poisson-Nernst-Planck models of ion channels
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DOI：
10.1016/s0006-3495(03)75091-7
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发表时间：
2003-06-01
影响因子：
3.4
通讯作者：
Chung, SH
中科院分区：
文献类型：
--
作者：
Corry, B;Kuyucak, S;Chung, SH
我们以前证明，两个连续介质理论广泛用于模拟生物离子通道时，管道的半径小于两个德拜长度给出不可靠的结果。这一失败的原因是忽略了渗透离子在蛋白质壁上引起的表面电荷。在这里，我们试图提高的泊松-玻尔兹曼和泊松-Nemst-普朗克理论的准确性，当应用到通道样的环境中，包括一个特定的介电自能项，以克服这些理论中固有的虚假屏蔽效应。通过与布朗动力学模拟结果的比较，我们表明，在方程中包含一个额外的长期产生显着的定性改进。修正后的理论在非常宽和非常窄的通道中表现良好，但在中等尺寸下不太成功。在多离子通道中，由于连续介质理论不能正确处理离子间的相互作用，情况更糟。因此，进一步的工作是必要的，如果这些连续理论是可靠的挽救在所有情况下的生物离子通道的定量研究。
We demonstrated previously that the two continuum theories widely used in modeling biological ion channels give unreliable results when the radius of the conduit is less than two Debye lengths. The reason for this failure is the neglect of surface charges on the protein wall induced by permeating ions. Here we attempt to improve the accuracy of the Poisson-Boltzmann and Poisson-Nemst-Planck theories, when applied to channel-like environments, by including a specific dielectric self-energy term to overcome spurious shielding effects inherent in these theories. By comparing results with Brownian dynamics simulations, we show that the inclusion of an additional term in the equations yields significant qualitative improvements. The modified theories perform well in very wide and very narrow channels, but are less successful at intermediate sizes. The situation is worse in multi-ion channels because of the inability of the continuum theories to handle the ion-to-ion interactions correctly. Thus, further work is required if these continuum theories are to be reliably salvaged for quantitative studies of biological ion channels in all situations.