Modeling the Ion Selectivity of the Phosphate Specific Channel OprP.
Modeling the Ion Selectivity of the Phosphate Specific Channel OprP.
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DOI：
10.1021/jz301637d
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发表时间：
2012-11
期刊：
影响因子：
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通讯作者：
Niraj Modi;R. Benz;R. Hancock;U. Kleinekathöfer
中科院分区：
文献类型：
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作者：
Niraj Modi;R. Benz;R. Hancock;U. Kleinekathöfer
离子转运系统的选择性是生物膜的基本特性。这些实体通过特定离子在运输过程中的选择性参与来调节多种生物过程。为了了解这一过程，我们利用全原子自由能分子动力学模拟研究了铜绿假单胞菌OprP孔蛋白的磷酸选择性。这些计算被用来定义磷酸盐、硫酸盐、氯化物和钾离子通过OprP转运的能量学。原子水平的分析表明，通道的整体静电环境决定了通道的阴离子选择性，而渗透离子与水之间的相互作用以及通道残留物之间的特定平衡决定了不同阴离子之间的选择性。OprP的选择性是根据研究充分的离子通道，是高度选择性的钾或氯讨论。
Ion selectivity of transport systems is an essential property of membranes from living organisms. These entities are used to regulate multifarious biological processes by virtue of selective participation of specific ions in transport processes. To understand this process, we studied the phosphate selectivity of the OprP porin from Pseudomonas aeruginosa using all-atom free-energy molecular dynamics simulations. These calculations were performed to define the energetics of phosphate, sulfate, chloride, and potassium ion transport through OprP. Atomic-level analysis revealed that the overall electrostatic environment of the channel was responsible for the anion selectivity of the channel, whereas the particular balance of interactions between the permeating ions and water as well as channel residues drove the selectivity between different anions. The selectivity of OprP is discussed in light of well-studied ion channels that are highly selective for potassium or chloride.