Ion Channels Made from a Single Membrane-Spanning DNA Duplex.
Ion Channels Made from a Single Membrane-Spanning DNA Duplex.
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DOI：
10.1021/acs.nanolett.6b02039
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发表时间：
2016-07-13
期刊：
影响因子：
10.8
通讯作者：
Keyser UF
中科院分区：
文献类型：
--
作者：
Göpfrich K;Li CY;Mames I;Bhamidimarri SP;Ricci M;Yoo J;Mames A;Ohmann A;Winterhalter M;Stulz E;Aksimentiev A;Keyser UF
由于其中空的内部，跨膜通道能够打开离子穿过活细胞脂质膜的通路。在这里，我们展示了一个单一的DNA双链体，缺乏一个中空的中央通道诱导的离子传导。我们的双链体装饰有六个卟啉标签，旨在跨越脂质膜。结合电生理测量与全原子分子动力学模拟，我们阐明了微观电导途径。离子在DNA-脂质界面处流动，因为脂质头部基团朝向两亲性双链体倾斜，形成充满水和离子的环形孔。由DNA-脂质通道产生的离子电流迹线显示出与传统蛋白质通道或合成孔所观察到的类似的明确的插入步骤、封闭和门控。通过模拟和实验得到的离子电导在很好的定量协议。这里实现的电导机制与最小的可能的DNA为基础的离子通道提供了一条路线，以设计一个新的类合成离子通道最简单。
Because of their hollow interior, transmembrane channels are capable of opening up pathways for ions across lipid membranes of living cells. Here, we demonstrate ion conduction induced by a single DNA duplex that lacks a hollow central channel. Decorated with six porpyrin-tags, our duplex is designed to span lipid membranes. Combining electrophysiology measurements with all-atom molecular dynamics simulations, we elucidate the microscopic conductance pathway. Ions flow at the DNA–lipid interface as the lipid head groups tilt toward the amphiphilic duplex forming a toroidal pore filled with water and ions. Ionic current traces produced by the DNA-lipid channel show well-defined insertion steps, closures, and gating similar to those observed for traditional protein channels or synthetic pores. Ionic conductances obtained through simulations and experiments are in excellent quantitative agreement. The conductance mechanism realized here with the smallest possible DNA-based ion channel offers a route to design a new class of synthetic ion channels with maximum simplicity.