nl6b02039_si_001.pdf (1.32 MB)
Ion Channels Made from a Single Membrane-Spanning DNA Duplex
Version 2 2016-07-13, 17:38
Version 1 2016-06-29, 17:23
journal contribution
posted on 2016-07-13, 00:00 authored by Kerstin Göpfrich, Chen-Yu Li, Iwona Mames, Satya Prathyusha Bhamidimarri, Maria Ricci, Jejoong Yoo, Adam Mames, Alexander Ohmann, Mathias Winterhalter, Eugen Stulz, Aleksei Aksimentiev, Ulrich F. KeyserBecause 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.
History
Usage metrics
Categories
Keywords
toroidal poreIonic conductancesion channelsconductance mechanismion conductiondynamics simulationsconductance pathwayelectrophysiology measurementsDNA duplexspan lipid membranesamphiphilic duplexprotein channelstransmembrane channelslipid head groups tiltlipid membranesIons flowinsertion stepsion Channels
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC