Ion channels made from a single membrane-spanning DNA duplex

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. Keyser

Research output: Contribution to journalArticlepeer-review

Abstract

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.

Original languageEnglish (US)
Pages (from-to)4665-4669
Number of pages5
JournalNano letters
Volume16
Issue number7
DOIs
StatePublished - Jul 13 2016

Keywords

  • DNA nanotechnology
  • lipid membrane
  • molecular dynamics
  • porphyrin
  • synthetic ion channel

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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