Temperature Effect on Ionic Current and ssDNA Transport through Nanopores - Aix-Marseille Université Access content directly
Journal Articles Biophysical Journal Year : 2015

Temperature Effect on Ionic Current and ssDNA Transport through Nanopores

Abstract

We have investigated the role of electrostatic interactions in the transport of nucleic acids and ions through nanopores. The passage of DNA through nanopores has so far been conjectured to involve a free-energy barrier for entry, followed by a downhill translocation where the driving voltage accelerates the polymer. We have tested the validity of this conjecture by using two toxins, α-hemolysin and aerolysin, which differ in their shape, size, and charge. The characteristic timescales in each toxin as a function of temperature show that the entry barrier is ∼15kBT and the translocation barrier is ∼35kBT, although the electrical force in the latter step is much stronger. Resolution of this fact, using a theoretical model, reveals that the attraction between DNA and the charges inside the barrel of the pore is the most dominant factor in determining the translocation speed and not merely the driving electrochemical potential gradient.

Dates and versions

hal-01444203 , version 1 (23-01-2017)

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Linda Payet, Marlène Martinho, Céline Merstorf, Manuela Pastoriza-Gallego, Juan Pelta, et al.. Temperature Effect on Ionic Current and ssDNA Transport through Nanopores. Biophysical Journal, 2015, 109 (8), pp.1600 - 1607. ⟨10.1016/j.bpj.2015.08.043⟩. ⟨hal-01444203⟩
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