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Updated: Mar 17, 2026

Application of Electrophysiology Measurement to Study the Activity of Electro-Neutral Transporters
Published on: February 3, 2018
Self-energy-limited ion transport in subnanometer channels
Douwe Jan Bonthuis1, Jingshan Zhang, Breton Hornblower
1Department of Physics and Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA.
Abstract:
The current-voltage characteristics of the alpha-Hemolysin protein pore during the passage of single-stranded DNA under varying ionic strength C are studied experimentally. We observe strong blockage of the current, weak superlinear growth of the current as a function of voltage, and a minimum of the current as a function of C. These observations are interpreted as the result of the ion electrostatic self-energy barrier originating from the large difference in the dielectric constants of water and the lipid bilayer. The dependence of DNA capture rate on C also agrees with our model.
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