Self-energy-limited ion transport in subnanometer channels.
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.
Bonthuis
Douwe Jan
DJ
Department of Physics and Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA.
Zhang
Jingshan
J
Hornblower
Breton
B
Mathé
Jérôme
J
Shklovskii
Boris I
BI
Meller
Amit
A
D000838:Anions; D001703:Biophysics / Q000379:methods*; D002463:Cell Membrane Permeability; D004247:DNA / Q000737:chemistry*; D004553:Electric Conductivity; D029968:Escherichia coli Proteins / Q000737:chemistry*; D006460:Hemolysin Proteins / Q000737:chemistry*; D007473:Ion Channels / Q000737:chemistry; D007477:Ions / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry; D008564:Membrane Potentials; D009690:Nucleic Acid Conformation; D011108:Polymers / Q000737:chemistry; D011188:Potassium / Q000737:chemistry; D055672:Static Electricity; D013696:Temperature
D000838:Anions; D029968:Escherichia coli Proteins; D006460:Hemolysin Proteins; C036507:Hlya protein, E coli; D007473:Ion Channels; D007477:Ions; D008051:Lipid Bilayers; D011108:Polymers; D004247:DNA; D011188:Potassium