Abstract
We measure current blockade and time distributions for single-stranded DNA polymers during voltage-driven translocations through a single alpha-hemolysin pore. We use these data to determine the velocity of the polymers in the pore. Our measurements imply that, while polymers longer than the pore are translocated at a constant speed, the velocity of shorter polymers increases with decreasing length. This velocity is nonlinear with the applied field. Based on this data, we estimate the effective diffusion coefficient and the energy penalty for extending a molecule into the pore.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Bacterial Toxins / chemistry*
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Bacterial Toxins / metabolism
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DNA, Single-Stranded / chemistry*
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DNA, Single-Stranded / metabolism
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Diffusion
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Electrochemistry
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Hemolysin Proteins / chemistry*
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Hemolysin Proteins / metabolism
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Lipid Bilayers / chemistry
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Lipid Bilayers / metabolism
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Membrane Potentials
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Membranes, Artificial
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Phosphatidylcholines / chemistry
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Phosphatidylcholines / metabolism
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Structure-Activity Relationship
Substances
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Bacterial Toxins
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DNA, Single-Stranded
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Hemolysin Proteins
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Lipid Bilayers
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Membranes, Artificial
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Phosphatidylcholines
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staphylococcal alpha-toxin