Simulation of polymer translocation through protein channels
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Communicated by Richard S. Stein, University of Massachusetts, Amherst, MA, December 20, 2005 (received for review June 2, 2005)
Abstract
A modeling algorithm is presented to compute simultaneously polymer conformations and ionic current, as single polymer molecules undergo translocation through protein channels. The method is based on a combination of Langevin dynamics for coarse-grained models of polymers and the Poisson–Nernst–Planck formalism for ionic current. For the illustrative example of ssDNA passing through the α-hemolysin pore, vivid details of conformational fluctuations of the polymer inside the vestibule and β-barrel compartments of the protein pore, and their consequent effects on the translocation time and extent of blocked ionic current are presented. In addition to yielding insights into several experimentally reported puzzles, our simulations offer experimental strategies to sequence polymers more efficiently.
Footnotes
- *To whom correspondence should be addressed. E-mail: muthu{at}polysci.umass.edu
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Conflict of interest statement: No conflicts declared.
- Abbreviations:
- αHL,
- α-hemolysin;
- PNP,
- Poisson–Nernst–Planck
Abbreviations:
- © 2006 by The National Academy of Sciences of the USA
