Abstract
In a recent experiment, a single DNA double helix is stretched and relaxed in the presence of spermidine, a short positive polyelectrolyte, and the pulling force is measured as a function of DNA extension. In a certain range of spermidine concentration, a force plateau appears whose value shows maximum as a function of spermidine concentration. We present a quantitative theory of this plateau force based on the theory of reentrant condensation and derive almost parabolic behavior of the plateau force as a function of the logarithm of the spermidine concentration in the range of condensation. Our result is in good agreement with experimental data.
Original language | English (US) |
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Pages (from-to) | 563-570 |
Number of pages | 8 |
Journal | Physica A: Statistical Mechanics and its Applications |
Volume | 349 |
Issue number | 3-4 |
DOIs | |
State | Published - Apr 15 2005 |
Bibliographical note
Funding Information:The authors are grateful to A.Yu. Grosberg, Y. Murayama, Y. Rabin, I. Rouzina, and J. Zhang for useful discussions. This work is supported by NSF No. DMR-9985785 and DMI-0210844.
Keywords
- Condensation
- DNA
- Pulling force
- Spermidine