The pulling force of a single DNA molecule condensed by spermidine
Abstract
In a recent experiment, a single DNA double helix is stretched and relaxed in the presence of spermidine, and the pulling force is measured [1]. A force plateau appears in a certain range of spermidine concentration. This plateau force shows maximum as a function of spermidine concentration which was related to reentrant condensation of DNA by spermidine. In our work, we presented a quantitative theory of the pulling force based on the theory of reentrant condensation [2]. We derived almost parabolic behavior of the force as a function of the logarithm of the spermidine concentration in the whole range of condensation. Our result agrees with experimental data without adjustable parameters. [1] Y. Murayama, Y. Sakamaki, and M. Sano, Phys. Rev. Lett., 90, 018102 (2003). Y. Murayama and M. Sano, J. Phys. Soc. Jpn., 70, 345 (2001). [2] T. T. Nguyen, I. Rouzina, and B. I. Shklovskii, J. Chem. Phys., 112, 2562 (2000).
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2004
- Bibcode:
- 2004APS..MAR.P8013Z