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Microscopic Elasticity of DNA from Torsionally-Constrained Stretching

Published online by Cambridge University Press:  15 February 2011

J. D. Moroz  and
P. Nelson
J. D. Moroz
Affiliation:
Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104
P. Nelson
Affiliation:
Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104
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Abstract

We investigate the statistical mechanics of a torsionally constrained polymer. The polymer is modelled as an inextensible chain with bend rigidity A, twist rigidity C, and twist-stretch coupling D. In such a model, thermal bend fluctuations couple geometrically to an applied torque through the relation Lk = Tw + Wr. We explore this coupling and find excellent agreement between the predictions of our model and the single λ-DNA molecule stretching experiments of Strick et al. [Science 271 (1996) 1835]. This analysis affords an experimental determination of the microscopic twist rigidity C. Quantitative agreement between theory and experiment is obtained using C = 120 nm and D = 50 nm. The theory further predicts a thermal reduction of the effective twist rigidity induced by bend fluctuations.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 489: Symposium K – Materials Science of the Cell , 1997 , 7
Copyright
Copyright © Materials Research Society 1998

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References

1. White, J. H., Am. J. Math. 91, 693 (1969).Google Scholar
2. Strick, T. R. et al., Science 271, 1835 (1996).Google Scholar
3. Love, A. E. H., Treatise on the Mathematical Theory of Elasticity (Cambridge, 1906).Google Scholar
4. Landau, L. D. and Lifschitz, E. M., Theory of Elasticity (Pergamon, 1959).Google Scholar
5. Marko, J. F. and Siggia, E. D., Phys. Rev. E52, 2912 (1995).Google Scholar
6. Wang, M. D. et al., Biophys. J. 72, 1335 (1997).Google Scholar
7. Record, M. et al., Ann. Rev. Biochem. 50, 997 (1981).Google Scholar
8. Hagerman, P. G., Ann. Rev. Biophys. Biophys. Chem. 17, 265 (1988).Google Scholar
9. Crother, D. M., Drak, J., Kahn, J. D., and Levene, S. D., Meth. Enzym. 212, 3 (1992).Google Scholar
10. Marko, J. F., Europhys. Lett. 38, 183 (1997).Google Scholar
11. Kamien, R. D., Lubensky, T. C., Nelson, P., and O'Hern, C. S., Europhys. Lett. 38, 183 (1997).Google Scholar
12. Moroz, J. D. and Nelson, P., (1997), [cond-mat/9712004].Google Scholar
13. Marko, J. F. and Siggia, E. D., Macromolecules 28, 8759 (1995).Google Scholar
14. Moroz, J. D. and Nelson, P., Proc. Nat. Acad. Sci. USA (1997), in press.Google Scholar
15. Bouchiat, C. and Mézard, M., (1997), [cond-mat/9706050].Google Scholar