Unzipping Dynamics of Long DNAs
arXiv:cond-mat/0207499 · doi:10.1103/PhysRevE.66.051914
Abstract
The two strands of the DNA double helix can be `unzipped' by application of 15 pN force. We analyze the dynamics of unzipping and rezipping, for the case where the molecule ends are separated and re-approached at constant velocity. For unzipping of 50 kilobase DNAs at less than about 1000 bases per second, thermal equilibrium-based theory applies. However, for higher unzipping velocities, rotational viscous drag creates a buildup of elastic torque to levels above kBT in the dsDNA region, causing the unzipping force to be well above or well below the equilibrium unzipping force during respectively unzipping and rezipping, in accord with recent experimental results of Thomen et al. [Phys. Rev. Lett. 88, 248102 (2002)]. Our analysis includes the effect of sequence on unzipping and rezipping, and the transient delay in buildup of the unzipping force due to the approach to the steady state.
15 pages Revtex file including 9 figures
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Cited by in corpus (6)
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- Elasticity of semiflexible polymers with and without self-interactions
- Base pair opening and bubble transport in a DNA double helix induced by a protein molecule in a viscous medium
- Stretching and relaxation dynamics in double stranded DNA
- Interfacial instability and DNA fork reversal by repair proteins
- DNA Unzipping Transition