Different pulling modes in DNA overstretching: a theoretical analysis.
We study the thermally driven denaturation of a double-stranded polymer in the presence of a stretching force via Monte-Carlo simulations. When one strand only is stretched, the denaturation transition is first order, while when both strands are stretched, melting is second order. By revisiting the Poland-Scheraga model for DNA melting, we show that at room temperature, the most likely scenario is that DNA melts as it overstretches. Our results are in general agreement with the most recent experiments and suggest how varying temperature and stretching mode may help settle the question whether S-DNA exists or not.
Marenduzzo
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D
SUPA, School of Physics, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, Scotland.
Orlandini
E
E
Seno
F
F
Trovato
A
A
D020029:Base Pairing; D001703:Biophysics / Q000379:methods*; D003198:Computer Simulation; D004247:DNA / Q000737:chemistry*; D004277:DNA, Single-Stranded / Q000737:chemistry; D006860:Hydrogen Bonding; D008390:Markov Chains; D018625:Microscopy, Atomic Force / Q000379:methods; D009010:Monte Carlo Method; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D011108:Polymers / Q000737:chemistry*; D013696:Temperature; D013816:Thermodynamics
D004277:DNA, Single-Stranded; D011108:Polymers; D004247:DNA