title: Coarse-grained simulations of DNA overstretching.
abstract: We use a recently developed coarse-grained model to simulate the overstretching of duplex DNA. Overstretching at 23 °C occurs at 74 pN in the model, about 6-7 pN higher than the experimental value at equivalent salt conditions. Furthermore, the model reproduces the temperature dependence of the overstretching force well. The mechanism of overstretching is always force-induced melting by unpeeling from the free ends. That we never see S-DNA (overstretched duplex DNA), even though there is clear experimental evidence for this mode of overstretching under certain conditions, suggests that S-DNA is not simply an unstacked but hydrogen-bonded duplex, but instead probably has a more exotic structure.
authors: Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom.
authors: Flavio
authors: F
authors: Romano
authors: Debayan
authors: D
authors: Chakraborty
authors: Jonathan P K
authors: JP
authors: Doye
authors: Thomas E
authors: TE
authors: Ouldridge
authors: Ard A
authors: AA
authors: Louis
mesh_terms: D001696:Biomechanical Phenomena; D004247:DNA / Q000737:chemistry*; D004277:DNA, Single-Stranded / Q000737:chemistry; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D013816:Thermodynamics; D044366:Transition Temperature
chemical_list: D004277:DNA, Single-Stranded; D004247:DNA