Mechanical transition in a highly stretched and torsionally constrained DNA
| Autor: | Wieslaw Nowak, Lukasz Peplowski, Aleksander Balter, Robert Lenartowski, J. Strzelecki |
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| Rok vydání: | 2012 |
| Předmět: |
Models
Molecular Quantitative Biology::Biomolecules Materials science Force spectroscopy Nanotechnology DNA Plateau (mathematics) Spectral line chemistry.chemical_compound Molecular dynamics chemistry Models Chemical Torque Chemical physics Elastic Modulus Helix Materials Testing Molecule Nucleic Acid Conformation Computer Simulation Stress Mechanical Nanomechanics |
| Zdroj: | Physical review. E, Statistical, nonlinear, and soft matter physics. 89(2) |
| ISSN: | 1550-2376 |
| Popis: | We show results of our high force (up to 1.8 nN) atomic force microscopy force spectroscopy measurements of a double stranded DNA. We have found that the force spectra of torsionally constrained molecules display a small plateau occurring at a force of approximately 1 nN. This transition is absent in molecules with rotational freedom. Based on all-atom molecular dynamics simulations, we suggest that this plateau is a result of reducing the diameter of a double helix through extreme stretching. The simulation suggests that the molecule is forced into a form resembling an underwound P-DNA, with bases protruding outside of the backbones. These results broaden our understanding of the fundamental aspects of DNA nanomechanics. |
| Databáze: | OpenAIRE |
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