Abstract
A unifying theory of the denaturation transition of DNA, driven by temperature or induced by an external mechanical torque is presented. Our model couples the hydrogen-bond opening and the untwisting of the helicoidal molecular structure. We describe denaturation as a first order transition from -DNA to -DNA phases. The coexistence region is naturally parametrized by the degree of supercoiling . The denaturation free energy, the temperature dependence of the twist angle, the phase diagram in the plane, and isotherms in the plane are calculated and show a good agreement with experimental data.
- Received 19 April 1999
DOI:https://doi.org/10.1103/PhysRevLett.83.5178
©1999 American Physical Society