Sharp DNA denaturation in a helicoidal mesoscopic model

Authors：Mateus Rodrigues Leal; Gerald Weber

Source：Chemical Physics Letters, 2020, 755: 137781.

DOI：10.1016/j.cplett.2020.137781

• DNA stability
• Mesoscopic models
• Peyrard Bishop model

The Peyrard-Bishop DNA model describes the molecular interactions with simple potentials which allow efficient calculations of melting temperatures. However, it is based on a Hamiltonian that does not consider the helical twist or any other relevant molecular dimensions. Here, we start from a more realistic 3D model and work out several approximations to arrive at a new non-linear 1D Hamiltonian with a twist angle dependence. Our approximations were numerically compared to full 3D calculations, and established its validity in the regime of small angles. For long DNA sequences we obtain sharp, first-order-like melting, transitions.