Dynamical versus statistical mesoscopic models for DNA denaturation.

Area of Science:

• * Biophysics
• * Computational Biology
• * Molecular Dynamics

Background:

• * Existing statistical models for DNA denaturation rely on site-dependent finite stacking and pairing enthalpies.
• * A previously proposed dynamical mesoscopic model for DNA requires parameter refinement for broader experimental validation.

Purpose of the Study:

• * To refine the parameters of a dynamical mesoscopic DNA model to match previously unaddressed experimental results.
• * To investigate the critical properties and phase transition behavior of DNA denaturation using the refined model.
• * To compare the physical insights from dynamical and statistical models of DNA melting.

Main Methods:

• * Parameter adjustment of a dynamical mesoscopic model based on site-dependent finite stacking and pairing enthalpies.
• * Comparison of model predictions with experimental data for mechanical unzipping and critical temperature evolution.
• * Analysis of critical properties and phase transition dynamics near the DNA melting critical temperature.

Main Results:

• * The refined dynamical model achieves quantitative agreement with statistical models and experimental data, including mechanical unzipping and critical temperature dependencies.
• * DNA denaturation exhibits characteristics of a first-order phase transition over a wide temperature range.
• * A crossover to a different dynamic regime occurs very close to the critical temperature, requiring further investigation.

Conclusions:

• * The refined dynamical mesoscopic model provides accurate predictions for DNA denaturation phenomena.
• * DNA melting displays complex phase transition behavior, transitioning from first-order to an emergent regime near the critical temperature.
• * Dynamical and statistical models offer complementary, though not identical, physical descriptions of the DNA melting transition, with implications for biological understanding.