An optimized potential function for the calculation of nucleic acid interaction energies I. base stacking.

Area of Science:

• Computational Chemistry
• Molecular Modeling
• Biophysics

Background:

• Base-stacking interactions are fundamental to DNA structure and function.
• Accurate modeling of these interactions is essential for understanding DNA behavior.
• Existing methods for calculating stacking energies can be computationally intensive.

Purpose of the Study:

• To develop and optimize a potential function for base-stacking interactions.
• To compare different electrostatic approximations for accuracy in predicting stacking minima.
• To evaluate the performance of the optimized potential against established methods.

Main Methods:

• Construction of an optimized potential function for base-stacking.
• Calculation of stacking energies as a function of rotational angle and separation.
• Comparison of monopole-monopole approximation (MMA) with segmented multipole-multipole representation (SMMA) for electrostatic components.
• Parameterization of Lennard-Jones potential components against theoretical expressions for polarization and dispersion energies.
• Comparison of optimized potential results with perturbation methods and experimental melting data.

Main Results:

• The optimized potential function correctly reproduces general features of stacking minima.
• Atomic charges from IEHT or CNDO methods yield accurate electrostatic components.
• Electrostatic interactions are key drivers for the location of stacking minima.
• The MMA reliably predicts stacking minima locations and characteristics, despite limitations elsewhere.
• Adjusting the Lennard-Jones exponent to 11.7 improves agreement for repulsive forces.
• The optimized potential method's results align well with experimental melting data, comparable to more complex methods.

Conclusions:

• An optimized potential function provides a reliable and efficient method for calculating base-stacking interactions.
• The study validates the use of specific atomic charge models and approximations for electrostatic contributions.
• This optimized potential offers a computationally feasible approach for studying DNA structure and dynamics.