Electrostatic contribution to DNA condensation - application of 'energy minimization' in a simple model in strong Coulomb coupling regime

TL;DR

This study uses energy minimization simulations to show that electrostatic forces in strong Coulomb coupling environments favor DNA bending into circular or toroidal forms, highlighting electrostatics as a key factor in DNA condensation.

Contribution

It introduces a simple energy minimization model to quantify electrostatic contributions to DNA bending in strong Coulomb coupling regimes.

Findings

Electrostatic potential energy decreases with DNA bending.

Bending is energetically favorable and spontaneous in presence of counterions.

Simulation technique effectively monitors electrostatic contributions.

Abstract

Bending of DNA from a straight rod to a circular form in presence of any of the mono-, di-, tri- or tetravalent counterions has been simulated in strong Coulomb coupling environment employing a previously developed energy minimization simulation technique. The inherent characteristics of the simulation technique allow monitoring the required electrostatic contribution to the bending. The curvature of the bending has been found to play crucial roles in facilitating electrostatic attractive potential energy. The total electrostatic potential energy has been found to decrease with bending which indicates that bending a straight DNA to a circular form or to a toroidal form in presence of neutralizing counterions is energetically favorable and practically is a spontaneous phenomenon.