Salt Effect on DNA Denaturation

We developed a method to evaluate the influence of salt on the chemical denaturation process of DNA. Our primary objective was to investigate the impact of specific physical forces on the chemical denaturation of DNA in the presence of salts. We used fractional cohesion parameters, as shown in the modified equations, which employ the cohesive energy density approach to expose these forces. The original cohesive energy density equation does not apply to ionic systems. So we modified this equation and developed a protocol for applying this modified equation to evaluate the influence of a salt. We did this by allocating salt effects to either the water or the denaturant, creating an "effective" cohesion parameter. Our theory has been developed for the chemical denaturation of DNA in the presence of salts. We demonstrate the influence of salts on hydrogen bonding, dispersion, polar forces, proton donor/acceptor ratio, dipole induction, orientation parameter, and electrostatic interactions during the denaturation process of DNA. By analyzing independent experimental data, we demonstrate that salt affects electrostatic repulsion forces, with the most significant compensating attractive forces being dispersion forces. The results also show that salt has the least effect on hydrogen bonding. However, an internal change in the electron donor and electron acceptor characteristics of hydrogen bonding is shown.