abstract

• The ionic atmosphere around a nucleic acid regulates its stability in aqueous salt solutions. One major source of complexity in biological activities involving nucleic acids arises from the strong influence of the surrounding ions and water molecules on their structural and thermodynamic properties. Here, we implement a classical density functional theory for cylindrical polyelectrolytes embedded in aqueous electrolytes containing explicit (neutral hard sphere) water molecules at experimental solvent concentrations. Our approach allows us to include ion correlations as well as solvent and ion excluded volume effects for studying the structural and thermodynamic properties of highly charged cylindrical polyelectrolytes. Several models of size and charge asymmetric mixtures of aqueous electrolytes at physiological concentrations are studied. Our results are in good agreement with Monte Carlo simulations. Our numerical calculations display significant differences in the ion density profiles for the different aqueous electrolyte models studied. However, similar results regarding the excess number of ions adsorbed to the B-DNA molecule are predicted by our theoretical approach for different aqueous electrolyte models. These findings suggest that ion counting experimental data should not be used alone to validate the performance of aqueous DNA-electrolyte models. © 2014 AIP Publishing LLC.

authors

• Fenley M.O.
• Guerrero García Guillermo Iván
• Marucho M.
• Medasani B.
• Olvera De La Cruz M.
• Ovanesyan Z.

publication date

• 2014-01-01

funding provided via

• DMR-0934218, DMR-1121262  Grant
• National Institute of General Medical Sciences, NIGMS: R44GM073391  Grant

published in

• Journal of Chemical Physics  Journal

keywords

• Bioinformatics; DNA; Electrolytes; Intelligent systems; Ionic conduction; Ions; Molecules; Monte Carlo methods; Physiological models; Polyelectrolytes; Thermodynamic properties; Aqueous electrolyte; Aqueous salt solution; Asymmetric mixtures; Excluded volume effects; Numerical calculation; Physiological concentrations; Solvent concentration; Theoretical approach; Density functional theory; DNA B; electrolyte; ion; chemical model; chemical structure; chemistry; computer simulation; Monte Carlo method; quantum theory; static electricity; Computer Simulation; DNA, B-Form; Electrolytes; Ions; Models, Chemical; Models, Molecular; Monte Carlo Method; Quantum Theory; Static Electricity

Digital Object Identifier (DOI)

• 10.1063/1.4902407

PubMed ID

• 25494770

start page

end page

volume

• 141

issue

• 22