A revised treatment of the non-electrostatic contribution to the solvation free energy of DNA-binding ligands

• Published in: Journal of molecular liquids 2011-10, Vol.163 (3), p.178-180
• Main Authors: Kostjukov, Viktor V., Evstigneev, Maxim P.
• Format: Article
• Language: English
• Subjects: DNA-binding drugs; Microscopic surface tension coefficient; Self/hetero-association; Solvation energy
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2011.09.012

A revised magnitude of the microscopic surface tension coefficient, γ vdW , is suggested to account for the van der Waals solvation energy, ΔG vdW solv , in the standard expression ΔG vdW solv = γ vdW ⋅ ΔA, where ∆ A is the change in solvent accessible surface area on complexation. The revised value of γ vdW = − 0.063(± 0.008) kcal/mol/Å 2 is based on the decomposition of the Gibbs free energy for 49 reactions of non-covalent bimolecular ligand–DNA and ligand–ligand complexation, involving 20 DNA-binding molecules that differ in structure and charge state. The total non-electrostatic contribution to the solvation free energy can also be calculated from the standard equation ΔG nel solv = γ nel ⋅ ΔA with the revised coefficient γ nel = − 0.013(± 0.008) kcal/mol/Å 2. It is proposed that these results may be utilized for analysis of any ligand–DNA or ligand–ligand interaction, if the structure and other physical properties of the interacting molecules do not change on complexation. [Display omitted] ► 49 reactions of non-covalent ligand–DNA and ligand–ligand complexation were analysed ► non-electrostatic contribution to the solvation free energy was discussed ► a revised magnitude of the microscopic surface tension coefficient is suggested