Investigation of the electric potential near the DNA-solvent interface: conclusions about the stability of B-DNA.
In the present paper DNA is treated as a crystal with symmetry corresponding to a double-helix surface charge density, due to the phosphate groups, immersed in a weak electrolyte. The surrounding solvent is treated via the nonlinear Poisson-Boltzmann equation and the boundary conditions of electrostatics are exactly fulfilled on the DNA-solvent interface. Analytical solutions for the electric potentials and fields inside and outside DNA are obtained. The results give the possibility for a map of the surface potential of DNA to be created. They also show that the electric field inside DNA may decay in two different ways if we change the chemical content of the surrounding solvent. According to this we can draw conclusions about the stability of DNA with respect to the internal and changeable parameters of the system such as chemical content of the aqueous solvent. The position of the condensed counterions around DNA in the Manning cloud can be determined.
Ouroushev
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Department of Condensed Matter Physics, Faculty of Physics, Sofia University, 5 James Bourchier Boulevard, 1164 Sofia, Bulgaria.
D055592:Biophysical Phenomena; D001703:Biophysics; D004247:DNA / Q000737:chemistry*; D004560:Electricity; D008962:Models, Theoretical; D009690:Nucleic Acid Conformation
D004247:DNA