Effect of spatial inhomogeneity in dielectric permittivity on DNA double layer formation.
In solutions of tetramethylammonium (TMA+) DNA (double stranded) without added low-molecular-weight salt, the counterion radial density is calculated using the cylindrical Poisson-Boltzmann equation with a distance-dependent quasimacroscopic dielectric permittivity. Comparisons with small-angle neutron scattering data indicate that any inhomogeneity in dielectric permittivity is confined to one or two solvent layers from the DNA surface. At least for TMA+, which may be too large to penetrate the grooves of DNA to any significant extent, dielectric inhomogeneity modeled in this way has no detectable effect on the radial distribution.
van der Maarel
J R
JR
Department of Biochemistry, University of Minnesota, St. Paul, Minnesota 55108, USA. j.maarel@rulgca.leidenuniv.nl
D055592:Biophysical Phenomena; D001703:Biophysics; D004247:DNA / Q000737:chemistry*; D007477:Ions; D008956:Models, Chemical; D009502:Neutrons; D000644:Quaternary Ammonium Compounds; D012542:Scattering, Radiation; D012996:Solutions; D055672:Static Electricity
D007477:Ions; D000644:Quaternary Ammonium Compounds; D012996:Solutions; D004247:DNA; C027917:tetramethylammonium