Counterion atmosphere around DNA double helix: trapping of counterions at the nanoscale

DNA is a strong polyelectrolyte macromolecule making metal ions (counterions) condense to cloud around the double helix. The counterions may be localized outside and inside minor major grooves of In present work, distribution condensed between inner outer regions has been studied using approaches counterion condensation theory. results have shown that number trapped should greater than 0.16 per one phosphate group. maximal helix limited about 0.4 group it much lower total counterions. To analyze structure molecular dynamics simulations B-DNA with K+ performed. obtained 0.22 ± 0.06 agree model estimations. developed describes general features able predict