Ion effects of Sr2+, Cs+ and I− on DNA in aqueous solutions

Molecular dynamics simulations of B-DNA in aqueous solution containing Na+ and K+ ions, or Na+, K+ and one kind of 90 Sr 2 + , 137 Cs + or 131 I - are investigated at 298 K. For the ions in the minor groove, K+ ions are dispersed as Sr2+ or Cs+ added, but Na+ ions dominate the minor groove when I− ions are added. For the ions in the major groove, the interaction of K+ and DNA becomes stronger as I− added. As for the DNA conformation, Cs+ ions affect most while Sr2+ ions the least.