Introduction of Cationic Charge into DNA Near the Major Groove Edge of a Guanine·Cytosine Base Pair: Characterization of Oligodeoxynucleotides Substituted with 7-Aminomethyl-7-deaza-2'-deoxyguanosine

摘要

The electrostatics of DNA is generally considered in terms of polyelectrolyte theory that treats DNA as a polyanionic cylinder. Even at relatively low salt concentrations, the cation concentration in the vicinity of DNA is estimated to be 1 M, and diffusible cations are treated without regard to high vs low occupancy sites. Accordingly, the release of electrostricted ions, which is a powerful entropic driving force in the equilibrium binding of molecules to DNA, is generally treated as nonsequence specific.