Radical Cation Transport and Reaction in Triplex DNA: Long-Range Guanine Damage

摘要: Radical cation injection, transport, and reaction in DNA structures containing a triplex region were examined. An anthraquinone-linked polypyrimidine oligonucleotide was designed to form pyrimidine· purine × pyrimidine (Y·R×Y) triplex. Spectroscopic DNase I footprinting experiments verified formation indicated intercalation of the anthraquinone group at triplex−duplex junction. Irradiation 350 nm (only absorbs) leads reactions remote locations both duplex regions. These are revealed as strand breaks by subsequent treatment irradiated samples with piperidine. cations injected junction migrate into through region. The effect cytosine protonation on radical migration observations support charge transport mechanism that we recently identified phonon-assisted polaron hopping.