Long-distance charge transport in DNA: the hopping mechanism.

Long-distance charge transport from a guanine radical cation (G(+)) to a G-rich sequence is of biological importance. This reaction was studied by selective charge injection into a G, monitoring the charge transport to a GGG sequence by competing H(2)O-trapping. The efficiency of the charge transport diminished dramatically with increasing number of A:T base pairs between G(+) and GGG. But in DNA strands where G's are located between the G(+*) and GGG sequence, long-distance charge transport occurred by a multistep hopping mechanism.