Charge Hopping through DNA
During the study of the radical induced DNA strand cleavage, we observed the appearance of a radical cation at the carbohydrate backbone.1 This radical cation is a strong oxidant that can be reduced by an adjacent guanosine (G).2 The so formed guanine radical cation initiates an electron transfer reaction through DNA.
Our studies demonstrate that long range electron transfer through DNA is possible via a multistep hopping process with the G-bases as relay stations.3 Each step is strongly distance dependent but the overall long range electron transfer from neutral G's to a positive charge in DNA depends upon the sequence and can be described quantitatively.4
1.A. Gugger, R. Batra, P. Rzadek, G. Rist, and B. Giese, J. Am. Chem. Soc. 119, 8740 (1997).
Department of Chemistry, University of Basel,