Long-distance charge transport through DNA. An extended hopping model

Long-distance transfer of a positive charge through DNA can be described by a hopping model. In double strands where the (A:T)(n) bridges between the guanines are short (n greater than or equal to 3), the charge hops only bet ween guanines, and each hopping step depends strongly upon the guanine to g uanine distances. In strands where the (A:T)(n) sequences between the guani nes are rather long (n greater than or equal to 4), also the adenines act a s charge carriers. To predict the yields of the H2O-trapping products one h as to take into account not only the charge-transfer rates but also the rat es of H2O-trapping reactions.