TUD

Based upon the structural properties of DNA and their counterion-water surrounding in solution, we have introduced a screw model describing DNA translocation through artificial nanopores in a qualitatively correct way.[1] This model represents DNA as a ?screw?, whereas the counterion-hydration shell is a ?nut?. When an electrical potential is applied across a membrane with a nanopore, the ?screw? and ?nut? begin to move with respect to each other, so that their mutual rotation is coupled with their mutual translation. As a result, there are peaks of electrical current connected with the mutual translocation of DNA and its counterion-hydration shell, if DNA has some non-regular base-pair sequence. The calculated peaks of current strongly resemble those observed in the pertinent experiments.

[1] E. B. Starikov, D. Hennig, H. Yamada, R. Gutierrez, G. Cuniberti, and B. Norden, submitted (2008)