Quantum transport anomalies in DNA containing mispairs.
The effect of mispairs on charge transport in DNA of sequence (GC)(TA)(N)(GC)(3) connected to platinum electrodes is studied using the tight-binding model. With parameters derived from an ab initio density functional result, we calculate the current versus bias voltage for DNA with and without a mispair and for different numbers of (TA) basepairs N between the single and triple (GC) basepairs. The current decays exponentially with N under low bias but reaches a minimum under high bias when a multichannel transport mechanism is established. A (GA) mispair substituting a (TA) basepair near the middle of the (TA)(N) sequence usually enhances the current by one order due to its low ionization energy but may decrease the current significantly when an established multichannel mechanism is broken.
Department of Physics, Soochow University, 1 Shizi Street, Suzhou 215006, People's Republic of China. xf_wang1969@yahoo.com
Xue-Feng
XF
Wang
Tapash
T
Chakraborty
J
J
Berashevich
D020137:Base Pair Mismatch; D001483:Base Sequence; D001692:Biological Transport; D004247:DNA / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D004566:Electrodes; D011789:Quantum Theory; D055672:Static Electricity
D004247:DNA