Sequence dependence of excess electron transfer in DNA.
DNA-mediated charge transfer has recently received a substantial attention because of its biological relevance in the DNA damage and DNA repair as well as the potential applications to nanoscale electronic devices. In contrast to the numerous mechanistic studies on oxidative hole transfer (HT) through DNA, our understanding of reductive electron transfer process still remains limited. In this article, we demonstrate the results of direct observation of the excess electron transfer (EET) through DNA, which conjugated with aminopyrene ((A)Py) and diphenylacetylene (DPA) as a photosensitizing donor and an acceptor of excess electron, respectively. By inserting dihydrothymine as a spacer between (A)Py and T or C, the yield of electron arrival to DPA was improved. It was indicated that EET through DNA completed within a few or a few tens nanosecond time scale even for EET over 34 Å for both consecutive T and C sequences. The various factors such as mismatch sequence and DNA length on the yield of electron arrival to DPA were examined.
The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan.
Kazuki
K
Tainaka
Mamoru
M
Fujitsuka
Tadao
T
Takada
Kiyohiko
K
Kawai
Tetsuro
T
Majima
D000114:Acetylene / Q000031:analogs & derivatives / Q000737:chemistry; D001483:Base Sequence; D004396:Coloring Agents / Q000737:chemistry; D004247:DNA / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D004579:Electron Transport; D055029:Inverted Repeat Sequences; D007700:Kinetics; D017319:Photosensitizing Agents / Q000737:chemistry; D011721:Pyrenes / Q000737:chemistry; D013057:Spectrum Analysis
D004396:Coloring Agents; D017319:Photosensitizing Agents; D011721:Pyrenes; C044735:biphenylacetylene; D004247:DNA; C030984:pyrene; D000114:Acetylene