title: Distance-dependent electron transfer in DNA hairpins.
abstract: The distance dependence of photoinduced electron transfer in duplex DNA was determined for a family of synthetic DNA hairpins in which a stilbene dicarboxamide forms a bridge connecting two oligonucleotide arms. Investigation of the fluorescence and transient absorption spectra of these hairpins established that no photoinduced electron transfer occurs for a hairpin that has six deoxyadenosine-deoxythymidine base pairs. However, the introduction of a single deoxyguanosine-deoxycytidine base pair resulted in distance-dependent fluorescence quenching and the formation of the stilbene anion radical. Kinetic analysis suggests that duplex DNA is somewhat more effective than proteins as a medium for electron transfer but that it does not function as a molecular wire.
authors.affiliation: Department of Chemistry, Northwestern University, Evanston, IL 60208, USA. IL 60439, USA. lewis@chem.nwu.edu
authors.forename: F D
authors.initials: FD
authors.lastname: Lewis
authors.forename: T
authors.initials: T
authors.lastname: Wu
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: R L
authors.initials: RL
authors.lastname: Letsinger
authors.forename: S R
authors.initials: SR
authors.lastname: Greenfield
authors.forename: M R
authors.initials: MR
authors.lastname: Wasielewski
mesh_terms: D001482:Base Composition; D004247:DNA / Q000737:chemistry*; D004583:Electrons; D008027:Light; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D010084:Oxidation-Reduction; D013050:Spectrometry, Fluorescence; D013057:Spectrum Analysis; D013267:Stilbenes / Q000737:chemistry
chemical_list: D013267:Stilbenes; D004247:DNA