Fast Photoinduced Electron Transfer through DNA Intercalation
Abstract
We report evidence for fast photoinduced electron transfer mediated by the DNA helix that requires metal complexes that are avid intercalators of DNA. Here the donor bis(phenanthroline)(dipyridophenazine)ruthenium(II) [Ru(phen)2dppz2+] and acceptor bis(9,10-phenanthrenequinone diimine)(phenanthroline)rhodium(III) [RH(phi)2phen3+] intercalate into DNA with Kb > 106 M-1. Luminescence quenching experiments in the presence of two different lengths of DNA yield upward-curving Stern-Volmer plots and the loss of luminescence intensity far exceeds the change in emission lifetimes. In the presence of a nonintercalative electron acceptor, Ru(NH3)3+6, Ru(phen)2dppz2+ luminescence is quenched much less efficiently compared to that found for the intercalative Rh(phi)2phen3+ quencher and follows linear Stern-Volmer kinetics; steady-state and time-resolved Stern-Volmer plots are comparable in scale. These experiments are consistent with a model involving fast long-range electron transfer between intercalators through the DNA helix.
Additional Information
© 1994 by National Academy of Sciences. Contributed by Nicholas J. Turro, January 18, 1994. We are grateful to Dr. J. Winkler for expert technical assistance. In addition, we thank the National Institutes of Health (Grant GM49216 to J.K.B.), the National Science Foundation (N.J.T.), and the Air Force Office of Scientific Research (N.J.T.) for their financial support, as well as the National Science Foundation (C.J.M. and M.R.A.) and the Deutsche Forschungsgemeinschaft (S.B.). The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.Attached Files
Published - MURpnas94.pdf
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Additional details
- PMCID
- PMC43985
- Eprint ID
- 722
- Resolver ID
- CaltechAUTHORS:MURpnas94
- GM49216
- NIH
- NSF
- Air Force Office of Scientific Research (AFOSR)
- Deutsche Forschungsgemeinschaft (DFG)
- Created
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2005-09-20Created from EPrint's datestamp field
- Updated
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2019-10-02Created from EPrint's last_modified field