Abstract
The singlet state of stilbene-4,4'-dicarboxamide can serve as a fluorescent probe of both DNA conformation and electron transfer. Covalent incorporation of the stilbene-dicarboxamide into DNA structures with restricted conformational mobility results in inhibition of stilbene isomerization and an increase in its fluorescence quantum yield and lifetime. The fluorescence of stilbenedicarboxamide is selectively quenched by proximate guanine, but not by the three other DNA nucleobases. Selective quenching occurs via an electron transfer mechanism in which stilbene serves as the electron acceptor and guanine as the electron donor. Kinetic analysis of the distance dependence of electron transfer in stilbene-bridged hairpins suggests that duplex DNA is more effective than proteins as a medium for electron transfer, but that it does not function as a molecular wire.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 215-221 |
| Number of pages | 7 |
| Journal | Journal of Biological Inorganic Chemistry |
| Volume | 3 |
| Issue number | 2 |
| DOIs | |
| State | Published - Apr 1998 |
Funding
Acknowledgements Fruitful collaborations with Michael R. Wa-sielewski (Argonne National Laboratory and Northwestern University) and Sigfried Schneider (Universität Erlangen-Nürnberg, Germany), the contributions of research students in our laboratories, and financial support from NIH (R.L.L.) and the Division of Chemical Sciences, Office of Basic Energy Sciences, US Department of Energy (F.D.L.) are gratefully acknowledged.
Keywords
- DNA
- Electron transfer
- Guanine
- Radical ions
- Stilbene
ASJC Scopus subject areas
- Biochemistry
- Inorganic Chemistry