Abstract
We studied fluorescence resonance energy transfer between donors and acceptors bound to double-helical DNA. The donor Hoechst 33258 binds to the minor groove of DNA and the acceptor propidium iodide (PI) is an intercalator. The time-resolved donor decays were measured in the frequency domain. The donor decays were consistent with a random 1-dimensional distribution of acceptors. The decays were analyzed in terms of three 1-dimensional models: a random continuous acceptor distribution; acceptors placed on discrete lattice sites; and a cylindrical model with the acceptor in the center, and the donors on a cylinder surface. The data were well described by all three models. Interpretation in terms of continuous distribution of acceptors revealed a minimum donor to acceptor distance of 13 Å, which is 3 bp from the center of Hoechst 33252. These results suggest that PI is excluded from the 4 bp covered by Hoechst 33252 when it is bound to the minor groove of DNA. (C) 2000 John Wiley and Sons, Inc.
Original language | English |
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Pages (from-to) | 306-315 |
Number of pages | 10 |
Journal | Biopolymers - Biospectroscopy Section |
Volume | 57 |
Issue number | 5 |
DOIs | |
State | Published - 2000 |
Keywords
- Acceptor
- Donor
- Double-helical DNA
- Fluorescence resonance energy transfer