Abstract
The interactions of spermine and polyamine analogues with synthetic polynucleotides of various base sequences complexed with ethidium bromide (EB) were investigated using measurements of fluorescence intensity and steady-state fluorescence polarization. Spermine and polyamine analogues displaced some but not all of the EB bound to poly(dA-dT) poly(dA-dT) or poly(dG-dC) poly(dG-dC), suggesting that polyamines may stabilize these polynucleotides in a conformation with reduced affinity for EB. Modifications of the aliphatic backbone of spermine have pronounced effects on its ability to displace EB from poly(dA-dT) poly(dA-dT) but not from poly (dG-dC) poly(dG-dC). Spermine and some but not all of the polyamine analogues caused fluorescence depolarization when they interacted with the complex of EB and poly(dA-dT) poly(dA-dT). Neither spermine nor any of the analogues, however, induced fluorescence depolarization in the complex of EB with poly(dG-dC) poly(dG-dC) or poly(dA) poly(dT). This suggests that spermine and some spermine analogues induce structural changes specific to alternating A-T sequences.
Original language | English (US) |
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Pages (from-to) | 269-274 |
Number of pages | 6 |
Journal | Biochemical Journal |
Volume | 291 |
Issue number | 1 |
DOIs | |
State | Published - 1993 |
ASJC Scopus subject areas
- Biochemistry
- Molecular Biology
- Cell Biology