Interaction of DNA with an aminooxy analogue of spermidine - an FT-TR and FT-Raman approach

The interaction of highly polymerized calf-thymus DNA with 1-aminooxy-3-N-( 3-aminopropyl)-aminopropane (ap-apa), an aminooxy analogue of the biogenic ornithine-derived polyamine spermidine. has been investigated by vibrationa l spectroscopy. Infrared and Raman spectra of DNA/ap-apa solutions, at diff erent polyamine concentrations, were registered. The infrared spectra were extended to solutions in heavy water in order to analyze the 1500-1700 cm(- 1) region. The spectroscopical data were discussed in terms of preferential binding sites between DNA and the aminooxy polyamine. The results support the existence of structural specifities in the interaction, at least under our experimental conditions; they also indicate differences at low and high ap-apa concentrations, which involve mainly base residues. (C) 2001 Elsevi er Science B.V. All rights reserved.