Study by optical spectroscopy and molecular dynamics of the interaction of acridine–spermine conjugate with DNA

Abstract

We report a spectroscopic and theoretical study of the interaction between double-stranded oligonucleotides containing either adenine-thymine or guanine-cytosine alternating sequences and N1-(Acridin-9-ylcarbonyl)-1,5,9,14,18-pentazaoctadecane, or ASC, which is formed by the covalent bonding of spermine and 9-amidoacridine moieties via a trimethylene chain. Solutions containing the oligonucleotides and the conjugate at different molar ratios were studied using complementary spectroscopic techniques, including electronic absorption, fluorescence emission, circular dichroism, and Raman spectroscopy. The spectroscopical properties of ASC at both the vibrational and the electronic levels were described by means of ab initio quantum-chemical calculations on 9-amidoacridine, used as a model compound. Molecular dynamics calculations, based on the QM/MM methodology, were also performed using previously docked structures of two oligonucleotide-ASC complexes containing the A-T and the G-C sequence. Our data, taken all together, allowed us to demonstrate that conjugation of spermine to acridine modulates and gives additional properties to the interaction of the latter with DNA. As the ASC molecule has a high affinity by the polyamine transport system, these results are promising for their application in the development of new anti-tumour drugs.

Identification of Ligands for the Tau Exon 10 Splicing Regulatory Element RNA by Using Dynamic Combinatorial Chemistry

“…This shift to higher wavelengths was smaller for Acr1-Nea (2 nm for the 360-nm band), which is consistent with previously reported results. [29] Although a similar hypochromism was observed in the case of Azq-Nea, the interference of the RNA absorbance near the azaquinolone band prevented the titration experiment from being completed (see the Supporting Information). Similar bathochromic effects were observed in fluorescence titration experiments, including reduction in the fluorescence intensity of the acridine moieties together with changes in the spectral profiles (see the Supporting Information).…”

Spectrometric study of crystal violet in presence of polyacrylic acid and polyethylenimine and its removal by polyelectrolyte enhanced ultrafiltration

“…Studies on binding of cationic dye to different synthetic and natural polymer by absorbance, fluorescence and circular dichroism experiments during the last few decades yielded significant contributions [18][19][20][21][22][23][24]. In those results the importance of both electrostatic and hydrophobic interactions is strongly emphasized.…”

Removal of dyes from wastewater using polyelectrolyte enhanced ultrafiltration (PEUF)

“…Studies on binding of cationic dye to different synthetic and natural polymer by absorbance, fluorescence and circular dichroism experiments during the last few decades yielded significant contributions [20][21][22][23][24][25]. In those results the importance of both electrostatic and hydrophobic interactions is strongly emphasized.…”