Competitive Binding of Novel Cyanine Dye AK3-5 and Europium Coordination Complexes to DNA
| Autor: | Anna Zabrudska, Galyna Gorbenko, Kateryna Vus, Todor Deligeorgiev, Uliana Tarabara, Atanas Kurutos, Olga Zhytniakivska, Valeriya Trusova |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Quenching (fluorescence)
Chemistry General Physics and Astronomy chemistry.chemical_element DNA europium coordination complexes antitumor drug Ligand (biochemistry) Photochemistry Fluorescence lcsh:QC1-999 DNA binding site chemistry.chemical_compound trimethine cyanine dye Nucleic acid General Materials Science Cyanine Europium lcsh:Physics |
| Zdroj: | East European Journal of Physics, Iss 3, Pp 63-70 (2019) |
| ISSN: | 2312-4334 |
| DOI: | 10.26565/2312-4334-2019-3-08 |
| Popis: | The present study was undertaken to assess the applicability of the novel trimethine cyanine dye AK3-5 as a competitive ligand for the antitumor agents, Eu(III) coordination complexes (EC), in the DNA-containing systems, using the displacement assay as an analytical instrument. The analysis of fluorescence spectra revealed a strong association of AK3-5 with nucleic acids, with the strength of interaction being higher for the double stranded DNA, compared to the single-stranded RNA. The binding parameters of the cyanine dye have been determined in terms of the McGhee & von Hippel neighbouring site-exclusion model and a classical Langmuir model. The AK3-5 association constant in the presence of DNA was found to be equal to 5.1×104 M-1, which is consistent to those of the well-known DNA intercalators. In turn, the binding of the cyanine to the RNA was characterized by a significantly lower association constant ( ~ 3.4×103 M-1) indicating either the external or “partially intercalated” binding mode. The addition of the europium complexes to the AK3-5-DNA system was followed by the fluorescence intensity decrease, with a magnitude of this effect being dependent on the EC structure. The observed fluorescence decrease of AK3-5 in the presence of europium complexes V7 and V9 points to the competition between the cyanine dye and antitumor drugs for the DNA binding sites. The dependencies of the AK3-5-DNA fluorescence intensity decrease vs. europium complex concentration were analyzed in terms of the Langmuir adsorption model, giving the values of the drug association constant equal to 5.4×104 M-1and 3.9×105 M-1 for the europium complexes V7 and V9, respectively. A more pronounced decrease of the AK3-5 fluorescence in the presence of V5 and V10 was interpreted in terms of the drug-induced quenching of the dye fluorescence, accompanying the competition between AK3-5 and Eu(III) complexes for the DNA binding sites. Cumulatively, the results presented here strongly suggest that AK3-5 can be effectively used in the nucleic acid studies and in the dye-drug displacement assays. |
| Databáze: | OpenAIRE |
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