The Study of the Effect of Dimethylsulfoxide (or Diethylsulfoxide) on Quinine Sulfate-DNA Binding by UV-Vis and Steady-State Fluorescence Spectroscopies.

Autor: Shahinyan GA; Deparment of Inorganic and Analytical Chemistry, Yerevan State University, 0025, Yerevan, Armenia., Markarian SA; Department of Physical and Colloid Chemistry, Yerevan State University, 0025, Yerevan, Armenia. shmarkar@ysu.am.
Jazyk: angličtina
Zdroj: Journal of fluorescence [J Fluoresc] 2024 Sep; Vol. 34 (5), pp. 2197-2208. Date of Electronic Publication: 2023 Sep 19.
DOI: 10.1007/s10895-023-03442-6
Abstrakt: The effect of dimethylsulfoxide (DMSO) and diethylsulfoxide (DESO) on binding between quinine sulfate (QS) and DNA was studied by virtue of UV-Vis absorption, steady-state fluorescence spectroscopies, and fluorescence polarization measurements. The binding constant was determined at three different temperatures and the values of standard Gibbs energy change, enthalpy and entropy of binding were determined. The mechanism of binding and the effect of sulfoxides on this process was revealed. The values of binding constant, fluorescence polarization and iodide quenching studies confirmed that the main binding mode in QS-DNA system is groove binding. Addition of sulfoxides does not change the binding mechanism. Moreover, with addition of sulfoxides binding constant increases due to the removal of water molecules from DNA grooves making them more available for QS molecules. To explain the effect of DMSO and DESO on QS-DNA binding the photophysical properties of QS in aqueous solutions of DMSO and DESO were also studied. On the basis of quantum yield of QS in water, DMSO and DESO the types of intermolecular interactions were discussed. The obtained results show that quantum yield of QS in sulfoxides is lower compared with that in water and aqueous solution of 0.1 M H 2 SO 4 . QS forms ground state complexes with both DMSO and DESO that are stronger fluorophores compared with free QS molecules.
(© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)
Databáze: MEDLINE
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