Mechanisms of formation of heteroassociates of ATP with ag⁺ ions

Abstract

Emission and excitation spectra of fluorescence (FL) were studied for aqueous solutions of ATP with AgNO₃ salt at different concentrations of silver nitride and temperatures. It is shown that with increasing Ag⁺ content and temperature, a complex nature of FL quenching occurs due to the formation of ATP - Ag⁺ complexes. This quenching occurs when the position of the emission bands and FL excitation of the ATP fluorophore is preserved, and the quenching corresponds to the Stern-Volmer linear dependence. At the same time, the values of K_SV and k_q and their dependence on the temperature indicate a static quenching mechanism. The binding parameter n indicates that the metal–ligand complexes have a stoichiometric ratio of 1:1, and K_A decreases with increasing temperature. In the heteroassociates, energy is transferred by the FRET mechanism, and binding of components is mainly realized due to electrostatic and van der Waals interaction.

Keywords:

• adenosine-5'-triphosphate
• Ag⁺ ions
• fluorescence quenching
• FL quenching and binding constants
• electrostatic and van der Waals interaction
• heteroassociates