Speaker
Description
Fluorescence quenching experiments were performed for aqueous BSA solutions at fixed protein concentration (2 μM) and varying ibuprofen concentrations in the range of 0–1.5 μM at three different temperatures (293, 303, and 313 K). Similar experiments were performed for aqueous solutions of BSA and ibuprofen with addition of Ar nanoparticles at fixed concentrations of ibuprofen and BSA and varying concentrations of nanoparticles.
Quenching behavior followed the Stern–Volmer relationship and revealed static quenching with binding constants increasing with temperature, suggesting a hydrophobic interaction mechanism. The calculated binding constants ranged from 4.3 to 5.0 with a binding stoichiometry close to 1:1. Thermodynamic analysis using the van’t Hoff equation revealed positive values of ΔH and ΔS, confirming the spontaneous and entropy-driven binding.
Molecular docking simulations using AutoDock 4.2.6 identified three main binding clusters with 20 binding modes in total. The most energetically favorable modes are formed by all types of interactions (van der Waals, hydrogen-bonding, hydrophobic and electrostatic), but the most numerous are contacts with hydrophobic amino acid residues of BSA. The proximity of some binding modes to tryptophan residues supports the observed fluorescence quenching.
Acknowledgment
This work was supported by the National Research Foundation of Ukraine within the project “Nanostructural Modification of Application Drugs for Military Medical Technologies” (Grant No. 2023.04/0140).
| Type of presence | Presence online |
|---|
