A multifaceted approach to investigate interactions of thifluzamide with haemoglobin

Abstract

This study explores the interaction between the pesticide thifluzamide (TF) and haemoglobin (Hb) to understand potential structural changes that might affect Hb's function. Using a combination of UV–visible and fluorescence spectroscopy, circular dichroism (CD), molecular docking, molecular dynamics (MD) simulations, and electrochemical methods, we investigated these interactions in detail. Spectroscopy results indicated the formation of a stable TF-Hb complex, with a binding constant of 6.64 × 105 M−1 at 298 K and a 1:1 binding ratio. The stability of this complex was confirmed by a free energy change (∆G) of −34.491 kJ mol−1. CD spectroscopy was employed to confirm structural changes in Hb due to thifluzamide binding. Molecular docking studies revealed that TF interacts with specific amino acids in Hb, such as ALA, HIS, VAL, LYS, and LEU, with a binding energy of −25.10 kJ mol−1. MD simulations supported these findings by showing conformational changes in Hb upon TF binding, as indicated by RMSD and RMSF analyses. Electrochemical experiments further confirmed the interaction, evidenced by a consistent decrease in the TF peak in the presence of Hb. Overall, our findings shed light on how TF binds to Hb, causing structural changes that could potentially impact its normal function. This research enhances our understanding of the biochemical effects of TF on Hb, which could have significant implications for biological systems.