A comprehensive insight into the effects of Methyl Thiophanate on pepsin enzyme: Multispectroscopy and simulations investigation

Abstract

Methyl thiophanate (MT) is a widely used fungicide in agriculture; however, it presents substantial health risks to humans. Exposure to MT can damage the human nervous and reproductive systems and inhibit pepsin, a crucial enzyme for digestion and metabolism. This research aimed to investigate the interaction between MT and pepsin using different spectroscopic techniques and dynamic simulations. The UV-Vis results further validated the Trp delocalization findings through molecular docking. At various temperature levels, the effective quenching constants (kq) were found to be 8.28×10³, 5.36×10³ and 2.43×10³ L mol⁻¹, respectively, indicating static quenching with a kq greater than 2 × 10¹⁰. Thermodynamic analysis revealed ${\Delta H}^0$= −56.56 kJ ${\mathrm{mol}}^{-1}$and${∆S}^0$ = −102 J ${\mathrm{mol}}^{-1}{K}^{-1}$, highlighting the significance of hydrogen bonds and Van der Waals interactions in the complex, consistent with docking analyses. By studying the interaction between pepsin and MT, valuable insights can be gained into its impact on digestive system enzymes, leading to a better understanding of MT's toxicological and inhibitory effects on digestion. This interaction disrupts protein digestion, which has broader implications for nutrient absorption and overall digestive health.