Assessing the impact of carbamate insecticide aminocarb on human plasma protein through biophysical and computational...

Aminocarb (AMC), a highly toxic carbamate insecticide, is widely used in India, leading to significant human exposure and subsequent toxicity. Its structural features enable binding to multiple receptors with varying affinities, thereby influencing the bioavailability of other substances through crucial binding interactions. The impact of AMC on Human Serum Albumin (HSA) was investigated using various spectroscopic and molecular modeling techniques to assess its binding characteristics, conformational flexibility, and structural stability. Fluorescence spectroscopic measurements revealed a static quenching mechanism and moderate binding affinity in the range of 10⁴ M^-1 and 10⁴ L M^-1 respectively. Thermodynamic assessments indicated that the binding was spontaneous (-22 to -28 KJ mol^-1), and entropy-driven (0.27-0.30 KJ mol^-1), primarily supported by hydrophobic contacts and van der Waals forces, consistent with the MM/PBSA results. Molecular docking further revealed that AMC binds in subdomain IB of HSA, a finding corroborated by displacement studies and molecular dynamics simulations. Quantum Mechanical analysis of AMC indicated that its electronic charge distribution supports the potential involvement of the pi-charge and dimethylamino moiety in pi-cationic, pi-alkyl, and alkyl-type interactions. This study provides crucial insights into the molecular interactions governing aminocarb-protein binding, contributing to a better understanding of its toxicological profile.