Molecular modeling and experimental confirmation of the search for agents mitigating toxic action of hydrogen sulfide

Abstract

Mathematical modeling is a promising method enabling in silico calculations with subsequent suggestion of cell membrane protective agents used to reduce the consequences of exposure to hydrogen sulfide-containing gas in emergency situations. This study aimed to investigate the nature of interaction of hydrogen sulfide (H2S) and N-Acetyl-L-Cycteine (NAC) with the components of cell membranes. We built a mathematical model of interatomic interactions of cell membrane components with H2S and NAC (two separate models), then made the quantum-chemical calculations using our proprietary technique and set up GAMESS Z-matrices reflecting type and position of atoms in the molecules. The structure of the molecules was optimized with the help of MOPAC package built into ChemOffice. Lecithin-based liposomes in a sulfide solution (with Na2S being the donor of H and HS ions) were used as an experimental model of the biological membrane. Redox potential in mV was the comparison parameter in assessment of interaction of the H2S system components and NAC with phospholipid. The results include patterns showing the phospholipid reactive centers blocked by NAC under toxic exposure to H2S. Liposomal models of cell membranes were formed and redox parameters measured. Biological experiment confirmed the acceptable accuracy of the designed method of calculation of intermolecular interactions when used as a basis for further selection of agents capable of adjusting toxic doses of hydrogen sulfide. Membrane models of H2S interaction with protein and lecithin were visualized in silico and in vitro. The possibility of using NAC as an H2S inhibitor has been confirmed.