Molecular Docking Study of Nicotine and Nornicotine With the Enzyme 5-Enolpyruvylshikimate-3-Phosphate Synthase

Abstract

Glyphosate is a polar organic acid consisting of a glycine molecule and a phosphonomethyl molecule, used as a broadspectrum herbicide as it inhibits the shikimate pathway, preventing the synthesis of aromatic amino acids. However, WHO has classified it as extremely toxic. In this study, a molecular docking analysis of the inhibitory activity of nicotine, nornicotine, and glyphosate on the binding site of the 5-enolpyruvylshikimate-3phosphate synthase enzyme was carried out. Glyphosate presented the most stable model, while the nicotine and nornicotine models exhibited higher binding energy and lower efficiency. Nicotine and nornicotine showed low affinity to the enzyme compared to glyphosate according to K i values. Glyphosate interacted with 18 residues, nornicotine interacted with 17, and nicotine interacted with 12. Only glyphosate and nornicotine interacted with residues belonging to the enzyme's binding site. The presence of a methyl group in nicotine and its absence in nornicotine affects the binding stability and affinity of the models, as well as interactions with the binding site residues.