Deciphering the Molecular Details of Interactions Between Heavy Metals and Proteins: Molecular Docking Study

Understanding the interaction of heavy metals with proteins is pivotal for unraveling their roles in biochemical processes and metal-induced diseases, with wide-ranging implications spanning medicine, environmental science, and biotechnology, thereby driving progress in therapeutics, pollution mitigation, and biomaterial innovation. In the present study the molecular docking technique was employed to identify and characterize the binding sites of the set of heavy metals (Cu2+, Fe3+, Mg2+, Mn2+, Zn2+, Cd2+, Fe2+, Ni2+, Hg2+, Co2+, Cu+, Au+, Ba2+, Pb2+, Pt2+, Sm3+, and Sr2+) and proteins ((β-lactoglobulin, 7S globulin and glycinin from soybeans) to evaluate the impact of protein structure on their ion-binding abilities and selectivity. Our docking results indicate that essential and toxic heavy metals interact with multiple binding sites of proteins, presumably by electrostatic interactions and metal chelation with cysteine, aspartic acid, glutamic acid, and histidine amino acid residues. The comparison of binding residues favorable for heavy metal complexation among different proteins indicates that metals exhibit distinct preferences for various amino acid residues highlighting the importance of both the metal and the protein properties for stabilizing protein-metal complexation.