Characterizing N-acetylcysteine (NAC) and N-acetylcysteine amide (NACA) binding for lead poisoning treatment

► Pb(II) binds more strongly to NACA than to NAC. ► Surface electrostatic interactions play a partial role in Pb-antioxidant binding. ► Supermolecular interaction energies account for enhanced Pb(II) binding to NACA.