Fig. 4: Ligand-ligand and ligand-A4V SOD1 interactions.
From: Ebselen as template for stabilization of A4V mutant dimer for motor neuron disease therapy
a A4V-ebselen, b A4V-compound 1, c A4V-compound 4 and d A4V-compound 6. The ligands are represented as yellow ball and stick, and waters are represented as red dots. The selenium atom (orange) of the ligand binds covalently to the sulphur atom (cyan) of Cys111. Hydrophobic interactions (pink dashed lines) are shown between the aromatic rings (π-π stacking) of the ligands bound at the dimer interface, between the phenyl ring of the ebselen and Gly108-Asp109 amide bond (amide-π stacking) of the A4V-ebselen structure, and between the chlorobenzyl group and Ile151 (σ-π interaction) of the A4V-compound 4 structure. An electrostatic anion-π interaction (orange dashed line) is shown between the aromatic ring of compound 6 and the side chain of Asp109. Water-bridged hydrogen bonds (blue dashed lines) are found in A4V-ebselen and A4V-compound 1 structures. An additional hydrogen bond (green dashed line) is also found between the nitrogen atom of the pyridine ring of compound 1 and Gly108 backbone amide.
