Towards Al3+-Induced Manganese-Containing Superoxide Dismutase Inactivation and Conformational Changes : An Integrating Study with Docking Simulations

Abstract EN

Superoxide dismutase (SOD, EC 1.15.1.1) plays an important antioxidant defense role in skins exposed to oxygen.

We studied the inhibitory effects of Al3+ on the activity and conformation of manganese-containing SOD (Mn-SOD).

Mn-SOD was significantly inactivated by Al3+ in a dose-dependent manner.

The kinetic studies showed that Al3+ inactivated Mn-SOD follows the first-order reaction.

Al3+ increased the degree of secondary structure of Mn-SOD and also disrupted the tertiary structure of Mn-SOD, which directly resulted in enzyme inactivation.

We further simulated the docking between Mn-SOD and Al3+ (binding energy for Dock 6.3: −14.07 kcal/mol) and suggested that ASP152 and GLU157 residues were predicted to interact with Al3+, which are not located in the Mn-contained active site.

Our results provide insight into the inactivation of Mn-SOD during unfolding in the presence of Al3+ and allow us to describe a ligand binding via inhibition kinetics combined with the computational prediction.