Structural Insights into the Reaction between Hydrogen Peroxide and Di-iron Complexes at the Ferroxidase Center of Ferritin.

The Fe(II) oxidation mechanism in the ferroxidase center of heavy chain ferritin has been studied extensively. However, the actual production of HO was found to be substantially lower than expected at low flux of Fe(II) to ferritin subunits. Here, we demonstrated that HO could interact with the di-iron nuclear center, leading to the production of hydroxyl radicals and oxygen. Two reaction intermediates were captured in the ferroxidase center by using the time-lapse crystallographic techniques in a shellfish ferritin. The crystal structures revealed the binding of HO as a μ -1,2-peroxo-diferric species and the binding of O to the diferric structure. This investigation sheds light on the reaction between the di-iron nuclear center and HO and provides insights for the exploitation of metalloenzymes.