Iron Oxidation in Escherichia coli Bacterioferritin Ferroxidase Centre, a Site Designed to React Rapidly with H₂O₂ but Slowly with O₂.

ABSTRACT: Both O₂ and H₂O₂ can oxidize iron at the ferroxidase center (FC) of Escherichia coli bacterioferritin (EcBfr) but mechanistic details of the two reactions need clarification. UV/Vis, EPR, and Mössbauer spectroscopies have been used to follow the reactions when apo-EcBfr, pre-loaded anaerobically with Fe²⁺, was exposed to O₂ or H₂O₂. We show that O₂ binds di-Fe²⁺ FC reversibly, two Fe²⁺ ions are oxidized in concert and a H₂O₂ molecule is formed and released to the solution. This peroxide molecule further oxidizes another di-Fe²⁺ FC, at a rate circa 1000 faster than O₂, ensuring an overall 1:4 stoichiometry of iron oxidation by O

SUBMITTER: Pullin J 

PROVIDER: S-EPMC10962548 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature