Spectroscopic evidence for the presence of a high-valent Fe(IV) species in the ferroxidase reaction of an archaeal ferritin

Kourosh Honarmand Ebrahimi*, Eckhard Bill, Peter Leon Hagedoorn, Wilfred R. Hagen

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

7 Citations (Scopus)


A high-valent Fe(IV) species is proposed to be generated from the decay of a peroxodiferric intermediate in the catalytic cycle at the di-iron cofactor center of dioxygen-activating enzymes such as methane monooxygenase. However, it is believed that this intermediate is not formed in the di-iron substrate site of ferritin, where oxidation of Fe(II) substrate to Fe(III) (the ferroxidase reaction) occurs also via a peroxodiferric intermediate. In opposition to this generally accepted view, here we present evidence for the occurrence of a high-valent Fe(IV) in the ferroxidase reaction of an archaeal ferritin, which is based on trapped intermediates obtained with the freeze-quench technique and combination of spectroscopic characterization. We hypothesize that a Fe(IV) intermediate catalyzes oxidation of excess Fe(II) nearby the ferroxidase center.

Original languageEnglish
Pages (from-to)1712-1719
Number of pages8
JournalFEBS Letters
Issue number12
Publication statusPublished - 1 Jun 2017


  • Fe(IV)
  • ferritin
  • ferroxidase
  • peroxodiferric
  • tyrosine radical

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