Non-heme Fe(IV)-oxo intermediates

Carsten Krebs, Danica Galonić Fujimori, Christopher T. Walsh, Joseph M. Bollinger, Jr.

Research output: Contribution to journalArticle

570 Citations (Scopus)

Abstract

High-valent non-heme iron-oxo intermediates have been proposed for decades as the key intermediates in numerous biological oxidation reactions. In the past three years, the first direct characterization of such intermediates has been provided by studies of several αKG-dependent oxygenases that catalyze either hydroxylation or halogenation of their substrates. In each case, the Fe(IV)-oxo intermediate is implicated in cleavage of the aliphatic C-H bond to initiate hydroxylation or halogenation. The observation of non-heme Fe(IV)-oxo intermediates and Fe(II)-containing product(s) complexes with almost identical spectroscopic parameters in the reactions of two distantly related αKG-dependent hydroxylases suggests that members of this subfamily follow a conserved mechanism for substrate hydroxylation. In contrast, for the αKG-dependent non-heme iron halogenase, CytC3, two distinct Fe(IV) complexes form and decay together, suggesting that they are in rapid equilibrium. The existence of two distinct conformers of the Fe site may be the key factor accounting for the divergence of the halogenase reaction from the more usual hydroxylation pathway after C-H bond cleavage. Distinct transformations catalyzed by other mononuclear non-heme enzymes are likely also to involve initial C-H bond cleavage by Fe(IV)-oxo complexes, followed by diverging reactivities of the resulting Fe(III)-hydroxo/ substrate radical intermediates.

Original languageEnglish (US)
Pages (from-to)484-492
Number of pages9
JournalAccounts of Chemical Research
Volume40
Issue number7
DOIs
StatePublished - Jul 1 2007

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Hydroxylation
Halogenation
Substrates
Iron
Oxygenases
Mixed Function Oxygenases
Oxidation
Enzymes

All Science Journal Classification (ASJC) codes

  • Chemistry(all)

Cite this

Krebs, Carsten ; Fujimori, Danica Galonić ; Walsh, Christopher T. ; Bollinger, Jr., Joseph M. / Non-heme Fe(IV)-oxo intermediates. In: Accounts of Chemical Research. 2007 ; Vol. 40, No. 7. pp. 484-492.
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Non-heme Fe(IV)-oxo intermediates. / Krebs, Carsten; Fujimori, Danica Galonić; Walsh, Christopher T.; Bollinger, Jr., Joseph M.

In: Accounts of Chemical Research, Vol. 40, No. 7, 01.07.2007, p. 484-492.

Research output: Contribution to journalArticle

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