» Articles » PMID: 23135387

Fe-O Versus O-O Bond Cleavage in Reactive Iron Peroxide Intermediates of Superoxide Reductase

Overview
Publisher Springer
Specialty Biochemistry
Date 2012 Nov 9
PMID 23135387
Citations 4
Authors
Affiliations
Soon will be listed here.
Abstract

It is generally accepted that the catalytic cycles of superoxide reductases (SORs) and cytochromes P450 involve a ferric hydroperoxo intermediate at a mononuclear iron center with a coordination sphere consisting of four equatorial nitrogen ligands and one axial cysteine thiolate trans to the hydroperoxide. However, although SORs and P450s have similar intermediates, SORs selectively cleave the Fe-O bond and liberate peroxide, whereas P450s cleave the O-O bond to yield a high-valent iron center. This difference has attracted the interest of researchers, and is further explored here. Meta hybrid DFT (M06-2X) results for the reactivity of the putative peroxo/hydroperoxo reaction intermediates in the catalytic cycle of SORs were found to indicate a high-spin preference in all cases. An exploration of the energy profiles for Fe-O and O-O bond cleavage in all spin states in both ferric and ferrous models revealed that Fe-O bond cleavage always occurs more easily than O-O bond cleavage. While O-O bond cleavage appears to be thermodynamically and kinetically unfeasible in ferric hydrogen peroxide complexes, it could occur as a minor (significantly disfavored) side reaction in the interaction of ferrous SOR with hydrogen peroxide.

Citing Articles

Globin ferryl species: what is the nature of the protonation event at pH < 5?.

Zagrean-Tuza C, Padurean L, Lehene M, Branzanic A, Silaghi-Dumitrescu R J Biol Inorg Chem. 2024; .

PMID: 39699649 DOI: 10.1007/s00775-024-02089-3.


A high-spin alkylperoxo-iron(iii) complex with -anionic ligands: implications for the superoxide reductase mechanism.

Devi T, Dutta K, Deutscher J, Mebs S, Kuhlmann U, Haumann M Chem Sci. 2024; 15(2):528-533.

PMID: 38179538 PMC: 10762717. DOI: 10.1039/d3sc05603a.


Mono- and binuclear non-heme iron chemistry from a theoretical perspective.

Rokob T, Chalupsky J, Bim D, Andrikopoulos P, Srnec M, Rulisek L J Biol Inorg Chem. 2016; 21(5-6):619-44.

PMID: 27229513 DOI: 10.1007/s00775-016-1357-8.


Superoxide dismutases and superoxide reductases.

Sheng Y, Abreu I, Cabelli D, Maroney M, Miller A, Teixeira M Chem Rev. 2014; 114(7):3854-918.

PMID: 24684599 PMC: 4317059. DOI: 10.1021/cr4005296.

References
1.
Silaghi-Dumitrescu R . Superoxide interaction with nickel and iron superoxide dismutases. J Mol Graph Model. 2009; 28(2):156-61. DOI: 10.1016/j.jmgm.2009.06.001. View

2.
Hoffman B . ENDOR of metalloenzymes. Acc Chem Res. 2003; 36(7):522-9. DOI: 10.1021/ar0202565. View

3.
Dey A, Solomon E . Density Functional Theory Calculations on Fe-O and O-O Cleavage of Ferric Hydroperoxide Species: Role of axial ligand and spin state. Inorganica Chim Acta. 2010; 363(12):2762-2767. PMC: 2967774. DOI: 10.1016/j.ica.2010.03.059. View

4.
Lombard M, Fontecave M, Touati D, Niviere V . Reaction of the desulfoferrodoxin from Desulfoarculus baarsii with superoxide anion. Evidence for a superoxide reductase activity. J Biol Chem. 2000; 275(1):115-21. DOI: 10.1074/jbc.275.1.115. View

5.
Horner O, Mouesca J, Oddou J, Jeandey C, Niviere V, Mattioli T . Mössbauer characterization of an unusual high-spin side-on peroxo-Fe3+ species in the active site of superoxide reductase from Desulfoarculus Baarsii. Density functional calculations on related models. Biochemistry. 2004; 43(27):8815-25. DOI: 10.1021/bi0498151. View