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Related Experiment Video

Updated: May 9, 2026

Simultaneous Measurement of Superoxide/Hydrogen Peroxide and NADH Production by Flavin-containing Mitochondrial Dehydrogenases

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Published on: February 24, 2018

Cytochrome c and superoxide.

Willem H Koppenol¹

¹Institute of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zürich, 8093, Zürich, Switzerland, koppenol@inorg.chem.ethz.ch.

Journal of Biological Inorganic Chemistry : JBIC : a Publication of the Society of Biological Inorganic Chemistry

|July 19, 2013

Summary

This summary is machine-generated.

The reduction of iron(III) cytochrome c by superoxide follows a solvent-accessible heme edge electron transfer mechanism. Previous claims of a new mechanism are refuted due to methodological deficiencies.

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Area of Science:

Biochemistry
Bioinorganic Chemistry
Electron Transfer Mechanisms

Background:

Human cytochrome c is a crucial protein in cellular respiration.
Superoxide is a reactive oxygen species involved in various biological processes.
Previous studies proposed novel mechanisms for the reduction of iron(III) cytochrome c by superoxide.

Purpose of the Study:

To re-evaluate the proposed mechanism for the reduction of iron(III) cytochrome c by superoxide.
To demonstrate the continued validity of the solvent-accessible heme edge electron transfer mechanism.
To identify and address deficiencies in the work by Wegerich et al.

Main Methods:

Analysis of electron transfer pathways in singly modified human cytochromes c.
Critique of experimental methodologies and data interpretation in Wegerich et al.
Comparison of proposed mechanisms with established biochemical principles.

Main Results:

Electron transfer via the solvent-accessible heme edge remains the predominant mechanism.
The mechanism proposed by Wegerich et al. is not supported by the evidence.
Significant methodological flaws in Wegerich et al. prevent valid comparisons.

Conclusions:

The solvent-accessible heme edge mechanism is the correct pathway for iron(III) cytochrome c reduction by superoxide.
The findings of Wegerich et al. are invalidated by critical deficiencies.
Further research must address these methodological issues for accurate comparisons in bioinorganic chemistry.