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Updated: Apr 24, 2026
![Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F55858.jpg&w=3840&q=50)
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Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase
Published on: December 4, 2017
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Iron to Cobalt Swapping in a Bioinspired Heme-Peroxidase: Structural Characterization and Functional Implications.
Marco Chino1, Corinne Cerrone1, Fabio Pirro1
1Department of Chemical Sciences, University of Naples Federico II, Via Cintia 21, Napoli 80126, Italy.
Inorganic Chemistry
|April 23, 2026
Summary
Artificial heme proteins called mimochromes (MCs) were investigated. Two regioisomers of a mimochrome VI analogue showed distinct structures and electronic properties, offering insights into designing novel biocatalysts.
Area of Science:
- Biochemistry
- Biophysical Chemistry
- Protein Engineering
Background:
- Artificial heme enzymes, or mimochromes (MCs), mimic natural heme enzymes.
- MCs offer a platform to study structure-function relationships and design novel biocatalysts.
- Previous work isolated two regioisomers of a Mimochrome VI (MC6) analogue, Lys9DabMC6*a.
Purpose of the Study:
- To spectroscopically and structurally investigate two regioisomers of a Mimochrome VI (MC6) analogue.
- To elucidate the structural differences and their impact on electronic properties.
- To provide insights for the rational design of artificial minienzymes.
Main Methods:
- Mössbauer and Electron Paramagnetic Resonance (EPR) spectroscopy to study Fe(III) complexes.
- Nuclear Magnetic Resonance (NMR) spectroscopy on diamagnetic Co(III) analogues for high-resolution structures.
- Analysis of electronic properties and structural features.
Main Results:
- Both regioisomers adopted the intended helix-heme-helix fold.
- Distinct pH-dependent high-spin and quantum mixed-spin states were observed.
- Structural differences in interhelical orientation and histidine positioning were identified despite identical peptide composition.
Conclusions:
- The two regioisomers exhibit distinct structural and electronic properties.
- These differences influence substrate affinity and turnover frequency.
- Minimal structural determinants are key for achieving catalytic diversity in artificial heme enzymes.
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