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Synthesis of Cationized Magnetoferritin for Ultra-fast Magnetization of Cells
Published on: December 13, 2016
A conserved tyrosine in ferritin is a molecular capacitor
Kourosh Honarmand Ebrahimi1, Peter-Leon Hagedoorn, Wilfred R Hagen
1Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628BC, Delft, The Netherlands.
Chembiochem : a European Journal of Chemical Biology
|June 6, 2013
Summary
A conserved tyrosine in ferritin acts as a molecular capacitor, facilitating iron oxidation. This finding unifies models of iron storage across different organisms.
Area of Science:
- Biochemistry
- Structural Biology
- Protein Function
Background:
- Ferritin, an iron-storage protein, possesses a conserved tyrosine residue near its di-iron catalytic center.
- The di-iron center is crucial for iron storage, catalyzing Fe(II) oxidation, with variations between eukaryotic (2 Fe(II)) and microbial (3 Fe(II)) ferritins.
- The precise role of the conserved tyrosine in this catalytic process remains largely unknown.
Purpose of the Study:
- To elucidate the function of the conserved tyrosine residue in the ferritin di-iron catalytic center.
- To investigate the intermediates and products of Fe(II) oxidation catalyzed by ferritin from different species.
- To propose a unified mechanism for Fe(II) oxidation in ferritin.
Main Methods:
- Spectroscopic studies were employed to analyze catalytic intermediates and products.
- Comparative analysis was performed on ferritin from Pyrococcus furiosus (archaeal) and human H ferritin (eukaryotic).
- Computational modeling was utilized to support experimental findings and propose a reaction mechanism.
Main Results:
- The study identified key intermediates and products during Fe(II) oxidation in both archaeal and eukaryotic ferritins.
- Spectroscopic data and modeling provided insights into the catalytic cycle involving the di-iron center.
- Evidence suggests the conserved tyrosine plays a critical role in facilitating electron transfer during Fe(II) oxidation.
Conclusions:
- A unified mechanism for Fe(II) oxidation in ferritin is proposed, merging models for eukaryotic and bacterial/archaeal ferritin.
- The conserved tyrosine residue functions as a single-electron molecular capacitor.
- This capacitor role of tyrosine is essential for efficient Fe(II) oxidation, highlighting its importance in the protein's vital iron-storage function.
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