A Conserved Tyrosine in Ferritin Is a Molecular Capacitor. Issue 9 (4th June 2013)

• Record Type: Journal Article
• Authors: Ebrahimi, Kourosh Honarmand; Hagedoorn, Peter‐Leon; Hagen, Wilfred R.
• Is Part Of: Chembiochem. Volume 14:Issue 9(2013)
• Page Start: 1123
• Page End: 1133
• Publication Date: 2013-06-04
• Subjects: Biochemistry -- Periodicals; Molecular biology -- Periodicals; Pharmaceutical chemistry -- Periodicals; 572
• DOI: 10.1002/cbic.201300149
• Languages: English
• ISSNs: 1439-4227

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>A highly conserved tyrosine residue of unknown function is present in the vicinity of the di‐iron catalytic center of the ubiquitous iron‐storage protein ferritin. The di‐iron center with a gateway Fe^II/Fe^III‐binding site nearby provides the vital iron‐storage mechanism of the protein. It is believed that, in eukaryotic ferritin, this center catalyzes simultaneous oxidation of two Fe^II ions, whereas in microbial ferritin it catalyzes simultaneous oxidation of three Fe^II ions. To understand the role of the conserved tyrosine, we studied the intermediates and products that are formed during catalysis of Fe^II oxidation in the di‐iron catalytic centers of the hyperthermophilic archaeal <italic>Pyrococcus furiosus</italic> ferritin and of eukaryotic human H ferritin. Based on our spectroscopic studies and modeling, we propose a merger of the models for eukaryotic and bacterial ferritin into a common mechanism of Fe^II oxidation in which the conserved tyrosine acts as a single‐electron molecular capacitor to facilitate oxidation of Fe^II.</p> </abstract>