科研之友
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摘要
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 Pyrococcus furiosus 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.
- 出版日期2013-6-17
