Methane monoxygenase iron

One particular feature of this mechanism is that the two metals in the active site can provide three electrons, which means that a fourth electron has to come from a different source, in this case a redox active tyrosine residue. A different solution to the same problem has been found in the enzyme methane monoxygenase, which involves a binuclear iron center and will be discussed subsequently. 

Rates of Fe binding/ oxidation by recombinant H and L ferritins differ over a 1000-fold. The L type of ferritin protein forms polynuclear complexes, as soon as the iron is oxidized, that are indistinguishable from the mineral (B. H. Huynh and E. C. Theil, unpublished results), whereas the H type ferritin proteins form a series of ferric intermediates that include a diferric-peroxo as the first product. The di-ferric peroxo species is similar to complexes that form in methane monoxygenase and ribonucleotide reductase (see Chapter 16). Thus, the Fe - - O2 inorganic chemistry... 

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