Mechanism of catalysis of Fe(II) oxidation by ferritin H chains
- 11 May 1992
- journal article
- Published by Wiley in FEBS Letters
- Vol. 302 (2) , 108-112
- https://doi.org/10.1016/0014-5793(92)80417-f
Abstract
Recombinant H chain ferritins bearing site‐directed amino acid substitutions at their ferroxidase centres have been used to study the mechanism of catalysis of Fe(II) oxidation by this protein. UV‐difference spectra have been obtained at various times after the aerobic addition of Fe(II) to the recombinants. These indicate that the first product of Fe(II) oxidation by wild type H chain apoferritin is an Fe(III) μ‐oxo‐bridged dimer. This suggests that fast oxidation is achieved by 2‐electron transfer from two Fe(II) to dioxygen. Modelling of Fe(III) dimer binding to human H chain apoferritin shows a solvent‐accessible site, which resembles that of ribonucleotide reductase in its ligands. Substitution of these ligands by other amino acids usually prevents dimer formation and leads to greatly reduced Fe(II) oxidation rates.Keywords
This publication has 17 references indexed in Scilit:
- Mössbauer spectroscopic investigation of structure-function relations in ferritinsBiochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology, 1991
- Influence of site-directed modifications on the formation of iron cores in ferritinJournal of Molecular Biology, 1991
- MOLSCRIPT: a program to produce both detailed and schematic plots of protein structuresJournal of Applied Crystallography, 1991
- Role of phosphate in initial iron deposition in apoferritinBiochemistry, 1991
- Three-dimensional structure of the free radical protein of ribonucleotide reductaseNature, 1990
- Identification of the ferroxidase centre in ferritinFEBS Letters, 1989
- Moessbauer spectroscopic study of the initial stages of iron-core formation in horse spleen apoferritin: evidence for both isolated iron(III) atoms and oxo-bridged iron(III) dimers as early intermediatesBiochemistry, 1989
- Recombinant H‐chain ferritins: Effects of changes in the 3‐fold channelsFEBS Letters, 1989
- Spectroscopic studies on the binding of Iron, Terbium, and Zinc by ApoferritinJournal of Inorganic Biochemistry, 1984
- Variable stoichiometry of Fe(II)‐oxidation in ferritinFEBS Letters, 1978