Mössbauer spectroscopic study of compound es of cytochrome c peroxidase

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Abstract

Mössbauer spectra of Compound ES of cytochrome c peroxidase have been observed over a range of temperature and applied magnetic field. These have been interpreted in terms of a crystal field model of the iron site in which the iron is assumed to be in the Fe(IV) state with unpaired spin S = 1. Detailed least-squares fitting of the spectra indicates that both the electric field gradient and the magnetic hyperfine interactions exhibit axial symmetry. With the choice of a single parameter, the axial crystal field, the magnetic properties are well reproduced. The model also provides the observed positive sign for the electric field gradient interaction, but overestimates its magnitude. This apparent discrepancy may be caused by the presence of significant electronic charge in filled bonding orbitals, a feature which is in keeping with expected covalent charge compensation of the extreme oxidation state. There is no evidence in the Mössbauer spectra of interaction between the iron and ESR-visible free radical. The suggests they are well separated.

References (19)

  • T. Yonetani et al.

    J. Biol. Chem.

    (1965)
  • A.M. Altschul et al.

    J. Biol. Chem.

    (1940)
  • T. Yonetani et al.

    J. Biol. Chem.

    (1966)
  • T. Yonetani

    J. Biol. Chem.

    (1965)
  • T. Yonetani

    J. Biol. Chem.

    (1966)
  • B. Chance

    Arch. Biochem. Biophys.

    (1952)
  • T. Iizuka et al.

    Biochim. Biophys. Acta

    (1968)
  • T. Yonetani et al.

    J. Biol. Chem.

    (1966)
  • T. Yonetani et al.

    J. Biol. Chem.

    (1968)
There are more references available in the full text version of this article.

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