Structure of the binuclear iron center in hemerythrin by X-ray absorption spectroscopy

Journal Article · Wed Nov 17 04:00:00 EST 1982 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00387a035· OSTI ID:5485850

Elam, W T ^[1]; Stern, E A; McCallum, J D; Sanders-Loehr, J

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1. Univ. of Washington, Seattle

Iron K-edge X-ray absorption data, including the near-edge structure and the extended X-ray absorption fine structure (EXAFS), have been measured for the respiratory protein hemerythrin in the biologically active oxy and deoxy forms of hemerythrin as well as metazido- and methydroxohemerythrin. The active-site structure is found to be very similar in the oxy and met forms, but distinctly different in deoxyhemerythrin. The binuclear iron center in oxy- and methemerythrins contains a ..mu..-oxo bridge similar to Fe/sub 2/O-containing standard compounds. The EXAFS data for metazidohemerythrin indicate that the average iron environment consists of a total of five nitrogen and oxygen ligands at 2.15 +/- 0.05 angstrom, and a bridging oxygen at 1.80 +/- 0.08 angstrom, implying a bridging bond angle of 152 (+28/-13)/sup 0/. Deoxyhemerythrin shows distinct changes in the first-shell EXAFS, and the iron-iron peak has disappeared, indicating loss of the ..mu..-oxo bridge upon reduction.

• OSTI ID: 5485850
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 104:23; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ABSORPTION SPECTRA
COMPARATIVE EVALUATIONS
COMPLEXES
FOURIER TRANSFORMATION
INTEGRAL TRANSFORMATIONS
IRON COMPLEXES
MOLECULAR STRUCTURE
SPECTRA
SPECTROSCOPY
STRUCTURAL CHEMICAL ANALYSIS
TRANSFORMATIONS
TRANSITION ELEMENT COMPLEXES
X-RAY SPECTROSCOPY