STATE OF IRON IN HEMERYTHRIN . A MOSSBAUER STUDY

Mössbauer spectra, and some ancillary magnetic susceptibilities, have been measured for hemerythrin in its deoxy, oxy, and several met states, as well as for a series of model binuclear, oxygenbridged, iron compounds. Isomer shifts and quadrupole splitting values for iron in the protein derivatives are comparable to those seen in the antiferromagnetically coupled iron model compounds. The Mössbauer spectra together with the susceptibility data and the known chemical nature of the methemerythrin complexes indicate that the two iron atoms in hemerythrin are in similar environments and are near enough to interact with each other. The data also provide evidence that the bridge formulation, FeO2Fe, for the active site of hemerythrin is correct. © 1969, American Chemical Society. All rights reserved.