Studies of temperature dependence of iron environment in an undecairon(III) oxo-hydroxo aggregate compound compared to horse spleen ferritin

Abstract

The iron core of ferritin is comprised of up to 4500 Fe(III) atoms as Fe2O3.nH2O which is maintained in solution by a surrounding, spherical coat of protein. To extend studies of the steps in polynuclear iron core formation, a recently characterized undecairon(III) oxo-hydroxo aggregate (Fe11 complex) was examined by x-ray absorption spectroscopy as a model for an intermediate. Differences betweenthe Fe11 complex and the full core of ferritin indicate the possibility of still more intermediates with features distinct from both Fe11 and the complete ferritin iron core.