The divalent high-spin iron in the P460 center of hydroxylamine oxidoreductase and in three possible "picket fence" heme models exhibit extremely large quadrupole splittings (∼4 mms-1). Their isomer shifts of about 1 mms-1 are consistent with the X-ray results of two of the models, i.e. that Fe(II) is pentacoordinated. The coordination geometry of iron deviates considerably from the common fourfold symmetry of the "picket fence" porphyrin due to a CH3CO2- ligand. This feature is also reflected by the significant anisotropies of g-factors, A tensor and rhombicity E/D.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Nuclear and High Energy Physics
- Condensed Matter Physics
- Physical and Theoretical Chemistry