Multifrequency high-field electron paramagnetic resonance characterization of the peroxyl radical location in horse heart myoglobin oxidized by H2O2

9-287 GHz electron paramagnetic resonance (EPR) spectroscopy is used to examine the location of peroxyl radical in horse heart myoglobin (Mb), oxidized with H2O2. The high-field EPR spectra of the Mb peroxyl radical are simulated using a Hamiltonian, which describes the exchange and dipolar interaction between an oxoferryl iron and a protein radical.