On the magnetic ordering of the iron storage proteins in tissues

Small angle neutron scattering data are indicative of ferritin aggregation in tissues (Rg of ca. 21-25 nm) in contrast to the isolated purified ferritin protein (Rg of ca. 5 nm). Dependence of the shape and position of the ferritin electron spin resonance spectra in tissues upon sample orientation relative steady state magnetic field points to the magnetic susceptibility anisotropy of ferritin aggregates. The magnetic ordering of ferritin results in dramatic increase in magnetic susceptibility of the ferritin iron in tissues compared to the crude and purified ferritin extracts