Biochemical Characterization of Ferritins.

The nematode contains genes for two types of ferritin ( and ) that express FTN-1 and FTN-2. We have expressed and purified both proteins and characterized them by X-ray crystallography, cryo-electron microscopy, transmission electron microscopy, dynamic light scattering, and kinetically by oxygen electrode and UV-vis spectroscopy. Both show ferroxidase activity, but although they have identical ferroxidase active sites, FTN-2 is shown to react approximately 10 times faster than FTN-1, with L-type ferritin character over longer time periods.