IRON MOBILIZATION FROM ULTRAVIOLET-IRRADIATED, IRON-SATURATED, TRANSFERRIN

Transferrin is the major iron transport protein of mammalian plasma. T he ultraviolet-B irradiation of 1.4 mg/ml iron saturated transferrin s olutions (similar to 32 mu M Fe3+) induces a Fe3+ loss accompanied by Fe2+ formation, The initial quantum yield of Fe3+ loss is wavelength d ependent (phi(313 nm)similar to 1.3 x 10(-3)) and oxygen independent s uggesting an intramolecular electron transfer from one of the Fe3+ Lig ands. ii photolysis of tryptophan residues parallels this photoreducti on.