The Effects of Irradiation on Human Serum Transferrin

Iron-free and iron-saturated human serum transferrins were irradiated at doses of 1-10× 10⁶, rads, and the resulting changes in their physical parameters were measured. It was found that tyrosyl groups and disulfide bonds were perturbed at the lowest levels of irradiation. Next, a perturbation of the iron-binding site was observed. Gross denaturation and aggregation of the protein molecules was observed only at the highest doses of irradiation. The effects of irradiation on the iron-binding sites were retarded by the presence of the iron therein, which possibly acted as an energy sink.