The effects of iron upon the radiation damage in non-heme iron proteins

Summary Radical yield measurements on irradiated ferritin and transferrin in the dry state have been carried out in order to test the role played by iron ions present in protein molecules on the radioresistance of these substances. In both cases, despite the high quantity of iron contained in ferritin and the direct linkage of two iron ions to the transferrin molecule, no difference between the radiation effects in native and iron-free proteins was observed.In the case of transferrin the lack of induction of secondary sulfur radicals by the presence of iron was observed.Some hypotheses about the interpretation of experimental results are discussed.This work was supported by C.N.R., Italy (grant no. 69.00682).We would like to express our thanks to the Paramagnetic Resonance Group of the University of Parma for permission and assistance in the use of EPR apparatus.