Interaction of ionizing radiation with proteins and their basic components

Radiation and chemical changes in amino acids, peptides and proteins depend on irradiation conditions, i.e., whether they are irradiated in solid state and a chemically pure form or in solution in the presence of other substances. The effect of these conditions of the formation and concentration of radicals during irradiation is discussed. Owing to great differences in the structure of the protein molecule the proteins have diverse sensitivity to ionizing radiation. This is illustrated by the table of relative values of radiosensitivity of enzymes irradiated in aqueous solutions. Proteins in foodstuffs are not as sensitive to radiation as chemically pure proteins in aqueous solutions. The irradiation dose 70 kGy did not affect the composition of amino acids in the proteins of rat diet. (E.F.)