IRRADIATION INCREASES PROTEOLYSIS IN ERYTHROCYTE-GHOSTS - A SPIN LABEL STUDY

X- and gamma-irradiation of human erythrocyte membranes (250-1000 Gy) was found to decrease the ratio of weakly to strongly immobilized sign al height of membrane-bound maleimide spin label (Mal-6). Subsequent i ncubation of spin-labeled membranes at ambient temperature (21-degrees -C) induced a progressive increase in this ratio, faster for membranes irradiated with low doses which was hampered by protease inhibitors. These results demonstrate that ionizing radiation stimulates proteolys is of erythrocyte membrane proteins by membrane-associated proteases.