Radiation-induced chemical transformations of human serum albumin in aqueous solution

The rate constant of reaction of human serum albumin (HSA) with OH radicals has been determined by the method of competing acceptors. Changes in aminoacid composition and certain biochemical properties of HSA during radiolysis in borate buffer at pH 7,4 saturated with N2O and O2 were compared quantitatively. It has been revealed that the yield of peptide bonds, that have lost their ability to be splitted by trypsin, exceeds the sum of the yields of arginine and lysine in HSA. The possibility of accumulation in blood of modified HSA in the course of irradiation is discussed. 21 refs., 6 figs., 1 tab