Interactions of oxidative radicals with N-phosphoryl dipeptide derivatives

The interactions of oxidative radicals (Br-2(.-), HO. etc.) with N-phosphor yl dipeptide derivatives (NDM-TrpOMe and NDT-MetOMe) have been investigated by using pulse radiolysis at different pH values. It has been found that B r-2(.-) and HO. radicals oxidize the Met-site and Trp-site in the dipeptide derivatives via formation of the three-electron-bonded intermediate and in dolyl radical simultaneously. Then the intramolecular electron transfer alo ng the peptide backbone occurs. The rate constants of electron transfer, k, have been determined and the reaction mechanism has been deduced.