Kinetics and mechanism of electron-induced splitting of a cyclobutane pyrimidine dimer with or without an electron acceptor
ABSTRACT Utilizing a pulse radiolysis equipment with time-resolved optical detector, kinetic processes of electron-induced splitting
of cis-syn 1,3-dimethyluracil cyclobutane dimer (DMUD) in aqueous solution were investigated in the presence or absence of riboflavin
(RF) or flavin adenine dinucleotide (FAD). It has been observed that the cyclobutane pyrimidine dimer reacting with hydrated
electron splits spontaneously to give a monomer and a monomer radical anion, and the anion transfers one electron to RF or
FAD. From the buildup kinetics of radical species, the rate constants of electron transfer from the monomer radical anion
to RF and FAD have been determined. On the basis of comparison of the interactions between DMUD and hydrated electron in the
presence and absence of RF or FAD, a chain reaction process in the absence of RF or FAD has been demonstrated.