[Study on laser flash spectroscopy of laser-induced interaction of DNA and polynucleotides with SO4*-]

The interactions of DNA and polynucleotides (poly[G],poly[A] and poly[C]) with SO4*- were investigated by 248 nm laser flash photolysis. The results show that, the reactions of poly[G] or poly[A] with SO4*- yield predominantly the corresponding one-electron-oxidated base radicals. With poly[C], it is suggested that SO4*- radical reacts predominantly by addition to the base moiety to produce C5-yl and C6-yl sulphate radical adducts,and subsequently H-abstraction yields C2'-sugar radical. The predominant species resulting from the reaction of DNA with SO4*- is DNA guanyl radical.