Département de chimie moléculaire

Ionizing radiations induce clustered damage sites known to be severely challenging for the cell's repair machinery. In the present study, we have grafted on a biochip four synthetic oligonucleotide duplexes contg. either a single 8-oxoguanine, a single 2'-deoxyribose abasic site or two different clustered damages contg. these two lesions on opposite strands. Using a SPR imaging-based DNA array, we qual. obsd. the hierarchy of lesion processing by the base excision repair (BER) enzyme Fpg (Formamidopyrimidine (fapy)-DNA glycosylase). We could notably show that Fpg can convert a cluster of lesions into a potentially lethal double strand break (DSB) and demonstrate that SPR imaging is suitable to investigate the incision steps occurring during the repair process. [on SciFinder(R)]