Redox chemistry of 8-oxopurine nucleosides and oligonucleotides and their potential role as primordial redox coenzymes

摘要: The RNA world hypothesis about the origin of life enjoys wide acceptance. fact that is capable catalyzing a range chemical reactions supports RNA-based primitive metabolism. Redox are very important to metabolism, and at present time, protein enzymes need assistance redox coenzymes such as flavin nicotinamide promote these processes. In our current work, we investigate potential role 8-oxopurine nucleosides including 8-oxo-7,8dihydroguanosine (OG) ribofuranosyl uric acid (RU) primordial could help in support More specifically, propose function flavins repairing cyclobutane pyrimidine dimers (CPD) photodamaged lesions nucleic acids currently repaired by flavin-dependent photolyase enzyme. this, incorporated OG proximal CPD double-stranded oligonucleotides investigated repair when selectively photoexcited. Our results showed able mediate following flavin-type mechansim. efficiency dependent upon base pair context well 5’ vs. 3’ orientation strand location. photorepair activity can operate on versatile environments directly stacking same pairing with one or other bases lesions. addition, also be mediated OG-containing dinucleotides closer mimics adenine dinucleotide. This finding further flavin. Although RU has slightly lower than OG, it not effective nucleoside model. shorter time photoexcited state probably responsible for this result. Furthermore, oxidation gives complicated mixture products might reduce possibility using multiple turnover catalyst. Nevertheless, studies an unusual example form DNA damage, oxidation, functioning another, photodimerization, may provide insight into origins prebiotic