Electrochemical approach to the repair of oxetanes mimicking DNA (6-4) photoproducts.
Electrochemical study of oxetanes mimicking DNA (6-4) photoproducts gives new insight into the repair mechanism by (6-4) photolyase. Both electrochemical oxidation and electrochemical reduction at carbon electrodes lead to the cleavage of the oxetanes in a retro-Paterno-Büchi sequence. Within the family of compounds investigated and the range of driving forces offered, transient formation of unstable radical ions is observed, for both oxidative and reductive cleavage. Taking advantage of the electrochemical signature of these mimics, enzymatic assay with Escherichia coli CPD photolyase coupled to electrochemical monitoring of the reaction brings evidence that enzymatic repair of (6-4) DNA photoproducts does involve a catalytic dissociative electron-transfer mechanism at the level of an oxetane intermediate.
Boussicault
Fabien
F
Laboratoire d'Electrochimie Moléculaire, Université de Paris 7-Denis Diderot, UMR CNRS 7591, Case Courrier 7107, 2 place Jussieu, 75251 Paris Cedex 05, France.
Robert
Marc
M
D004247:DNA / Q000737:chemistry*; D004563:Electrochemistry / Q000379:methods*; D004988:Ethers, Cyclic / Q000737:chemistry*; D008027:Light; D015394:Molecular Structure
D004988:Ethers, Cyclic; D004247:DNA; C005287:oxetane