title: Site-specific cleavage of single-stranded DNAs at unique sites by a copper-dependent redox reaction.
abstract: Metal ions play a crucial role not only in the formation and maintenance of nucleic acid structure, but also in important biochemical conversions of polynucleotides. Some aqueous metal ions, acting as general acid/base (or electrophilic/nucleophilic) catalysts, can induce site-specific cleavage of RNA. DNA is not cleaved efficiently by the non-redox metal-induced mechanism. However, DNA degradation by radicals formed in the metal-catalysed auto-oxidation of ascorbate (or other reducing agents) is well known. In the past, the observed cleavage reactions have not been very specific. Here, we report a non-enzymatic cleavage of single-stranded DNA occurring at unique sites due to redox reactions involving copper. This could be considered a 'self-cleavage' reaction, by analogy with the lead-induced non-redox RNA cleavage reaction. This site-specific cleavage of DNA, stimulated by ascorbate and hydrogen peroxide, is most efficient under physiological conditions, so this phenomenon may have biological significance.
authors.affiliation: Institute of Bioorganic Chemistry, Siberian Division of the USSR Academy of Sciences, Novosibirsk.
authors.forename: S A
authors.initials: SA
authors.lastname: Kazakov
authors.forename: T G
authors.initials: TG
authors.lastname: Astashkina
authors.forename: S V
authors.initials: SV
authors.lastname: Mamaev
authors.forename: V V
authors.initials: VV
authors.lastname: Vlassov
mesh_terms: D001205:Ascorbic Acid / Q000494:pharmacology; D001345:Autoradiography; D003300:Copper / Q000494:pharmacology*; D004277:DNA, Single-Stranded / Q000187:drug effects*; D004591:Electrophoresis, Polyacrylamide Gel; D006861:Hydrogen Peroxide / Q000494:pharmacology; D010084:Oxidation-Reduction; D013696:Temperature
chemical_list: D004277:DNA, Single-Stranded; D003300:Copper; D006861:Hydrogen Peroxide; D001205:Ascorbic Acid