title: Selective DNA strand scission with binuclear copper complexes: implications for an active Cu2-O2 species.
abstract: A homologous series of binuclear copper(II) complexes [Cu(II)(2)(Nn)(Y)(2)](2+) (1-3) (n = 3-5 and Y = (ClO(4))(-) or (NO(3))(-)) were studied to investigate the intermediate(s) responsible for selective DNA strand scission in the presence of MPA/O(2) (MPA = 3-mercaptopropanoic acid). While the N3 complex does not react, the N4 and N5 analogues show comparable activity with strand scission occurring at a single-strand/double-strand junction. Identical reactivity is also observed in the alternate presence of H(2)O(2). Spectroscopic and reactivity studies with [Cu(II)(2)(N4)(Y)(2)](2+) (2) and H(2)O(2) are consistent with DNA oxidation mediated by formation of a side-on peroxodicopper(II) (Cu(2)-O(2)) complex.
authors.affiliation: Department of Chemistry, Johns Hopkins University, Baltimore, MD 21218, USA.
authors.forename: Sunita
authors.initials: S
authors.lastname: Thyagarajan
authors.forename: Narasimha N
authors.initials: NN
authors.lastname: Murthy
authors.forename: Amy A
authors.initials: AA
authors.lastname: Narducci Sarjeant
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Karlin
authors.forename: Steve E
authors.initials: SE
authors.lastname: Rokita
mesh_terms: D015097:3-Mercaptopropionic Acid / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D016166:Free Radical Scavengers / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D008024:Ligands; D009692:Nucleic Acid Heteroduplexes / Q000737:chemistry; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet
chemical_list: D016166:Free Radical Scavengers; D008024:Ligands; D009692:Nucleic Acid Heteroduplexes; D003300:Copper; D004247:DNA; D015097:3-Mercaptopropionic Acid; D006861:Hydrogen Peroxide; D010100:Oxygen