title: A minor groove binding copper-phenanthroline conjugate produces direct strand breaks via beta-elimination of 2-deoxyribonolactone.
abstract: Copper-phenanthroline complexes and their conjugates are useful reagents for studying nucleic acid interactions. Although DNA cleavage by such complexes was discovered more than 20 years ago, significant questions remain unanswered regarding the chemical mechanism(s) by which DNA is damaged. Kinetic evidence is provided, which demonstrates that the major pathway for DNA damage by a minor groove binding molecule conjugated to copper phenanthroline (6) involves C1'-oxidation. Additional experiments using 6 and a DNA substrate containing 2-deoxyribonolactone (1) show that direct strand breaks are produced via beta-elimination from 1. These studies support the original mechanism for DNA damage by copper phenanthroline put forth by Sigman and a more recent proposal concerning the mechanism for direct strand break formation.
authors.affiliation: Laboratoire de Chimie de Coordination du CNRS, Toulouse, France.
authors.forename: Brian C
authors.initials: BC
authors.lastname: Bales
authors.forename: Marguerite
authors.initials: M
authors.lastname: Pitié
authors.forename: Bernard
authors.initials: B
authors.lastname: Meunier
authors.forename: Marc M
authors.initials: MM
authors.lastname: Greenberg
mesh_terms: D002851:Chromatography, High Pressure Liquid; D003300:Copper / Q000737:chemistry*; D004249:DNA Damage / Q000187:drug effects*; D007202:Indicators and Reagents; D007700:Kinetics; D013058:Mass Spectrometry; D010084:Oxidation-Reduction; D010618:Phenanthrolines / Q000737:chemistry*; D013400:Sugar Acids / Q000737:chemistry*
chemical_list: D007202:Indicators and Reagents; D010618:Phenanthrolines; D013400:Sugar Acids; C056405:2,4,5-trihydroxypentanoic acid gamma-lactone; D003300:Copper