title: Anthraquinone photonucleases: a surprising role for chloride in the sequence-neutral cleavage of DNA and the footprinting of minor groove-bound ligands.
abstract: Irradiation of water-soluble anthraquinone (AQ) reagents in the presence of chloride ions results in the spontaneous, sequence-neutral cleavage of DNA. Mechanistic studies indicate that cleavage is initiated by chlorine atoms, produced by charge transfer interaction between chloride anion and AQ triplet states. High-resolution gel electrophoresis suggests that cleavage arises from abstraction of a hydrogen atom from C-4' of deoxyribose units. The targeting of this hydrogen, which is located in the minor groove of duplex DNA, can be effectively blocked by netropsin and, to a lesser degree, berenil, leading to photofootprinting of these minor groove-binding drugs.
authors.affiliation: School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta 30332-0400, USA.
authors.forename: B
authors.initials: B
authors.lastname: Armitage
authors.forename: G B
authors.initials: GB
authors.lastname: Schuster
mesh_terms: D000880:Anthraquinones / Q000378:metabolism*; D002712:Chlorides / Q000378:metabolism*; D004247:DNA / Q000378:metabolism*; D004249:DNA Damage; D018983:DNA Footprinting; D004133:Diminazene / Q000031:analogs & derivatives / Q000378:metabolism; D006859:Hydrogen / Q000378:metabolism; D017665:Hydroxyl Radical / Q000378:metabolism; D007364:Intercalating Agents / Q000378:metabolism; D008024:Ligands; D009429:Netropsin / Q000378:metabolism; D010777:Photochemistry; D013481:Superoxides / Q000378:metabolism
chemical_list: D000880:Anthraquinones; D002712:Chlorides; D007364:Intercalating Agents; D008024:Ligands; D013481:Superoxides; D017665:Hydroxyl Radical; D009429:Netropsin; D006859:Hydrogen; D004247:DNA; C003915:diminazene aceturate; D004133:Diminazene