title: Zinc tetraruthenated porphyrin binding and photoinduced oxidation of calf-thymus DNA.
abstract: The photooxidation of calf-thymus DNA has been investigated in the presence of a supramolecular tetraruthenated zincporphyrin (ZnTRP) sensitizer. A strong interaction of ZnTRP with DNA has been observed, exhibiting a gradual transition from a non-specific electrostatic binding mode to a more specific one at high DNA concentrations. Formation of O2(1delta(g)) has been detected from its near-infrared emission, after the excitation of ZnTRP in dioxygen-containing solutions. In the presence of DNA and dioxygen, ZnTRP promotes efficient photocatalytic oxidation of the 2'-deoxyguanosine sites, via their direct reaction with O2(1delta(g)), as in a previous work on the ZnTRP-photoinduced oxidation of the free nucleosides.
authors.affiliation: Instituto de Química, Universidade de São Paulo, SP, Brazil. koiaraki@iq.usp.br
authors.forename: K
authors.initials: K
authors.lastname: Araki
authors.forename: C A
authors.initials: CA
authors.lastname: Silva
authors.forename: H E
authors.initials: HE
authors.lastname: Toma
authors.forename: L H
authors.initials: LH
authors.lastname: Catalani
authors.forename: M H
authors.initials: MH
authors.lastname: Medeiros
authors.forename: P
authors.initials: P
authors.lastname: Di Mascio
mesh_terms: D000818:Animals; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D004247:DNA / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D004305:Dose-Response Relationship, Drug; D007700:Kinetics; D008027:Light; D008956:Models, Chemical; D009942:Organometallic Compounds / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D011166:Porphyrins / Q000378:metabolism*; D011485:Protein Binding; D013050:Spectrometry, Fluorescence; D013950:Thymus Gland / Q000378:metabolism*; D013997:Time Factors; D015032:Zinc / Q000378:metabolism*
chemical_list: D009942:Organometallic Compounds; D011166:Porphyrins; C099070:tetraruthenated porphyrin; D004247:DNA; D015032:Zinc; D010100:Oxygen