title: Guanine-specific binding by bleomycin-nickel(III) complex and its reactivity for guanine-quartet telomeric DNA.
abstract: Bleomycin-Ni(III) [BLM-Ni(III)] complex, generated from oxidation of the corresponding BLM-Ni(II) complex with Ir(IV) or oxone, binds to single-stranded DNA and causes strand scission at specific guanine sites. In the telomeric-like oligodeoxynucleotide d(T2G4)4, the cleavage by the BLM-Ni(III) complex occurs preferentially at positions G-9 and G-15 in loop regions. By contrast, this Ni(III) complex does not induce cleavage of G-quartet d(G4T4G4)2, which contains no loop guanines, ESR evidence supports that binding of the N-7 position of guanine occurs axially to the Ni(III) center in BLM. The present results provide interesting insights into Ni-BLM chemistry.
authors.affiliation: Institute for Chemical Research, Kyoto University, Japan.
authors.forename: L L
authors.initials: LL
authors.lastname: Guan
authors.forename: J
authors.initials: J
authors.lastname: Kuwahara
authors.forename: Y
authors.initials: Y
authors.lastname: Sugiura
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D001761:Bleomycin / Q000378:metabolism* / Q000031:analogs & derivatives; D004247:DNA / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy; D006147:Guanine / Q000378:metabolism*; D008969:Molecular Sequence Data; D009532:Nickel / Q000378:metabolism; D016615:Telomere
chemical_list: C048319:nickel bleomycin; D001761:Bleomycin; D006147:Guanine; D009532:Nickel; D004247:DNA