title: Recognition and photo-induced cleavage and cross-linking of nucleic acids by oligonucleotides covalently linked to ellipticine.
abstract: Oligopyrimidines covalently linked to ellipticine derivatives form duplex and triplex structures with target single-stranded oligopurine sequences. They also bind to duplex DNA at homopurine-homopyrimidine sequences where they form local triple helices. Irradiation at wavelengths longer than 300 nm of the complex formed by an oligonucleotide-ellipticine conjugate with its target sequence induced (i) cleavage of the target at bases located in close proximity to the dye and (ii) cross-linking of the target sequence to the derivatized oligonucleotide. Both cross-linking and cleavage reactions decreased when temperature increased with a half-transition corresponding to the dissociation of the oligonucleotide-ellipticine conjugate from its target nucleic acid, demonstrating that the observed photochemical effects are dependent on hybrid formation. When the target was a double-stranded DNA, photochemical reactions were observed on both strands of the duplex. Photo-induced cross-linking was more efficient than cleavage when the target was single-stranded; the reverse was observed when the target was duplex DNA.
authors.affiliation: Laboratoire de Biophysique, INSERM U 201, Paris, France.
authors.forename: T
authors.initials: T
authors.lastname: Le Doan
authors.forename: L
authors.initials: L
authors.lastname: Perrouault
authors.forename: U
authors.initials: U
authors.lastname: Asseline
authors.forename: N T
authors.initials: NT
authors.lastname: Thuong
authors.forename: C
authors.initials: C
authors.lastname: Rivalle
authors.forename: E
authors.initials: E
authors.lastname: Bisagni
authors.forename: C
authors.initials: C
authors.lastname: Hélène
mesh_terms: D001483:Base Sequence; D003432:Cross-Linking Reagents; D004247:DNA / Q000737:chemistry* / Q000528:radiation effects; D004611:Ellipticines / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009841:Oligonucleotides / Q000737:chemistry*; D010777:Photochemistry; D010880:Piperidines / Q000737:chemistry; D013696:Temperature; D014466:Ultraviolet Rays
chemical_list: D003432:Cross-Linking Reagents; D004611:Ellipticines; D046911:Macromolecular Substances; D009841:Oligonucleotides; D010880:Piperidines; C034192:ellipticine; C032727:piperidine; D004247:DNA