Mono- and polynuclear ruthenium(II) complexes, photo-probes and reagents for targeted DNA sites

✍ Scribed by Andrée Kirsch-De Mesmaeker; Cécile Moucheron; Nathalie Boutonnet

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 340 KB
• Volume: 11
• Category: Article
• ISSN: 0894-3230
• DOI: 10.1002/(sici)1099-1395(199808/09)11:8/9<566::aid-poc63>3.0.co;2-#

✦ Synopsis

Several luminescent ruthenium(II) complexes were designed whose main characteristic is their photoreactivity towards mononucleotides and DNA. It was clearly demonstrated that this photoreactivity originates from a photoinduced electron transfer from a guanine to the excited complex. This process leads to the formation of an adduct which was characterized. The structure shows that the complex is anchored to the nucleotidic base via one of its polyazaaromatic ligands, thus marking irreversibly the DNA guanines. Interestingly, this property can be used in order to target, for example, (i) specific DNA sequences and (ii) particular DNA topologies. For each purpose a specific Ru(II) complex was designed. Synthetic oligonucleotides derivatized with mononuclear complexes were prepared to target and damage specific DNA sequences containing G sites. In these systems, it is shown that the DNA damage consists of an irreversible photo-crosslinking of the derivatized oligonucleotide with the complementary strand. In order to target portions of important deformation along double-stranded DNA, the dinuclear complex [Ru(phen) 2 ] 2 HAT 4 was prepared and studied. This complex is too large to penetrate inside the major or minor grooves of a DNA double helix, so that only single-stranded portions of denatured DNA are accessible to this compound.