title: Studies on synthesis, characterization, and G-quadruplex binding of Ru(II) complexes containing two dppz ligands.
abstract: In this work, the interaction between the guanine-rich single-strand oligomer AG(3)(T(2)AG(3))(3) quadruplex and two Ru(II) complexes, [Ru(L(1))(dppz)(2)](PF(6))(4) (1) and [Ru(L(2))(dppz)(2)](PF(6))(4) (2) (L(1) = 5,5'-di(1-(trimethylammonio)methyl)-2,2'-dipyridyl cation, L(2) = 5,5'-di(1-(triethylammonio)methyl)-2,2'-dipyridyl cation, dppz = dipyrido[3,2-a:2',3'-c] phenazine), has been studied by UV-Visible, fluorescence, DNA melting, and circular dichroism in K(+) buffer. The two complexes after binding to G-quadruplex have shown different DNA stability and fluorescence enhancement. The results show that both complexes can induce the stabilization of quadruplex DNA. ΔT(m) values of complexes 1 and 2 at [Ru]/[DNA] ratio of 1:1 were 9.4 and 7.0, respectively. Binding stoichiometry along with the quadruplex was investigated through a luminescence-based Job plot. The major inflection points for complexes 1 and 2 were 0.49 and 0.46, respectively. The data were consistent with the binding mode at a [quadruplex]/[complex] ratio of 1:1. In addition, the conformation of G-quadruplex was not changed by the complexes at the high ionic strength of K(+) buffer.
authors.affiliation: MOE Key laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou, 510275, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Sun
authors.forename: Yan
authors.initials: Y
authors.lastname: An
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.forename: Huo-Yan
authors.initials: HY
authors.lastname: Chen
authors.forename: Yan
authors.initials: Y
authors.lastname: Han
authors.forename: Yu-Jia
authors.initials: YJ
authors.lastname: Wang
authors.forename: Zong-Wan
authors.initials: ZW
authors.lastname: Mao
authors.forename: Liang-Nian
authors.initials: LN
authors.lastname: Ji
mesh_terms: D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry; D002942:Circular Dichroism; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry*; D018360:Crystallography, X-Ray; D054856:G-Quadruplexes; D006801:Humans; D008968:Molecular Conformation; D010619:Phenazines / Q000737:chemistry*; D012428:Ruthenium; D044366:Transition Temperature
chemical_list: D000970:Antineoplastic Agents; D056831:Coordination Complexes; D010619:Phenazines; C443808:dipyrido(3,2-a-2',3'-c)phenazine; D012428:Ruthenium