title: Assembly of palladium(II) and platinum(II) metallo-rectangles with a guanosine-substituted terpyridine and study of their interactions with quadruplex DNA.
abstract: Two novel [2+2] metallo-assemblies based on a guanosine-substituted terpyridine ligand (1) coordinated to palladium(II) (2 a) and platinum(II) (2 b) are reported. These supramolecular assemblies have been fully characterized by NMR spectroscopy, ESI mass spectrometry and elemental analyses. The palladium(II) complex (2 a) has also been characterized by single crystal X-ray diffraction studies confirming that the system is a [2+2] metallo-rectangle in the solid state. The stabilities of these [2+2] assemblies in solution have been confirmed by DOSY studies as well as by variable temperature (1)H NMR spectroscopy. The ability of these dinuclear complexes to interact with quadruplex and duplex DNA was investigated by fluorescent intercalator displacement (FID) assays, fluorescence resonance energy transfer (FRET) melting studies, and electrospray mass spectrometry (ESI-MS). These studies have shown that both these assemblies interact selectively with quadruplex DNA (human telomeric DNA and the G-rich promoter region of c-myc oncogene) over duplex DNA, and are able to induce dimerization of parallel G-quadruplex structures.
authors.affiliation: Department of Chemistry, Imperial College London, London SW7 2AZ (UK).
authors.forename: Sushobhan
authors.initials: S
authors.lastname: Ghosh
authors.forename: Oscar
authors.initials: O
authors.lastname: Mendoza
authors.forename: Leticia
authors.initials: L
authors.lastname: Cubo
authors.forename: Frédéric
authors.initials: F
authors.lastname: Rosu
authors.forename: Valérie
authors.initials: V
authors.lastname: Gabelica
authors.forename: Andrew J P
authors.initials: AJ
authors.lastname: White
authors.forename: Ramon
authors.initials: R
authors.lastname: Vilar
mesh_terms: D001665:Binding Sites; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry*; D018360:Crystallography, X-Ray; D054856:G-Quadruplexes; D006151:Guanosine / Q000737:chemistry*; D008024:Ligands; D008968:Molecular Conformation; D062105:Molecular Docking Simulation; D009690:Nucleic Acid Conformation; D010165:Palladium / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry
chemical_list: D056831:Coordination Complexes; D008024:Ligands; D011725:Pyridines; D006151:Guanosine; D010984:Platinum; D010165:Palladium
keywords: G-quadruplexes; molecular rectangles; palladium; platinum; self-assembly