title: Tetra-2,3-pyrazinoporphyrazines with externally appended pyridine rings. 10. A water-soluble bimetallic (Zn(II)/Pt(II)) porphyrazine hexacation as potential plurimodal agent for cancer therapy: exploring the behavior as ligand of telomeric DNA G-quadruplex structures.
abstract: The behavior of a bimetallic water-soluble (Zn(II)/Pt(II)) porphyrazine hexacation as ligand of G-quadruplex (G4) structures adopted by a human telomeric DNA sequence has been examined with different spectroscopic techniques. In K(+) rich solution the hexacationic Zn(II) porphyrazine ligand bearing a peripheral cis-platin-like functionality changes the G-quadruplex conformational equilibrium of the human telomeric sequence 5'-d[AGGG(TTAGGG)(3)]-3' and drives it exclusively toward a very stable parallel G4 form in the complex with 2:1 stoichiometry. An increase of the melting temperature of more than 20 °C is observed in this complex compared to the G4 alone. On the contrary ligand binding to G-quadruplex of the same telomeric sequence in Na(+) rich solution neither markedly influences the predominant basket conformation nor confers increased thermal stability to the G4 structure.
authors.affiliation: Istituto per la Sintesi Organica e la Fotoreattività, Consiglio Nazionale delle Ricerche, via Gobetti 101, 40129 Bologna, Italy. manet@isof.cnr.it
authors.forename: Ilse
authors.initials: I
authors.lastname: Manet
authors.forename: Francesco
authors.initials: F
authors.lastname: Manoli
authors.forename: Maria Pia
authors.initials: MP
authors.lastname: Donzello
authors.forename: Claudio
authors.initials: C
authors.lastname: Ercolani
authors.forename: Daniela
authors.initials: D
authors.lastname: Vittori
authors.forename: Luciano
authors.initials: L
authors.lastname: Cellai
authors.forename: Annalisa
authors.initials: A
authors.lastname: Masi
authors.forename: Sandra
authors.initials: S
authors.lastname: Monti
mesh_terms: D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry*; D054856:G-Quadruplexes; D006801:Humans; D008024:Ligands; D008958:Models, Molecular; D015394:Molecular Structure; D010984:Platinum / Q000737:chemistry*; D011166:Porphyrins / Q000138:chemical synthesis / Q000737:chemistry*; D011714:Pyrans / Q000138:chemical synthesis / Q000737:chemistry; D011725:Pyridines / Q000138:chemical synthesis / Q000737:chemistry; D012995:Solubility; D014867:Water / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*
chemical_list: D000970:Antineoplastic Agents; D008024:Ligands; D011166:Porphyrins; D011714:Pyrans; D011725:Pyridines; D014867:Water; D010984:Platinum; D015032:Zinc