title: Interaction of metallacrown complexes with G-quadruplex DNA.
abstract: Interactions of the G-quadruplex (GQ) DNA with two pentacoordinate lanthanide (III) metallacrown (MC) complexes containing phenylalanine hydroxamic acid (pheHA) and copper(II) ions of the formula Eu 15-[MCCu,pheHA]-5 (1) and Tb 15-[MCCu,pheHA]-5 (2) were investigated. Binding of both metallacrowns to human telomeric G-quadruplex DNA was followed using CD spectroscopy, DNA melting profiles, and fluorescent intercalator displacement (FID) assay. A new G-quadruplex binding assay based of quenching of Tb(III)-GQ luminescence was proposed and evaluated. All performed tests confirmed interactions of MCs with studied GQ structure. Binding affinities of MCs were appreciable (KMC ~2-5×10(5)M(-1)). Higher concentration of MCs (the ratio of GQ:MC above 2.5) caused destabilization of tetraplex structure of GQ as evidenced by CD spectroscopy, melting temperatures, and Tb(III)-GQ luminescence quenching results.
authors.affiliation: Adam Mickiewicz University in Poznan, Faculty of Chemistry, Umultowska 89b, 61-614 Poznan, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Rajczak
authors.affiliation: Adam Mickiewicz University in Poznan, Faculty of Chemistry, Umultowska 89b, 61-614 Poznan, Poland.
authors.forename: Agata
authors.initials: A
authors.lastname: Gluszynska
authors.affiliation: Adam Mickiewicz University in Poznan, Faculty of Chemistry, Umultowska 89b, 61-614 Poznan, Poland. Electronic address: juskowia@amu.edu.pl.
authors.forename: Bernard
authors.initials: B
authors.lastname: Juskowiak
mesh_terms: D002942:Circular Dichroism; D047248:Crown Compounds / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D054856:G-Quadruplexes; D006801:Humans; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
chemical_list: D047248:Crown Compounds; D028581:Lanthanoid Series Elements; D004247:DNA
keywords: FID assay; G-quadruplex destabilization; Ligand binding; Metallacrown; Tb(III) luminescence