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Updated: Apr 21, 2026

Single-Molecule Fluorescence Visualization of DNA Polymerase Dynamics at G-Quadruplexes
Published on: April 4, 2025
Syntheses of polypyridyl metal complexes and studies of their interaction with quadruplex DNA
Verity S Stafford1, Kogularamanan Suntharalingam, Arun Shivalingam
1Department of Chemistry, Imperial College London, London SW7 2AZ, UK. r.vilar@imperial.ac.uk.
Abstract:
A series of mono- and bi-metallic metal complexes (with Cu(II), Pt(II) and Zn(II)) with substituted polypyridyl ligands have been prepared and their binding affinities towards quadruplex (c-Myc and human telomeric) and duplex DNA (ds26 and calf thymus) determined using fluorescent indicator displacement (FID) assays and UV/vis spectroscopic titrations. These studies have shown that the number of aromatic rings and number/position of cyclic amine substituents on the ligands, play an important role in defining the DNA binding abilities of the resulting metal complexes. We also show that bi-metallic complexes prepared using a novel terpyridine-cyclen ligand have higher affinity towards G-quadruplex DNA as compared to their mono-metallic counterparts. Cytotoxicity assays were carried out for all the new complexes against an osteosarcoma cancer cell line (U2OS) as well as a normal fibroblast cell line (GM05757). Several of these compounds displayed cytotoxicity similar to that of cisplatin.
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