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Single-Molecule Fluorescence Visualization of DNA Polymerase Dynamics at G-Quadruplexes
Published on: April 4, 2025
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Interaction of metallacrown complexes with G-quadruplex DNA
Ewa Rajczak1, Agata Gluszynska1, Bernard Juskowiak1
1Adam Mickiewicz University in Poznan, Faculty of Chemistry, Umultowska 89b, 61-614 Poznan, Poland.
Journal of Inorganic Biochemistry
|December 22, 2015
Summary
Lanthanide metallacrown complexes interact with G-quadruplex (GQ) DNA. Higher concentrations destabilize the GQ tetraplex structure, confirmed by various assays.
Area of Science:
- Bioinorganic Chemistry
- DNA Biophysics
- Coordination Chemistry
Background:
- G-quadruplex (GQ) DNA structures are crucial in telomere maintenance and gene regulation.
- Lanthanide (III) metallacrown (MC) complexes offer unique properties for interacting with nucleic acids.
Purpose of the Study:
- Investigate the interaction of specific lanthanide (III) metallacrown complexes with human telomeric G-quadruplex DNA.
- Evaluate the binding affinities and structural effects of these complexes on GQ DNA.
Main Methods:
- Circular Dichroism (CD) spectroscopy to monitor structural changes.
- DNA melting profiles to assess thermal stability.
- Fluorescent Intercalator Displacement (FID) assay for binding quantification.
- Development and evaluation of a novel Tb(III)-GQ luminescence quenching assay.
Main Results:
- Confirmed interactions between the metallacrown complexes (Eu and Tb based) and G-quadruplex DNA.
- Quantified appreciable binding affinities (KMC ~2-5×10(5)M(-1)).
- Observed destabilization of the GQ tetraplex structure at higher metallacrown concentrations (GQ:MC ratio > 2.5).
Conclusions:
- The studied lanthanide metallacrown complexes effectively bind to G-quadruplex DNA.
- Metallacrown concentration is a critical factor influencing GQ DNA structural integrity.
- The developed luminescence quenching assay provides a new method for studying DNA-binding events.
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