Related Experiment Video
Updated: Jun 25, 2025
05:37
Single-Molecule Fluorescence Visualization of DNA Polymerase Dynamics at G-Quadruplexes
Published on: April 4, 2025
533
Heavy metal ions interactions with G-quadruplex-prone DNA sequences
Seyyed-Ali Mehrdad1, Anne Cucchiarini2, Jean-Louis Mergny2
1Department of Biology, Faculty of Basic Sciences, Hakim Sabzevari University, Sabzevar, Iran.
Biochimie
|May 31, 2024
Summary
Industrial metal pollutants impact G-rich sequences, affecting G-quadruplex (GQ) stability and structure. Toxic heavy metals like lead and mercury alter GQ conformation in a sequence-dependent manner, influencing gene expression.
Area of Science:
- Environmental Science
- Biochemistry
- Molecular Biology
Background:
- Industrial activities release various metal pollutants into the environment.
- G-rich nucleic acid sequences can fold into G-quadruplex (GQ) structures.
- The impact of metal pollutants on GQ stability and conformation is not fully understood.
Purpose of the Study:
- To investigate the effect of heavy metal ions on the thermal stability and conformation of G-quadruplex (GQ) structures.
- To determine how different metal ions interact with various GQ sequences.
Main Methods:
- Thermal FRET (fluorescence resonance energy transfer)
- Transition FRET (t-FRET)
- Circular Dichroism (CD) spectroscopy
- Analysis of G-rich oligonucleotides with various heavy metal salts at different molar ratios.
Main Results:
- Metal ions differentially affected the thermal stability (Tm) of GQs.
- Aluminum (Al3+), cadmium (Cd2+), lead (Pb2+), mercury (Hg2+), and zinc (Zn2+) significantly altered GQ thermal stability and structural features.
- Lead (Pb2+) and mercury (Hg2+) showed differential interactions with telomere, c-myc, and c-kit GQs.
- Effects were sequence and topology dependent.
Conclusions:
- Toxic heavy metals can destabilize or alter the structure of G-quadruplexes.
- The interaction of metals with GQs is specific to the metal ion and the GQ sequence/topology.
- Heavy metal exposure may influence cellular responses and gene expression through modulation of GQ structures.
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