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Single-Molecule Fluorescence Visualization of DNA Polymerase Dynamics at G-Quadruplexes
Published on: April 4, 2025
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A novel pyrimidine tetrad contributing to stabilize tetramolecular G-quadruplex structures
V Esposito1, A Pepe2, R Filosa3
1Department of Pharmacy, University of Naples "Federico II", Via D. Montesano, 49, 80131 Naples, Italy. galeone@unina.it antonella.virgilio@unina.it.
Organic & Biomolecular Chemistry
|February 16, 2016
Summary
Modified DNA sequences form stable G-quadruplex structures. A novel amino-modified uridine tetrad significantly enhances G-quadruplex stability compared to standard or bromo-modified versions.
Area of Science:
- Biochemistry
- Molecular Biology
- Oligonucleotide Chemistry
Background:
- G-quadruplexes are four-stranded nucleic acid structures with significant biological relevance.
- Modified nucleobases can influence G-quadruplex stability and formation.
Purpose of the Study:
- To investigate the G-quadruplex forming properties of modified oligodeoxyribonucleotides.
- To compare the structural stability of G-quadruplexes containing standard, amino-, and bromo-modified uridines.
Main Methods:
- Circular dichroism spectroscopy
- Nuclear magnetic resonance (NMR) spectroscopy
- Gel electrophoresis
- Molecular modeling
Main Results:
- All 7-mer oligodeoxyribonucleotides (AM, BR, TH) formed parallel, tetramolecular G-quadruplex structures.
- All residues adopted anti glycosidic bonds in the G-quadruplex structures.
- The amino-modified uridine (AM) formed a novel U(NH2)-tetrad with eight hydrogen bonds, enhancing stability.
Conclusions:
- Modified uridines can form stable G-quadruplex structures.
- The novel U(NH2)-tetrad offers superior stabilization compared to U(Br)- and T-tetrads.
- These findings have implications for G-quadruplex-based therapeutics and nanotechnology.
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