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Updated: Jan 17, 2026
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Single-molecule Manipulation of G-quadruplexes by Magnetic Tweezers
Published on: September 19, 2017
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Probing Residual Water in G-Quadruplex Structures through Molecular Vibrations
Valeria Libera1, Sara Catalini2,3, Francesca Ripanti4
1Dipartimento di Fisica e Geologia, Università di Perugia, Via Pascoli, 06123 Perugia, Italy.
The Journal of Physical Chemistry. B
|September 19, 2025
Summary
This study reveals how water interacts differently with hybrid and parallel G-quadruplexes (GQs) using dual spectroscopy. This finding deepens our understanding of G-quadruplex stability and function in biological systems.
Area of Science:
- Biophysics
- Structural Biology
- Spectroscopy
Background:
- G-quadruplexes (GQs) are noncanonical DNA structures crucial for gene regulation and genome stability.
- GQ structural polymorphism is significantly influenced by their surrounding solvation environment.
- Understanding solute-solvent interactions is key to elucidating GQ stability and function.
Purpose of the Study:
- To investigate the role of solvation environment on G-quadruplex (GQ) structural polymorphism.
- To probe solute-solvent interactions in GQ dilute solutions during thermal unfolding.
- To correlate vibrational properties with secondary structural features of GQs.
Main Methods:
- Employed a dual-spectroscopy approach combining ultraviolet resonance Raman (UVRR) scattering and circular dichroism (CD).
- Utilized UVRR scattering to enhance vibrational features of GQs and probe solute-solvent interactions.
- Analyzed the O-H stretching vibrational band to study the hydrogen-bonded water network.
Main Results:
- Demonstrated differential water molecule interactions with hybrid and parallel GQ conformers.
- Showcased the ability of coupled UVRR and CD spectroscopy to link vibrational properties with secondary structures.
- Confirmed the utility of UVRR scattering for studying GQs, a novel application for this biosystem.
Conclusions:
- The combined UVRR and CD spectroscopy approach effectively correlates vibrational data with GQ secondary structures, even with significant solvent contributions.
- Water molecules interact distinctively with different GQ conformers, highlighting the importance of solvation.
- This methodology offers a promising avenue for deeper insights into GQ stability and function across various GQ structures.
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