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Updated: Jul 19, 2025
11:19
Site Directed Spin Labeling and EPR Spectroscopic Studies of Pentameric Ligand-Gated Ion Channels
Published on: July 4, 2016
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Revealing light-induced structural shifts in G-quadruplex-porphyrin complexes: a pulsed dipolar EPR study
Natalya E Sannikova1,2, Mikhail I Kolokolov1,2, Tamara A Khlynova1,2
1International Tomography Center SB RAS, 630090 Novosibirsk, Russia. mfedin@tomo.nsc.ru.
Physical Chemistry Chemical Physics : PCCP
|August 15, 2023
Summary
Laser-induced dipolar EPR spectroscopy reveals light-induced structural changes in G-quadruplex DNA (G4) complexes with photosensitizers. This new method shows G4 unfolding and dimer formation, aiding photodynamic therapy development.
Area of Science:
- Medicinal Chemistry
- Biophysics
- Photodynamic Therapy
Background:
- G-quadruplexes (G4s) are crucial in medicinal chemistry for photodynamic therapy.
- Ligand binding and light exposure induce structural changes in G4s, impacting their biological roles.
- Studying G4-ligand complexes is challenging due to G4 structural diversity.
Purpose of the Study:
- Introduce laser-induced dipolar EPR as a novel method for characterizing G4-photosensitizer complexes.
- Investigate light-induced structural modifications in G4-photosensitizer systems.
- Elucidate mechanisms of photoinduced structural changes in HTel-22/TMPyP4 complexes for therapeutic advancement.
Main Methods:
- Application of laser-induced dipolar EPR spectroscopy.
- Characterization of human telomeric G-quadruplex (HTel-22) complexes with TMPyP4.
- Analysis of light-induced structural modifications.
Main Results:
- Demonstrated the feasibility of laser-induced dipolar EPR for G4-photosensitizer studies.
- Observed G-quadruplex unfolding upon light exposure.
- Detected dimer formation in HTel-22/TMPyP4 complexes after light treatment.
Conclusions:
- EPR spectroscopy is a valuable tool for studying G4 complexes with photosensitizers.
- Light exposure induces significant structural changes, including unfolding and dimerization.
- Findings advance understanding of G4-ligand interactions under light for photodynamic therapy.
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