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Updated: Jun 15, 2026
06:48
CD Spectroscopy to Study DNA-Protein Interactions
Published on: February 10, 2022
Intensities of DNA ion-phosphate modes in the low-frequency Raman spectra
1Bogolyubov Institute for Theoretical Physics, NAS of Ukraine, 14-b Metrologichna St., 03680, Kiev, Ukraine. perepelytsya@bitp.kiev.ua
The European Physical Journal. E, Soft Matter
|March 4, 2010
Summary
Raman spectroscopy reveals distinct low-frequency spectral differences in B-DNA based on alkali metal counterions. Heavy counterions like cesium (Cs+) show intense ion-phosphate modes, unlike light ions such as sodium (Na+).
Area of Science:
- Biophysics
- Spectroscopy
- Computational Chemistry
Background:
- B-DNA's low-frequency spectra (< 200 cm(-1)) are influenced by counterions.
- Understanding ion-phosphate interactions is crucial for DNA dynamics.
Purpose of the Study:
- To calculate and analyze Raman intensities of ion-phosphate modes in B-DNA with various alkali metal counterions.
- To elucidate the impact of counterion mass on DNA low-frequency vibrational spectra.
Main Methods:
- Utilized a model for DNA conformational vibrations.
- Employed the valence-optic approach for calculations.
- Calculated Raman intensities for ion-phosphate modes.
Main Results:
- Spectra of B-DNA with heavy counterions (Rb+, Cs+) differ significantly from those with light counterions (Na+, K+).
- Heavy counterions exhibit intensive ion-phosphate modes forming a band near 115 cm(-1).
- Light counterions show weaker, higher-frequency ion-phosphate modes near 180 cm(-1).
Conclusions:
- The study confirms the existence of ion-phosphate modes in DNA low-frequency spectra.
- Counterion type demonstrably affects the intensity and frequency of these modes.
- Calculations explain the experimental observation of these modes in Cs-DNA but not Na-DNA.
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