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11:42
Iterative Optimization of DNA Duplexes for Crystallization of SeqA-DNA Complexes
Published on: November 1, 2012
Electron attachment to DNA single strands: gas phase and aqueous solution
Jiande Gu1, Yaoming Xie, Henry F Schaefer
1Drug Design & Discovery Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, CAS, Shanghai 201203, PR China. jiandegush@go.com
Nucleic Acids Research
|July 31, 2007
Summary
DNA single strands readily capture electrons, with electron affinity increasing in aqueous solutions. Pyrimidine nucleotides form stable radical anions, potentially leading to DNA strand breakage.
Area of Science:
- Computational Chemistry
- Biophysics
- Molecular Biology
Background:
- DNA single strands are fundamental to genetic processes.
- Understanding their electronic properties is crucial for predicting DNA behavior.
- Smallest units of DNA single strands, diphosphates of deoxyribonucleosides, serve as effective models.
Purpose of the Study:
- To investigate the electron-capturing capabilities of DNA single-strand subunits.
- To predict the properties of DNA single strands using density functional methods.
- To explore the influence of aqueous environments on electron affinity.
Main Methods:
- Density functional theory (DFT) calculations were employed.
- Vertical Attachment Energies (VEAs) and Adiabatic Electron Affinities (AEAs) were computed.
- Simulations of aqueous solutions were performed to assess solvent effects.
Main Results:
- DNA single strands exhibit a strong tendency to capture low-energy electrons.
- Adiabatic Electron Affinities (AEAs) range from 0.22 to 0.52 eV, with 3',5'-dTDP showing the highest value.
- Aqueous solution simulations significantly enhance electron-attracting properties.
- Electron distribution varies: favoring bases in pyrimidines and 3'-phosphate in purines (gas phase).
- Solvent effects shift electron localization, particularly for guanosine nucleotides.
Conclusions:
- DNA single strands possess significant electron affinity, enhanced in aqueous solutions.
- Pyrimidine nucleotides form stable radical anions, suggesting a role in DNA single-strand breakage.
- The electronic behavior of DNA single strands is influenced by both base composition and the surrounding environment.
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