Modeling DNA oxidation in water.

Area of Science:

• Computational chemistry
• Molecular biophysics
• DNA electronic properties

Background:

• Understanding charge transport in DNA is crucial for fields like molecular electronics and DNA damage studies.
• Existing models often struggle to accurately predict hole trapping efficiencies and transport rates.
• Accurate theoretical parameters are needed to bridge the gap between computational models and experimental observations.

Purpose of the Study:

• To propose a novel set of parameters for predicting DNA hole trapping efficiencies and hole transport rates in oxidized DNA.
• To develop a simplified tight-binding approximation framework for these predictions.
• To validate the proposed parameters against experimental data.

Main Methods:

• Inferred novel hole-site energies and electronic coupling parameters from density functional calculations.
• Included the sugar-phosphate ionic backbone and aqueous environment effects in the calculations.
• Utilized a simplified tight-binding approximation framework.

Main Results:

• The proposed parameters differ significantly from previously reported values.
• The new parameters accurately reproduce experimental oxidation free energies for DNA tracts and oligonucleotides.
• Validation against photoelectron spectroscopy and voltammetric measurements shows high accuracy.
• Sequence-dependent parameters were not required for accurate predictions.

Conclusions:

• The developed parameters provide a reliable and accurate method for predicting charge transport in DNA.
• The simplified tight-binding approach with these parameters offers a computationally efficient tool.
• This work advances the understanding of electronic processes in DNA and has implications for DNA-based technologies.