Rationalizing Sequence and Conformational Effects on the Guanine Oxidation in Different DNA Conformations

Area of Science:

• Biochemistry
• Computational Chemistry
• Molecular Biology

Background:

• The redox potential of guanine is crucial for DNA function and stability.
• Previous experimental studies suggested environmental factors influence guanine redox properties.

Purpose of the Study:

• To computationally investigate the impact of DNA sequence and conformation on guanine redox potential.
• To provide a quantitative estimate of these effects in various DNA structures.

Main Methods:

• Theoretical-computational approach.
• Analysis of single-stranded DNA, double-stranded DNA oligomers, and G-rich quadruplexes.

Main Results:

• Confirmed that consecutive guanine bases reduce the guanine redox potential in DNA oligomers.
• Observed a more significant reduction in G-quadruplex structures.
• Demonstrated enhanced stabilization of the oxidized guanine form in G-quadruplexes.

Conclusions:

• Sequence and conformational effects significantly modulate guanine redox potential.
• G-quadruplexes exhibit a particularly pronounced stabilization of oxidized guanine.
• This study provides the first computational quantification of these guanine redox potential dependencies.