Breaking action of ascorbic acid on nucleic acids

Area of Science:

• Biochemistry
• Molecular Biology
• Chemical Biology

Background:

• Nucleic acid stability and degradation are critical in biological systems.
• Ascorbic acid (AsA) and its derivatives are known antioxidants with potential roles in biological processes.

Purpose of the Study:

• To investigate the effect of Ascorbic acid (AsA), Erythorbic acid (EA), and Ascorbic acid-3-phosphate (AsA-3-P) on nucleic acid structure and function.
• To elucidate the role of the enediol group and copper ions (Cu2+) in the degradation of DNA and RNA.

Main Methods:

• Viscosity measurements of DNA solutions.
• Sucrose density gradient centrifugation to analyze DNA strand scissions.
• Assessment of RNA degradation.
• Analysis of reducing activity and priming activity of DNA polymerase.

Main Results:

• AsA and EA significantly reduced DNA viscosity and induced single- and double-strand scissions, an effect enhanced by Cu2+.
• AsA-3-P showed weaker activity, causing only single-strand scissions in DNA with Cu2+ and similar effects on RNA.
• The enediol group of AsA is crucial for nucleic acid breakage, with Cu2+ enhancing this action. DNA priming activity was altered by AsA treatment.

Conclusions:

• The enediol group of Ascorbic acid is essential for breaking nucleic acids, with copper ions potentiating the effect.
• Ascorbic acid and Erythorbic acid can degrade DNA and RNA, impacting their structure and function.
• The findings suggest specific mechanisms for AsA-mediated nucleic acid damage and potential implications for biological systems.