Commentary: possible mechanisms for strand-breaks in DNA induced by stirring
1The Bone and Joint Research Unit St. Bartholomews Hospital School of Medicine London EC1M 6BQ, UK.
Free Radical Research
|May 30, 2001
Summary
Stirring DNA solutions causes strand breaks, not through homolysis, but likely via hydrolysis at bent DNA regions. This research reveals a novel mechanism for DNA damage in aqueous environments.
Area of Science:
- Biochemistry
- Molecular Biology
- Physical Chemistry
Background:
- Aqueous solutions of DNA are susceptible to damage.
- Mechanical forces can induce changes in DNA structure.
Purpose of the Study:
- To investigate the mechanism of DNA strand breaks induced by stirring.
- To determine if DNA damage occurs via homolysis.
Main Methods:
- Stirring aqueous DNA solutions at room temperature.
- Utilizing electron paramagnetic resonance (EPR) spectroscopy.
- Employing various spin-traps to detect radical species.
Main Results:
- Extensive DNA strand breaks were observed upon stirring.
- No evidence for homolytic cleavage was found.
- The results suggest an alternative mechanism for DNA breakage.
Conclusions:
- DNA strand breaks induced by stirring do not proceed via homolysis.
- Hydrolysis at transiently formed, strongly bent DNA regions is the suggested mechanism.
- Mechanical stress can lead to non-homolytic DNA damage.
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