Journal ArticleDOI
Toxic DNA damage by hydrogen peroxide through the Fenton reaction in vivo and in vitro.
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TLDR
An in vitro Fenton system was established that generates DNA strand breaks and inactivates bacteriophage and that also reproduces the suppression of DNA damage by high concentrations of peroxide.Abstract:
Exposure of Escherichia coli to low concentrations of hydrogen peroxide results in DNA damage that causes mutagenesis and kills the bacteria, whereas higher concentrations of peroxide reduce the amount of such damage. Earlier studies indicated that the direct DNA oxidant is a derivative of hydrogen peroxide whose formation is dependent on cell metabolism. The generation of this oxidant depends on the availability of both reducing equivalents and an iron species, which together mediate a Fenton reaction in which ferrous iron reduces hydrogen peroxide to a reactive radical. An in vitro Fenton system was established that generates DNA strand breaks and inactivates bacteriophage and that also reproduces the suppression of DNA damage by high concentrations of peroxide. The direct DNA oxidant both in vivo and in this in vitro system exhibits reactivity unlike that of a free hydroxyl radical and may instead be a ferryl radical.read more
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Reactive Oxygen Species (ROS)-Based Nanomedicine.
Bowen Yang,Yu Chen,Jianlin Shi +2 more
TL;DR: In this article, the intrinsic biochemical properties of reactive oxygen species (ROS) underlie the mechanisms that regulate various physiological functions of living organisms, and they play an essential role in regulating various physiological function.
Journal ArticleDOI
Free Radicals in Biology: Oxidative Stress and the Effects of Ionizing Radiation
TL;DR: The most important electron acceptor in the biosphere is molecular oxygen which, by virtue of its bi-radical nature, readily accepts unpaired electrons to give rise to a series of partially reduced species collectively known as reduced (or ‘reactive’) oxygen species (ROS).
Journal ArticleDOI
Oxidative stress responses in Escherichia coli and Salmonella typhimurium.
TL;DR: The products of Oxy-R- and SoxRS-regulated genes, such as catalases and superoxide dismutases, are involved in the prevention of oxidative damage, whereas others play a role in the repair of oxidativeDamage.
Journal ArticleDOI
Mechanisms of DNA damage, repair, and mutagenesis.
TL;DR: This introductory review will delineate mechanisms of DNA damage and the counteracting repair/tolerance pathways to provide insights into the molecular basis of genotoxicity in cells that lays the foundation for subsequent articles in this issue.
Journal ArticleDOI
The iron-sulfur clusters of dehydratases are primary intracellular targets of copper toxicity.
Lee Macomber,James A. Imlay +1 more
TL;DR: Mutants of Escherichia coli that lack copper homeostatic systems were used to identify intracellular targets and to test the hypothesis that toxicity involves the action of reactive oxygen species.
References
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Journal ArticleDOI
The biology of oxygen radicals
TL;DR: The reactive superoxide radical, O2-, formerly of concern only to radiation chemists and radiobiologists, is now understood to be a normal product of the biological reduction of molecular oxygen.
Journal ArticleDOI
The catalytic decomposition of hydrogen peroxide by iron salts
Fritz Haber,Joseph Weiss +1 more
TL;DR: Wansbrough-Jones as discussed by the authors gave the manuscript of this paper to Professor Sir William Pope, but the final revision for the press had not been made and in its original from the paper was not suitable for publication in an English journal; but since, Professor Haber had considered carefully how he wished to present the results embodied in it, the form and sequence of the paper remain unmodified.