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
Citations
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An update on iron physiology
TL;DR: In chronic inflammation, the excess of hepcidin decreases iron absorption and prevents iron recycling, which results in hypoferremia and iron-restricted erythropoiesis, despite normal iron stores (functional ID), and anemia of chronic disease (ACD), which can evolve to ACD plus true ID (ACC + ID).
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Bacterial defenses against oxidative stress
TL;DR: Bacteria treated with low doses of oxidants such as hydrogen peroxide adapt to subsequent high doses of these oxidants by inducing the expression of numerous genes, giving general insights into what oxidants are hazardous to cells, what cell constituents are damaged by oxidants, and how cells sense and respond to oxidative stress.
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Building Fe–S proteins: bacterial strategies
Béatrice Py,Frédéric Barras +1 more
TL;DR: The multiprotein systems that are required to build Fe-S proteins have been identified, but the in vivo roles of some of the components remain to be clarified and the way in which cellular Fe–S cluster trafficking pathways are organized remains a key issue for future studies.
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pH-induced mechanistic changeover from hydroxyl radicals to iron(IV) in the Fenton reaction
TL;DR: In this article, the authors show that Fe(IV) is a less efficient oxidant for DMSO at pH 6-7 than is (H2O)5FeO2+, generated by ozone oxidation of Fe(H2 O)62+, in acidic solutions.
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Manganese import is a key element of the OxyR response to hydrogen peroxide in Escherichia coli
TL;DR: It is found that manganese does not protect peroxide‐stressed cells by scavenging peroxide, and the beneficial effects ofManganese correlate with its ability to metallate mononuclear enzymes, which may prevent protein damage.
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.
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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.