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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Production of Superoxide in Bacteria Is Stress- and Cell State-Dependent: A Gating-Optimized Flow Cytometry Method that Minimizes ROS Measurement Artifacts with Fluorescent Dyes
Megan E. McBee,Yok Hian Chionh,Mariam L. Sharaf,Peiying Ho,Maggie W. L. Cai,Maggie W. L. Cai,Peter C. Dedon +6 more
TL;DR: It is demonstrated that properly controlled flow cytometry coupled with fluorescent probes provides precise and accurate quantitative analysis of ROS generation and metabolic changes in stressed bacteria.
Journal ArticleDOI
Localization of Fe(2+) at an RTGR sequence within a DNA duplex explains preferential cleavage by Fe(2+) and H2O2.
TL;DR: NMR studies on the basis of preferential nicking of duplex DNA by the iron-mediated Fenton reaction show that Fe 2+ interacts preferentially and reversibly at the ATGA site within the duplex at a rate that is rapid relative to the chemical-shift timescale, while selective paramagnetic NMR line-broadening of the AT GA guanine H8 suggests that Fe2+ interacts with the guanin N7 moiety.
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Induction of p21 Mediated by Reactive Oxygen Species Formed during the Metabolism of Aziridinylbenzoquinones by HCT116 Cells
TL;DR: It is suggested that p21 induction is mediated by an increase in the cellular steady-state concentration of oxygen radicals and that the greater effectiveness in p 21 induction by DZQ may be related to its efficient metabolism by NAD(P)H:quinone oxidoreductase activity in HCT116 cells.
Journal ArticleDOI
8-Oxodeoxyguanosine formation in the DNA of cultured cells after exposure to H2O2 alone or with UVB or UVA irradiation.
TL;DR: It is revealed that both UVA or UVB can promote H2O2 generation of reactive oxygen species (ROS) in whole cells resulting in an increase in the formation of 8‐oxo‐dG, although the photodynamic generation of ROS from H2 O2 occurs with a much higher efficiency in the presence of UVB.
Journal ArticleDOI
Rescue of DNA damage after constricted migration reveals a mechano-regulated threshold for cell cycle.
Yuntao Xia,Charlotte R. Pfeifer,Kuangzheng Zhu,Jerome Irianto,Dazhen Liu,Kalia Pannell,Emily J. H. Chen,Lawrence J. Dooling,Michael P. Tobin,Mai Wang,Irena L. Ivanovska,Lucas R. Smith,Roger A. Greenberg,Dennis E. Discher +13 more
TL;DR: It is shown that constricted migration causes DNA damage and a cell cycle block that is rescued by antioxidant plus myosin II inhibition or overexpressed repair factors exhibits a threshold in the mechanically induced DNA 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.
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.