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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Hydrogen peroxide induced cell death: One or two modes of action?
TL;DR: It is demonstrated (mathematically and numerically) that free available iron decrease is necessary to explain mode one killing which cannot appear without it and that H2O2 quenching or consumption is not responsible for mode-one death.
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Protein tyrosine kinase, PtkA, is required for Mycobacterium tuberculosis growth in macrophages.
Dennis Wong,Wu Li,Joseph D. Chao,Peifu Zhou,Gagandeep Narula,Clement K. M. Tsui,Mary Ko,Jianping Xie,Carlos Martinez-Frailes,Yossef Av-Gay +9 more
TL;DR: A ∆ptkA deletion mutant in Mtb is constructed and found that the mutant exhibited impaired intracellular survival in the THP-1 macrophage infection model, correlated with the strain’s inability to inhibit macrophages phagosome acidification.
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Single-molecule visualization of ROS-induced DNA damage in large DNA molecules
TL;DR: Single DNA molecule analysis provides a sensitive analytical platform for ROS-induced DNA damage and suggests an interesting biochemical insight that the genome primarily active during the lysogenic cycle may have less probability for oxidative DNA damage.
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Retinal light damage: structural and functional effects of the antioxidant glutathione peroxidase-1.
Andrew D. Gosbell,Nada Stefanovic,Lyndee L. Scurr,Josefa Pete,Ismail Kola,Ian Favilla,Judy B. de Haan +6 more
TL;DR: The hypothesis that increased oxidative stress provides a "preconditioning" environment in which protective mechanisms paradoxically render GPx1-deficient retinas less vulnerable to light-induced oxidative damage is given rise to.
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Infrared spectral models demonstrate that exposure to environmental chemicals leads to new forms of DNA.
TL;DR: Exposure to environmental chemicals results in new, structurally diverse forms of DNA that likely play an important role in carcinogenesis, as demonstrated by principal components analysis of Fourier transform infrared spectra.
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.