tert-Butoxyl radicals generate mainly 7,8-dihydro-8-oxoguanine in DNA

Mahler, Hanns‐Christian; Schulz, Ina; Adam, Waldemar; Grimm, Günther N.; Saha‐Möller, Chantu R.; Epe, Bernd

doi:10.1016/s0921-8777(00)00057-4

Cited by 20 publications

(17 citation statements)

References 54 publications

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“…Nitrosative and oxidative stress conditions were modelled by exposure to acidified sodium nitrite and t -butyl hydroperoxide, respectively (Figure 1c and d), which have been shown previously to cause these types of damage (40,41). The survival of the uvrA mutant was reduced compared with the wild-type by exposure to either of these agents.…”

Section: Resultsmentioning

confidence: 99%

The biological and structural characterization of Mycobacterium tuberculosis UvrA provides novel insights into its mechanism of action

Rossi

Khanduja

Bortoluzzi

et al. 2011

Nucleic Acids Research

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Mycobacterium tuberculosis is an extremely well adapted intracellular human pathogen that is exposed to multiple DNA damaging chemical assaults originating from the host defence mechanisms. As a consequence, this bacterium is thought to possess highly efficient DNA repair machineries, the nucleotide excision repair (NER) system amongst these. Although NER is of central importance to DNA repair in M. tuberculosis, our understanding of the processes in this species is limited. The conserved UvrABC endonuclease represents the multi-enzymatic core in bacterial NER, where the UvrA ATPase provides the DNA lesion-sensing function. The herein reported genetic analysis demonstrates that M. tuberculosis UvrA is important for the repair of nitrosative and oxidative DNA damage. Moreover, our biochemical and structural characterization of recombinant M. tuberculosis UvrA contributes new insights into its mechanism of action. In particular, the structural investigation reveals an unprecedented conformation of the UvrB-binding domain that we propose to be of functional relevance. Taken together, our data suggest UvrA as a potential target for the development of novel anti-tubercular agents and provide a biochemical framework for the identification of small-molecule inhibitors interfering with the NER activity in M. tuberculosis.

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Section: Resultsmentioning

confidence: 99%

The biological and structural characterization of Mycobacterium tuberculosis UvrA provides novel insights into its mechanism of action

Rossi

Khanduja

Bortoluzzi

et al. 2011

Nucleic Acids Research

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“…[1,2] Indeed, hastening oxidative processes can lead to an altered intracellular redox status causing cellular dysfunction or death [1,2] and related events, most prominently oxidative DNA damage, [3][4][5][6] a primary process of carcinogenesis. It comes as no surprise that the development of pathogenic oxidative processes in human organism is lifestyle dependent.…”

Section: Introductionmentioning

confidence: 99%

Effects of Different Phases of Cigarette Smoke on Lipid Peroxidation and Membrane Structure in Liposomes

et al. 2014

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This paper discloses for the first time the effects of the gas phase (GP) and the tar of cigarette smoke on lipid peroxidation (LPO) and on the structure of different lipid regions in liposomes. The LPO development was analysed in terms of the total unsaturation of lipids (double-bond, DB, content) and the formation of dienic conjugates (DC), ketodienes (KD), and malonic dialdehyde (MDA). As expected, the exposure of liposomes to either the GP or the tar led to a significant decrease in the DB content. However, the formation of oxidation products revealed different dynamics: MDA generation was inhibited, while the formation of DC and KD increased during the first few hours of the LPO development followed by its inhibition. The smoke constituents exhibited opposite effects on the structure of the lipid bilayer of liposomes: the GP markedly enhanced the microviscosity of liposomal membranes, whereas the tar caused a drastic lowering of microviscosity.

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“…They have been reported to induce strand breaks in supercoiled pBR322 DNA and may play a significant role in the tumor‐promoting activity of peroxides . Strand break formation and base oxidation have been observed as necessary modifications induced by the alkoxyl radicals in DNA damage . Tert‐B utyl hydroperoxide ( t ‐BHP) is a recognized oxidant that has been used as a model oxygen‐centered radical for the study of mechanisms of oxidative cell injury in mammalian cells and to investigate mechanisms of its interaction with polyphenols .…”

Section: Introductionmentioning

confidence: 99%

Photo‐oxidation of some flavonoids with photochemically generatedt‐BuO^•radicals in at‐BuOH water system using a kinetic approach

Mallepu

Potlapally

2018

J Chinese Chemical Soc

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As a dietary component, flavonoids are thought to have a variety of pharmacological and health‐promoting properties in both in vivo and in vitro systems. This variety is attributed to their high antioxidant capacity, which in turn is associated with their free radical scavenging properties. In order to understand the mechanism of t‐BuO• radical scavenging properties of some flavonoids, viz, quercetin (QU), apigenin (AP), daidzein (DA), genistein (GE), myricetin (MY), and kaempferol (KA), a kinetic study of photo‐oxidation of these flavonoids with photochemically generated t‐BuO• radicals in a t‐BuOH water (2:1 v/v) system was carried out. The oxidation of flavonoids by t‐BuO• radicals was performed spectrophotometrically by measuring the absorbance of quercetin (375 nm), apigenin (340 nm), daidzein (250 nm), genistein (263 nm), myricetin (255 nm), and kaempferol (375 nm) at their respective λmax. The initial rates of oxidation of flavonoids increased with [flavonoid], [t‐BuOOH], and light intensity. The quantum yields (φ) were considered from the initial rate of oxidation of flavonoids by t‐BuO• radicals and measured light intensity at 254 nm. The order on [flavonoid] and [t‐BuOOH] was found to be fractional, whereas the order on light intensity was found to be one. The products of the oxidation of flavonoids by t‐BuO• radicals were identified using LC–MS and FTIR analysis.

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tert-Butoxyl radicals generate mainly 7,8-dihydro-8-oxoguanine in DNA

Cited by 20 publications

References 54 publications

The biological and structural characterization of Mycobacterium tuberculosis UvrA provides novel insights into its mechanism of action

The biological and structural characterization of Mycobacterium tuberculosis UvrA provides novel insights into its mechanism of action

Effects of Different Phases of Cigarette Smoke on Lipid Peroxidation and Membrane Structure in Liposomes

Photo‐oxidation of some flavonoids with photochemically generatedt‐BuO^•radicals in at‐BuOH water system using a kinetic approach

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tert-Butoxyl radicals generate mainly 7,8-dihydro-8-oxoguanine in DNA

Cited by 20 publications

References 54 publications

The biological and structural characterization of Mycobacterium tuberculosis UvrA provides novel insights into its mechanism of action

The biological and structural characterization of Mycobacterium tuberculosis UvrA provides novel insights into its mechanism of action

Effects of Different Phases of Cigarette Smoke on Lipid Peroxidation and Membrane Structure in Liposomes

Photo‐oxidation of some flavonoids with photochemically generatedt‐BuO•radicals in at‐BuOH water system using a kinetic approach

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Photo‐oxidation of some flavonoids with photochemically generatedt‐BuO^•radicals in at‐BuOH water system using a kinetic approach