Oxidative DNA Damage Associated with Combination of Guanine and Superoxide Radicals and Repair Mechanisms via Radical Trapping

Misiaszek, Richard; Crean, Conor; Joffe, Avrum; Geacintov, Nicholas E.; Shafirovich, Vladimir

doi:10.1074/jbc.m313904200

Cited by 210 publications

(277 citation statements)

References 54 publications

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“…Some studies have shown that there is no evidence to the existence of N 2 O − at low electron energies (<1 eV) (Chantry, 1969) (Burtt and Kircher, 1958). O 2 •− is the same product formed from presence of O 2 under irradiation, and it is a highly reactive radical known to cause oxidative DNA damage through its combination with guanine neutral radicals (Misiaszek et al, 2004). In addition, some N 2 O molecules can react with electronically excited oxygen atoms via N 2 O + O( 1 D) → 2NO and N 2 O + O( 1 D) → N 2 + O 2 that the latter is a source of formation of molecular oxygen which can induce significant damage of DNA due to oxygen fixation hypothesis (Burtt and Kircher, 1958).…”

Section: Discussionmentioning

confidence: 99%

Induction of strand breaks in DNA films by low energy electrons and soft X-ray under nitrous oxide atmosphere

Alizadeh

Sanche

2012

Radiation Physics and Chemistry

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Five-monolayer (5ML) plasmid DNA films deposited on glass and tantalum substrates were exposed to Al K α X-rays of 1.5 keV under gaseous nitrous oxide (N 2 O) at atmospheric pressure and temperature. Whereas the damage yields for DNA deposited on glass are due to soft X-rays, those arising from DNA on tantalum are due to both the interaction of low energy photoelectrons from the metal and X-rays. Then, the differences in the yields of damage on glass and tantalum substrates, essentially arises from interaction of essentially low-energy electrons (LEEs) with DNA molecules and the surrounding atmosphere. The G-values (i.e., the number of moles of product per Joule of energy absorbed) for DNA strand breaks induced by LEEs (G LEE ) and the lower limit of G-values for soft X-ray photons (G XL ) were calculated and the results compared to those from previous studies under atmospheric conditions and other ambient gases, such as N 2 and O 2 . Under N 2 O, the G-values for loss of supercoiled DNA are 103±15 nmol/J for X-rays, and 737±110 nmol/J for LEEs. Compared to corresponding values in an O 2 atmosphere, the effectiveness of X-rays to damage DNA in N 2 O is less, but the G value for LEEs in N 2 O is more than twice the corresponding value for an oxygenated environment. This result indicates a higher effectiveness for LEEs relative to N 2 and O 2 environments in causing SSB and DSB in an N 2 O environment. Thus, the previously observed radiosensitization of cells by N 2 O may not be only due to OH • radicals but also to the reaction of LEE with N 2 O molecules near DNA. The previous experiments with N 2 and O 2 and the present one demonstrate the possibility to investigate damage induced by LEEs to biomolecules under various type of surrounding atmospheres.

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Section: Discussionmentioning

confidence: 99%

Induction of strand breaks in DNA films by low energy electrons and soft X-ray under nitrous oxide atmosphere

Alizadeh

Sanche

2012

Radiation Physics and Chemistry

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“…32,34 In the presence of oxygen, the hydrated electrons are rapidly scavenged by O 2 to form superoxide radical anions (reaction 2) that do not react directly with DNA. 36 Thus, the BPT •+ radicals can be used to oxidize guanine in oligonucleotides (reaction 3). 32 The CO 3 •− radicals are generated by two consecutive reactions that begin with the photodissociation of persulfate anions into SO 4 •− radical anions (reaction 5, Table 2) induced by intense 308 nm excimer laser pulses.…”

Section: Laser Flash Photolysis and Measurements Of Electron Transfermentioning

confidence: 99%

“…We have shown that, in the case of BPT •+ , the lifetimes of guanine radicals are determined by bimolecular reactions with O 2 •− radicals derived from the trapping of hydrated electrons by dissolved O 2 , 55 or by bimolecular reactions with CO 3 •− radicals. 29,36 Hence, the distributions of oxidatively modified guanines can differ from the distributions created by hole hopping mechanisms, because chemical trapping can be also sequence dependent. In gel electrophoresis experiments, oxidatively modified bases are cleaved by hot piperidine or enzymatic treatments.…”

Section: Effects Of Base Sequence Context: Insights Into Relationshipmentioning

confidence: 99%

Oxidation of Guanine in G, GG, and GGG Sequence Contexts by Aromatic Pyrenyl Radical Cations and Carbonate Radical Anions: Relationship between Kinetics and Distribution of Alkali-Labile Lesions

et al. 2008

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Oxidatively generated DNA damage induced by the aromatic radical cation of the pyrene derivative 7,8,9,10-tetrahydroxytetrahydrobenzo[a]pyrene (BPT), and by carbonate radicals anions, was monitored from the initial one-electron transfer, or hole injection step, to the formation of hot alkali-labile chemical end-products monitored by gel electrophoresis. The fractions of BPT molecules bound to double-stranded 20-35-mer oligonucleotdes with noncontiguous guanines G, and grouped as contiguous GG and GGG sequences, were determined by a fluorescence quenching method. Utilizing intense nanosecond 355 nm Nd: Yag laser pulses, the DNA-bound BPT molecules were photoionized to BPT •+ radicals by a consecutive two-photon ionization mechanism. The BPT •+ radicals thus generated within the duplexes selectively oxidize guanine by intraduplex electron transfer reactions, and the rate constants of these reactions follow the trend 5′-..GGG.. > 5′-..GG.. > 5′-..G… In the case of CO 3 •− radicals, the oxidation of guanine occurs by intermolecular collision pathways and the bimolecular rate constants are independent of base sequence context. However, the distributions of the end-products generated by CO 3 •− radicals, as well as by BPT •+ , is base sequence context-dependent and is greater than in isolated guanines at the 5′-G in 5′-…GG… sequences, and the first two 5′-guanines in the 5′-..GGG sequences. These results help to clarify the conditions that lead to a similar or different base sequence dependence of the initial hole injection step and the final distribution of oxidized, alkalilabile guanine products. In the case of the intermolecular one-electron oxidant CO 3 •− , the rate constant of hole injection is similar for contiguous and isolated guanines, but the subsequent equilibration of holes by hopping favors trapping and product formation at contiguous guanines, and the sequence dependence of these two phenomena are not correlated. In contrast, in the case of the DNA bound oxidant BPT •+ , the hole injection rate constants, as well as hole equilibration, exhibit a similar dependence on base sequence context, and are thus correlated to one another.

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“…Among all ROS, the hydroxyl radical (•OH) has been found to be the most harmful one (for example, in cell-produced reactions, via the Haber-Weiss reaction), while the hydrogen peroxide (H 2 O 2 ) and superoxide radical (O 2 •─ ) can be recognized as low-active species [5]. In a cell, O 2 •─ formed as a by-product of respiratory cycles, is rapidly converted into oxygen and H 2 O 2 by a superoxide dismutase (SOD) or in a self-dismutation process [6]. Subsequently, catalase converts hydrogen peroxide to a "safe" water molecule [2].…”

Section: Introductionmentioning

confidence: 99%

The influence of the phosphorothioate diester bond on the DNA oxidation process

Karwowski¹

2015

Open Chemistry

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This study describes the influence of the phosphorothioate internucleotide bond on the deoxyribonucleic acid (DNA) oxidation process. The interaction of an ultraviolet radiation (UVA) with a targeted double-stranded (ds) oligonucleotide, in which one strand contains an antraquinone (AQ) moiety on the 5'-end, may lead to a hole migration process through the double helix. In the end, the migration of theformed radical cation terminates in a suitable place. Usually, this is a guanine-rich sequence. In another experiment, phosphorothioate internucleotide bonds were detected in the bacterial genome as a natural modification. In this study, a polyacrylamide gel electrophoresis (PAGE) autoradiogram analysis of irradiated ds-DNA showed that the oxidation reaction was not inhibited by an isolated guanine. Instead, irrespective of the absence or presence of a phosphorothioate bond, the termination of the ds-DNA oxidation process was predominantly observed on the thymine moieties. Based on the obtained results, it can be concluded that in the discussed case, a hole migration by a hopping mechanism is in competition with an oxidation reaction with a superoxide radical anion. Alternatively, the radical cation migration process is sequence-dependent due to its different ionization potentials. Therefore, the presence of a phosphorothioate internucleotide bond did not change the stability of ds-DNA under UVA irradiation conditions.

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Oxidative DNA Damage Associated with Combination of Guanine and Superoxide Radicals and Repair Mechanisms via Radical Trapping

Cited by 210 publications

References 54 publications

Induction of strand breaks in DNA films by low energy electrons and soft X-ray under nitrous oxide atmosphere

Induction of strand breaks in DNA films by low energy electrons and soft X-ray under nitrous oxide atmosphere

Oxidation of Guanine in G, GG, and GGG Sequence Contexts by Aromatic Pyrenyl Radical Cations and Carbonate Radical Anions: Relationship between Kinetics and Distribution of Alkali-Labile Lesions

The influence of the phosphorothioate diester bond on the DNA oxidation process

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