One- and two-electron oxidation of reduced glutathione by peroxidases.

Harman, Laura S.; Carver, D K; Schreiber, Jörg; Mason, Ronald P.

doi:10.1016/s0021-9258(17)35988-4

Cited by 156 publications

(22 citation statements)

References 29 publications

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“…However, the slight difference between the spectrum of Figure 6e and the spectrum of Figure 6a suggests the possible formation of a low amount of glutathione-DMPO adduct. The hyperfine coupling constants of glutathione-DMPO (as -15.4 G and au -16.2 G; Harman et al, 1986) are similar to those of L-cysteine-DMPO. The formation of the glutathione-DMPO adduct is suggested by the partial overlap of central lines.…”

Section: Resultsmentioning

confidence: 62%

Role of thiols in the targeting of S-nitroso thiols to red blood cells

Pietraforte

Mallozzi²,

Scorza³

et al. 1995

Biochemistry

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We compared the nitric oxide (.NO)-releasing characteristics of two NO donors, the S-nitroso adduct of bovine serum albumin (BSANO) and the S-nitroso adduct of L-glutathione (GSNO). In oxygenated phosphate buffer (pH 7.4) and in hemoglobin solution, both NO donors released .NO only in the presence of a low molecular weight thiol (the most active was L-cysteine). The requirement of thiol to release .NO strongly suggests that a transnitrosation reaction occurs between the S-nitroso adduct of the NO donor and the sulfhydryl group of the NO acceptor. The reaction produced a labile S-nitroso-L-cysteine intermediate that released .NO. As shown by spin-trapping experiments, the transnitrosation reaction involved the formation of .NO (trapped by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide) and .S radicals (trapped by 5,5'-dimethyl-1-pyrroline N-oxide) of both the NO donors and the NO acceptor (L-cysteine). The reaction leading to .S radical formation was distinct from the transnitrosation reaction, since it was oxygen-dependent. We suggest that .S radicals are formed from oxidizing species produced after a reaction between .NO and molecular oxygen (.NO2 is a likely candidate). As for pure .NO gas, the major oxidation product of NO donors, in phosphate buffer (pH 7.4), was NO2-, with no formation of NO3-. In the presence of oxyhemoglobin, both NO donors produced only NO3-. BSANO and GSNO showed distinct patterns of .NO release both in phosphate buffer and in the presence of hemoglobin.(ABSTRACT TRUNCATED AT 250 WORDS)

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Section: Resultsmentioning

confidence: 62%

Role of thiols in the targeting of S-nitroso thiols to red blood cells

Pietraforte

Mallozzi²,

Scorza³

et al. 1995

Biochemistry

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“…When the preincubated mixture (2 min) of glutathione and hydrogen peroxide was assayed for glutathione concentration according to Ellman's assay (20), the results clearly showed that reaction of glutathione with hydrogen peroxide was rapid, leading to less availability of hydrogen peroxide and glutathione for reaction with chromium(VI). The reaction of glutathione with hydrogen peroxide is of biological significance, providing a pathway for the detoxification of peroxides by glutathione, and is catalyzed by peroxidases (22), leading to formation of oxidized glutathione and water. This reaction has also been shown to occur to a significant extent (~80%) within 2 min of incubation of 250 mM glutathione with equimolar hydrogen peroxide at pH 7.6 in the absence of peroxidases or other catalysts (23).…”

Section: Discussionmentioning

confidence: 99%

Reaction of chromium(VI) with hydrogen peroxide in the presence of glutathione: reactive intermediates and resulting DNA damage

Aiyar¹,

Berkovits²,

Floyd³

et al. 1990

Chem. Res. Toxicol.

114

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The reaction of chromium(VI) with hydrogen peroxide was studied in the presence of glutathione. In vitro, reaction of chromium(VI) with hydrogen peroxide alone led to production of hydroxyl radical as the significant reactive intermediate, while reaction of chromium(VI) with glutathione led to formation of two chromium(V)-glutathione complexes and the glutathione thiyl radical. Incubation of chromium(VI) with glutathione prior to addition of hydrogen peroxide led to formation of peroxochromium(V) species and a dramatic increase in hydroxyl radical production over that detected in the reaction of chromium(VI) with hydrogen peroxide alone. In contrast, addition of chromium(VI) to a preincubated mixture of glutathione and hydrogen peroxide led to a decrease in hydroxyl radical production over that obtained in the reaction of chromium(VI) with hydrogen peroxide. When pBR322 DNA was added to the above reactions, the extent of chromium(VI)-induced DNA strand breakage correlated with the relative amount of hydroxyl radical formed. Reaction of chromium(VI) with calf thymus DNA in the presence of a preincubated mixture of glutathione and hydrogen peroxide led to detection of the 8-hydroxydeoxyguanosine adduct, whose formation correlated with that of hydroxyl radical production. No significant chromium-DNA adduct formation was detected. The results suggest that, in the cellular metabolism of chromium(VI), preformed chromium(V)-glutathione complexes may react with hydrogen peroxide in a Fenton-type manner to produce hydroxyl radical as the DNA-damaging agent. However, if glutathione reacts with hydrogen peroxide prior to exposure to chromium(VI), the amount of hydroxyl radical generated may not be sufficient to cause significant DNA damage.(ABSTRACT TRUNCATED AT 250 WORDS)

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“…In this study we have investigated the role of the Forrester–Hepburn mechanism in ESR spin-trapping experiments using horseradish peroxidase/H 2 O 2 with the method suggested by Timmins et al In addition to sodium sulfite, we reinvestigated several other good nucleophiles known to form free radicals that may play a role in biochemistry and toxicology, i.e., cyanide, l -cysteine, and glutathione …”

Section: Introductionmentioning

confidence: 99%

Evaluation of the Forrester–Hepburn Mechanism As an Artifact Source in ESR Spin-Trapping

Leinisch

Ranguelova

DeRose

et al. 2011

Chem. Res. Toxicol.

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Nitrone spin traps such as 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) are commonly used for free radical detection. Though proven examples are rare, artifact formation must be considered. For example, the Forrester-Hepburn mechanism yields the same radical adduct as formed by genuine radical trapping. A hydroxylamine is formed by nucleophilic attack of the substrate to DMPO and subsequently oxidized to the respective nitroxide radical. One potential candidate for this artifact is the sulfur trioxide radical adduct (DMPO/·SO3−), as detected in spin-trapping experiments with horseradish peroxidase and sulfite. It has previously been shown by NMR experiments that the hydroxylamine intermediate does indeed form, but no direct proof for the ESR artifact has been provided. Here we used isotopically labeled DMPO with horseradish peroxidase and ferricyanide to test for the Forrester-Hepburn artifact directly in a spin-trapping experiment. Besides sulfite, we investigated other nucleophiles such as cyanide, cysteine and glutathione. Neither sulfite nor biological thiols produced detectable spin-trapping artifacts, but with cyanide the relatively weak signal originated almost entirely from the nucleophilic reaction. The hydroxylamine intermediate, which is more abundant with cyanide than with sulfite, was identified as cyano-hydroxylamine by means of 2D NMR experiments. Although our study found that spin trapping provided authentic free radical signals with most of the substrates, the occurrence of the Forrester Hepburn mechanism artifact with cyanide emphasizes the importance of isotope measurements with nucleophile substrates.

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One- and two-electron oxidation of reduced glutathione by peroxidases.

Cited by 156 publications

References 29 publications

Role of thiols in the targeting of S-nitroso thiols to red blood cells

Role of thiols in the targeting of S-nitroso thiols to red blood cells

Reaction of chromium(VI) with hydrogen peroxide in the presence of glutathione: reactive intermediates and resulting DNA damage

Evaluation of the Forrester–Hepburn Mechanism As an Artifact Source in ESR Spin-Trapping

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