Homolysis of the Peroxynitrite Anion Detected with Permanganate

Sturzbecher, Manuel; Kissner, Reinhard; Nauser, Thomas; Koppenol, Willem H.

doi:10.1021/ic7013978

Cited by 14 publications

(30 citation statements)

References 34 publications

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“…Permanganate is the oxidant capable of eliminating both peroxynitrite and NO 2 in close to neutral conditions [E′ o 1.7 v for MnO − 4 /MnO 2 (Standard electrode potential data)]. It has been previously used for a chemical titration of the peroxynitrite solutions (Sturzbecher et al, 2007). We incubated dSterne Sups with a range of potassium permanganate concentrations for 1 h and found a strong protection of HSAECs from Sup toxicity at >0.1 mM KMnO 4 (Figure 11).…”

Section: Resultsmentioning

confidence: 99%

Bacillus anthracis co-opts nitric oxide and host serum albumin for pathogenicity in hypoxic conditions

John¹,

Blower²,

Popova³

et al. 2013

Front. Cell. Infect. Microbiol.

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Bacillus anthracis is a dangerous pathogen of humans and many animal species. Its virulence has been mainly attributed to the production of Lethal and Edema toxins as well as the antiphagocytic capsule. Recent data indicate that the nitric oxide (NO) synthase (baNOS) plays an important pathogenic role at the early stage of disease by protecting bacteria from the host reactive species and S-nytrosylating the mitochondrial proteins in macrophages. In this study we for the first time present evidence that bacteria-derived NO participates in the generation of highly reactive oxidizing species which could be abolished by the NOS inhibitor L - NAME, free thiols, and superoxide dismutase but not catalase. The formation of toxicants is likely a result of the simultaneous formation of NO and superoxide leading to a labile peroxynitrite and its stable decomposition product, nitrogen dioxide. The toxicity of bacteria could be potentiated in the presence of bovine serum albumin. This effect is consistent with the property of serum albumin to serves as a trap of a volatile NO accelerating its reactions. Our data suggest that during infection in the hypoxic environment of pre-mortal host the accumulated NO is expected to have a broad toxic impact on host cell functions.

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Section: Resultsmentioning

confidence: 99%

Bacillus anthracis co-opts nitric oxide and host serum albumin for pathogenicity in hypoxic conditions

John¹,

Blower²,

Popova³

et al. 2013

Front. Cell. Infect. Microbiol.

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“…, [35][36][37][38] and the electrode potential thought to correspond to E8(ONOOC/ONOO À ), + 0.51 V, [14] to give D f G8A C H T U N G T R E N N U N G (ONOOC aq ) = + + 117 kJ mol À1 ; the uncertainty in this estimate may be as high as 10 kJ mol By…”

Section: Kinetics Data Analysismentioning

confidence: 97%

“…Estimates of Gibbs energies of formation of ONOOC and NO 3 C: The Gibbs energy of formation of ONOOC is calculated from the Gibbs energy of formation of peroxynitrite, [35][36][37][38] and the electrode potential thought to correspond to E8(ONOOC/ONOO À ), + 0.51 V, [14] to give D f G8A C H T U N G T R E N N U N G (ONOOC aq ) = + + 117 kJ mol À1 ; the uncertainty in this estimate may be as high as 10 kJ mol À1 . With an estimated Gibbs hydration energy of + 15 kJ mol À1 -similar to that of NOC-D f G8A C H T U N G T R E N N U N G (ONOOC g ) = + 102 kJ mol À1 .…”

Section: Kinetics Data Analysismentioning

confidence: 99%

Intermediates in the Autoxidation of Nitrogen Monoxide

Galliker

Kissner

Nauser

et al. 2009

Chemistry A European J

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We have identified two intermediates in the autoxidation of NO*: ONOO*, which was detected by EPR spectroscopy at 295 K and atmospheric pressure in the gas phase, and ONOONO, a red substance produced at 113 K in 2-methylbutane. The red compound is diamagnetic and absorbs maximally at 500 nm. The ONOONO intermediate is unstable above the melting point of 2-methylbutane and rapidly converts to O2NNO2. From the semiquantitative determination of mole fractions present in the gas phase by EPR spectroscopy, we estimated the rate constants for the steps that lead to ONOO* and ONOONO, from the known overall rate constant of the autoxidation reaction, by assuming that a quasi-stationary mechanism applies. The rate constant for the rate-determining formation of ONOO* is about 3.1 x 10(-18) cm3 molecule(-1) s(-1) (or 80 s(-1) in mole fractions), the dissociation rate constant of ONOO* is about 6.5 x 10(3) s(-1), and ONOONO is formed with a rate constant of k=7.7 x 10(-14) cm3 molecule(-1) s(-1) (1.9 x 10(6) s(-1) in mole fractions). From these constants, we estimate that the equilibrium constant for the formation of ONOO* from NO* and O2 (K(ONOO*)) is 4.8 x 10(-22) cm3 molecule(-1) (1.2 x 10(-2)), and, therefore, DeltaG=+11.0 kJ mol(-1). In water, the Gibbs energy change is close to zero. The presence of ONOO* at steady-state concentrations under dioxygen excess may be important not only for reactions in the atmosphere, but especially for reactions in aerosols and biological environments, because the rate constant for formation in solution is higher than that in the gas phase, and, therefore, the half-life of ONOO* is longer.

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“…Now there are several possibilities in theory, but none of them is practical: Dissociation of ONOO – could yield the necessary NO • , but this reaction is slow, 0.02 s –1 . 34 More likely is protonation of ONOO – to yield ONOOH, which oxidizes or nitrates other molecules in the vicinity. Formation of RSNO with a second NO • is kinetically unlikely.…”

Section: Nitrosation By N2o3mentioning

confidence: 99%

Nitrosation, Thiols, and Hemoglobin: Energetics and Kinetics

Koppenol

2012

Inorg. Chem.

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Nitrosothiols are powerful vasodilators. Although the mechanism of their formation near neutral pH is an area of intense research, neither the energetics nor the kinetics of this reaction or of subsequent reactions have been addressed. The following considerations may help to guide experiments. (1) The standard Gibbs energy for the homolysis reaction RSNO → RS• + NO•(aq) is +110 ± 5 kJ mol–1. (2) The electrode potential of the RSNO, H+/RSH, NO•(aq) couple is −0.20 ± 0.06 V at pH 7. (3) Thiol nitrosation by NO2– is favorable by 37 ± 5 kJ mol–1 at pH 7. (4) N2O3 is not involved in in vivo nitrosation mechanisms for thermodynamic — its formation from NO2– costs 59 kJ mol–1 — or kinetic — the reaction being second-order in NO2– — reasons. (5) Hemoglobin (Hb) cannot catalyze formation of N2O3, be it via the intermediacy of the reaction of Hb[FeNO2]2+ with NO• (+81 kJ mol–1) or reaction of Hb[FeNO]3+ with NO2– (+88 kJ mol–1). (6) Energetically and kinetically viable are nitrosations that involve HNO2 or NO• in the presence of an electron acceptor with an electrode potential higher than −0.20 V. These considerations are derived from existing thermochemical and kinetics data.

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Homolysis of the Peroxynitrite Anion Detected with Permanganate

Cited by 14 publications

References 34 publications

Bacillus anthracis co-opts nitric oxide and host serum albumin for pathogenicity in hypoxic conditions

Bacillus anthracis co-opts nitric oxide and host serum albumin for pathogenicity in hypoxic conditions

Intermediates in the Autoxidation of Nitrogen Monoxide

Nitrosation, Thiols, and Hemoglobin: Energetics and Kinetics

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