Comprehensive analysis of how experimental parameters affect H2S measurements by the monobromobimane method

Ditrói, Tamás; Nagy, Attila; Martinelli, Diego; Rosta, András; Kožich, Viktor; Nagy, Péter

doi:10.1016/j.freeradbiomed.2019.04.006

Cited by 47 publications

(41 citation statements)

References 42 publications

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“…The peak at m/z 339.1 could correspond to the protonated homolysis product GSS • . Fragments of m/z 192 were assigned to the bimane protonated radical as previously observed(7,30,36).…”

mentioning

confidence: 64%

“…To measure accurate concentrations, the derivatization step must be faster than the interconversion of species (30). Since reaction rates are the products of rate constants and concentrations, it can be calculated that labeling was ≥ 100-fold faster than interconversion in our conditions (3,30,(35)(36)(37)(38). Indeed, the detected concentrations of GSH and GSSH were independent of the amount of mBrB applied ( Figure S1).…”

Section: Quantification Of Gsshmentioning

confidence: 99%

“…The contributions of GSH and H2S to the fluorescence change were calculated from the known rate constants, initial concentrations, and pKa values, and found to be negligible (e.g. 0.015 and 0.007 %, respectively, of the contribution of GSSH at pH 6) (30,(35)(36)(37)(38).…”

Section: Acidity Of Gssh and Kinetics Of The Reaction With Mbrbmentioning

confidence: 99%

“…The fluorescence increases were biphasic and exponential plus straight line functions were fitted. The fast exponential phase was attributed to the reaction of mBrB with GSSH, while the slow linear phase was attributed to the reaction with GSH and, secondarily, with H2S, based on controls and on the rate constants for GSH and H2S ( Figure 3B) (30,(35)(36)(37)(38). Moreover, the amplitude was consistent with independent HPLC determinations of GSS-B, assuming similar fluorescence quantum yield as GS-B.…”

Section: Acidity Of Gssh and Kinetics Of The Reaction With Mbrbmentioning

confidence: 99%

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Acidity and nucleophilic reactivity of glutathione persulfide

Benchoam

Semelak

Cuevasanta

et al. 2020

Journal of Biological Chemistry

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Persulfides (RSSH/RSS-) participate in sulfur trafficking and metabolic processes, and are proposed to mediate the signaling effects of H2S. Despite their growing relevance, their chemical properties are poorly understood. Herein, we studied experimentally and computationally the formation, acidity, and nucleophilicity of glutathione persulfide (GSSH/GSS-), the derivative of the abundant cellular thiol, glutathione (GSH). We characterized the kinetics and equilibrium of GSSH formation from glutathione disulfide and H2S. A pKa of 5.45 for GSSH was determined, which is 3.49 units below that of GSH. The reactions of GSSH with the physiologically-relevant electrophiles peroxynitrite and hydrogen peroxide, as well as with the probe monobromobimane, were studied and compared with those of thiols. These reactions occurred through SN2 mechanisms. At neutral pH, GSSH reacted faster than GSH due to increased availability of the anion and, depending on the electrophile, increased reactivity. In addition, GSS- presented higher nucleophilicity with respect to a thiolate with similar basicity. This can be interpreted in terms of the so-called alpha effect, i.e. the increased reactivity of a nucleophile when the atom adjacent to the nucleophilic atom has high electron density. The magnitude of the alpha effect correlated with the Brønsted nucleophilic factor, βnuc, for the reactions with thiolates and with the ability of the leaving group. Our study constitutes the first determination of the pKa of a biological persulfide and the first examination of the alpha effect in sulfur nucleophiles, and sheds light on the chemical basis of the biological properties of persulfides.

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“…The peak at m/z 339.1 could correspond to the protonated homolysis product GSS • . Fragments of m/z 192 were assigned to the bimane protonated radical as previously observed(7,30,36).…”

mentioning

confidence: 64%

Section: Quantification Of Gsshmentioning

confidence: 99%

Section: Acidity Of Gssh and Kinetics Of The Reaction With Mbrbmentioning

confidence: 99%

Section: Acidity Of Gssh and Kinetics Of The Reaction With Mbrbmentioning

confidence: 99%

See 2 more Smart Citations

Acidity and nucleophilic reactivity of glutathione persulfide

Benchoam

Semelak

Cuevasanta

et al. 2020

Journal of Biological Chemistry

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“…6D) (17,20,47,53,96). It was recently shown that quantitation of H 2 S by MBB is sensitive to small variations in pH, alkylation time, and temperature, thus emphasizing the importance of controlling reaction conditions when comparing samples (174). Bogdandi and co-workers (175) also showed that the electrophilicity of the alkylating agent also impacts quantitation of RSS to varying degrees.…”

Section: Quantification Of H 2 S/rss In Cell Lysatesmentioning

confidence: 99%

H2S and reactive sulfur signaling at the host-bacterial pathogen interface

Walsh

Giedroc

2020

Journal of Biological Chemistry

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Bacterial pathogens that cause invasive disease in the vertebrate host must adapt to host efforts to cripple their viability. Major host insults are reactive oxygen and reactive nitrogen species as well as cellular stress induced by antibiotics. Hydrogen sulfide (H2S) is emerging as an important player in cytoprotection against these stressors, which may well be attributed to downstream more oxidized sulfur species termed reactive sulfur species (RSS). In this review, we summarize recent work that suggests that H2S/RSS impacts bacterial survival in infected cells and animals. We discuss the mechanisms of biogenesis and clearance of RSS in the context of a bacterial H2S/RSS homeostasis model, and the bacterial transcriptional regulatory proteins that act as “sensors” of cellular RSS that maintain H2S/RSS homeostasis. In addition, we cover fluorescence imaging- and mass spectrometry-based approaches used to detect and quantify RSS in bacterial cells. Lastly, we discuss proteome persulfidation (S-sulfuration) as potential mediators of H2S/RSS signaling in bacteria in the context of the writer-reader-eraser paradigm, and progress toward ascribing regulatory significance to this widespread post-translational modification.

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