Characterization of Polysulfides, Polysulfanes, and Other Unique Species in the Reaction between GSNO and H2S

Abstract

Glutathione-based products, GSnX, of the reaction of hydrogen sulfide, H2S, S-nitroso glutathione, and GSNO, at varied stoichiometries have been analyzed by liquid chromatography high-resolution mass spectrometry (LC-HRMS) and chemical trapping experiments. A wide variety of glutathione-based species with catenated sulfur chains have been identified including sulfanes (GSSnG), sulfides (GSSnH), and sulfenic acids (GSnOH); sulfinic (GSnO2H) and sulfonic (GSnO3H) acids are also seen in reactions exposed to air. The presence of each species of GSnX within the original reaction mixtures was confirmed using Single Ion Chromatograms (SICs), to demonstrate the separation on the LC column, and given approximate quantification by the peak area of the SIC. Further, confirmation for different GSnX families was obtained by trapping with species-specific reagents. Several unique GSnX families have been characterized, including bridging mixed di- and tetra-valent polysulfanes and internal trithionitrates (GSNHSnH) with polysulfane branches. Competitive trapping experiments suggest that the polysulfane chains are formed via the intermediacy of sulfenic acid species, GSSnOH. In the presence of radical trap vinylcyclopropane (VCP) the relative distributions of polysulfane speciation are relatively unaffected, suggesting that radical coupling is not a dominant pathway. Therefore, we suggest polysulfane catenation occurs via reaction of sulfides with sulfenic acids.

Human Cystathionine γ-Lyase Is Inhibited by s-Nitrosation: A New Crosstalk Mechanism between NO and H2S

“…In this manner, the possible reaction of NO with CSE-generated H 2 S is also prevented, thereby excluding the formation to any significant extent of hybrid H 2 S/NO species that could themselves react with CSE [ 26 ]. Under the tested conditions, given the reactants’ concentrations and ratios and the timescale of the experiments, the possible reaction of H 2 S with GSNO is also unlikely to interfere with the measurements [ 50 , 51 , 52 ]. GSNO 0.5 mM (or buffer in control samples) was added to the reaction mixture and incubated for 30 min.…”

Expanding the Reactive Sulfur Metabolome: Intracellular and Efflux Measurements of Small Oxoacids of Sulfur (SOS) and H2S in Human Primary Vascular Cell Culture

“…The shift of sulfur speciation with a concomitant reduction in mitochondrial respiration emphasizes the role of H 2 S oxidation in mitochondrial function under hypoxia. Oxidized S-species display higher reactivities than H 2 S, both as reductants [ 55 ] and sulfonylating agents [ 49 ]; thus, these species may be important intermediates in processes canonically attributed to H 2 S. Distinguishing which small molecules regulate vascular functions both intracellularly and extracellularly may help clarify the paradoxical effect of a small, simple molecule such as H 2 S having biological specificity and control.…”

“…We and others have proposed that sulfhydration proceeds through the action of small oxoacids of sulfur (SOS) [ 45 ], simple metabolites of H 2 S such as sulfenic and sulfoxylic acids, HSOH and HOSOH, shown in Scheme 1 , analogous to cysteine sulfenic and sulfinic acids [ 46 , 47 ]. Initially, we found that species such as HSOH, HOSOH, and other S-catenated species including polysulfides and polysulfide oxides such as thiosulfenic acids were generated by the oxidation of H 2 S with a variety of different oxidants such as peroxides, metmyoglobin and nitroso-glutathione, all of which can be found endogenously in biological systems [ 48 , 49 ]. These species were observed trapped in situ using the nucleophilic dimedone, DH, and an electrophilic trap iodoacetamide IAM [ 50 ], and then analyzed by liquid chromatography separation and high-definition mass spectrometry, LC HD MS.…”

The Roles of NO and H2S in Sperm Biology: Recent Advances and New Perspectives

“…It seems that GSNO serves as an intracellular storage for NO, which can be released by the reaction with GPX or thioredoxin reductase [59]. GSNO can also release stored NO upon reaction with H 2 S or HS - [135], and can also lead to formation of polysulfane species [136]. In addition, Berenyiova et al [137] proposed that sulfide reaction with GSNO may lead to HNO synthesis.…”