S-sulfhydration as a cellular redox regulation (original) (raw)

Biological hydropersulfides and related polysulfides - a new concept and perspective in redox biology

FEBS letters, 2018

The chemical biology of thiols (RSH, e.g., cysteine and cysteine-containing proteins/peptides) has been a topic of extreme interest for many decades due to their reported roles in protein structure/folding, redox signaling, metal ligation, cellular protection, and enzymology. While many of the studies on thiol/sulfur biochemistry have focused on thiols, relatively ignored have been hydropersulfides (RSSH) and higher order polysulfur species (RSS H, RSS R, n > 1). Recent and provocative work has alluded to the prevalence and likely physiological importance of RSSH and related RSS H. RSSH of cysteine (Cys-SSH) has been found to be prevalent in mammalian systems along with Cys-SSH-containing proteins. The RSSH functionality has not been examined to the extent of other biologically relevant sulfur derivatives (e.g., sulfenic acids, disulfides, etc.), whose roles in cell signaling are strongly indicated. The recent finding of Cys-SSH biosynthesis and translational incorporation into p...

Redox chemistry and chemical biology of H2S, hydropersulfides, and derived species: Implications of their possible biological activity and utility

Free Radical Biology and Medicine, 2014

Hydrogen sulfide (H 2 S) is an endogenously generated and putative signaling/effector molecule. Despite its numerous reported functions, the chemistry by which it elicits its functions is not understood. Moreover, recent studies allude to the existence of other sulfur species besides H 2 S that may play critical physiological roles. Herein, the basic chemical biology of H 2 S as well as other related or derived species is discussed and reviewed. This review particularly focuses on the per-and polysulfides which are likely in equilibrium with free H 2 S and which may be important biological effectors themselves.

The Redox Biochemistry of Protein Sulfenylation and Sulfinylation

Journal of Biological Chemistry, 2013

Controlled generation of reactive oxygen species orchestrates numerous physiological signaling events (Finkel, T. (2011) Signal transduction by reactive oxygen species. J. Cell Biol. 194, 7-15). A major cellular target of reactive oxygen species is the thiol side chain (RSH) of Cys, which may assume a wide range of oxidation states (i.e. ؊2 to ؉4). Within this context, Cys sulfenic (Cys-SOH) and sulfinic (Cys-SO 2 H) acids have emerged as important mechanisms for regulation of protein function. Although this area has been under investigation for over a decade, the scope and biological role of sulfenic/sulfinic acid modifications have been recently expanded with the introduction of new tools for monitoring cysteine oxidation in vitro and directly in cells. This minireview discusses selected recent examples of protein sulfenylation and sulfinylation from the literature, highlighting the role of these post-translational modifications in cell signaling.

Biogenesis of reactive sulfur species for signaling by hydrogen sulfide oxidation pathways

Nature chemical biology, 2015

The chemical species involved in H2S signaling remain elusive despite the profound and pleiotropic physiological effects elicited by this molecule. The dominant candidate mechanism for sulfide signaling is persulfidation of target proteins. However, the relatively poor reactivity of H2S toward oxidized thiols, such as disulfides, the low concentration of disulfides in the reducing milieu of the cell and the low steady-state concentration of H2S raise questions about the plausibility of persulfide formation via reaction between an oxidized thiol and a sulfide anion or a reduced thiol and oxidized hydrogen disulfide. In contrast, sulfide oxidation pathways, considered to be primarily mechanisms for disposing of excess sulfide, generate a series of reactive sulfur species, including persulfides, polysulfides and thiosulfate, that could modify target proteins. We posit that sulfide oxidation pathways mediate sulfide signaling and that sulfurtransferases ensure target specificity.

Thiosulfoxide (sulfane) sulfur: new chemistry and new regulatory roles in biology

Molecules (Basel, Switzerland), 2014

The understanding of sulfur bonding is undergoing change. Old theories on hypervalency of sulfur and the nature of the chalcogen-chalcogen bond are now questioned. At the same time, there is a rapidly expanding literature on the effects of sulfur in regulating biological systems. The two fields are inter-related because the new understanding of the thiosulfoxide bond helps to explain the newfound roles of sulfur in biology. This review examines the nature of thiosulfoxide (sulfane, S0) sulfur, the history of its regulatory role, its generation in biological systems, and its functions in cells. The functions include synthesis of cofactors (molybdenum cofactor, iron-sulfur clusters), sulfuration of tRNA, modulation of enzyme activities, and regulating the redox environment by several mechanisms (including the enhancement of the reductive capacity of glutathione). A brief review of the analogous form of selenium suggests that the toxicity of selenium may be due to over-reduction caused...

Protein-Sulfenic Acids: Diverse Roles for an Unlikely Player in Enzyme Catalysis and Redox Regulation

Biochemistry, 1999

While it has been known for more than 20 years that unusually stable cysteine-sulfenic acid (Cys-SOH) derivatives can be introduced in selected proteins by mild oxidation, only recently have chemical and crystallographic evidence for functional Cys-SOH been presented with native proteins such as NADH peroxidase and NADH oxidase, nitrile hydratase, and the hORF6 and AhpC peroxiredoxins. In addition, Cys-SOH forms of protein tyrosine phosphatases and glutathione reductase have been suggested to play key roles in the reversible inhibition of these enzymes during tyrosine phosphorylation-dependent signal transduction events and nitrosative stress, respectively. Substantial chemical data have also been presented which implicate Cys-SOH in redox regulation of transcription factors such as Fos and Jun (activator protein-1) and bovine papillomavirus-1 E2 protein. Functionally, the Cys-SOHs in NADH peroxidase, NADH oxidase, and the peroxiredoxins serve as either catalytically essential redox centers or transient intermediates during peroxide reduction. In nitrile hydratase, the active-site Cys-SOH functions in both iron coordination and NO binding but does not play any catalytic redox role. In Fos and Jun and the E2 protein, on the other hand, a key Cys-SH serves as a sensor for intracellular redox status; reversible oxidation to Cys-SOH as proposed inhibits the corresponding DNA binding activity. These functional Cys-SOHs have roles in diverse cellular processes, including signal transduction, oxygen metabolism and the oxidative stress response, and transcriptional regulation, as well as in the industrial production of acrylamide, and their detailed analyses are beginning to provide the chemical foundation necessary for understanding protein-SOH stabilization and function. †

Effects of sulfite on glutathione S-sulfonate and the glutathione status of lung cells

Chemico-Biological Interactions, 1989

A mechanistic study was performed to elucidate the biochemical events connected with the cocarcinogenic effect of sulfur dioxide (S02). Glutathione S-sulfonate (GSS03H), a competitive inhibitor of the glutathione S-transferases, forms in lung cells exposed in culture to sulfite, the hydrated form of S02. Changes in glutathione status (total GSH) were also observed during a 1-h exposure. Some cells were pretreated with 1,3-bis(2-chloroethyl)-l-nitrosourea (BCNU) to inhibit glutathione reductase. In human lung cells GSSO3H formed in a concentration-dependent manner, while glutathione (GSH) increased and glutathione disulfide (GSSG) decreased as the extraceUular sulfite concentration was increased from 0 to 20 raM. The ratio of GSH/ GSSG increased greater than 5-fold and the GSH/GSSO3H ratio decreased to 10 with increasing sulfite concentration. GSSO3H formed in rat lung cells exposed to sulfite, with no detectable effect on GSH and GSSG. GSSOsH also formed from cellular GSH mixed disulfides. GSSO3H formed rapidly, reaching its maximum value in 15 min. The viability of both cell types was unaffected except at 20 mM sulfite. GSSO3H incubated with human lung cells did not affect cellular viability. BCNU inhibited cellular GSSO3H reductase to the same extent as GSSG reductase. These results indicate that GSSO3H is formed in cells exposed to sulfite, and could be the active metabolite of sulfite responsible for the cocarcinogenic effect of SO 2 by inhibiting conjugation of electrophiles by GSH.

Biochemical basis of sulphenomics: how protein sulphenic acids may be stabilized by the protein microenvironment

Plant, Cell & Environment, 2016

Among protein residues, cysteines are one of the prominent candidates to ROS-mediated and RNS-mediated posttranslational modifications, and hydrogen peroxide (H 2 O 2) is the main ROS candidate for inducing cysteine oxidation. The reaction with H 2 O 2 is not common to all cysteine residues, being their reactivity an utmost prerequisite for the sensitivity towards H 2 O 2. Indeed, only deprotonated Cys (i.e. thiolate form,-S À) can react with H 2 O 2 leading to sulphenic acid formation (-SOH), which is considered as a major/central player of ROS sensing pathways. However, cysteine sulphenic acids are generally unstable because they can be further oxidized to irreversible forms (sulphinic and sulphonic acids,-SO 2 H and-SO 3 H, respectively), or alternatively, they can proceed towards further modifications including disulphide bond formation (-SS-), S-glutathionylation (-SSG) and sulphenamide formation (-SN¼). To understand why and how cysteine residues undergo primary oxidation to sulphenic acid, and to explore the stability of cysteine sulphenic acids, a combination of biochemical, structural and computational studies are required. Here, we will discuss the current knowledge of the structural determinants for cysteine reactivity and sulphenic acid stability within protein microenvironments.

Synthesis of Sulfides and Persulfides Is Not Impeded by Disruption of Three Canonical Enzymes in Sulfur Metabolism

Antioxidants

Reactive sulfur species, or persulfides and polysulfides, such as cysteine hydropersulfide and glutathione persulfide, are endogenously produced in abundance in both prokaryotes and eukaryotes, including mammals. Various forms of reactive persulfides occur in both low-molecular-weight and protein-bound thiols. The chemical properties and great supply of these molecular species suggest a pivotal role for reactive persulfides/polysulfides in different cellular regulatory processes (e.g., energy metabolism and redox signaling). We demonstrated earlier that cysteinyl-tRNA synthetase (CARS) is a new cysteine persulfide synthase (CPERS) and is responsible for the in vivo production of most reactive persulfides (polysulfides). Some researchers continue to suggest that 3-mercaptopyruvate sulfurtransferase (3-MST), cystathionine β-synthase (CBS), and cystathionine γ-lyase (CSE) may also produce hydrogen sulfide and persulfides that may be generated during the transfer of sulfur from 3-mercap...

Protein Radical Formation Resulting from Eosinophil Peroxidase-catalyzed Oxidation of Sulfite

Journal of Biological Chemistry, 2010

Eosinophil peroxidase (EPO) is an abundant heme protein in eosinophils that catalyzes the formation of cytotoxic oxidants implicated in asthma, allergic inflammatory disorders, and cancer. It is known that some proteins with peroxidase activity (horseradish peroxidase and prostaglandin hydroperoxidase) can catalyze oxidation of bisulfite (hydrated sulfur dioxide), leading to the formation of sulfur trioxide anion radical ( ⅐ SO 3 ؊ ). This free radical further reacts with oxygen to form peroxymonosulfate anion radical ( ؊ O 3 SOO ⅐ ) and the very reactive sulfate anion radical (SO 4 . ),