Inactivation of cystathionine β-synthase with peroxynitrite

Celano, Laura; Gil, Magdalena; Carballal, Sebastián; Durán, Rosario; Denicola, Ana; Banerjee, Ruma; Álvarez, Beatriz

doi:10.1016/j.abb.2009.08.022

Cited by 27 publications

(26 citation statements)

References 62 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We demonstrate that glutathionylation of human cystathionine b-synthase under oxidizing conditions increases its activity, thereby supporting increased cysteine synthesis. residues in CBS by peroxynitrite results in alterations in the heme pocket, leading to loss of cysteinate coordination by the heme ligand Cys52 and concomitant inactivation of CBS (5). While a structural role for the heme in stabilizing the CBS structure has been invoked (29), homologous CBSs from lower organisms, for example, yeast, are stable without this cofactor (18).…”

Section: Innovationmentioning

confidence: 99%

S-Glutathionylation Enhances Human Cystathionine β-Synthase Activity Under Oxidative Stress Conditions

Niu

Yadav

Adamec

et al. 2015

Antioxidants & Redox Signaling

Self Cite

View full text Add to dashboard Cite

Aims: Cystathionine b-synthase (CBS) catalyzes the first and rate-limiting step in the two-step trans-sulfuration pathway that converts homocysteine to cysteine. It is also one of three major enzymes responsible for the biogenesis of H 2 S, a signaling molecule. We have previously demonstrated that CBS is activated in cells challenged by oxidative stress, but the underlying molecular mechanism of this regulation has remained unclear. Results: Here, we demonstrate that S-glutathionylation of CBS enhances its activity *2-fold in vitro. Loss of this post-translational modification in the presence of dithiothreitol results in reversal to basal activity. Cys346 was identified as the site for S-glutathionylation by a combination of mass spectrometric, mutagenesis, and activity analyses. To test the physiological relevance of S-glutathionylation-dependent regulation of CBS, HEK293 cells were oxidatively challenged with peroxide, which is known to enhance the trans-sulfuration flux. Under these conditions, CBS glutathionylation levels increased and were correlated with a *3-fold increase in CBS activity. Innovation: Collectively, our results reveal a novel post-translational modification of CBS, that is, glutathionylation, which functions as an allosteric activator under oxidative stress conditions permitting enhanced synthesis of both cysteine and H 2 S. Conclusions: Our study elucidates a molecular mechanism for increased cysteine and therefore glutathione, synthesis via glutathionylation of CBS. They also demonstrate the potential for increased H 2 S production under oxidative stress conditions, particularly in tissues where CBS is a major source of H 2 S. Antioxid. Redox Signal. 22,[350][351][352][353][354][355][356][357][358][359][360][361]

show abstract

Section: Innovationmentioning

confidence: 99%

S-Glutathionylation Enhances Human Cystathionine β-Synthase Activity Under Oxidative Stress Conditions

Niu

Yadav

Adamec

et al. 2015

Antioxidants & Redox Signaling

Self Cite

View full text Add to dashboard Cite

show abstract

“…Neither nitric oxide (21) nor calmodulin (22,23), reported to modulate the activities of CSE and CBS, appears to do so (13,15). 3 Peroxynitrite (24) and carbon monoxide (25) inhibit human CBS.…”

Section: Biogenesis Of H 2 Smentioning

confidence: 99%

Redox Biochemistry of Hydrogen Sulfide

Kabil

Banerjee

2010

Journal of Biological Chemistry

Self Cite

686

526

View full text Add to dashboard Cite

H 2 S, the most recently discovered gasotransmitter, might in fact be the evolutionary matriarch of this family, being both ancient and highly reduced. Disruption of ␥-cystathionase in mice leads to cardiovascular dysfunction and marked hypertension, suggesting a key role for this enzyme in H 2 S production in the vasculature. However, patients with inherited deficiency in ␥-cystathionase apparently do not present vascular pathology. A mitochondrial pathway disposes sulfide and couples it to oxidative phosphorylation while also exposing cytochrome c oxidase to this metabolic poison. This report focuses on the biochemistry of H 2 S biogenesis and clearance, on the molecular mechanisms of its action, and on its varied biological effects.Sulfur cycles through several biologically relevant oxidation states ranging from Ϫ2 as in hydrogen and metal sulfides to ϩ6 in sulfate. H 2 S, a colorless gas with the odor of rotten eggs, is important in the biogeochemical sulfur cycle and is used as an energy source by microbes such as the purple and green sulfur bacteria. It is a weak acid with pK a1 and pK a2 of 6.9 and Ͼ12 (1) and an aqueous solubility of ϳ80 mM at 37°C. Hence, at the physiological pH of 7.4, the ratio of HS Ϫ :H 2 S is 3:1. For brevity, H 2 S is used to refer to the total free sulfide pool (i.e. H 2 S ϩ HS Ϫ ϩ S 2Ϫ ) in this report unless noted otherwise. The ready ionization of H 2 S at physiological pH suggests impeded permeation through the lipid bilayer when compared with other gases, viz. NO or CO. On the other hand, transport of the gas, H 2 S, across the membrane does not appear to be facilitated (2).The toxicity of H 2 S is thought to have influenced evolution. The presence of a metastable H 2 S-enriched oceanic stratum is postulated to have limited early metazoan colonization of the continental shelf (3), and an increase in H 2 S has been implicated in the Permian-Triassic extinction Ͼ250 million years ago (4). However, the reputation of H 2 S as a toxic gas is enjoying a facelift, with increasing numbers of reports that it modulates a range of biological processes. Despite the rising interest in H 2 S biochemistry, fundamental questions regarding regulation of its production, its mechanism of action, and its destruction remain. In addition, perhaps most critical to the field is the issue of what constitutes biologically relevant levels of H 2 S with reports varying over a 10 5 -fold concentration range. Using a gas chromatography-based chemiluminescent sulfur detection method, free H 2 S (H 2 S ϩ HS Ϫ ) in blood was estimated to be ϳ100 pM, and in tissues, it was estimated to be ϳ15 nM (5). These values are considerably lower than the ϳ30 -300 M concentrations reported in a spate of recent studies (reviewed in Ref. 6). The high values can be ascribed to technical artifacts introduced by long processing times and harsh (either acidic or alkaline) conditions used to shift the equilibrium toward H 2 S or S 2Ϫ , respectively. Under these conditions, sulfide leaches from iron-sulfur cluster-containing p...

show abstract

“…The N-terminal domain binds the heme cofactor, which seems to function as a redox sensor (13) that inhibits CBS activity by means of binding of CO or NO (14)(15)(16)(17) or during reduction of nitrite (18,19). Nitration of tryptophan residues in CBS results in alterations of the heme pocket, which lead to the loss of cysteinate coordination by the ligand Cys52 and concomitant inactivation of CBS (20). Additionally, a structural role for the heme in the proper folding of CBS has been described (21).…”

Section: Introductionmentioning

confidence: 99%

Allosteric control of human cystathionine β-synthase activity by a redox active disulfide bond

Niu¹,

Wang²,

Qian

et al. 2018

Journal of Biological Chemistry

View full text Add to dashboard Cite

Cystathionine β-synthase (CBS) is the central enzyme in the trans-sulfuration pathway that converts homocysteine to cysteine. It is also one of the three major enzymes involved in the biogenesis of H 2 S. CBS is a complex protein with a modular three-domain architecture, the central domain of which contains a C 272 XXC 275 motif whose function has yet to be determined. In the present study, we demonstrated that the CXXC motif exists in oxidized and reduced states in the recombinant enzyme by mass spectroscopic analysis and a thiol labeling assay. The activity of reduced CBS is ~2-to 3-fold greater than that of the oxidized enzyme, and substitution of either cysteine in CXXC motif leads to a loss of redox sensitivity. The Cys 272 -Cys 275 disulfide bond in CBS has a midpoint potential of -314 mV at pH 7.4. Additionally, the CXXC motif also exists in oxidized and reduced states in human embryonic kidney 293 (HEK293) cells under oxidative and reductive conditions, and stressing these cells with dithiothreitol (DTT) results in more reduced enzyme and a concomitant increase in H 2 S production in live HEK293 cells as determined using a H 2 S fluorescent probe. By contrast, incubation of cells with aminooxyacetic acid (AOAA), an inhibitor of CBS and cystathionine γ-lyase (CSE), eliminates the increase of H 2 S production after the cells were exposed to DTT. These findings indicate that CBS is post-translationally regulated by a redox-active disulfide bond in the CXXC motif. The results als o demonstrate that CBS-derived H 2 S production is increased in cells under reductive stress conditions.

show abstract

Inactivation of cystathionine β-synthase with peroxynitrite

Cited by 27 publications

References 62 publications

S-Glutathionylation Enhances Human Cystathionine β-Synthase Activity Under Oxidative Stress Conditions

S-Glutathionylation Enhances Human Cystathionine β-Synthase Activity Under Oxidative Stress Conditions

Redox Biochemistry of Hydrogen Sulfide

Allosteric control of human cystathionine β-synthase activity by a redox active disulfide bond

Contact Info

Product

Resources

About