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1.
Nat Rev Mol Cell Biol ; 13(8): 499-507, 2012 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-22781905

RESUMEN

Hydrogen sulfide (H(2)S) has recently emerged as a mammalian gaseous messenger molecule, akin to nitric oxide and carbon monoxide. H(2)S is predominantly formed from Cys or its derivatives by the enzymes cystathionine ß-synthase and cystathionine γ-lyase. One of the mechanisms by which H(2)S signals is by sulfhydration of reactive Cys residues in target proteins. Although analogous to protein nitrosylation, sulfhydration is substantially more prevalent and usually increases the catalytic activity of targeted proteins. Physiological actions of sulfhydration include the regulation of inflammation and endoplasmic reticulum stress signalling as well as of vascular tension.


Asunto(s)
Cistationina betasintasa/metabolismo , Cistationina gamma-Liasa/metabolismo , Cisteína , Sulfuro de Hidrógeno/metabolismo , Proteínas , Animales , Cistationina betasintasa/química , Cistationina gamma-Liasa/química , Cisteína/química , Cisteína/metabolismo , Estrés del Retículo Endoplásmico/fisiología , Gases/química , Gases/metabolismo , Humanos , Sulfuro de Hidrógeno/química , Inflamación/metabolismo , Proteínas/química , Proteínas/metabolismo , Transducción de Señal , Vasodilatación/fisiología
2.
Biosci Biotechnol Biochem ; 86(11): 1536-1542, 2022 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-36085174

RESUMEN

Various d-amino acids play important physiological roles in mammals, but the pathways of their production remain unknown except for d-serine, which is generated by serine racemase. Previously, we found that Escherichia coli cystathionine ß-lyase possesses amino acid racemase activity in addition to ß-lyase activity. In the present work, we evaluated the enzymatic activities of human cystathionine γ-lyase, which shares a relatively high amino acid sequence identity with cystathionine ß-lyase. The enzyme did not show racemase activity toward various amino acids including alanine and lyase and dehydratase activities were highest toward l-cystathionine and l-homoserine, respectively. The enzyme also showed weak activity toward l-cysteine and l-serine but no activity toward d-amino acids. Intriguingly, the pH and temperature profiles of lyase activity were distinct from those of dehydratase activity. Catalytic efficiency was higher for lyase activity than for dehydratase activity.


Asunto(s)
Isomerasas de Aminoácido , Liasas , Humanos , Animales , Cistationina gamma-Liasa/química , Cistationina gamma-Liasa/metabolismo , Aminoácidos , Cistationina , Cisteína , Homoserina , Liasas/metabolismo , Escherichia coli/metabolismo , Serina , Racemasas y Epimerasas , Alanina , Hidroliasas , Mamíferos/metabolismo
3.
Chem Rev ; 118(3): 1253-1337, 2018 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-29112440

RESUMEN

Signaling by H2S is proposed to occur via persulfidation, a posttranslational modification of cysteine residues (RSH) to persulfides (RSSH). Persulfidation provides a framework for understanding the physiological and pharmacological effects of H2S. Due to the inherent instability of persulfides, their chemistry is understudied. In this review, we discuss the biologically relevant chemistry of H2S and the enzymatic routes for its production and oxidation. We cover the chemical biology of persulfides and the chemical probes for detecting them. We conclude by discussing the roles ascribed to protein persulfidation in cell signaling pathways.


Asunto(s)
Sulfuro de Hidrógeno/metabolismo , Sulfurtransferasas/metabolismo , Animales , Cistationina betasintasa/química , Cistationina betasintasa/metabolismo , Cistationina gamma-Liasa/química , Cistationina gamma-Liasa/metabolismo , Humanos , Sulfuro de Hidrógeno/análisis , Sulfuro de Hidrógeno/química , Oxidorreductasas actuantes sobre Donantes de Grupos Sulfuro/química , Oxidorreductasas actuantes sobre Donantes de Grupos Sulfuro/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal , Sulfito-Oxidasa/química , Sulfito-Oxidasa/metabolismo
4.
Proc Natl Acad Sci U S A ; 113(19): 5275-80, 2016 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-27118834

RESUMEN

Nature has evolved several unique biomineralization strategies to direct the synthesis and growth of inorganic materials. These natural systems are complex, involving the interaction of multiple biomolecules to catalyze biomineralization and template growth. Herein we describe the first report to our knowledge of a single enzyme capable of both catalyzing mineralization in otherwise unreactive solution and of templating nanocrystal growth. A recombinant putative cystathionine γ-lyase (smCSE) mineralizes CdS from an aqueous cadmium acetate solution via reactive H2S generation from l-cysteine and controls nanocrystal growth within the quantum confined size range. The role of enzymatic nanocrystal templating is demonstrated by substituting reactive Na2S as the sulfur source. Whereas bulk CdS is formed in the absence of the enzyme or other capping agents, nanocrystal formation is observed when smCSE is present to control the growth. This dual-function, single-enzyme, aerobic, and aqueous route to functional material synthesis demonstrates the powerful potential of engineered functional material biomineralization.


Asunto(s)
Compuestos de Cadmio/sangre , Cristalización/métodos , Cistationina gamma-Liasa/química , Minerales/síntesis química , Nanopartículas/química , Nanopartículas/ultraestructura , Sulfuros/sangre , Productos Biológicos/química , Catálisis , Activación Enzimática , Luz , Ensayo de Materiales , Conformación Molecular , Tamaño de la Partícula , Refractometría , Dispersión de Radiación , Propiedades de Superficie
5.
Biochemistry ; 56(6): 876-885, 2017 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-28106980

RESUMEN

Enzyme therapeutics that can degrade l-methionine (l-Met) are of great interest as numerous malignancies are exquisitely sensitive to l-Met depletion. To exhaust the pool of methionine in human serum, we previously engineered an l-Met-degrading enzyme based on the human cystathionine-γ-lyase scaffold (hCGL-NLV) to circumvent immunogenicity and stability issues observed in the preclinical application of bacterially derived methionine-γ-lyases. To gain further insights into the structure-activity relationships governing the chemistry of the hCGL-NLV lead molecule, we undertook a biophysical characterization campaign that captured crystal structures (2.2 Å) of hCGL-NLV with distinct reaction intermediates, including internal aldimine, substrate-bound, gem-diamine, and external aldimine forms. Curiously, an alternate form of hCGL-NLV that crystallized under higher-salt conditions revealed a locally unfolded active site, correlating with inhibition of activity as a function of ionic strength. Subsequent mutational and kinetic experiments pinpointed that a salt bridge between the phosphate of the essential cofactor pyridoxal 5'-phosphate (PLP) and residue R62 plays an important role in catalyzing ß- and γ-eliminations. Our study suggests that solvent ions such as NaCl disrupt electrostatic interactions between R62 and PLP, decreasing catalytic efficiency.


Asunto(s)
Liasas de Carbono-Azufre/metabolismo , Cistationina gamma-Liasa/metabolismo , Metionina/metabolismo , Modelos Moleculares , Selenometionina/metabolismo , Sustitución de Aminoácidos , Arginina/química , Biocatálisis , Liasas de Carbono-Azufre/química , Liasas de Carbono-Azufre/genética , Dominio Catalítico , Cistationina/metabolismo , Cistationina gamma-Liasa/química , Cistationina gamma-Liasa/genética , Cisteína/metabolismo , Estabilidad de Enzimas , Humanos , Enlace de Hidrógeno , Hidrólisis , Mutagénesis Sitio-Dirigida , Concentración Osmolar , Conformación Proteica , Ingeniería de Proteínas , Fosfato de Piridoxal/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Especificidad por Sustrato
6.
Molecules ; 21(1): 78, 2016 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-26771591

RESUMEN

The present research aimed to isolate the non-polar secondary metabolites that produce the vasodilator effects induced by the dichloromethane extract of Prunus serotina (P. serotina) fruits and to determine whether the NO/cGMP and the H2S/KATP channel pathways are involved in their mechanism of action. A bioactivity-directed fractionation of the dichloromethane extract of P. serotina fruits led to the isolation of ursolic acid and uvaol as the main non-polar vasodilator compounds. These compounds showed significant relaxant effect on rat aortic rings in an endothelium- and concentration-dependent manner, which was inhibited by NG-nitro-L-arginine methyl ester (L-NAME), DL-propargylglycine (PAG) and glibenclamide (Gli). Additionally, both triterpenes increased NO and H2S production in aortic tissue. Molecular docking studies showed that ursolic acid and uvaol are able to bind to endothelial NOS and CSE with high affinity for residues that form the oligomeric interface of both enzymes. These results suggest that the vasodilator effect produced by ursolic acid and uvaol contained in P. serotina fruits, involves activation of the NO/cGMP and H2S/KATP channel pathways, possibly through direct activation of NOS and CSE.


Asunto(s)
Sulfuro de Hidrógeno/agonistas , Óxido Nítrico/agonistas , Prunus avium/química , Triterpenos/farmacología , Vasodilatación/efectos de los fármacos , Vasodilatadores/farmacología , Alquinos/antagonistas & inhibidores , Alquinos/farmacología , Animales , Aorta/citología , Aorta/efectos de los fármacos , Aorta/metabolismo , GMP Cíclico/metabolismo , Cistationina gamma-Liasa/química , Cistationina gamma-Liasa/metabolismo , Endotelio Vascular/citología , Endotelio Vascular/efectos de los fármacos , Activación Enzimática/efectos de los fármacos , Frutas/química , Gliburida/antagonistas & inhibidores , Gliburida/farmacología , Glicina/análogos & derivados , Glicina/antagonistas & inhibidores , Glicina/farmacología , Sulfuro de Hidrógeno/metabolismo , Canales KATP/agonistas , Canales KATP/metabolismo , Masculino , Simulación del Acoplamiento Molecular , NG-Nitroarginina Metil Éster/antagonistas & inhibidores , NG-Nitroarginina Metil Éster/farmacología , Óxido Nítrico/biosíntesis , Óxido Nítrico Sintasa de Tipo III/química , Óxido Nítrico Sintasa de Tipo III/metabolismo , Extractos Vegetales/química , Unión Proteica , Ratas , Triterpenos/aislamiento & purificación , Vasodilatadores/aislamiento & purificación , Ácido Ursólico
7.
Biochim Biophys Acta ; 1844(2): 465-72, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24291053

RESUMEN

Cystathionine γ-lyase (CGL) catalyzes the hydrolysis of l-cystathionine (l-Cth), producing l-cysteine (l-Cys), α-ketobutyrate and ammonia, in the second step of the reverse transsulfuration pathway, which converts l-homocysteine (l-Hcys) to l-Cys. Site-directed variants substituting residues E48 and E333 with alanine, aspartate and glutamine were characterized to probe the roles of these acidic residues, conserved in fungal and mammalian CGL sequences, in the active-site of CGL from Saccharomyces cerevisiae (yCGL). The pH optimum of variants containing the alanine or glutamine substitutions of E333 is increased by 0.4-1.2 pH units, likely due to repositioning of the cofactor and modification of the pKa of the pyridinium nitrogen. The pH profile of yCGL-E48A/E333A resembles that of Escherichia coli cystathionine ß-lyase. The effect of substituting E48, E333 or both residues is the 1.3-3, 26-58 and 124-568-fold reduction, respectively, of the catalytic efficiency of l-Cth hydrolysis. The Km(l-Cth) of E333 substitution variants is increased ~17-fold, while Km(l-OAS) is within 2.5-fold of the wild-type enzyme, indicating that residue E333 interacts with the distal amine moiety of l-Cth, which is not present in the alternative substrate O-acetyl-l-serine. The catalytic efficiency of yCGL for α,γ-elimination of O-succinyl-l-homoserine (kcat/Km(l-OSHS)=7±2), which possesses a distal carboxylate, but lacks an amino group, is 300-fold lower than that of the physiological l-Cth substrate (kcat/Km(l-Cth)=2100±100) and 260-fold higher than that of l-Hcys (kcat/Km(l-Hcys)=0.027±0.005), which lacks both distal polar moieties. The results of this study suggest that the glutamate residue at position 333 is a determinant of specificity.


Asunto(s)
Cistationina gamma-Liasa/química , Cistationina gamma-Liasa/metabolismo , Ácido Glutámico/fisiología , Saccharomyces cerevisiae/enzimología , Dominio Catalítico , Cistationina gamma-Liasa/genética , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Concentración de Iones de Hidrógeno , Hidrólisis , Liasas/química , Liasas/metabolismo , Mutagénesis Sitio-Dirigida , Unión Proteica , Dominios y Motivos de Interacción de Proteínas/fisiología , Saccharomyces cerevisiae/genética , Especificidad por Sustrato
8.
J Am Chem Soc ; 137(26): 8490-8, 2015 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-26070091

RESUMEN

H2S produced in small amounts by mammalian cells has been identified in mediating biological signaling functions. However, the in situ trapping of endogenous H2S generation is still handicapped by a lack of straightforward methods with high selectivity and fast response. Here, we encapsulate a semi-cyanine-BODIPY hybrid dye (BODInD-Cl) and its complementary energy donor (BODIPY1) into the hydrophobic interior of an amphiphilic copolymer (mPEG-DSPE), especially for building up a ratiometric fluorescent H2S nanoprobe with extraordinarily fast response. A remarkable red-shift in the absorption band with a gap of 200 nm in the H2S response can efficiently switch off the Förster resonance energy transfer (FRET) from BODIPY1 to BODInD-Cl, subsequently recovering the donor fluorescence. Impressively, both the interior hydrophobicity of supramolecular micelles and electron-withdrawing nature of indolium unit in BODInD-Cl can sharply increase aromatic nucleophilic substitution with H2S. The ratiometric strategy based on the unique self-assembled micellar aggregate NanoBODIPY achieves an extremely fast response, enabling in situ imaging of endogenous H2S production and mapping its physiological and pathological consequences. Moreover, the amphiphilic copolymer renders the micellar assembly biocompatible and soluble in aqueous solution. The established FRET-switchable macromolecular envelope around BODInD-Cl and BODIPY1 enables cellular uptake, and makes a breakthrough in the trapping of endogenous H2S generation within raw264.7 macrophages upon stimulation with fluvastatin. This study manifests that cystathione γ-lyase (CSE) upregulation contributes to endogenous H2S generation in fluvastatin-stimulated macrophages, along with a correlation between CSE/H2S and activating Akt signaling pathway.


Asunto(s)
Ácidos Grasos Monoinsaturados/química , Transferencia Resonante de Energía de Fluorescencia/métodos , Sulfuro de Hidrógeno/química , Indoles/química , Nanopartículas/química , Animales , Compuestos de Boro/química , Cistationina gamma-Liasa/química , Colorantes Fluorescentes/química , Fluvastatina , Macrófagos/metabolismo , Ratones , Micelas , Microscopía Confocal , Microscopía Fluorescente/métodos , Polímeros/química , Células RAW 264.7 , Regulación hacia Arriba
9.
Postepy Hig Med Dosw (Online) ; 68: 1-9, 2014 Jan 15.
Artículo en Polaco | MEDLINE | ID: mdl-24491890

RESUMEN

γ-Cystathionase (CTH, EC: 4.4.1.1), an enzyme widely distributed in the world of prokaryotic and eukaryotic organisms, catalyzes the formation and transformations of sulfane sulfur-containing compounds and plays a pivotal role in the L-cysteine desulfuration pathway. Human, tetrameric CTH is composed of two dimers and each monomer binds pyridoxal phosphate (PLP). The gene, located on the short arm of chromosome 1, consists of 13 exons and 12 introns. As a result of alternative splicing, three isoforms of human CTH arise. Analysis of genetic variations of the CTH encoding gene showed a large number of polymorphisms. A decrease of the expression of CTH entails a drop in the level of cysteine , glutathione (GSH), taurine and hydrogen sulfide (H2S) in the cells and, more importantly, leads to cystathioninuria. H2S, endogenously formed by CTH, affects the vasodilation and regulation of blood pressure. CTH knockout mice have decreased levels of H2S, hypertension, and reduced capacity for vascular endothelium relaxation. Overexpression of the gene encoding CTH in the cells leads to increased production of H2S. H2S plays a role in protection of neurons against oxidative stress, and stimulates an increase in γ-glutamylcysteine synthetase and thereby an increase in the level of GSH. Sulfurtransferases, including CTH, can locally prevent oxidative stress due to reversible oxidation of - SH groups in the presence of increased levels of reactive oxygen species, and reduction in the presence of GSH and/or reduced thioredoxin.


Asunto(s)
Cistationina gamma-Liasa/química , Cistationina gamma-Liasa/genética , Hiperhomocisteinemia/genética , Polimorfismo Genético , Animales , Cisteína/metabolismo , Cisteína/orina , Expresión Génica , Glutatión/metabolismo , Humanos , Sulfuro de Hidrógeno/metabolismo , Hiperhomocisteinemia/complicaciones , Hipertensión/etiología , Ratones , Ratones Noqueados , Oxidación-Reducción , Estrés Oxidativo , Especies Reactivas de Oxígeno
10.
J Agric Food Chem ; 72(17): 9937-9946, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38651303

RESUMEN

The engineered human cystathionine-γ-lyase (hCGL) resulting in enhanced activity toward both cysteine and cystine unveils a potential robust antitumor activity. However, the presence of cysteine residues has the potential to induce oligomerization or incorrect disulfide bonding, which may decrease the bioavailability of biopharmaceuticals. Through a meticulous design process targeting the cysteine residues within engineered hCGL, a set of potential beneficial mutants were obtained by virtual screening employing Rosetta and ABACUS. Experimental measurements have revealed that most of the mutants showed increased activity toward both substrates l-Cys and CSSC. Furthermore, mutants C109V and C229D demonstrated Tm value increases of 8.2 and 1.8 °C, respectively. After an 80 min incubation at 60 °C, mutant C229D still maintained high residual activity. Unexpectedly, mutant C109V, displaying activity approximately 2-fold higher than the activity of wild type (WT) for both substrates, showed disappointing instability in plasma, which suggests that computational design still requires further consideration. Analysis of their structure and molecular dynamics (MD) simulation revealed the impact of hydrophobic interaction, hydrogen bonds, and near-attack conformation (NAC) stability on activity and stability. This study acquired information about mutants that exhibit enhanced activity or thermal resistance and serve as valuable guidance for subsequent specific cysteine modifications.


Asunto(s)
Cistationina gamma-Liasa , Cisteína , Simulación de Dinámica Molecular , Ingeniería de Proteínas , Cisteína/química , Cisteína/metabolismo , Humanos , Cistationina gamma-Liasa/genética , Cistationina gamma-Liasa/química , Cistationina gamma-Liasa/metabolismo , Estabilidad de Enzimas , Cistina/química , Enlace de Hidrógeno , Mutación , Cinética
11.
Sci Rep ; 14(1): 9364, 2024 04 23.
Artículo en Inglés | MEDLINE | ID: mdl-38654065

RESUMEN

The escalating drug resistance among microorganisms underscores the urgent need for innovative therapeutic strategies and a comprehensive understanding of bacteria's defense mechanisms against oxidative stress and antibiotics. Among the recently discovered barriers, the endogenous production of hydrogen sulfide (H2S) via the reverse transsulfuration pathway, emerges as a noteworthy factor. In this study, we have explored the catalytic capabilities and crystal structure of cystathionine γ-lyase from Pseudomonas aeruginosa (PaCGL), a multidrug-opportunistic pathogen chiefly responsible for nosocomial infections. In addition to a canonical L-cystathionine hydrolysis, PaCGL efficiently catalyzes the production of H2S using L-cysteine and/or L-homocysteine as alternative substrates. Comparative analysis with the human enzyme and counterparts from other pathogens revealed distinct structural features within the primary enzyme cavities. Specifically, a distinctly folded entrance loop could potentially modulate the access of substrates and/or inhibitors to the catalytic site. Our findings offer significant insights into the structural evolution of CGL enzymes across different pathogens and provide novel opportunities for developing specific inhibitors targeting PaCGL.


Asunto(s)
Dominio Catalítico , Cistationina gamma-Liasa , Sulfuro de Hidrógeno , Pseudomonas aeruginosa , Pseudomonas aeruginosa/enzimología , Cistationina gamma-Liasa/metabolismo , Cistationina gamma-Liasa/química , Cristalografía por Rayos X , Especificidad por Sustrato , Sulfuro de Hidrógeno/metabolismo , Sulfuro de Hidrógeno/química , Modelos Moleculares , Cisteína/metabolismo , Cisteína/química , Conformación Proteica , Proteínas Bacterianas/química , Proteínas Bacterianas/metabolismo , Humanos , Homocisteína/metabolismo , Homocisteína/química , Catálisis
12.
J Cell Mol Med ; 17(7): 879-88, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23742697

RESUMEN

Hydrogen sulfide (H2 S) and nitric oxide (NO) are major gasotransmitters produced in endothelial cells (ECs), contributing to the regulation of vascular contractility and structural integrity. Their interaction at different levels would have a profound impact on angiogenesis. Here, we showed that H2 S and NO stimulated the formation of new microvessels. Incubation of human umbilical vein endothelial cells (HUVECs-926) with NaHS (a H2 S donor) stimulated the phosphorylation of endothelial NO synthase (eNOS) and enhanced NO production. H2 S had little effect on eNOS protein expression in ECs. L-cysteine, a precursor of H2 S, stimulated NO production whereas blockage of the activity of H2 S-generating enzyme, cystathionine gamma-lyase (CSE), inhibited this action. CSE knockdown inhibited, but CSE overexpression increased, NO production as well as EC proliferation. LY294002 (Akt/PI3-K inhibitor) or SB203580 (p38 MAPK inhibitor) abolished the effects of H2 S on eNOS phosphorylation, NO production, cell proliferation and tube formation. Blockade of NO production by eNOS-specific siRNA or nitro-L-arginine methyl ester (L-NAME) reversed, but eNOS overexpression potentiated, the proliferative effect of H2 S on ECs. Our results suggest that H2 S stimulates the phosphorylation of eNOS through a p38 MAPK and Akt-dependent pathway, thus increasing NO production in ECs and vascular tissues and contributing to H2 S-induced angiogenesis.


Asunto(s)
Cistationina gamma-Liasa/química , Células Endoteliales/citología , Sulfuro de Hidrógeno/química , Óxido Nítrico Sintasa de Tipo III/química , Óxido Nítrico/química , Proliferación Celular , Cromonas/farmacología , Colágeno/química , Combinación de Medicamentos , Células Endoteliales/metabolismo , Inhibidores Enzimáticos/farmacología , Células Endoteliales de la Vena Umbilical Humana , Humanos , Laminina/química , Microcirculación , Morfolinas/farmacología , Neovascularización Patológica , Neovascularización Fisiológica , Fosforilación , Proteoglicanos/química , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
13.
J Am Chem Soc ; 135(44): 16697-704, 2013 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-24093945

RESUMEN

Hydrogen sulfide (H2S) is now recognized as an important biological regulator and signaling agent that is active in many physiological processes and diseases. Understanding the important roles of this emerging signaling molecule has remained challenging, in part due to the limited methods available for detecting endogenous H2S. Here we report two reaction-based ChemiLuminescent Sulfide Sensors, CLSS-1 and CLSS-2, with strong luminescence responses toward H2S (128- and 48-fold, respectively) and H2S detection limits (0.7 ± 0.3, 4.6 ± 2.0 µM, respectively) compatible with biological H2S levels. CLSS-2 is highly selective for H2S over other reactive sulfur, nitrogen, and oxygen species (RSONS) including GSH, Cys, Hcy, S2O3(2­), NO2(­), HNO, ONOO(­), and NO. Despite its similar chemical structure, CLSS-1 displays lower selectivity toward amino acid-derived thiols than CLSS-2. The origin of this differential selectivity was investigated using both computational DFT studies and NMR experiments. Our results suggest a model in which amino acid binding to the hydrazide moiety of the luminol-derived probes provides differential access to the reactive azide in CLSS-1 and CLSS-2, thus eroding the selectivity of CLSS-1 for H2S over Cys and GSH. On the basis of its high selectivity for H2S, we used CLSS-2 to detect enzymatically produced H2S from isolated cystathionine γ-lyase (CSE) enzymes (p < 0.001) and also from C6 cells expressing CSE (p < 0.001). CLSS-2 can readily differentiate between H2S production in active CSE and CSE inhibited with ß-cyanoalanine (BCA) in both isolated CSE enzymes (p < 0.005) and in C6 cells (p < 0.005). In addition to providing a highly sensitive and selective reaction-based tool for chemiluminescent H2S detection and quantification, the insights into substrate­probe interactions controlling the selectivity for H2S over biologically relevant thiols may guide the design of other selective H2S detection scaffolds.


Asunto(s)
Cistationina gamma-Liasa/metabolismo , Sulfuro de Hidrógeno/análisis , Luminiscencia , Compuestos de Sulfhidrilo/química , Animales , Cistationina gamma-Liasa/química , Enlace de Hidrógeno , Sulfuro de Hidrógeno/metabolismo , Mediciones Luminiscentes , Modelos Moleculares , Estructura Molecular , Teoría Cuántica , Ratas , Especificidad por Sustrato , Células Tumorales Cultivadas
14.
Biochem Biophys Res Commun ; 431(2): 131-5, 2013 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-23313510

RESUMEN

Hydrogen sulfide (H(2)S) is recognized as a physiologic mediator produced in a variety of tissues. It is produced by three enzymes, cystathionine ß-synthase (CBS), cystathionine γ-lyase (CSE) and 3-mercaptopyruvate sulfurtransferase (3MST). However, the regulation of H(2)S production by CSE has not well been understood. Here we show that H(2)S producing activity of CSE is regulated by intracellular Ca(2+) concentrations. In the presence of pyridoxal 5'-phosphate (PLP) CSE efficiently produces H(2)S at the steady-state low Ca(2+) concentrations but is suppressed at high Ca(2+) concentrations. In the absence of PLP H(2)S production maintains the suppressed levels at high Ca(2+) concentrations and decreased further at low Ca(2+) concentrations. These observations suggest that CSE produces H(2)S at the steady-state in cells and that the production is suppressed when the intracellular Ca(2+) concentrations are increased.


Asunto(s)
Calcio/metabolismo , Cistationina gamma-Liasa/metabolismo , Sulfuro de Hidrógeno/metabolismo , Animales , Calcio/química , Cistationina gamma-Liasa/química , Sulfuro de Hidrógeno/química , Cinética , Masculino , Fosfato de Piridoxal/química , Ratas , Ratas Wistar
15.
Protein Sci ; 32(4): e4619, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36883335

RESUMEN

Cystathionine γ-lyase (CGL) is a PLP-dependent enzyme that catalyzes the last step of the reverse transsulfuration route for endogenous cysteine biosynthesis. The canonical CGL-catalyzed process consists of an α,γ-elimination reaction that breaks down cystathionine into cysteine, α-ketobutyrate, and ammonia. In some species, the enzyme can alternatively use cysteine as a substrate, resulting in the production of hydrogen sulfide (H2 S). Importantly, inhibition of the enzyme and consequently of its H2 S production activity, makes multiresistant bacteria considerably more susceptible to antibiotics. Other organisms, such as Toxoplasma gondii, the causative agent of toxoplasmosis, encode a CGL enzyme (TgCGL) that almost exclusively catalyzes the canonical process, with only minor reactivity to cysteine. Interestingly, the substitution of N360 by a serine (the equivalent amino acid residue in the human enzyme) at the active site changes the specificity of TgCGL for the catalysis of cystathionine, resulting in an enzyme that can cleave both the CγS and the CßS bond of cystathionine. Based on these findings and to deepen the molecular basis underlying the enzyme-substrate specificity, we have elucidated the crystal structures of native TgCGL and the variant TgCGL-N360S from crystals grown in the presence of cystathionine, cysteine, and the inhibitor d,l-propargylglycine (PPG). Our structures reveal the binding mode of each molecule within the catalytic cavity and help explain the inhibitory behavior of cysteine and PPG. A specific inhibitory mechanism of TgCGL by PPG is proposed.


Asunto(s)
Cistationina gamma-Liasa , Toxoplasma , Humanos , Cistationina gamma-Liasa/química , Cistationina gamma-Liasa/metabolismo , Cisteína , Toxoplasma/metabolismo , Cistationina/metabolismo
16.
Biochim Biophys Acta ; 1814(11): 1518-27, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21315854

RESUMEN

The role of endogenously produced H(2)S in mediating varied physiological effects in mammals has spurred enormous recent interest in understanding its biology and in exploiting its pharmacological potential. In these early days in the field of H(2)S signaling, large gaps exist in our understanding of its biological targets, its mechanisms of action and the regulation of its biogenesis and its clearance. Two branches within the sulfur metabolic pathway contribute to H(2)S production: (i) the reverse transsulfuration pathway in which two pyridoxal 5'-phosphate-dependent (PLP) enzymes, cystathionine ß-synthase and cystathionine γ-lyase convert homocysteine successively to cystathionine and cysteine and (ii) a branch of the cysteine catabolic pathway which converts cysteine to mercaptopyruvate via a PLP-dependent cysteine aminotransferase and subsequently, to mercaptopyruvate sulfur transferase-bound persulfide from which H(2)S can be liberated. In this review, we present an overview of the kinetics of the H(2)S-generating reactions, compare the structures of the PLP-enzymes involved in its biogenesis and discuss strategies for their regulation. This article is part of a Special Issue entitled: Pyridoxal Phospate Enzymology.


Asunto(s)
Sulfuro de Hidrógeno/metabolismo , Fosfato de Piridoxal/metabolismo , Animales , Dominio Catalítico , Cistationina betasintasa/química , Cistationina betasintasa/metabolismo , Cistationina gamma-Liasa/química , Cistationina gamma-Liasa/metabolismo , Cinética , Modelos Moleculares
17.
J Bacteriol ; 193(4): 944-51, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21169490

RESUMEN

Application of in vivo expression technology (IVET) to Yersinia ruckeri, an important fish pathogen, allowed the identification of two adjacent genes that represent a novel bacterial system involved in the uptake and degradation of l-cysteine. Analysis of the translational products of both genes showed permease domains (open reading frame 1 [ORF1]) and amino acid position identities (ORF2) with the l-cysteine desulfidase from Methanocaldococcus jannaschii, a new type of enzyme involved in the breakdown of l-cysteine. The operon was named cdsAB (cysteine desulfidase) and is found widely in anaerobic and facultative bacteria. cdsAB promoter analysis using lacZY gene fusion showed highest induction in the presence of l-cysteine. Two cdsA and cdsB mutant strains were generated. The limited toxic effect and the low utilization of l-cysteine observed in the cdsA mutant, together with radiolabeled experiments, strongly suggested that CdsA is an l-cysteine permease. Fifty percent lethal dose (LD(50)) and competence index experiments showed that both the cdsA and cdsB loci were involved in the pathogenesis of the bacteria. In conclusion, this study has shown for the first time in bacteria the existence of an l-cysteine uptake system that together with an additional l-cysteine desulfidase-encoding gene constitutes a novel operon involved in bacterial virulence.


Asunto(s)
Proteínas Bacterianas/metabolismo , Cistationina gamma-Liasa/metabolismo , Cisteína/metabolismo , Enfermedades de los Peces/microbiología , Proteínas de Transporte de Membrana/metabolismo , Operón , Yersiniosis/veterinaria , Yersinia ruckeri/patogenicidad , Secuencia de Aminoácidos , Animales , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Transporte Biológico , Cistationina gamma-Liasa/química , Cistationina gamma-Liasa/genética , Proteínas de Transporte de Membrana/química , Proteínas de Transporte de Membrana/genética , Datos de Secuencia Molecular , Oncorhynchus mykiss/microbiología , Alineación de Secuencia , Yersiniosis/microbiología , Yersinia ruckeri/enzimología , Yersinia ruckeri/genética , Yersinia ruckeri/metabolismo
18.
Acta Crystallogr D Biol Crystallogr ; 67(Pt 10): 831-8, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21931214

RESUMEN

O-Acetylhomoserine sulfhydrylase (OAHS) is a pyridoxal 5'-phosphate (PLP) dependent sulfide-utilizing enzyme in the L-cysteine and L-methionine biosynthetic pathways of various enteric bacteria and fungi. OAHS catalyzes the conversion of O-acetylhomoserine to homocysteine using sulfide in a process known as direct sulfhydrylation. However, the source of the sulfur has not been identified and no structures of OAHS have been reported in the literature. Here, the crystal structure of Wolinella succinogenes OAHS (MetY) determined at 2.2 Šresolution is reported. MetY crystallized in space group C2 with two monomers in the asymmetric unit. Size-exclusion chromatography, dynamic light scattering and crystal packing indicate that the biological unit is a tetramer in solution. This is further supported by the crystal structure, in which a tetramer is formed using a combination of noncrystallographic and crystallographic twofold axes. A search for structurally homologous proteins revealed that MetY has the same fold as cystathionine γ-lyase and methionine γ-lyase. The active sites of these enzymes, which are also PLP-dependent, share a high degree of structural similarity, suggesting that MetY belongs to the γ-elimination subclass of the Cys/Met metabolism PLP-dependent family of enzymes. The structure of MetY, together with biochemical data, provides insight into the mechanism of sulfur transfer to a small molecule via a protein thiocarboxylate intermediate.


Asunto(s)
Liasas de Carbono-Oxígeno/química , Liasas de Carbono-Oxígeno/metabolismo , Wolinella/metabolismo , Vías Biosintéticas , Liasas de Carbono-Azufre/química , Dominio Catalítico , Cristalografía por Rayos X , Cistationina gamma-Liasa/química , Cisteína/metabolismo , Metionina/metabolismo , Conformación Proteica , Pliegue de Proteína , Fosfato de Piridoxal/metabolismo , Homología Estructural de Proteína , Azufre/metabolismo
19.
Int J Biol Macromol ; 174: 42-51, 2021 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-33497694

RESUMEN

The development and utilization of inorganic material biosynthesis have evolved into single macromolecular systems. A putative cystathionine γ-lyase of bacteria Stenotrophomonas maltophilia (smCSE) is a newly identified biomolecule that enables the synthesis of nanomaterials. Due to the lack of structural information, the mechanism of smCSE biosynthesis remains unclear. Herein, we obtain two atomic-resolution smCSE-form X-ray structures and confirm that the conformational changes of Tyr108 and Lys206 within the enzyme active sites are critical for the protein-driven synthesis of metal sulfide quantum dots (QDs). The structural stability of tetramer and the specificity of surface amino acids are the basis for smCSE to synthesize quantum dots. The size of QD products can be regulated by predesigned amino acids and the morphology can be controlled through proteolytic treatments. The growth rate is enhanced by the stabilization of a flexible loop in the active site, as shown by the X-ray structure of the engineered protein which fused with a dodecapeptide. We further prove that the smCSE-driven route can be applied to the general synthesis of other metal sulfide nanoparticles. These results provide a better understanding of the mechanism of QD biosynthesis and a new perspective on the control of this biosynthesis by protein modification.


Asunto(s)
Cistationina gamma-Liasa/metabolismo , Cistationina gamma-Liasa/ultraestructura , Puntos Cuánticos/química , Aminoácidos , Bacterias/metabolismo , Cistationina gamma-Liasa/química , Sustancias Macromoleculares , Metales , Nanoestructuras , Stenotrophomonas maltophilia/enzimología , Stenotrophomonas maltophilia/metabolismo , Sulfuros/química
20.
Nat Commun ; 12(1): 1745, 2021 03 19.
Artículo en Inglés | MEDLINE | ID: mdl-33741971

RESUMEN

Hydrogen sulfide (H2S) is a cytoprotective redox-active metabolite that signals through protein persulfidation (R-SSnH). Despite the known importance of persulfidation, tissue-specific persulfidome profiles and their associated functions are not well characterized, specifically under conditions and interventions known to modulate H2S production. We hypothesize that dietary restriction (DR), which increases lifespan and can boost H2S production, expands tissue-specific persulfidomes. Here, we find protein persulfidation enriched in liver, kidney, muscle, and brain but decreased in heart of young and aged male mice under two forms of DR, with DR promoting persulfidation in numerous metabolic and aging-related pathways. Mice lacking cystathionine γ-lyase (CGL) have overall decreased tissue protein persulfidation numbers and fail to functionally augment persulfidomes in response to DR, predominantly in kidney, muscle, and brain. Here, we define tissue- and CGL-dependent persulfidomes and how diet transforms their makeup, underscoring the breadth for DR and H2S to impact biological processes and organismal health.


Asunto(s)
Cistationina gamma-Liasa/química , Cistationina gamma-Liasa/metabolismo , Dieta , Proteínas/química , Proteínas/metabolismo , Envejecimiento/metabolismo , Animales , Encéfalo/metabolismo , Cistationina gamma-Liasa/genética , Sulfuro de Hidrógeno/metabolismo , Riñón/metabolismo , Hígado/metabolismo , Longevidad , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Músculos/metabolismo , Proteínas/genética , Transcriptoma
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