1
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Gong W, Liu Y, Zhao Y, Wang S, Han Z, Li C. Equally Weighted Multiscale Elastic Network Model and Its Comparison with Traditional and Parameter-Free Models. J Chem Inf Model 2021; 61:921-937. [PMID: 33496590 DOI: 10.1021/acs.jcim.0c01178] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Dynamical properties of proteins play an essential role in their function exertion. The elastic network model (ENM) is an effective and efficient tool in characterizing the intrinsic dynamical properties encoded in biomacromolecule structures. The Gaussian network model (GNM) and anisotropic network model (ANM) are the two often-used ENM models. Here, we introduce an equally weighted multiscale ENM (equally weighted mENM) based on the original mENM (denoted as mENM), in which fitting weights of Kirchhoff/Hessian matrixes in mENM are removed since they neglect the details of pairwise interactions. Then, we perform its comparison with the mENM, traditional ENM, and parameter-free ENM (pfENM) in reproducing dynamical properties for the six representative proteins whose molecular dynamics (MD) trajectories are available in http://mmb.pcb.ub.es/MoDEL/. In the results, for B-factor prediction, mENM performs best, while the equally weighted mENM performs also well, better than the traditional ENM and pfENM models. As to the dynamical cross-correlation map calculation, mENM performs worst, while the results produced from the equally weighted mENM and pfENM models are close to those from MD trajectories with the latter a little better than the former. Furthermore, encouragingly, the equally weighted mANM displays the best performance in capturing the functional motional modes, followed by pfANM and traditional ANM models, while the mANM fails in all the cases. This work is helpful for strengthening the understanding of the elastic network model and provides a valuable guide for researchers to utilize the model to explore protein dynamics.
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Affiliation(s)
- Weikang Gong
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing 100124, China.,Beijing International Science and Technology Cooperation Base for Intelligent Physiological Measurement and Clinical Transformation, Beijing University of Technology, Beijing 100124, China
| | - Yang Liu
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing 100124, China.,Beijing International Science and Technology Cooperation Base for Intelligent Physiological Measurement and Clinical Transformation, Beijing University of Technology, Beijing 100124, China
| | - Yanpeng Zhao
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing 100124, China.,Beijing International Science and Technology Cooperation Base for Intelligent Physiological Measurement and Clinical Transformation, Beijing University of Technology, Beijing 100124, China
| | - Shihao Wang
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing 100124, China.,Beijing International Science and Technology Cooperation Base for Intelligent Physiological Measurement and Clinical Transformation, Beijing University of Technology, Beijing 100124, China
| | - Zhongjie Han
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing 100124, China.,Beijing International Science and Technology Cooperation Base for Intelligent Physiological Measurement and Clinical Transformation, Beijing University of Technology, Beijing 100124, China
| | - Chunhua Li
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing 100124, China.,Beijing International Science and Technology Cooperation Base for Intelligent Physiological Measurement and Clinical Transformation, Beijing University of Technology, Beijing 100124, China
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2
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Chia SB, Elko EA, Aboushousha R, Manuel AM, van de Wetering C, Druso JE, van der Velden J, Seward DJ, Anathy V, Irvin CG, Lam YW, van der Vliet A, Janssen-Heininger YMW. Dysregulation of the glutaredoxin/ S-glutathionylation redox axis in lung diseases. Am J Physiol Cell Physiol 2019; 318:C304-C327. [PMID: 31693398 DOI: 10.1152/ajpcell.00410.2019] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Glutathione is a major redox buffer, reaching millimolar concentrations within cells and high micromolar concentrations in airways. While glutathione has been traditionally known as an antioxidant defense mechanism that protects the lung tissue from oxidative stress, glutathione more recently has become recognized for its ability to become covalently conjugated to reactive cysteines within proteins, a modification known as S-glutathionylation (or S-glutathiolation or protein mixed disulfide). S-glutathionylation has the potential to change the structure and function of the target protein, owing to its size (the addition of three amino acids) and charge (glutamic acid). S-glutathionylation also protects proteins from irreversible oxidation, allowing them to be enzymatically regenerated. Numerous enzymes have been identified to catalyze the glutathionylation/deglutathionylation reactions, including glutathione S-transferases and glutaredoxins. Although protein S-glutathionylation has been implicated in numerous biological processes, S-glutathionylated proteomes have largely remained unknown. In this paper, we focus on the pathways that regulate GSH homeostasis, S-glutathionylated proteins, and glutaredoxins, and we review methods required toward identification of glutathionylated proteomes. Finally, we present the latest findings on the role of glutathionylation/glutaredoxins in various lung diseases: idiopathic pulmonary fibrosis, asthma, and chronic obstructive pulmonary disease.
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Affiliation(s)
- Shi B Chia
- Department of Pathology and Laboratory Medicine, University of Vermont, Burlington, Vermont
| | - Evan A Elko
- Department of Pathology and Laboratory Medicine, University of Vermont, Burlington, Vermont
| | - Reem Aboushousha
- Department of Pathology and Laboratory Medicine, University of Vermont, Burlington, Vermont
| | - Allison M Manuel
- Department of Pathology and Laboratory Medicine, University of Vermont, Burlington, Vermont
| | - Cheryl van de Wetering
- Department of Pathology and Laboratory Medicine, University of Vermont, Burlington, Vermont
| | - Joseph E Druso
- Department of Pathology and Laboratory Medicine, University of Vermont, Burlington, Vermont
| | - Jos van der Velden
- Department of Pathology and Laboratory Medicine, University of Vermont, Burlington, Vermont
| | - David J Seward
- Department of Pathology and Laboratory Medicine, University of Vermont, Burlington, Vermont
| | - Vikas Anathy
- Department of Pathology and Laboratory Medicine, University of Vermont, Burlington, Vermont
| | - Charles G Irvin
- Department of Medicine, University of Vermont, Burlington, Vermont
| | - Ying-Wai Lam
- Department of Biology, University of Vermont, Burlington, Vermont
| | - Albert van der Vliet
- Department of Pathology and Laboratory Medicine, University of Vermont, Burlington, Vermont
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3
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Sousa SF, Neves RP, Waheed SO, Fernandes PA, Ramos MJ. Structural and mechanistic aspects of S-S bonds in the thioredoxin-like family of proteins. Biol Chem 2018; 400:575-587. [DOI: 10.1515/hsz-2018-0319] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 10/22/2018] [Indexed: 02/06/2023]
Abstract
Abstract
Disulfide bonds play a critical role in a variety of structural and mechanistic processes associated with proteins inside the cells and in the extracellular environment. The thioredoxin family of proteins like thioredoxin (Trx), glutaredoxin (Grx) and protein disulfide isomerase, are involved in the formation, transfer or isomerization of disulfide bonds through a characteristic thiol-disulfide exchange reaction. Here, we review the structural and mechanistic determinants behind the thiol-disulfide exchange reactions for the different enzyme types within this family, rationalizing the known experimental data in light of the results from computational studies. The analysis sheds new atomic-level insight into the structural and mechanistic variations that characterize the different enzymes in the family, helping to explain the associated functional diversity. Furthermore, we review here a pattern of stabilization/destabilization of the conserved active-site cysteine residues presented beforehand, which is fully consistent with the observed roles played by the thioredoxin family of enzymes.
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Affiliation(s)
- Sérgio F. Sousa
- UCIBIO@REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências , Universidade do Porto , Rua do Campo Alegre, s/n , 4169-007 Porto , Portugal
| | - Rui P.P. Neves
- UCIBIO@REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências , Universidade do Porto , Rua do Campo Alegre, s/n , 4169-007 Porto , Portugal
| | - Sodiq O. Waheed
- UCIBIO@REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências , Universidade do Porto , Rua do Campo Alegre, s/n , 4169-007 Porto , Portugal
| | - Pedro A. Fernandes
- UCIBIO@REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências , Universidade do Porto , Rua do Campo Alegre, s/n , 4169-007 Porto , Portugal
| | - Maria João Ramos
- UCIBIO@REQUIMTE, Departamento de Química e Bioquímica, Faculdade de Ciências , Universidade do Porto , Rua do Campo Alegre, s/n , 4169-007 Porto , Portugal
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4
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Zanello P. The competition between chemistry and biology in assembling iron–sulfur derivatives. Molecular structures and electrochemistry. Part II. {[Fe2S2](SγCys)4} proteins. Coord Chem Rev 2014. [DOI: 10.1016/j.ccr.2014.08.003] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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5
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Yogavel M, Tripathi T, Gupta A, Banday MM, Rahlfs S, Becker K, Belrhali H, Sharma A. Atomic resolution crystal structure of glutaredoxin 1 from Plasmodium falciparum and comparison with other glutaredoxins. ACTA ACUST UNITED AC 2013; 70:91-100. [PMID: 24419382 DOI: 10.1107/s1399004713025285] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 09/11/2013] [Indexed: 12/30/2022]
Abstract
Glutaredoxins (Grxs) are redox proteins that use glutathione ((γ)Glu-Cys-Gly; GSH) as a cofactor. Plasmodium falciparum has one classic dithiol (CXXC) glutaredoxin (glutaredoxin 1; PfGrx1) and three monothiol (CXXS) Grx-like proteins (GLPs), which have five residue insertions prior to the active-site Cys. Here, the crystal structure of PfGrx1 has been determined by the sulfur single-wavelength anomalous diffraction (S-SAD) method utilizing intrinsic protein and solvent S atoms. Several residues were modelled with alternate conformations, and an alternate position was refined for the active-site Cys29 owing to radiation damage. The GSH-binding site is occupied by water polygons and buffer molecules. Structural comparison of PfGrx1 with other Grxs and Grx-like proteins revealed that the GSH-binding motifs (CXXC/CXXS, TVP, CDD, Lys26 and Gln/Arg63) are structurally conserved. Both the monothiol and dithiol Grxs possess three conserved water molecules; two of these were located in the GSH-binding site. PfGrx1 has several polar and charged amino-acid substitutions that provide structurally important additional hydrogen bonds and salt bridges missing in other Grxs.
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Affiliation(s)
- Manickam Yogavel
- Structural and Computational Biology Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Road, New Delhi 110 067, India
| | - Timir Tripathi
- Department of Biochemistry, North-Eastern Hill University, Shillong 792 022, India
| | - Ankita Gupta
- Department of Biochemistry, North-Eastern Hill University, Shillong 792 022, India
| | - Mudassir Meraj Banday
- Structural and Computational Biology Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Road, New Delhi 110 067, India
| | - Stefan Rahlfs
- Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University Giessen, 35392 Giessen, Germany
| | - Katja Becker
- Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University Giessen, 35392 Giessen, Germany
| | - Hassan Belrhali
- European Molecular Biology Laboratory, 6 Rue Jules Horowitz, BP 181, 38042 Grenoble, France
| | - Amit Sharma
- Structural and Computational Biology Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Road, New Delhi 110 067, India
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6
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Deponte M. Glutathione catalysis and the reaction mechanisms of glutathione-dependent enzymes. Biochim Biophys Acta Gen Subj 2013; 1830:3217-66. [DOI: 10.1016/j.bbagen.2012.09.018] [Citation(s) in RCA: 625] [Impact Index Per Article: 56.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 09/25/2012] [Indexed: 12/12/2022]
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7
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Structural insights into omega-class glutathione transferases: a snapshot of enzyme reduction and identification of a non-catalytic ligandin site. PLoS One 2013; 8:e60324. [PMID: 23593192 PMCID: PMC3621891 DOI: 10.1371/journal.pone.0060324] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Accepted: 02/25/2013] [Indexed: 12/02/2022] Open
Abstract
Glutathione transferases (GSTs) are dimeric enzymes containing one active-site per monomer. The omega-class GSTs (hGSTO1-1 and hGSTO2-2 in humans) are homodimeric and carry out a range of reactions including the glutathione-dependant reduction of a range of compounds and the reduction of S-(phenacyl)glutathiones to acetophenones. Both types of reaction result in the formation of a mixed-disulfide of the enzyme with glutathione through the catalytic cysteine (C32). Recycling of the enzyme utilizes a second glutathione molecule and results in oxidized glutathione (GSSG) release. The crystal structure of an active-site mutant (C32A) of the hGSTO1-1 isozyme in complex with GSSG provides a snapshot of the enzyme in the process of regeneration. GSSG occupies both the G (GSH-binding) and H (hydrophobic-binding) sites and causes re-arrangement of some H-site residues. In the same structure we demonstrate the existence of a novel “ligandin” binding site deep within in the dimer interface of this enzyme, containing S-(4-nitrophenacyl)glutathione, an isozyme-specific substrate for hGSTO1-1. The ligandin site, conserved in Omega class GSTs from a range of species, is hydrophobic in nature and may represent the binding location for tocopherol esters that are uncompetitive hGSTO1-1 inhibitors.
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Li L, Cheng N, Hirschi KD, Wang X. Structure of Arabidopsis chloroplastic monothiol glutaredoxin AtGRXcp. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2010; 66:725-32. [PMID: 20516625 PMCID: PMC2879357 DOI: 10.1107/s0907444910013119] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Accepted: 04/08/2010] [Indexed: 01/13/2023]
Abstract
The structure of Arabidopsis monothiol glutaredoxin AtGRXcp has been determined and reveals unique structural features of monothiol glutaredoxins, key residues for their interaction with glutathione and structural determinants for their distinct biochemical properties. Monothiol glutaredoxins (Grxs) play important roles in maintaining redox homeostasis in living cells and are conserved across species. Arabidopsis thaliana monothiol glutaredoxin AtGRXcp is critical for protection from oxidative stress in chloroplasts. The crystal structure of AtGRXcp has been determined at 2.4 Å resolution. AtGRXcp has a glutaredoxin/thioredoxin-like fold with distinct structural features that differ from those of dithiol Grxs. The structure reveals that the putative active-site motif CGFS is well defined and is located on the molecular surface and that a long groove extends to both sides of the catalytic Cys97. Structural comparison and molecular modeling suggest that glutathione can bind in this groove and form extensive interactions with conserved charged residues including Lys89, Arg126 and Asp152. Further comparative studies reveal that a unique loop with five additional residues adjacent to the active-site motif may be a key structural feature of monothiol Grxs and may influence their function. This study provides the first structural information on plant CGFS-type monothiol Grxs, allowing a better understanding of the redox-regulation mechanism mediated by these plant Grxs.
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Affiliation(s)
- Lenong Li
- Plant Biology Division, Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, Oklahoma 73401, USA
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9
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Terada T, Okamoto KI, Nishikawa JI, Miura T, Nishinaka T, Nishihara T. Site-directed mutagenesis of rat thioltransferase: effects of essential cysteine residues for the protection against oxidative stress. J Biochem Mol Toxicol 2010; 24:60-5. [PMID: 20175144 DOI: 10.1002/jbt.20312] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
A cDNA of rat liver thioltransferase was cloned and then expressed using pMAL-c expression vector in Escherichia coli. Recombinant rat liver thioltransferase was expressed as a fusion protein with maltose-binding protein and then purified by amylose resin column chromatography to be homogeneity on 12.5% SDS-polyacrylamide gel electrophoretic analysis. The expressed proteins were shown as two bands at around 53 and 41 kDa, suggesting that the high molecular one was a fusion protein of recombinant thioltransferase (11.7 plus 41 kDa) and the other (smaller one) was a maltose-binding protein (41 kDa). A recombinant thioltransferase catalyzed a thiol/disulfide exchange reaction in the same way as thioltransferases purified from various sources. Compared with wild type, the mutants C23A, C26A, C79A, and C83A showed 0%, 17%, 82%, and 86% in the enzymatic activity, respectively. In addition, wild-type-transfected bacteria expressed in bacterial cells showed a strong resistance to H(2)O(2) treatment as well as the case of active mutants (C79A and C83A), but inactive mutants (C23A and C26A) showed no resistance to H(2)O(2) treatment as same as mocktransfection. Thioltransferase can be important for survival of bacterial cells under oxidative stress.
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Affiliation(s)
- Tomoyuki Terada
- Laboratory of Biochemistry, Faculty of Pharmacy, Osaka Ohtani University, Tondabayashi, Osaka 584-8540, Japan.
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10
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Mutations in Grxcr1 are the basis for inner ear dysfunction in the pirouette mouse. Am J Hum Genet 2010; 86:148-60. [PMID: 20137774 DOI: 10.1016/j.ajhg.2010.01.016] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Revised: 01/18/2010] [Accepted: 01/19/2010] [Indexed: 01/03/2023] Open
Abstract
Recessive mutations at the mouse pirouette (pi) locus result in hearing loss and vestibular dysfunction due to neuroepithelial defects in the inner ear. Using a positional cloning strategy, we have identified mutations in the gene Grxcr1 (glutaredoxin cysteine-rich 1) in five independent allelic strains of pirouette mice. We also provide sequence data of GRXCR1 from humans with profound hearing loss suggesting that pirouette is a model for studying the mechanism of nonsyndromic deafness DFNB25. Grxcr1 encodes a 290 amino acid protein that contains a region of similarity to glutaredoxin proteins and a cysteine-rich region at its C terminus. Grxcr1 is expressed in sensory epithelia of the inner ear, and its encoded protein is localized along the length of stereocilia, the actin-filament-rich mechanosensory structures at the apical surface of auditory and vestibular hair cells. The precise architecture of hair cell stereocilia is essential for normal hearing. Loss of function of Grxcr1 in homozygous pirouette mice results in abnormally thin and slightly shortened stereocilia. When overexpressed in transfected cells, GRXCR1 localizes along the length of actin-filament-rich structures at the dorsal-apical surface and induces structures with greater actin filament content and/or increased lengths in a subset of cells. Our results suggest that deafness in pirouette mutants is associated with loss of GRXCR1 function in modulating actin cytoskeletal architecture in the developing stereocilia of sensory hair cells.
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11
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Saaranen MJ, Salo KEH, Latva-Ranta MK, Kinnula VL, Ruddock LW. The C-terminal active site cysteine of Escherichia coli glutaredoxin 1 determines the glutathione specificity of the second step of peptide deglutathionylation. Antioxid Redox Signal 2009; 11:1819-28. [PMID: 19361272 DOI: 10.1089/ars.2008.2387] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Glutaredoxins are oxidoreductases specialized in reducing glutathione-protein mixed disulfides. In the first step of deglutathionylation, glutaredoxins form a mixed disulfide with glutathione, releasing reduced peptide. The specificity of this reaction is based on the unusual amide linkage formed between the gamma-carboxylate of the N-terminal glutamic acid and the alpha-amino group of the cysteine present in glutathione. In the second step of deglutathionylation, glutathione reduces the glutaredoxin-glutathione mixed disulfide. Here we show that the specificity of this second reaction for Escherichia coli Grx1, but not for human or yeast Grx1, also is based on the unusual gamma-linkage present in glutathione. Mutating Tyr13, Thr58, and/or Asp74 to alanine in E. coli Grx1 results in the glutaredoxin-peptide mixed disulfide being thermodynamically favored over the glutaredoxin-glutathione mixed disulfide in the first step of the reaction. An increased propensity to form glutaredoxin-protein mixed disulfides was observed in vivo for these same mutants. Furthermore, we demonstrate that all mutations studied in Cys14, the C-terminal active site cysteine, abolish the specificity of E. coli Grx1 for glutathione over the corresponding tripeptide Glu-Cys-Gly, which has a normal peptide bond linking Glu-Cys instead of the gamma-linkage present in glutathione, in the second step of deglutathionylation.
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12
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Discola KF, de Oliveira MA, Rosa Cussiol JR, Monteiro G, Bárcena JA, Porras P, Padilla CA, Guimarães BG, Netto LES. Structural Aspects of the Distinct Biochemical Properties of Glutaredoxin 1 and Glutaredoxin 2 from Saccharomyces cerevisiae. J Mol Biol 2009; 385:889-901. [DOI: 10.1016/j.jmb.2008.10.055] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2008] [Revised: 10/06/2008] [Accepted: 10/15/2008] [Indexed: 01/09/2023]
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13
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Sharma M, Khanna S, Bulusu G, Mitra A. Comparative modeling of thioredoxin glutathione reductase from Schistosoma mansoni: a multifunctional target for antischistosomal therapy. J Mol Graph Model 2008; 27:665-75. [PMID: 19070522 DOI: 10.1016/j.jmgm.2008.10.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Revised: 10/07/2008] [Accepted: 10/27/2008] [Indexed: 11/27/2022]
Abstract
Schistosoma mansoni, a trematode parasite, which causes schistosomiasis and affects more than 200 million people worldwide, lives in an aerobic environment and therefore needs an effective redox mechanism for surviving reactive oxygen species from its host. Although, the host has two different redox systems: glutaredoxin and thioredoxin, the parasite has only one unique multifunctional enzyme, thioredoxin glutathione reductase (TGR) involving a fusion of two proteins, glutaredoxin (Grx) and thioredoxin reductase (TR), for performing all the redox activities. This dependence of S. mansoni on a single protein, TGR, for its protection from oxidative stress, makes it a promising drug target. Here, we describe a suitably validated, homology model for S. mansoni TGR (SmTGR), developed using both TR and Grx templates, functionally complete in the dimeric form with cofactors NADP(H) and FAD. Comparative analysis of substrate and inhibitor binding pockets of our model with crystal structures of parent TR as well as with that of glutathione reductase (GR), which is an essential component of the Grx system, appears to provide greater insight into the functioning of TGR. This also augments recent observations reported on the basis of X-ray structure data on SmTGR monomer lacking the C-terminal selenocysteine tail.
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Affiliation(s)
- Monika Sharma
- Center for Computational Natural Sciences and Bioinformatics, International Institute of Information Technology (IIIT-H), Gachibowli, Hyderabad 500032, India
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14
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Lee JY, Kang YK. The rate enhancement for prolyl cis-to-trans isomerization of cyclic CPFC peptide is caused by an increase in the vibrational entropy of the transition state. J Phys Chem B 2008; 112:3287-9. [PMID: 18302366 DOI: 10.1021/jp711715j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The conformational preferences and prolyl cis-trans isomerization of oxidized and reduced Ac-Cys-Pro-Phe-Cys-NH2 (CPFC peptides) have been carried out using the ab initio HF/6-31+G(d) and hybrid density functional B3LYP/6-311++G(d,p) levels of theory. The most preferred conformations of oxidized and reduced CPFC peptides with the trans prolyl peptide bond have a type-I beta-turn for the Pro-Phe sequence in common. In particular, the transition states for both forms are stabilized by the intramolecular hydrogen bonds between the prolyl nitrogen and the N-H group of the Phe3 residue. The rotational barrier DeltaGct to the cis-to-trans isomerization for the oxidized CPFC peptide is calculated to be 19.37 kcal/mol at the B3LYP/6-311++G(d,p)//HF/6-31+G(d) level of theory, which is lower by 0.88 kcal/mol than that of the reduced CPFC peptide. This may indicate that the rate constant kc-->t of the prolyl cis-to-trans isomerization for the oxidized form is about 4 times larger than that of the reduced form, which is reasonably consistent with the value deduced from NMR experiments. In particular, the increase in vibrational entropy for the transition state of the oxidized form over that of the reduced form contributes to enhance the rate constant for the prolyl cis-to-trans isomerization of the oxidized form.
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Affiliation(s)
- Joo Yun Lee
- Department of Chemistry, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea
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15
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Mi W, Liang YH, Li L, Su XD. The crystal structure of human chloride intracellular channel protein 2: A disulfide bond with functional implications. Proteins 2008; 71:509-13. [DOI: 10.1002/prot.21922] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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16
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Hishiya S, Hatakeyama W, Mizota Y, Hosoya-Matsuda N, Motohashi K, Ikeuchi M, Hisabori T. Binary Reducing Equivalent Pathways Using NADPH-Thioredoxin Reductase and Ferredoxin-Thioredoxin Reductase in the Cyanobacterium Synechocystis sp. Strain PCC 6803. ACTA ACUST UNITED AC 2008; 49:11-8. [DOI: 10.1093/pcp/pcm158] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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17
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Matsuhira T, Tsuchihashi K, Yamamoto H, Okamura TA, Ueyama N. Novel photosystem involving protonation and deprotonation processes modelled on a PYP photocycle. Org Biomol Chem 2008; 6:3118-26. [DOI: 10.1039/b807417h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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18
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Foloppe N, Nilsson L. Stabilization of the Catalytic Thiolate in a Mammalian Glutaredoxin: Structure, Dynamics and Electrostatics of Reduced Pig Glutaredoxin and its Mutants. J Mol Biol 2007; 372:798-816. [PMID: 17681533 DOI: 10.1016/j.jmb.2007.05.101] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2007] [Revised: 05/15/2007] [Accepted: 05/15/2007] [Indexed: 11/23/2022]
Abstract
The variety of functions performed by proteins of the thioredoxin superfamily, including glutaredoxins, involves the wide range of redox potential associated with the -Cys-X-X-Cys- motif found in their active sites. The determinants of these differences in redox potential are still obscure. A better understanding requires a detailed characterization of the reduced state of these enzymes, especially because the lowered pK(a) of the reduced N-terminal active-site cysteine is a key feature of these enzymes' chemistry, including their redox potential. Analysis of the factors controlling this pK(a) is complicated by the apparent structural heterogeneity of the reduced active sites across glutaredoxins. In this family, pig glutaredoxin (pGrx) was one of the first to be functionally characterized, including some intriguing mutagenesis data, but a structure of its reduced state has been lacking. We used long molecular dynamics simulations and electrostatic calculations to analyze the structure, dynamics and electrostatics of reduced pGrx and some of its mutants. Comparison with experimental data is drawn whenever possible. It is shown that a dynamic model is essential to capture the structural properties of the cationic side-chains around the -Cys22-Pro23-Phe24-Cys25- sequence in the pGrx active site. Examples include Arg26, which can swing to stack on this sequence, and Lys19 which can contact the thiolate. However, contrary to a commonly held hypothesis, these cationic side-chains provide little stabilization for the thiolate, implying that they affect the enzymatic activity via other mechanisms. The pK(a) value of nucleophilic cysteine 22 (pK(a)(22)) is dominated by local hydrogen-bonds, formed only in a well-defined active-site conformation, supported by a comparison between the calculated and experimental values of pK(a)(22). The edge of the aromatic ring of Phe24 is polar enough to contribute to stabilize the thiolate, consistent with the conserved aromatic side-chain at this position in the glutaredoxin motif. The locality and directionality of the hydrogen bonds in the active site suffice to explain the vast difference between the pK(a) values of its two cysteine residues. A control of the cysteine pK(a) values by local hydrogen bonds implies that the peripheral ionized side-chains can evolve independently of the maintenance of these pK(a) values, maybe guided instead by substrate recognition. Comparison with other glutaredoxins indicates that the calculated pK(a) values of the N-terminal cysteine are better conserved than those of the C-terminal cysteine. Overall, a methodological strategy to systematically compare all reduced enzymes of this family emerges.
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Affiliation(s)
- Nicolas Foloppe
- Department of Biosciences and Nutrition, Karolinska Institutet, S-141 57, Huddinge, Sweden.
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19
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Hashemy SI, Johansson C, Berndt C, Lillig CH, Holmgren A. Oxidation and S-Nitrosylation of Cysteines in Human Cytosolic and Mitochondrial Glutaredoxins. J Biol Chem 2007; 282:14428-36. [PMID: 17355958 DOI: 10.1074/jbc.m700927200] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Glutathione (GSH) is the major intracellular thiol present in 1-10-mm concentrations in human cells. However, the redox potential of the 2GSH/GSSG (glutathione disulfide) couple in cells varies in association with proliferation, differentiation, or apoptosis from -260 mV to -200 or -170 mV. Hydrogen peroxide is transiently produced as second messenger in receptor-mediated growth factor signaling. To understand oxidation mechanisms by GSSG or nitric oxide-related nitrosylation we studied effects on glutaredoxins (Grx), which catalyze GSH-dependent thiol-disulfide redox reactions, particularly reversible glutathionylation of protein sulfhydryl groups. Human Grx1 and Grx2 contain Cys-Pro-Tyr-Cys and Cys-Ser-Tyr-Cys active sites and have three and two additional structural Cys residues, respectively. We analyzed the redox state and disulfide pairing of Cys residues upon GSSG oxidation and S-nitrosylation. Cytosolic/nuclear Grx1 was partly inactivated by both S-nitrosylation and oxidation. Inhibition by nitrosylation was reversible under anaerobic conditions; aerobically it was stronger and irreversible, indicating inactivation by nitration. Oxidation of Grx1 induced a complex pattern of disulfide-bonded dimers and oligomers formed between Cys-8 and either Cys-79 or Cys-83. In addition, an intramolecular disulfide between Cys-79 and Cys-83 was identified, predicted to have a profound effect on the three-dimensional structure. In contrast, mitochondrial Grx2 retains activity upon oxidation, did not form disulfide-bonded dimers or oligomers, and could not be S-nitrosylated. The dimeric iron sulfur cluster-coordinating inactive form of Grx2 dissociated upon nitrosylation, leading to activation of the protein. The striking differences between Grx1 and Grx2 reflect their diverse regulatory functions in vivo and also adaptation to different subcellular localization.
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Affiliation(s)
- Seyed Isaac Hashemy
- Medical Nobel Institute for Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden
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20
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Bacik JP, Hazes B. Crystal Structures of a Poxviral Glutaredoxin in the Oxidized and Reduced States Show Redox-correlated Structural Changes. J Mol Biol 2007; 365:1545-58. [PMID: 17137595 DOI: 10.1016/j.jmb.2006.11.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2006] [Revised: 10/20/2006] [Indexed: 10/23/2022]
Abstract
Glutaredoxins act as reducing agents for the large subunit of ribonucleotide reductase (R1) in many prokaryotes and eukaryotes, including humans. The same relationship has been proposed for the glutaredoxin and R1 proteins expressed by all orthopoxviruses, including vaccinia, variola, and ectromelia virus. Interestingly, the orthopoxviral proteins share 45% and 78% sequence identity with human glutaredoxin-1 (Grx-1) and R1, respectively. To study structure-function relationships of the vertebrate Grx-1 family, and reveal potential viral adaptations, we have determined crystal structures of the ectromelia virus glutaredoxin, EVM053, in the oxidized and reduced states. The structures show a large redox-induced conformational rearrangement of Tyr21 and Thr22 near the active site. We predict that the movement of Tyr21 is a viral-specific adaptation that increases the redox potential by stabilizing the reduced state. The conformational switch of Thr22 appears to be shared by vertebrate Grx-1 and may affect the strictly conserved Lys20. A crystal packing-induced structural change in residues 68-70 affects the GSH-binding loop, and our structures reveal a potential interaction network that connects the GSH-binding loop and the active site. EVM053 also exhibits a novel cis-proline (Pro53) in a loop that has been shown to contribute to R1-binding in Escherichia coli Grx-1. The cis-peptide bond of Pro53 may be required to promote electrostatic interactions between Lys52 and the C-terminal carboxylate of R1. Finally, dimethylarsenite was covalently attached to Cys23 in one reduced EVM053 structure and our preliminary data show that EVM053 has dimethylarsenate reductase activity.
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Affiliation(s)
- John-Paul Bacik
- Department of Medical Microbiology and Immunology, 1-15 Medical Sciences Building, University of Alberta, Edmonton, Alberta, Canada T6G 2H7
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21
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Ströher E, Dietz KJ. Concepts and approaches towards understanding the cellular redox proteome. PLANT BIOLOGY (STUTTGART, GERMANY) 2006; 8:407-18. [PMID: 16906481 DOI: 10.1055/s-2006-923961] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The physiological activity of a significant subset of cell proteins is modified by the redox state of regulatory thiols. The cellular redox homeostasis depends on the balance between oxidation of thiols through oxygen and reactive oxygen species and reduction by thiol-disulfide transfer reactions. Novel and improved methodology has been designed during recent years to address the level of thiol/disulfide regulation on a genome-wide scale. The approaches are either based on gel electrophoresis or on chromatographic techniques coupled to high end mass spectrometry. The review addresses diagonal 2D-SDS-PAGE, targeted identification of specific redox-interactions, affinity chromatography with thioredoxins and glutaredoxins, gel-based and non-gel based labelling techniques with fluorophores (such as Cy3, Cy5, ICy), radioisotopes, or with isotope-coded affinity tags (ICAT), differential gel electrophoresis (DIGE) and combined fractional diagonal chromatography (COFRADIC). The extended methodological repertoire promises fast and new insight into the intricate regulation network of the redox proteome of animals, bacteria, and plants.
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Affiliation(s)
- E Ströher
- Faculty of Biology--W5-134, Bielefeld University, Universitätsstrasse 25, 33501 Bielefeld, Germany
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22
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Noguera V, Walker O, Rouhier N, Jacquot JP, Krimm I, Lancelin JM. NMR Reveals a Novel Glutaredoxin–Glutaredoxin Interaction Interface. J Mol Biol 2005; 353:629-41. [PMID: 16181638 DOI: 10.1016/j.jmb.2005.08.035] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2005] [Revised: 08/01/2005] [Accepted: 08/17/2005] [Indexed: 11/25/2022]
Abstract
Glutaredoxins (Grx) represent a large family of glutathione (GSH)-dependent oxidoreductases that catalyse the reduction of disulfides or glutathione mixed disulfide. Grx domains from pathogenic bacteria and plant Grxs have been recently reported to target specific peroxiredoxins (Prxs). The specificity that triggers the interaction between Grx and Prx is poorly understood and is only based on the structure of Haemophilus influenzae Prx-Grx hybrid (hyPrx5). We report here an NMR study of the Populus tremula Grx C4 that targets a P.tremula D-type II Prx. We show that Grx C4 specifically self-associates in a monomer-dimer equilibrium with an apparent K(d) of ca 2.6 mM. Grx C4 homodimer was docked under experimental restraints. The results reveal a novel Grx-Grx interface that is unrelated to the hyPrx5 Grx-Grx dimer interface. Chemical-shift perturbations and 15N spin-relaxation measurements show that the auto-association surface comprises both the active site and the GSH binding site. Reduced GSH is demonstrated to bind reduced Grx with a K(d) of ca 8.6 mM. The potential biological significance of the new Grx-Grx interaction interface is discussed.
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Affiliation(s)
- Valerie Noguera
- RMN Biomoléculaire, Université Claude Bernard, Lyon 1, CNRS UMR 5180 Sciences Analytiques, ESCPE-Lyon, 69622 Villeurbanne, France
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23
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Carvalho AP, Fernandes PA, Ramos MJ. Similarities and differences in the thioredoxin superfamily. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2005; 91:229-48. [PMID: 16098567 DOI: 10.1016/j.pbiomolbio.2005.06.012] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/05/2005] [Indexed: 01/23/2023]
Abstract
There is growing interest in the proteins involved in protein folding. This is mainly due to the large number of human diseases related to defects in folding, which include cystic fibrosis, Alzheimer's and cancer. However, equally important as the oxidation and concomitant formation of disulfide bridges of the extracellular or secretory proteins is the reduction and maintenance in the reduced state of the proteins within the cell. Interestingly, the proteins that are responsible for maintenance of the reduced state belong to the same superfamily as those responsible for the formation of disulfide bridges: all are members of the thioredoxin superfamily. In this article, we highlight the main features of those thioredoxin-like proteins directly involved in the redox reactions. We describe their biological functions, cytoplasmic location, mechanisms of action, structures and active site features, and discuss the principal hypotheses concerning origins of the different reduction potentials and unusual pK(a)'s of the catalytic residues.
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Affiliation(s)
- Alexandra P Carvalho
- Requimte, Departamento de Química, Faculdade de Ciências, Universidade do Porto, Portugal.
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24
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Fladvad M, Bellanda M, Fernandes AP, Mammi S, Vlamis-Gardikas A, Holmgren A, Sunnerhagen M. Molecular Mapping of Functionalities in the Solution Structure of Reduced Grx4, a Monothiol Glutaredoxin from Escherichia coli. J Biol Chem 2005; 280:24553-61. [PMID: 15840565 DOI: 10.1074/jbc.m500679200] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The ubiquitous glutaredoxin protein family is present in both prokaryotes and eukaryotes, and is closely related to the thioredoxins, which reduce their substrates using a dithiol mechanism as part of the cellular defense against oxidative stress. Recently identified monothiol glutaredoxins, which must use a different functional mechanism, appear to be essential in both Escherichia coli and yeast and are well conserved in higher order genomes. We have employed high resolution NMR to determine the three-dimensional solution structure of a monothiol glutaredoxin, the reduced E. coli Grx4. The Grx4 structure comprises a glutaredoxin-like alpha-beta fold, founded on a limited set of strictly conserved and structurally critical residues. A tight hydrophobic core, together with a stringent set of secondary structure elements, is thus likely to be present in all monothiol glutaredoxins. A set of exposed and conserved residues form a surface region, implied in glutathione binding from a known structure of E. coli Grx3. The absence of glutaredoxin activity in E. coli Grx4 can be understood based on small but significant differences in the glutathione binding region, and through the lack of a conserved second GSH binding site. MALDI experiments suggest that disulfide formation on glutathionylation is accompanied by significant structural changes, in contrast with dithiol thioredoxins and glutaredoxins, where differences between oxidized and reduced forms are subtle and local. Structural and functional implications are discussed with particular emphasis on identifying common monothiol glutaredoxin properties in substrate specificity and ligand binding events, linking the thioredoxin and glutaredoxin systems.
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Affiliation(s)
- Malin Fladvad
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 77 Stockholm, Sweden
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25
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Bacik JP, Brigley AM, Channon LD, Audette GF, Hazes B. Purification, crystallization and preliminary diffraction studies of an ectromelia virus glutaredoxin. Acta Crystallogr Sect F Struct Biol Cryst Commun 2005; 61:550-2. [PMID: 16511093 PMCID: PMC1952336 DOI: 10.1107/s1744309105013278] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2005] [Accepted: 04/26/2005] [Indexed: 11/10/2022]
Abstract
Ectromelia, vaccinia, smallpox and other closely related viruses of the orthopoxvirus genus encode a glutaredoxin gene that is not present in poxviruses outside of this genus. The vaccinia glutaredoxin O2L has been implicated as the reducing agent for ribonucleotide reductase and may thus play an important role in viral deoxyribonucleotide synthesis. As part of an effort to understand nucleotide metabolism by poxviruses, EVM053, the O2L ortholog of the ectromelia virus, has been crystallized. EVM053 crystallizes in space group C222(1), with unit-cell parameters a = 61.98, b = 67.57, c = 108.55 A. Diffraction data have been processed to 1.8 A resolution and a self-rotation function indicates that there are two molecules per asymmetric unit.
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Affiliation(s)
- John-Paul Bacik
- Department of Medical Microbiology and Immunology, 1-15 Medical Sciences Building, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Angela M. Brigley
- Department of Medical Microbiology and Immunology, 1-15 Medical Sciences Building, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Lisa D. Channon
- Department of Medical Microbiology and Immunology, 1-15 Medical Sciences Building, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Gerald F. Audette
- Department of Medical Microbiology and Immunology, 1-15 Medical Sciences Building, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Bart Hazes
- Department of Medical Microbiology and Immunology, 1-15 Medical Sciences Building, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
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26
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Hisabori T, Hara S, Fujii T, Yamazaki D, Hosoya-Matsuda N, Motohashi K. Thioredoxin affinity chromatography: a useful method for further understanding the thioredoxin network. JOURNAL OF EXPERIMENTAL BOTANY 2005; 56:1463-1468. [PMID: 15851412 DOI: 10.1093/jxb/eri170] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Thioredoxin affinity chromatography can be used to recognize the target proteins of thioredoxin or thioredoxin-related proteins in whole cells or certain cellular compartments. In the last couple of years, many potential target proteins have been identified from various organelles and organisms by this method. Based on the information on the target proteins provided by these studies, the complete thioredoxin-related redox networks can now be efficiently described.
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Affiliation(s)
- Toru Hisabori
- Chemical Resources Laboratory, Tokyo Institute of Technology, Nagatsuta 4259, Midori-ku, Yokohama 226-8503, Japan.
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27
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Discola KF, de Oliveira MA, Monteiro Silva G, Barcena JA, Porras P, Padilla A, Netto LES, Guimarães BG. Crystallization and preliminary X-ray crystallographic studies of glutaredoxin 2 from Saccharomyces cerevisiae in different oxidation states. Acta Crystallogr Sect F Struct Biol Cryst Commun 2005; 61:445-7. [PMID: 16511065 PMCID: PMC1952414 DOI: 10.1107/s1744309105008730] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2005] [Accepted: 03/17/2005] [Indexed: 01/17/2023]
Abstract
Glutaredoxins are small (9-12 kDa) heat-stable proteins that are highly conserved throughout evolution; the glutaredoxin active site (Cys-Pro-Tyr-Cys) is conserved in most species. Five glutaredoxin genes have been identified in Saccharomyces cerevisiae; however, Grx2 is responsible for the majority of oxidoreductase activity in the cell, suggesting that its primary function may be the detoxification of mixed disulfides generated by reactive oxygen species (ROS). Recombinant Grx2 was expressed in Escherichia coli as a 6xHis-tagged fusion protein and purified by nickel-affinity chromatography. Prior to crystallization trials, the enzyme was submitted to various treatments with reducing agents and peroxides. Crystals suitable for X-ray diffraction experiments were obtained from untreated protein and protein oxidized with t-butyl hydroperoxide (10 mM). Complete data sets were collected to resolutions 2.15 and 2.05 A for untreated and oxidized Grx2, respectively, using a synchrotron-radiation source. The crystals belong to space group P4(1)2(1)2, with similar unit-cell parameters.
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Affiliation(s)
- Karen Fulan Discola
- Departamento de Biologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão 277, São Paulo, SP, Brazil
| | - Marcos Antonio de Oliveira
- Departamento de Biologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão 277, São Paulo, SP, Brazil
| | - Gustavo Monteiro Silva
- Departamento de Biologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão 277, São Paulo, SP, Brazil
| | - José Antonio Barcena
- Departamento de Bioquímica y Biología Molecular, Campus de Rabanales, Edificio ‘Severo Ochoa’, Universidad de Córdoba, 14071 Córdoba, Spain
| | - Pablo Porras
- Departamento de Bioquímica y Biología Molecular, Campus de Rabanales, Edificio ‘Severo Ochoa’, Universidad de Córdoba, 14071 Córdoba, Spain
| | - Alicia Padilla
- Departamento de Bioquímica y Biología Molecular, Campus de Rabanales, Edificio ‘Severo Ochoa’, Universidad de Córdoba, 14071 Córdoba, Spain
| | - Luis Eduardo Soares Netto
- Departamento de Biologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão 277, São Paulo, SP, Brazil
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28
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Abstract
Glutaredoxin-like proteins form a new subgroup of glutaredoxins with a serine replacing the second cysteine in the CxxC-motif of the active site. Yeast Grx5 is the only glutaredoxin-like protein studied biochemically so far. We identified and cloned three genes encoding glutaredoxin-like proteins from the malaria parasite Plasmodium falciparum (Pf Glp1, Pf Glp2, and Pf Glp3) containing a conserved cysteine in the CGFS-, CKFS-, and CKYS-motif, respectively. Here, we describe biochemical properties of Pf Glp1 and Pf Glp2. Cys 99, the only cysteine residue in Pf Glp1, has a pK(a) value as low as 5.5 and is able to mediate covalent homodimerization. Monomeric and dimeric Pf Glp1 react with GSSG and GSH, respectively. Pf Glp2 is monomeric and both of its cysteine residues can be glutathionylated. Molecular models reveal a thioredoxin fold for the putative C-terminal domain of Pf Glp1, Pf Glp2, and Pf Glp3, as well as conserved residues presumably required for glutathione binding. However, Pf Glp1 and Pf Glp2 neither possess activity in a classical glutaredoxin assay nor display activity as glutathione peroxidase or glutathione S-transferase. Mutation of Ser 102 in the CGFS-motif of Pf Glp1 to cysteine did not generate glutaredoxin activity either. We conclude that, despite their ability to react with glutathione, glutaredoxin-like proteins are a mechanistically and functionally heterogeneous group with only little similarities to canonical glutaredoxins.
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Affiliation(s)
- Marcel Deponte
- Interdisciplinary Research Center, Justus Liebig University, Heinrich-Buff-Ring 26-32, D-35392 Giessen, Germany
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29
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Nardini M, Mazzocco M, Massaro A, Maffei M, Vergano A, Donadini A, Scartezzini P, Bolognesi M. Crystal structure of the glutaredoxin-like protein SH3BGRL3 at 1.6Å resolution. Biochem Biophys Res Commun 2004; 318:470-6. [PMID: 15120624 DOI: 10.1016/j.bbrc.2004.04.050] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2004] [Indexed: 11/19/2022]
Abstract
We report the 1.6 Angstrom resolution crystal structure of SH3BGRL3, a member of a new mammalian protein family of unknown function. The observed "thioredoxin fold" of SH3BGRL3 matches the tertiary structure of glutaredoxins, even in the N-terminal region where the sequence similarity between the two protein families is negligible. In particular, SH3BGRL3 displays structural modifications at the N-terminal Cys-x-x-Cys loop, responsible for glutathione binding and catalysis in glutaredoxins. The loop hosts a six residue insertion, yielding an extra N-terminal-capped helical turn, first observed here for the thioredoxin fold. This, together with deletion of both Cys residues, results in a substantial reshaping of the neighboring cleft, where glutathione is hosted in glutaredoxins. While not active in redox reaction and glutathione binding, SH3BGRL3 may act as an endogenous modulator of glutaredoxin activities by competing, with its fully conserved thioredoxin fold, for binding to yet unknown target proteins.
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Affiliation(s)
- Marco Nardini
- Dipartimento di Fisica-INFM e Centro di Eccellenza per la Ricerca Biomedica, Università di Genova, Via Dodecaneso 33, 16146 Genoa, Italy
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30
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Fernandes AP, Holmgren A. Glutaredoxins: glutathione-dependent redox enzymes with functions far beyond a simple thioredoxin backup system. Antioxid Redox Signal 2004; 6:63-74. [PMID: 14713336 DOI: 10.1089/152308604771978354] [Citation(s) in RCA: 480] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Most cells contain high levels of glutathione and multiple glutaredoxins, which utilize the reducing power of glutathione to catalyze disulfide reductions in the presence of NADPH and glutathione reductase (the glutaredoxin system). Glutaredoxins, like thioredoxins, may operate as dithiol reductants and are involved as alternative pathways in cellular functions such as formation of deoxyribonucleotides for DNA synthesis (by reducing the essential enzyme ribonucleotide reductase), the generation of reduced sulfur (via 3'-phosphoadenylylsulfate reductase), signal transduction, and the defense against oxidative stress. The three dithiol glutaredoxins of E. coli with the active-site sequence CPYC and a glutathione binding site in a thioredoxin/glutaredoxin fold display surprisingly different properties. These include the inducible OxyR-regulated 10-kDa Grx1 or the highly abundant 24-kDa glutathione S-transferase-like Grx2 (with Grx3 it accounts for 1% of total protein). Glutaredoxins uniquely reduce mixed disulfides with glutathione via a monothiol mechanism where only an N-terminal low pKa Cys residue is required, by using their glutathione binding site. Glutaredoxins also catalyze formation of mixed disulfides (glutathionylation), which is an important redox regulatory mechanism, particularly in mammalian cells under oxidative stress conditions, to sense cellular redox potential.
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Affiliation(s)
- Aristi Potamitou Fernandes
- Medical Nobel Institute for Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 77 Stockholm, Sweden
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31
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Johansson C, Lillig CH, Holmgren A. Human mitochondrial glutaredoxin reduces S-glutathionylated proteins with high affinity accepting electrons from either glutathione or thioredoxin reductase. J Biol Chem 2003; 279:7537-43. [PMID: 14676218 DOI: 10.1074/jbc.m312719200] [Citation(s) in RCA: 227] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Glutaredoxins catalyze glutathione-dependent thiol disulfide oxidoreductions via a GSH-binding site and active cysteines. Recently a second human glutaredoxin (Grx2), which is targeted to either mitochondria or the nucleus, was cloned. Grx2 contains the active site sequence CSYC, which is different from the conserved CPYC motif present in the cytosolic Grx1. Here we have compared the activity of Grx2 and Grx1 using glutathionylated substrates and active site mutants. The kinetic studies showed that Grx2 catalyzes the reduction of glutathionylated substrates with a lower rate but higher affinity compared with Grx1, resulting in almost identical catalytic efficiencies (k(cat)/K(m)). Permutation of the active site motifs of Grx1 and Grx2 revealed that the CSYC sequence of Grx2 is a prerequisite for its high affinity toward glutathionylated proteins, which comes at the price of lower k(cat). Furthermore Grx2 was a substrate for NADPH and thioredoxin reductase, which efficiently reduced both the active site disulfide and the GSH-glutaredoxin intermediate formed in the reduction of glutathionylated substrates. Using this novel electron donor pathway, Grx2 reduced low molecular weight disulfides such as CoA but with particular high efficiency glutathionylated substrates including GSSG. These results suggest an important role for Grx2 in protection and recovery from oxidative stress.
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Affiliation(s)
- Catrine Johansson
- Medical Nobel Institute for Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institute, S-171 77 Stockholm, Sweden
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32
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Park HS, Kim C, Kang YK. Preferred conformations of cyclic Ac-Cys-Pro-Xaa-Cys-NHMe peptides: a model for chain reversal and active site of disulfide oxidoreductase. Biophys Chem 2003; 105:89-104. [PMID: 12932582 DOI: 10.1016/s0301-4622(03)00139-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The conformational study on cyclic Ac-Cys-Pro-Xaa-Cys-NHMe (Ac-CPXC-NHMe; X=Ala, Val, Leu, Aib, Gly, His, Phe, Tyr, Asn and Ser) peptides has been carried out using the Empirical Conformational Energy Program for Peptides, version 3 (ECEPP/3) force field and the hydration shell model in the unhydrated and hydrated states. This work has been undertaken to investigate structural implications of the CPXC sequence as the chain reversal for the initiation of protein folding and as the motif for active site of disulfide oxidoreductases. The backbone conformation DAAA is commonly the most feasible for cyclic CPXC peptides in the hydrated state, which has a type I beta-turn at the Pro-Xaa sequence. The proline residue and the hydrogen bond between backbones of two cystines as well as the formation of disulfide bond appear to play a role in stabilizing this preferred conformation of cyclic CPXC peptides. However, the distributions of backbone conformations and beta-turns may indicate that the cyclic CPXC peptide seems to exist as an ensemble of beta-turns and coiled conformations in aqueous solution. The intrinsic stability of the cyclic CPXC motif itself for the active conformation seems to play a role in determining electrochemical properties of disulfide oxidoreductases.
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Affiliation(s)
- Hae Sook Park
- Department of Radiotechnology, Cheju-halla College, Cheju 690-708, South Korea
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33
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Bellí G, Polaina J, Tamarit J, De La Torre MA, Rodríguez-Manzaneque MT, Ros J, Herrero E. Structure-function analysis of yeast Grx5 monothiol glutaredoxin defines essential amino acids for the function of the protein. J Biol Chem 2002; 277:37590-6. [PMID: 12138088 DOI: 10.1074/jbc.m201688200] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Grx5 defines a family of yeast monothiol glutaredoxins that also includes Grx3 and Grx4. All three proteins display significant sequence homology with proteins found from bacteria to humans. Grx5 is involved in iron/sulfur cluster assembly at the mitochondria, but the function of Grx3 and Grx4 is unknown. Three-dimensional modeling based on known dithiol glutaredoxin structures predicted a thioredoxin fold structure for Grx5. Positionally conserved amino acids in this glutaredoxin family were replaced in Grx5, and the effect on the biological function of the protein has been tested. For all changes studied, there was a correlation between the effects on several different phenotypes: sensitivity to oxidants, constitutive protein oxidation, ability for respiratory growth, auxotrophy for a number of amino acids, and iron accumulation. Cys(60) and Gly(61) are essential for Grx5 function, whereas other single or double substitutions in the same region had no phenotypic effects. Gly(115) and Gly(116) could be important for the formation of a glutathione cleft on the Grx5 surface, in contrast to adjacent Cys(117). Substitution of Phe(50) alters the beta-sheet in the thioredoxin fold structure and inhibits Grx5 function. None of the substitutions tested affect the structure at a significant enough level to reduce protein stability.
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Affiliation(s)
- Gemma Bellí
- Departament de Ciències Mèdiques Bàsiques, Facultat de Medicina, Universitat de Lleida, Rovira Roure 44, 25198-Lleida, Spain
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34
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Dixon DP, Davis BG, Edwards R. Functional divergence in the glutathione transferase superfamily in plants. Identification of two classes with putative functions in redox homeostasis in Arabidopsis thaliana. J Biol Chem 2002; 277:30859-69. [PMID: 12077129 DOI: 10.1074/jbc.m202919200] [Citation(s) in RCA: 326] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Searches with the human Omega glutathione transferase (GST) identified two outlying groups of the GST superfamily in Arabidopsis thaliana which differed from all other plant GSTs by containing a cysteine in place of a serine at the active site. One group consisted of four genes, three of which encoded active glutathione-dependent dehydroascorbate reductases (DHARs). Two DHARs were predicted to be cytosolic, whereas the other contained a chloroplast targeting peptide. The DHARs were also active as thiol transferases but had no glutathione conjugating activity. Unlike most other GSTs, DHARs were monomeric. The other class of GST comprised two genes termed the Lambda GSTs (GSTLs). The recombinant GSTLs were also monomeric and had glutathione-dependent thiol transferase activity. One GSTL was cytosolic, whereas the other was chloroplast-targeted. When incubated with oxidized glutathione, the putative active site cysteine of the GSTLs and cytosolic DHARs formed mixed disulfides with glutathione, whereas the plastidic DHAR formed an intramolecular disulfide. DHAR S-glutathionylation was consistent with a proposed catalytic mechanism for dehydroascorbate reduction. Roles for the cytosolic DHARs and GSTLs as antioxidant enzymes were also inferred from the induction of the respective genes following exposure to chemicals and oxidative stress.
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Affiliation(s)
- David P Dixon
- School of Biological and Biomedical Sciences, University of Durham, Durham DH1 3LE, United Kingdom
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35
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Gladyshev VN, Liu A, Novoselov SV, Krysan K, Sun QA, Kryukov VM, Kryukov GV, Lou MF. Identification and characterization of a new mammalian glutaredoxin (thioltransferase), Grx2. J Biol Chem 2001; 276:30374-80. [PMID: 11397793 DOI: 10.1074/jbc.m100020200] [Citation(s) in RCA: 185] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A thiol/disulfide oxidoreductase component of the GSH system, glutaredoxin (Grx), is involved in the reduction of GSH-based mixed disulfides and participates in a variety of cellular redox pathways. A single cytosolic Grx (Grx1) was previously described in mammals. We now report identification and characterization of a second mammalian Grx, designated Grx2. Grx2 exhibited 36% identity with Grx1 and had a disulfide active center containing the Cys-Ser-Tyr-Cys motif. Grx2 was encoded in the genomes of mammals and birds and expressed in a variety of cell types. The gene for human Grx2 consisted of four exons and three introns, spanned 10 kilobase pairs, and localized to chromosome 1q31.2-31.3. The coding sequence was present in all exons, with the first exon encoding a mitochondrial signal peptide. The mitochondrial leader sequence was also present in mouse and rat Grx2 sequences and was shown to direct either Grx2 or green fluorescent protein to mitochondria. Alternative splicing forms of mammalian Grx2 mRNAs were identified that differed in sequences upstream of exon 2. To functionally characterize the new protein, human and mouse Grx2 proteins were expressed in Escherichia coli, and the purified proteins were shown to reduce mixed disulfides formed between GSH and S-sulfocysteine, hydroxyethyldisulfide, or cystine. Grx1 and Grx2 were sensitive to inactivation by iodoacetamide and H(2)O(2) and exhibited similar pH dependence of catalytic activity. However, H(2)O(2)-inactivated Grx2 could only be reactivated with 5 mm GSH, whereas Grx1 could also be reactivated with dithiothreitol or thioredoxin/thioredoxin reductase. The Grx2 structural model suggested a common reaction mechanism for this class of proteins. The data provide the first example of a mitochondrial Grx and also indicate the occurrence of a second functional Grx in mammals.
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Affiliation(s)
- V N Gladyshev
- Department of Biochemistry, University of Nebraska, Lincoln, Nebraska 68588, USA.
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36
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Di Gennaro JA, Siew N, Hoffman BT, Zhang L, Skolnick J, Neilson LI, Fetrow JS. Enhanced functional annotation of protein sequences via the use of structural descriptors. J Struct Biol 2001; 134:232-45. [PMID: 11551182 DOI: 10.1006/jsbi.2001.4391] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In order to circumvent limitations of sequence based methods in the process of making functional predictions for proteins, we have developed a methodology that uses a sequence-to-structure-to-function paradigm. First, an approximate three-dimensional structure is predicted. Then, a three-dimensional descriptor of the functional site, termed a Fuzzy Functional Form, or FFF, is used to screen the structure for the presence of the functional site of interest (Fetrow et al., 1998; Fetrow and Skolnick, 1998). Previously, a disulfide oxidoreductase FFF was developed and applied to predicted structures obtained from a small structural database. Here, using a substantially larger structural database, we expand the analysis of the disulfide oxidoreductase FFF to the B. subtilis genome. To ascertain the performance of the FFF, its results are compared to those obtained using both the sequence alignment method BLAST and three local sequence motif databases: PRINTS, Prosite, and Blocks. The FFF method is then compared in detail to Blocks and it is shown that the FFF is more flexible and sensitive in finding a specific function in a set of unknown proteins. In addition, the estimated false positive rate of function prediction is significantly lower using the FFF structural motif, rather than the standard sequence motif methods. We also present a second FFF and describe a specific example of the results of its whole-genome application to D. melanogaster using a newer threading algorithm. Our results from all of these studies indicate that the addition of three-dimensional structural information adds significant value in the prediction of biochemical function of genomic sequences.
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Affiliation(s)
- J A Di Gennaro
- GeneFormatics, Incorporated, 5830 Oberlin Drive, Suite 200, San Diego, California 92121, USA.
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37
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Cho YW, Kim HG, Park EH, Fuchs JA, Lim CJ. Cloning, expression and regulation of Schizosaccharomyces pombe gene encoding thioltransferase. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1517:171-5. [PMID: 11118633 DOI: 10.1016/s0167-4781(00)00242-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The genomic DNA encoding thioltransferase was isolated from Schizosaccharomyces pombe using the polymerase chain reaction. The amplified DNA fragment was confirmed by Southern hybridization, completely digested with HindIII and BamHI, and then ligated into the yeast-Escherichia coli shuttle vector pRS316, which resulted in plasmid pEH1. The insert of plasmid pEH1 was transferred into the multi-copy vector YEp357 to generate plasmid pYEH1. The determined nucleotide sequence harbors an open reading frame consisting of four exons and three introns, which encodes a polypeptide of 101 amino acids with a molecular mass of 11261 Da. Thioltransferase activity was increased 1.6-fold in Saccharomyces cerevisiae containing plasmid pYEH1, and 1.8- and 2.7-fold in S. pombe containing plasmid pEH1 and pYEH1, respectively. The upstream sequence and the region encoding the N-terminal six amino acids were fused into promoterless beta-galactosidase gene of the shuttle vector YEp357R to generate the fusion plasmid pYEHR1. Synthesis of beta-galactosidase from the fusion plasmid was found to be enhanced by zinc and NO-generating S-nitroso-N-acetylpenicillamine.
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Affiliation(s)
- Y W Cho
- Division of Life Sciences, College of Natural Sciences, Kangwon National University, Chuncheon, South Korea
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38
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Nordstrand K, Sandström A, Aslund F, Holmgren A, Otting G, Berndt KD. NMR structure of oxidized glutaredoxin 3 from Escherichia coli. J Mol Biol 2000; 303:423-32. [PMID: 11031118 DOI: 10.1006/jmbi.2000.4145] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A high precision NMR structure of oxidized glutaredoxin 3 [C65Y] from Escherichia coli has been determined. The conformation of the active site including the disulphide bridge is highly similar to those in glutaredoxins from pig liver and T4 phage. A comparison with the previously determined structure of glutaredoxin 3 [C14S, C65Y] in a complex with glutathione reveals conformational changes between the free and substrate-bound form which includes the sidechain of the conserved, active site tyrosine residue. In the oxidized form this tyrosine is solvent exposed, while it adopts a less exposed conformation, stabilized by hydrogen bonds, in the mixed disulfide with glutathione. The structures further suggest that the formation of a covalent linkage between glutathione and glutaredoxin 3 is necessary in order to induce these structural changes upon binding of the glutathione peptide. This could explain the observed low affinity of glutaredoxins for S-blocked glutathione analogues, in spite of the fact that glutaredoxins are highly specific reductants of glutathione mixed disulfides.
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Affiliation(s)
- K Nordstrand
- Center for Structural Biochemistry Karolinska Institutet, Huddinge, S-141 57, Sweden
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39
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Qin J, Yang Y, Velyvis A, Gronenborn A. Molecular views of redox regulation: three-dimensional structures of redox regulatory proteins and protein complexes. Antioxid Redox Signal 2000; 2:827-40. [PMID: 11213487 DOI: 10.1089/ars.2000.2.4-827] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The last decade has witnessed the explosion of research on redox-controlled cellular and biochemical processes. Whereas the vast majority of these studies have centered on clinical, genetic, and biochemical aspects of redox signaling and regulation inside and outside the cell, a significant number of nuclear magnetic resonance (NMR) and crystallographic studies have been undertaken to obtain an atomic-level understanding of the mechanisms of the redox regulation. This review highlights the recent progress of three-dimensional structure determination of key proteins and protein complexes involved in redox regulation. An increased list of such class of protein structures and their complexes with ligands will provide invaluable insight into the molecular basis of redox-regulatory processes and may be useful for the future development of therapeutic agents for redox-related diseases.
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Affiliation(s)
- J Qin
- Structural Biology Program, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
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40
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Berardi MJ, Bushweller JH. Binding specificity and mechanistic insight into glutaredoxin-catalyzed protein disulfide reduction. J Mol Biol 1999; 292:151-61. [PMID: 10493864 DOI: 10.1006/jmbi.1999.3067] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The reduction equivalents necessary for the ribonucleotide reductase (RNR)-catalyzed production of deoxyribonucleotides are provided by glutaredoxin (Grx) or thioredoxin (Trx). The initial location for transfer of reducing equivalents to RNR is located at the C terminus of the B1 subunit and involves the reduction of a disulfide between Cys754 and Cys759. We have used a 25-mer peptide corresponding to residues 737-761 of RNR B1 (C754-->S) to synthesize a stable mixed disulfide with Escherichia coli Grx-1 (C14-->S) resembling the structure of an intermediate in the reaction. The high-resolution solution structure of the mixed disulfide has been obtained by NMR with an RMSD of 0.56 A for all the backbone atoms of the protein and the well-defined portion of the peptide. The binding interactions responsible for specificity have been identified demonstrating the importance of electrostatic interactions in this system and providing a rationale for the specificity of the Grx-RNR interaction. The disulfide is buried in this complex, implying a solely intra-molecular mechanism of reduction in contrast to the previously determined structure of the glutathione complex where the disulfide was exposed; mutagenesis studies have shown the relevance of intermolecular reduction processes. Substantial conformational changes in the helices of the protein are associated with peptide binding which have significant mechanistic implications for protein disulfide reduction by glutaredoxins.
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Affiliation(s)
- M J Berardi
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22906-0011, USA
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41
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Alphey MS, Leonard GA, Gourley DG, Tetaud E, Fairlamb AH, Hunter WN. The high resolution crystal structure of recombinant Crithidia fasciculata tryparedoxin-I. J Biol Chem 1999; 274:25613-22. [PMID: 10464297 DOI: 10.1074/jbc.274.36.25613] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tryparedoxin-I is a recently discovered thiol-disulfide oxidoreductase involved in the regulation of oxidative stress in parasitic trypanosomatids. The crystal structure of recombinant Crithidia fasciculata tryparedoxin-I in the oxidized state has been determined using multi-wavelength anomalous dispersion methods applied to a selenomethionyl derivative. The model comprises residues 3 to 145 with 236 water molecules and has been refined using all data between a 19- and 1.4-A resolution to an R-factor and R-free of 19.1 and 22.3%, respectively. Despite sharing only about 20% sequence identity, tryparedoxin-I presents a five-stranded twisted beta-sheet and two elements of helical structure in the same type of fold as displayed by thioredoxin, the archetypal thiol-disulfide oxidoreductase. However, the relationship of secondary structure with the linear amino acid sequences is different for each protein, producing a distinctive topology. The beta-sheet core is extended in the trypanosomatid protein with an N-terminal beta-hairpin. There are also differences in the content and orientation of helical elements of secondary structure positioned at the surface of the proteins, which leads to different shapes and charge distributions between human thioredoxin and tryparedoxin-I. A right-handed redox-active disulfide is formed between Cys-40 and Cys-43 at the N-terminal region of a distorted alpha-helix (alpha1). Cys-40 is solvent-accessible, and Cys-43 is positioned in a hydrophilic cavity. Three C-H...O hydrogen bonds donated from two proline residues serve to stabilize the disulfide-carrying helix and support the correct alignment of active site residues. The accurate model for tryparedoxin-I allows for comparisons with the family of thiol-disulfide oxidoreductases and provides a template for the discovery or design of selective inhibitors of hydroperoxide metabolism in trypanosomes. Such inhibitors are sought as potential therapies against a range of human pathogens.
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Affiliation(s)
- M S Alphey
- Department of Biochemistry, The Wellcome Trust Building, University of Dundee, Dundee, DD1 5EH, Scotland, United Kingdom
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42
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Nordstrand K, slund F, Holmgren A, Otting G, Berndt KD. NMR structure of Escherichia coli glutaredoxin 3-glutathione mixed disulfide complex: implications for the enzymatic mechanism. J Mol Biol 1999; 286:541-52. [PMID: 9973569 DOI: 10.1006/jmbi.1998.2444] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Glutaredoxins (Grxs) catalyze reversible oxidation/reduction of protein disulfide groups and glutathione-containing mixed disulfide groups via an active site Grx-glutathione mixed disulfide (Grx-SG) intermediate. The NMR solution structure of the Escherichia coli Grx3 mixed disulfide with glutathione (Grx3-SG) was determined using a C14S mutant which traps this intermediate in the redox reaction. The structure contains a thioredoxin fold, with a well-defined binding site for glutathione which involves two intermolecular backbone-backbone hydrogen bonds forming an antiparallel intermolecular beta-bridge between the protein and glutathione. The solution structure of E. coli Grx3-SG also suggests a binding site for a second glutathione in the reduction of the Grx3-SG intermediate, which is consistent with the specificity of reduction observed in Grxs. Molecular details of the structure in relation to the stability of the intermediate and the activity of Grx3 as a reductant of glutathione mixed disulfide groups are discussed. A comparison of glutathione binding in Grx3-SG and ligand binding in other members of the thioredoxin superfamily is presented, which illustrates the highly conserved intermolecular interactions in this protein family.
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Affiliation(s)
- K Nordstrand
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, S-171 77, Stockholm, Sweden
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43
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Schröder E, Ponting CP. Evidence that peroxiredoxins are novel members of the thioredoxin fold superfamily. Protein Sci 1998; 7:2465-8. [PMID: 9828014 PMCID: PMC2143874 DOI: 10.1002/pro.5560071125] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Peroxiredoxins catalyze reduction of hydrogen peroxide or alkyl peroxide, to water or the corresponding alcohol. Detailed analysis of their sequences indicates that these enzymes possess a thioredoxin (Trx)-like fold and consequently are homologues of both thioredoxin and glutathione peroxidase (GPx). Sequence- and structure-based multiple sequence alignments indicate that the peroxiredoxin active site cysteine and GPx active site selenocysteine are structurally equivalent. Homologous peroxiredoxin and GPx enzymes are predicted to catalyze equivalent reactions via similar reaction intermediates.
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Affiliation(s)
- E Schröder
- Department of Chemistry, University of Exeter, United Kingdom
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44
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Fetrow JS, Skolnick J. Method for prediction of protein function from sequence using the sequence-to-structure-to-function paradigm with application to glutaredoxins/thioredoxins and T1 ribonucleases. J Mol Biol 1998; 281:949-68. [PMID: 9719646 DOI: 10.1006/jmbi.1998.1993] [Citation(s) in RCA: 170] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The practical exploitation of the vast numbers of sequences in the genome sequence databases is crucially dependent on the ability to identify the function of each sequence. Unfortunately, current methods, including global sequence alignment and local sequence motif identification, are limited by the extent of sequence similarity between sequences of unknown and known function; these methods increasingly fail as the sequence identity diverges into and beyond the twilight zone of sequence identity. To address this problem, a novel method for identification of protein function based directly on the sequence-to-structure-to-function paradigm is described. Descriptors of protein active sites, termed "fuzzy functional forms" or FFFs, are created based on the geometry and conformation of the active site. By way of illustration, the active sites responsible for the disulfide oxidoreductase activity of the glutaredoxin/thioredoxin family and the RNA hydrolytic activity of the T1 ribonuclease family are presented. First, the FFFs are shown to correctly identify their corresponding active sites in a library of exact protein models produced by crystallography or NMR spectroscopy, most of which lack the specified activity. Next, these FFFs are used to screen for active sites in low-to-moderate resolution models produced by ab initio folding or threading prediction algorithms. Again, the FFFs can specifically identify the functional sites of these proteins from their predicted structures. The results demonstrate that low-to-moderate resolution models as produced by state-of-the-art tertiary structure prediction algorithms are sufficient to identify protein active sites. Prediction of a novel function for the gamma subunit of a yeast glycosyl transferase and prediction of the function of two hypothetical yeast proteins whose models were produced via threading are presented. This work suggests a means for the large-scale functional screening of genomic sequence databases based on the prediction of structure from sequence, then on the identification of functional active sites in the predicted structure.
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Affiliation(s)
- J S Fetrow
- Center for Biochemistry and Biophysics, University at Albany, SUNY, 1400 Washington Avenue, Albany, NY 12222, USA
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45
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Sun C, Berardi MJ, Bushweller JH. The NMR solution structure of human glutaredoxin in the fully reduced form. J Mol Biol 1998; 280:687-701. [PMID: 9677297 DOI: 10.1006/jmbi.1998.1913] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The determination of the nuclear magnetic resonance (NMR) solution structure of fully reduced human glutaredoxin is described. A total of 1159 useful nuclear Overhauser effect (NOE) upper distance constraints and 187 dihedral angle constraints were obtained as the input for the structure calculations for which the torsion angle dynamics program DYANA has been utilized followed by energy minimization in water with the AMBER force field as implemented in the program OPAL. The resulting 20 conformers have an average root-mean-square deviation value relative to the mean coordinates of 0.54 A for all the backbone atoms N, Calpha and C', and of 1.01 A for all heavy atoms. Human glutaredoxin consists of a four-stranded mixed beta-sheet composed of residues 15 to 19, 43 to 47, 72 to 75 and 78 to 81, and five alpha-helices composed of residues 4 to 9, 24 to 34, 54 to 65, 83 to 91, and 94 to 100. Comparisons with the structures of Escherichia coli glutaredoxin-1, pig liver glutaredoxin and human thioredoxin were made. Electrostatic calculations on the human glutaredoxin structure and that of related proteins provide an understanding of the variation of pKa values for the nucleophilic cysteine in the active site observed among these proteins. In addition, the high-resolution NMR solution structure of human glutaredoxin has been used to model the binding site for glutathione and for ribonucleotide reductase B1 by molecular dynamics simulations.
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Affiliation(s)
- C Sun
- Department of Chemistry, Dartmouth College, Hanover, NH 03755, USA
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46
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Huber-Wunderlich M, Glockshuber R. A single dipeptide sequence modulates the redox properties of a whole enzyme family. FOLDING & DESIGN 1998; 3:161-71. [PMID: 9562546 DOI: 10.1016/s1359-0278(98)00024-8] [Citation(s) in RCA: 165] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Disulfide exchange reactions are catalyzed by thiol/disulfide oxidoreductases. These enzymes possess a thioredoxin fold and contain a catalytic disulfide with the sequence Cys-X-X-Cys at the N terminus of an alpha helix. Despite these similarities, the various members differ strongly in their redox potentials (-122 mV to -270 mV). Using the strong oxidant DsbA from Escherichia coli as a model system, we investigated whether the redox properties of these enzymes can be modulated rationally by exchange of the X-X dipeptide. RESULTS The X-X dipeptide of DsbA (Cys30-Pro31-His32-Cys33) was exchanged by the dipeptides of eukaryotic protein disulfide isomerase (PDI; Gly-His), glutaredoxin (Pro-Tyr), and thioredoxin (Gly-Pro) from E. coli. All variants were less oxidizing than wild-type DsbA and their redox potentials were in the order of the related natural enzymes (DsbA > PDI > glutaredoxin > thioredoxin). The equilibrium constant between glutathione and the thioredoxin-like variant increased 1200-fold compared with wild-type DsbA. The variants also showed a strong increase in the pKa of the nucleophilic cysteine (Cys30). As for glutaredoxin and thioredoxin, the catalytic disulfide stabilized the corresponding variants while destabilizing wild-type DsbA and the PDI-like variant. CONCLUSIONS The X-X dipeptide in the active site of thiol/disulfide oxidoreductases appears to be the main determinant of the redox properties of these enzymes. This empirical finding should be very useful for the design of new thiol/disulfide oxidoreductases with altered redox potentials and for studying the function of these enzymes in vivo.
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Affiliation(s)
- M Huber-Wunderlich
- Institut für Molekularbiologie und Biophysik, Eidgenössische Technische Hochschule, Hönggerberg CH-8093, Zürich, Switzerland
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47
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Mössner E, Huber-Wunderlich M, Glockshuber R. Characterization of Escherichia coli thioredoxin variants mimicking the active-sites of other thiol/disulfide oxidoreductases. Protein Sci 1998; 7:1233-44. [PMID: 9605329 PMCID: PMC2144011 DOI: 10.1002/pro.5560070519] [Citation(s) in RCA: 149] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Thiol/disulfide oxidoreductases like thioredoxin, glutaredoxin, DsbA, or protein disulfide isomerase (PDI) share the thioredoxin fold and a catalytic disulfide bond with the sequence Cys-Xaa-Xaa-Cys (Xaa corresponds to any amino acid). Despite their structural similarities, the enzymes have very different redox properties, which is reflected by a 100,000-fold difference in the equilibrium constant (K(eq)) with glutathione between the most oxidizing member, DsbA, and the most reducing member, thioredoxin. Here we present a systematic study on a series of variants of thioredoxin from Escherichia coli, in which the Xaa-Xaa dipeptide was exchanged by that of glutaredoxin, PDI, and DsbA. Like the corresponding natural enzymes, all thioredoxin variants proved to be stronger oxidants than the wild-type, with the order wild-type < PDI-type < DsbA-type < glutaredoxin-type. The most oxidizing, glutaredoxin-like variant has a 420-fold decreased value of K(eq), corresponding to an increase in redox potential by 75 mV. While oxidized wild-type thioredoxin is more stable than the reduced form (delta deltaG(ox/red) = 16.9 kJ/mol), both redox forms have almost the same stability in the variants. The pH-dependence of the reactivity with the alkylating agent iodoacetamide proved to be the best method to determine the pKa value of thioredoxin's nucleophilic active-site thiol (Cys32). A pKa of 7.1 was measured for Cys32 in the reduced wild-type. All variants showed a lowered pKa of Cys32, with the lowest value of 5.9 for the glutaredoxin-like variant. A correlation of redox potential and the Cys32 pKa value could be established on a quantitative level. However, the predicted correlation between the measured delta deltaG(ox/red) values and Cys32 pKa values was only qualitative.
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Affiliation(s)
- E Mössner
- Institut für Molekularbiologie und Biophysik, Eidgenössische Technische Hochschule Hönggerberg, Zürich, Switzerland
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Moutiez M, Quéméneur E, Sergheraert C, Lucas V, Tartar A, Davioud-Charvet E. Glutathione-dependent activities of Trypanosoma cruzi p52 makes it a new member of the thiol:disulphide oxidoreductase family. Biochem J 1997; 322 ( Pt 1):43-8. [PMID: 9078241 PMCID: PMC1218156 DOI: 10.1042/bj3220043] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Trypanothione: glutathione disulphide thioltransferase of Try-panosoma cruzi (p52) is a key enzyme in the regulation of the intracellular thiol-disulphide redox balance by reducing glutathione disulphide. Here we show that p52, like other disulphide oxidoreductases possessing the CXXC active site motif, catalyses the reduction of low-molecular-mass disulphides (hydroxyethyl-disulphide) as well as protein disulphides (insulin). However, p52 seems to be a poor oxidase under physiological conditions as evidenced by its very low rate for oxidative renaturation of reduced ribonuclease A Like thioltransferase and protein disulphide isomerase, p52 was found to possess a glutathione-dependent dehydroascorbate reductase activity. The kinetic parameters were in the same range as those determined for mammalian dehydroascorbate reductases. A catalytic mechanism taking into account both trypanothione- and glutathione-dependent reduction reactions was proposed. This newly characterized enzyme is specific for the parasite and provides a new target for specific chemotherapy.
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Affiliation(s)
- M Moutiez
- Service de Chimie des biomolécules, URA CNRS 1309, Institut Pasteur de Lille, France
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49
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Sun C, Holmgren A, Bushweller JH. Complete 1H, 13C, and 15N NMR resonance assignments and secondary structure of human glutaredoxin in the fully reduced form. Protein Sci 1997; 6:383-90. [PMID: 9041640 PMCID: PMC2143634 DOI: 10.1002/pro.5560060214] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Human glutaredoxin is a member of the glutaredoxin family, which is characterized by a glutathione binding site and a redox-active dithiol/disulfide in the active site. Unlike Escherichia coli glutaredoxin-1, this protein has additional cysteine residues that have been suggested to play a regulatory role in its activity. Human glutaredoxin (106 amino acid residues, M(r) = 12,000) has been purified from a pET expression vector with both uniform 15N labeling and 13C/15N double labeling. The combination of three-dimensional 15N-edited TOCSY, 15N-edited NOESY, HNCA, HN(CO)CA, and gradient sensitivity-enhanced HNCACB and HNCO spectra were used to obtain sequential assignments for residues 2-106 of the protein. The gradient-enhanced version of the HCCH-TOCSY pulse sequence and HCCH-COSY were used to obtain side chain 1H and 13C assignments. The secondary structural elements in the reduced protein were identified based on NOE information, amide proton exchange data, and chemical shift index data. Human glutaredoxin contains five helices extending approximately from residues 4-10, 24-36, 53-64, 83-92, and 94-104. The secondary structure also shows four beta-strands comprised of residues 15-19, 43-48, 71-75, 78-80, which form a beta-sheet almost identical to that found in E. coli glutaredoxin-1. Complete 1H, 13C, and 15N assignments and the secondary structure of fully reduced human glutaredoxin are presented. Comparison to the structures of other glutaredoxins is presented and differences in the secondary structure elements are discussed.
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Affiliation(s)
- C Sun
- Department of Chemistry, Dartmouth College, Hanover, New Hampshire 03755, USA
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