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Tang M, Li J, Cai X, Sun T, Chen C. Single-atom Nanozymes for Biomedical Applications: Recent Advances and Challenges. Chem Asian J 2022; 17:e202101422. [PMID: 35143111 DOI: 10.1002/asia.202101422] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 02/08/2022] [Indexed: 11/07/2022]
Abstract
Nanozymes have received extensive attention in the fields of sensing and detection, medical therapy, industry, and agriculture thanks to the combination of the catalytic properties of natural enzymes and the physicochemical properties of nanomaterials, coupled with superior stability and ease of preparation. Despite the promise of nanozymes, conventional nanozymes are constrained by their oversized size and low catalytic capacity in sophisticated practical application environments. single-atom nanozymes (SAzymes) were characterized as nanozymes with high catalytic efficiency by uniformly distributed single atoms as catalysis sites, thus effectively addressing the defects of conventional nanozymes. This paper reviews the activity improvement scheme and catalytic mechanism of SAzymes and highlights the latest research progress of SAzymes in the fields of biomedical sensing and therapy. Eventually, the challenges and future directions of SAzymes are discussed in this paper.
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Affiliation(s)
- Minglu Tang
- Northeast Forestry University, Department of chemistry, CHINA
| | - Jingqi Li
- Northeast Forestry University, Department of chemistry, CHINA
| | - Xinda Cai
- Northeast Forestry University, Department of chemistry, CHINA
| | - Tiedong Sun
- Northeast Forestry University, 26 Hexing road, Xiangfang district, Harbin city, Heilongjiang province, 150040, Harbin, CHINA
| | - Chunxia Chen
- Northeast Forestry University, Department of chemistry, CHINA
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Bacterial Metabolites of Human Gut Microbiota Correlating with Depression. Int J Mol Sci 2020; 21:ijms21239234. [PMID: 33287416 PMCID: PMC7730936 DOI: 10.3390/ijms21239234] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 11/23/2020] [Accepted: 12/02/2020] [Indexed: 02/06/2023] Open
Abstract
Depression is a global threat to mental health that affects around 264 million people worldwide. Despite the considerable evolution in our understanding of the pathophysiology of depression, no reliable biomarkers that have contributed to objective diagnoses and clinical therapy currently exist. The discovery of the microbiota-gut-brain axis induced scientists to study the role of gut microbiota (GM) in the pathogenesis of depression. Over the last decade, many of studies were conducted in this field. The productions of metabolites and compounds with neuroactive and immunomodulatory properties among mechanisms such as the mediating effects of the GM on the brain, have been identified. This comprehensive review was focused on low molecular weight compounds implicated in depression as potential products of the GM. The other possible mechanisms of GM involvement in depression were presented, as well as changes in the composition of the microbiota of patients with depression. In conclusion, the therapeutic potential of functional foods and psychobiotics in relieving depression were considered. The described biomarkers associated with GM could potentially enhance the diagnostic criteria for depressive disorders in clinical practice and represent a potential future diagnostic tool based on metagenomic technologies for assessing the development of depressive disorders.
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Mavi PS, Singh S, Kumar A. Reductive Stress: New Insights in Physiology and Drug Tolerance of Mycobacterium. Antioxid Redox Signal 2020; 32:1348-1366. [PMID: 31621379 DOI: 10.1089/ars.2019.7867] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Significance:Mycobacterium tuberculosis (Mtb) encounters reductive stress during its infection cycle. Notably, host-generated protective responses, such as acidic pH inside phagosomes and lysosomes, exposure to glutathione in alveolar hypophase (i.e., a thin liquid lining consisting of surfactant and proteins in the alveolus), and hypoxic environments inside granulomas are associated with the accumulation of reduced cofactors, such as nicotinamide adenine dinucleotide (reduced form), nicotinamide adenine dinucleotide phosphate, flavin adenine dinucleotide (reduced form), and nonprotein thiols (e.g., mycothiol), leading to reductive stress in Mtb cells. Dissipation of this reductive stress is important for survival of the bacterium. If reductive stress is not dissipated, it leads to generation of reactive oxygen species, which may be fatal for the cells. Recent Advances: This review focuses on mechanisms utilized by mycobacteria to sense and respond to reductive stress. Importantly, exposure of Mtb cells to reductive stress leads to growth inhibition, altered metabolism, modulation of virulence, and drug tolerance. Mtb is equipped with thiol buffering systems of mycothiol and ergothioneine to protect itself from various redox stresses. These systems are complemented by thioredoxin and thioredoxin reductase (TR) systems for maintaining cellular redox homeostasis. A diverse array of sensors is used by Mycobacterium for monitoring its intracellular redox status. Upon sensing reductive stress, Mtb uses a flexible and robust metabolic system for its dissipation. Branched electron transport chain allows Mycobacterium to function with different terminal electron acceptors and modulate proton motive force to fulfill energy requirements under diverse scenarios. Interestingly, Mtb utilizes variations in the tricarboxylic cycle and a number of dehydrogenases to dissipate reductive stress. Upon prolonged exposure to reductive stress, Mtb utilizes biosynthesis of storage and virulence lipids as a dissipative mechanism. Critical Issues: The mechanisms utilized by Mycobacterium for sensing and tackling reductive stress are not well characterized. Future Directions: The precise role of thiol buffering and TR systems in neutralizing reductive stress is not well defined. Genetic systems that respond to metabolic reductive stress and thiol reductive stress need to be mapped. Genetic screens could aid in identification of such systems. Given that management of reductive stress is critical for both actively replicating and persister mycobacteria, an improved understanding of the mechanisms used by mycobacteria for dissipation of reductive stress may lead to identification of vulnerable choke points that could be targeted for killing Mtb in vivo.
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Affiliation(s)
- Parminder Singh Mavi
- Institute of Microbial Technology, Council of Scientific and Industrial Research, Chandigarh, India
| | - Shweta Singh
- Institute of Microbial Technology, Council of Scientific and Industrial Research, Chandigarh, India
| | - Ashwani Kumar
- Institute of Microbial Technology, Council of Scientific and Industrial Research, Chandigarh, India.,Academy of Scientific and Innovative Research, Ghaziabad, India
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Al-Madboly LA, Ali SM, Fakharany EME, Ragab AE, Khedr EG, Elokely KM. Stress-Based Production, and Characterization of Glutathione Peroxidase and Glutathione S-Transferase Enzymes From Lactobacillus plantarum. Front Bioeng Biotechnol 2020; 8:78. [PMID: 32181246 PMCID: PMC7057912 DOI: 10.3389/fbioe.2020.00078] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 01/29/2020] [Indexed: 01/08/2023] Open
Abstract
More attention has been recently directed toward glutathione peroxidase and s-transferase enzymes because of the great importance they hold with respect to their applications in the pharmaceutical field. This work was conducted to optimize the production and characterize glutathione peroxidase and glutathione s-transferase produced by Lactobacillus plantarum KU720558 using Plackett-Burman and Box-Behnken statistical designs. To assess the impact of the culture conditions on the microbial production of the enzymes, colorimetric methods were used. Following data analysis, the optimum conditions that enhanced the s-transferase yield were the De Man-Rogosa-Sharp (MRS) broth as a basal medium supplemented with 0.1% urea, 0.075% H2O2, 0.5% 1-butanol, 0.0125% amino acids, and 0.05% SDS at pH 6.0 and anaerobically incubated for 24 h at 40°C. The optimum s-transferase specific activity was 1789.5 U/mg of protein, which was ~12 times the activity of the basal medium. For peroxidase, the best medium composition was 0.17% urea, 0.025% bile salt, 7.5% Na Cl, 0.05% H2O2, 0.05% SDS, and 2% ethanol added to the MRS broth at pH 6.0 and anaerobically incubated for 24 h at 40°C. Furthermore, the optimum peroxidase specific activity was 612.5 U/mg of protein, indicating that its activity was 22 times higher than the activity recorded in the basal medium. After SDS-PAGE analysis, GST and GPx showed a single protein band of 25 and 18 kDa, respectively. They were able to retain their activities at an optimal temperature of 40°C for an hour and pH range 4–7. The 3D model of both enzymes was constructed showing helical structures, sheet and loops. Protein cavities were also detected to define druggable sites. GST model had two large pockets; 185Å3 and 71 Å3 with druggability score 0.5–0.8. For GPx, the pockets were relatively smaller, 71 Å3 and 32 Å3 with druggability score (0.65–0.66). Therefore, the present study showed that the consortium components as well as the stress-based conditions used could express both enzymes with enhanced productivity, recommending their application based on the obtained results.
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Affiliation(s)
- Lamiaa A Al-Madboly
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, Tanta University, Tanta, Egypt
| | - Safaa M Ali
- Nucleic Acid Research Department, Genetic Engineering and Biotechnology Research Institute (GEBRI), City for Scientific Research and Technology Applications, Alexandria, Egypt
| | - Esmail M El Fakharany
- Protein Research Department, Genetic Engineering and Biotechnology Research Institute GEBRI, City for Scientific Research and Technology Applications, New Borg EL Arab, Egypt
| | - Amany E Ragab
- Department of Pharmacognosy, Faculty of Pharmacy, Tanta University, Tanta, Egypt
| | - Eman G Khedr
- Department of Biochemistry, Faculty of Pharmacy, Tanta University, Tanta, Egypt
| | - Khaled M Elokely
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Tanta University, Tanta, Egypt.,Institute for Computational Molecular Science, and Department of Chemistry, Temple University, Philadelphia, PA, United States.,Division of Pharmaceutical Sciences, Arnold and Marie Schwartz College of Pharmacy and Health Sciences, Long Island University, Brooklyn, NY, United States
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Cross Talk between SigB and PrfA in Listeria monocytogenes Facilitates Transitions between Extra- and Intracellular Environments. Microbiol Mol Biol Rev 2019; 83:83/4/e00034-19. [PMID: 31484692 DOI: 10.1128/mmbr.00034-19] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The foodborne pathogen Listeria monocytogenes can modulate its transcriptome and proteome to ensure its survival during transmission through vastly differing environmental conditions. While L. monocytogenes utilizes a large array of regulators to achieve survival and growth in different intra- and extrahost environments, the alternative sigma factor σB and the transcriptional activator of virulence genes protein PrfA are two key transcriptional regulators essential for responding to environmental stress conditions and for host infection. Importantly, emerging evidence suggests that the shift from extrahost environments to the host gastrointestinal tract and, subsequently, to intracellular environments requires regulatory interplay between σB and PrfA at transcriptional, posttranscriptional, and protein activity levels. Here, we review the current evidence for cross talk and interplay between σB and PrfA and their respective regulons and highlight the plasticity of σB and PrfA cross talk and the role of this cross talk in facilitating successful transition of L. monocytogenes from diverse extrahost to diverse extra- and intracellular host environments.
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Miller CG, Holmgren A, Arnér ESJ, Schmidt EE. NADPH-dependent and -independent disulfide reductase systems. Free Radic Biol Med 2018; 127:248-261. [PMID: 29609022 PMCID: PMC6165701 DOI: 10.1016/j.freeradbiomed.2018.03.051] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 03/26/2018] [Accepted: 03/29/2018] [Indexed: 12/20/2022]
Abstract
Over the past seven decades, research on autotrophic and heterotrophic model organisms has defined how the flow of electrons ("reducing power") from high-energy inorganic sources, through biological systems, to low-energy inorganic products like water, powers all of Life's processes. Universally, an initial major biological recipient of these electrons is nicotinamide adenine dinucleotide-phosphate, which thereby transits from an oxidized state (NADP+) to a reduced state (NADPH). A portion of this reducing power is then distributed via the cellular NADPH-dependent disulfide reductase systems as sequential reductions of disulfide bonds. Along the disulfide reduction pathways, some enzymes have active sites that use the selenium-containing amino acid, selenocysteine, in place of the common but less reactive sulfur-containing cysteine. In particular, the mammalian/metazoan thioredoxin systems are usually selenium-dependent as, across metazoan phyla, most thioredoxin reductases are selenoproteins. Among the roles of the NADPH-dependent disulfide reductase systems, the most universal is that they provide the reducing power for the production of DNA precursors by ribonucleotide reductase (RNR). Some studies, however, have uncovered examples of NADPH-independent disulfide reductase systems that can also support RNR. These systems are summarized here and their implications are discussed.
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Affiliation(s)
- Colin G Miller
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, MT 59717, USA; Department of Microbiology & Immunology, Montana State University, Bozeman, MT 59717, USA
| | - Arne Holmgren
- Division of Biochemistry, Department of Medical Biochemistry & Biophysics, Karolinska Institutet, SE 171 77 Stockholm, Sweden
| | - Elias S J Arnér
- Division of Biochemistry, Department of Medical Biochemistry & Biophysics, Karolinska Institutet, SE 171 77 Stockholm, Sweden
| | - Edward E Schmidt
- Department of Microbiology & Immunology, Montana State University, Bozeman, MT 59717, USA.
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Low-Molecular-Weight Thiols and Thioredoxins Are Important Players in Hg(II) Resistance in Thermus thermophilus HB27. Appl Environ Microbiol 2018; 84:AEM.01931-17. [PMID: 29150497 DOI: 10.1128/aem.01931-17] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 10/24/2017] [Indexed: 12/31/2022] Open
Abstract
Mercury (Hg), one of the most toxic and widely distributed heavy metals, has a high affinity for thiol groups. Thiol groups reduce and sequester Hg. Therefore, low-molecular-weight (LMW) and protein thiols may be important cell components used in Hg resistance. To date, the role of low-molecular-weight thiols in Hg detoxification remains understudied. The mercury resistance (mer) operon of Thermus thermophilus suggests an evolutionary link between Hg(II) resistance and low-molecular-weight thiol metabolism. The mer operon encodes an enzyme involved in methionine biosynthesis, Oah. Challenge with Hg(II) resulted in increased expression of genes involved in the biosynthesis of multiple low-molecular-weight thiols (cysteine, homocysteine, and bacillithiol), as well as the thioredoxin system. Phenotypic analysis of gene replacement mutants indicated that Oah contributes to Hg resistance under sulfur-limiting conditions, and strains lacking bacillithiol and/or thioredoxins are more sensitive to Hg(II) than the wild type. Growth in the presence of either a thiol-oxidizing agent or a thiol-alkylating agent increased sensitivity to Hg(II). Furthermore, exposure to 3 μM Hg(II) consumed all intracellular reduced bacillithiol and cysteine. Database searches indicate that oah2 is present in all Thermus sp. mer operons. The presence of a thiol-related gene was also detected in some alphaproteobacterial mer operons, in which a glutathione reductase gene was present, supporting the role of thiols in Hg(II) detoxification. These results have led to a working model in which LMW thiols act as Hg(II)-buffering agents while Hg is reduced by MerA.IMPORTANCE The survival of microorganisms in the presence of toxic metals is central to life's sustainability. The affinity of thiol groups for toxic heavy metals drives microbe-metal interactions and modulates metal toxicity. Mercury detoxification (mer) genes likely originated early in microbial evolution in geothermal environments. Little is known about how mer systems interact with cellular thiol systems. Thermus spp. possess a simple mer operon in which a low-molecular-weight thiol biosynthesis gene is present, along with merR and merA In this study, we present experimental evidence for the role of thiol systems in mercury resistance. Our data suggest that, in T. thermophilus, thiolated compounds may function side by side with mer genes to detoxify mercury. Thus, thiol systems function in consort with mer-mediated resistance to mercury, suggesting exciting new questions for future research.
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Dead-end complex, lipid interactions and catalytic mechanism of microsomal glutathione transferase 1, an electron crystallography and mutagenesis investigation. Sci Rep 2017; 7:7897. [PMID: 28801553 PMCID: PMC5554250 DOI: 10.1038/s41598-017-07912-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 07/04/2017] [Indexed: 01/01/2023] Open
Abstract
Microsomal glutathione transferase 1 (MGST1) is a detoxification enzyme belonging to the Membrane Associated Proteins in Eicosanoid and Glutathione Metabolism (MAPEG) superfamily. Here we have used electron crystallography of two-dimensional crystals in order to determine an atomic model of rat MGST1 in a lipid environment. The model comprises 123 of the 155 amino acid residues, two structured phospholipid molecules, two aliphatic chains and one glutathione (GSH) molecule. The functional unit is a homotrimer centered on the crystallographic three-fold axes of the unit cell. The GSH substrate binds in an extended conformation at the interface between two subunits of the trimer supported by new in vitro mutagenesis data. Mutation of Arginine 130 to alanine resulted in complete loss of activity consistent with a role for Arginine 130 in stabilizing the strongly nucleophilic GSH thiolate required for catalysis. Based on the new model and an electron diffraction data set from crystals soaked with trinitrobenzene, that forms a dead-end Meisenheimer complex with GSH, a difference map was calculated. The map reveals side chain movements opening a cavity that defines the second substrate site.
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Mora-Lorca JA, Sáenz-Narciso B, Gaffney CJ, Naranjo-Galindo FJ, Pedrajas JR, Guerrero-Gómez D, Dobrzynska A, Askjaer P, Szewczyk NJ, Cabello J, Miranda-Vizuete A. Glutathione reductase gsr-1 is an essential gene required for Caenorhabditis elegans early embryonic development. Free Radic Biol Med 2016; 96:446-61. [PMID: 27117030 PMCID: PMC8386055 DOI: 10.1016/j.freeradbiomed.2016.04.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 04/18/2016] [Indexed: 12/22/2022]
Abstract
Glutathione is the most abundant thiol in the vast majority of organisms and is maintained in its reduced form by the flavoenzyme glutathione reductase. In this work, we describe the genetic and functional analysis of the Caenorhabditis elegans gsr-1 gene that encodes the only glutathione reductase protein in this model organism. By using green fluorescent protein reporters we demonstrate that gsr-1 produces two GSR-1 isoforms, one located in the cytoplasm and one in the mitochondria. gsr-1 loss of function mutants display a fully penetrant embryonic lethal phenotype characterized by a progressive and robust cell division delay accompanied by an aberrant distribution of interphasic chromatin in the periphery of the cell nucleus. Maternally expressed GSR-1 is sufficient to support embryonic development but these animals are short-lived, sensitized to chemical stress, have increased mitochondrial fragmentation and lower mitochondrial DNA content. Furthermore, the embryonic lethality of gsr-1 worms is prevented by restoring GSR-1 activity in the cytoplasm but not in mitochondria. Given the fact that the thioredoxin redox systems are dispensable in C. elegans, our data support a prominent role of the glutathione reductase/glutathione pathway in maintaining redox homeostasis in the nematode.
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Affiliation(s)
- José Antonio Mora-Lorca
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, 41013 Sevilla, Spain; Departamento de Farmacología, Facultad de Farmacia, Universidad de Sevilla, 41012 Sevilla, Spain
| | | | - Christopher J Gaffney
- MRC/ARUK Centre for Musculoskeletal Ageing Research, University of Nottingham and Medical School Royal Derby Hospital, DE22 3DT Derby, United Kingdom
| | - Francisco José Naranjo-Galindo
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, 41013 Sevilla, Spain
| | - José Rafael Pedrajas
- Grupo de Bioquímica y Señalización Celular, Departamento de Biología Experimental, Universidad de Jaén, 23071 Jaén, Spain
| | - David Guerrero-Gómez
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, 41013 Sevilla, Spain
| | - Agnieszka Dobrzynska
- Andalusian Center for Developmental Biology (CABD), CSIC/JA/Universidad Pablo de Olavide, 41013 Seville, Spain
| | - Peter Askjaer
- Andalusian Center for Developmental Biology (CABD), CSIC/JA/Universidad Pablo de Olavide, 41013 Seville, Spain
| | - Nathaniel J Szewczyk
- MRC/ARUK Centre for Musculoskeletal Ageing Research, University of Nottingham and Medical School Royal Derby Hospital, DE22 3DT Derby, United Kingdom
| | - Juan Cabello
- Center for Biomedical Research of La Rioja (CIBIR), 26006 Logroño, Spain.
| | - Antonio Miranda-Vizuete
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, 41013 Sevilla, Spain.
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Edgcomb VP, Pachiadaki MG, Mara P, Kormas KA, Leadbetter ER, Bernhard JM. Gene expression profiling of microbial activities and interactions in sediments under haloclines of E. Mediterranean deep hypersaline anoxic basins. ISME JOURNAL 2016; 10:2643-2657. [PMID: 27093045 DOI: 10.1038/ismej.2016.58] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 02/11/2016] [Accepted: 03/03/2016] [Indexed: 11/09/2022]
Abstract
Deep-sea hypersaline anoxic basins (DHABs) in the Eastern Mediterranean Sea are considered some of the most polyextreme habitats on Earth. In comparison to microbial activities occurring within the haloclines and brines of these unusual water column habitats near the Mediterranean seafloor, relatively little is known about microbial metabolic activities in the underlying sediments. In addition, it is not known whether activities are shaped by the unique chemistries of the different DHAB brines and whether evidence exists for active microbial eukaryotes in those sediments. Metatranscriptome analysis was applied to sediment samples collected using ROV Jason from underneath the haloclines of Urania, Discovery and L'Atalante DHABs and a control site. We report on expression of genes associated with sulfur and nitrogen cycling, putative osmolyte biosynthetic pathways and ion transporters, trace metal detoxification, selected eukaryotic activities (particularly of fungi), microbe-microbe interactions, and motility in sediments underlying the haloclines of three DHABs. Relative to our control sediment sample collected outside of Urania Basin, microbial communities (including eukaryotes) in the Urania and Discovery DHAB sediments showed upregulation of expressed genes associated with nitrogen transformations, osmolyte biosynthesis, heavy metals resistance and metabolism, eukaryotic organelle functions, and cell-cell interactions. Sediments underlying DHAB haloclines that have cumulative physico-chemical stressors within the limits of tolerance for microoorganisms can therefore be hotspots of activity in the deep Mediterranean Sea.
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Affiliation(s)
- Virginia P Edgcomb
- Department of Geology & Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Maria G Pachiadaki
- Department of Geology & Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Paraskevi Mara
- Department of Chemistry, University of Crete, Heraklion, Greece
| | - Konstantinos A Kormas
- Department of Ichthyology & Aquatic Environment, University of Thessaly, Volos, Greece
| | - Edward R Leadbetter
- Department of Geology & Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
| | - Joan M Bernhard
- Department of Geology & Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, USA
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Abstract
Chemical signaling between cells is an effective way to coordinate behavior within a community. Although cell-to-cell signaling has mostly been studied in single species, it is now appreciated that the sensing of chemical signals across kingdoms can be an important regulator of nutrient acquisition, virulence, and host defense. In this review, we focus on the role of interkingdom signaling in the interactions that occur between bacterial pathogens and their mammalian hosts. We discuss the quorum-sensing (QS) systems and other mechanisms used by these bacteria to sense, respond to, and modulate host signals that include hormones, immune factors, and nutrients. We also describe cross talk between these signaling pathways and strategies used by the host to interfere with bacterial signaling, highlighting the complex bidirectional signaling networks that are established across kingdoms.
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Liu H, Zhuang W, Zhang S, Rensing C, Huang J, Li J, Wang G. Global Regulator IscR Positively Contributes to Antimonite Resistance and Oxidation in Comamonas testosteroni S44. Front Mol Biosci 2015; 2:70. [PMID: 26734615 PMCID: PMC4683182 DOI: 10.3389/fmolb.2015.00070] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2015] [Accepted: 11/29/2015] [Indexed: 11/13/2022] Open
Abstract
Antimonial compounds can be found as a toxic contaminant in the environment. Knowledge on mechanisms of microbial Sb oxidation and its role in microbial tolerance are limited. Previously, we found that Comamonas testosteroni S44 was resistant to multiple heavy metals and was able to oxidize the toxic antimonite [Sb(III)] to the much less toxic antimonate [Sb(V)]. In this study, transposon mutagenesis was performed in C. testosteroni S44 to isolate genes responsible for Sb(III) resistance and oxidation. An insertion mutation into iscR, which regulates genes involved in the biosynthesis of Fe-S clusters, generated a strain called iscR-280. This mutant strain was complemented with a plasmid carrying iscR to generate strain iscR-280C. Compared to the wild type S44 and iscR-280C, strain iscR-280 showed lower resistance to Sb(III) and a lower Sb(III) oxidation rate. Strain iscR-280 also showed lower resistance to As(III), Cd(II), Cu(II), and H2O2. In addition, intracellular γ-glutamylcysteine ligase (γ-GCL) activity and glutathione (GSH) content were decreased in the mutated strain iscR-280. Real-time RT-PCR and lacZ fusion expression assay indicated that transcription of iscR and iscS was induced by Sb(III). Results of electrophoretic mobility shift assay (EMSA) and bacterial one-hybrid (B1H) system demonstrated a positive interaction between IscR and its promoter region. The diverse defective phenotypes and various expression patterns suggest a role for IscR in contributing to multi-metal(loid)s resistance and Sb(III) oxidation via Fe-S cluster biogenesis and oxidative stress protection. Bacterial Sb(III) oxidation is a detoxification reaction.
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Affiliation(s)
- Hongliang Liu
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural UniversityWuhan, China; Shandong Provincial Research Center for Bioinformatic Engineering and Technique, School of Life Sciences, Shandong University of TechnologyZibo, China
| | - Weiping Zhuang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University Wuhan, China
| | - Shengzhe Zhang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University Wuhan, China
| | - Christopher Rensing
- Department of Plant and Environmental Sciences, University of Copenhagen Frederiksberg, Denmark
| | - Jun Huang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University Wuhan, China
| | - Jie Li
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University Wuhan, China
| | - Gejiao Wang
- State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University Wuhan, China
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Matsushita M, Freigang S, Schneider C, Conrad M, Bornkamm GW, Kopf M. T cell lipid peroxidation induces ferroptosis and prevents immunity to infection. ACTA ACUST UNITED AC 2015; 212:555-68. [PMID: 25824823 PMCID: PMC4387287 DOI: 10.1084/jem.20140857] [Citation(s) in RCA: 416] [Impact Index Per Article: 46.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 03/10/2015] [Indexed: 01/04/2023]
Abstract
Matsushita et al. investigated the role of the selenoenzyme glutathione peroxidae 4 (Gpx4) in T cell responses and found that loss of Gpx4 results in an intrinsic T cell developmental defect in the periphery, which leads to a failure to expand and protect from acute viral and parasitic infection.The defects were rescued with dietary supplementation of vitamin E. The Gp4−/− T cells accumulate membrane lipid peroxides and undergo cell death by ferroptosis. The selenoenzyme glutathione peroxidase 4 (Gpx4) is a major scavenger of phospholipid hydroperoxides. Although Gpx4 represents a key component of the reactive oxygen species-scavenging network, its relevance in the immune system is yet to be defined. Here, we investigated the importance of Gpx4 for physiological T cell responses by using T cell–specific Gpx4-deficient mice. Our results revealed that, despite normal thymic T cell development, CD8+ T cells from TΔGpx4/ΔGpx4 mice had an intrinsic defect in maintaining homeostatic balance in the periphery. Moreover, both antigen-specific CD8+ and CD4+ T cells lacking Gpx4 failed to expand and to protect from acute lymphocytic choriomeningitis virus and Leishmania major parasite infections, which were rescued with diet supplementation of high dosage of vitamin E. Notably, depletion of the Gpx4 gene in the memory phase of viral infection did not affect T cell recall responses upon secondary infection. Ex vivo, Gpx4-deficient T cells rapidly accumulated membrane lipid peroxides and concomitantly underwent cell death driven by ferroptosis but not necroptosis. These studies unveil an essential role of Gpx4 for T cell immunity.
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Affiliation(s)
- Mai Matsushita
- Molecular Biomedicine, Institute of Molecular Health Science, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Stefan Freigang
- Molecular Biomedicine, Institute of Molecular Health Science, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Christoph Schneider
- Molecular Biomedicine, Institute of Molecular Health Science, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Marcus Conrad
- Helmholtz Zentrum München, Institute of Developmental Genetics, 85764 Neuherberg, Germany
| | - Georg W Bornkamm
- Helmholtz Zentrum München, Institute of Clinical Molecular Biology and Tumor Genetics, 81377 Munich, Germany
| | - Manfred Kopf
- Molecular Biomedicine, Institute of Molecular Health Science, Department of Biology, ETH Zurich, 8093 Zurich, Switzerland
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Lin JCY, Chiang BY, Chou CC, Chen TC, Chen YJ, Chen YJ, Lin CH. Glutathionylspermidine in the modification of protein SH groups: the enzymology and its application to study protein glutathionylation. Molecules 2015; 20:1452-74. [PMID: 25599150 PMCID: PMC6272389 DOI: 10.3390/molecules20011452] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 12/15/2014] [Indexed: 11/29/2022] Open
Abstract
Cysteine is very susceptible to reactive oxygen species. In response; posttranslational thiol modifications such as reversible disulfide bond formation have arisen as protective mechanisms against undesired in vivo cysteine oxidation. In Gram-negative bacteria a major defense mechanism against cysteine overoxidation is the formation of mixed protein disulfides with low molecular weight thiols such as glutathione and glutathionylspermidine. In this review we discuss some of the mechanistic aspects of glutathionylspermidine in prokaryotes and extend its potential use to eukaryotes in proteomics and biochemical applications through an example with tissue transglutaminase and its S-glutathionylation.
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Affiliation(s)
- Jason Ching-Yao Lin
- Institute of Biological Chemistry, Academia Sinica, 128 Academia Road Section 2, Taipei 11529, Taiwan.
| | - Bing-Yu Chiang
- Institute of Biological Chemistry, Academia Sinica, 128 Academia Road Section 2, Taipei 11529, Taiwan.
| | - Chi-Chi Chou
- Institute of Biological Chemistry, Academia Sinica, 128 Academia Road Section 2, Taipei 11529, Taiwan.
| | - Tzu-Chieh Chen
- Institute of Biological Chemistry, Academia Sinica, 128 Academia Road Section 2, Taipei 11529, Taiwan.
| | - Yi-Ju Chen
- Institute of Chemistry, Academia Sinica, 128 Academia Road Section 2, Taipei 11529, Taiwan.
| | - Yu-Ju Chen
- Institute of Chemistry, Academia Sinica, 128 Academia Road Section 2, Taipei 11529, Taiwan.
| | - Chun-Hung Lin
- Institute of Biological Chemistry, Academia Sinica, 128 Academia Road Section 2, Taipei 11529, Taiwan.
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Pandey T, Chhetri G, Chinta R, Kumar B, Singh DB, Tripathi T, Singh AK. Functional classification and biochemical characterization of a novel rho class glutathione S-transferase in Synechocystis PCC 6803. FEBS Open Bio 2014; 5:1-7. [PMID: 25685659 PMCID: PMC4309839 DOI: 10.1016/j.fob.2014.11.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 11/11/2014] [Accepted: 11/18/2014] [Indexed: 01/17/2023] Open
Abstract
A novel class of glutathione S-transferase (GST) is reported. This GST catalyzes dichloroacetate (DCA) degradation and hydroperoxide reactions. Functionally this GST is similar to zeta and theta/alpha classes but structurally very different. In contrast to other bacterial GSTs, this GST exists as a monomer in solution. First report of DCA degradation by any bacterial GST and has potential biotechnological applications.
We report a novel class of glutathione S-transferase (GST) from the model cyanobacterium Synechocystis PCC 6803 (sll1545) which catalyzes the detoxification of the water pollutant dichloroacetate and also shows strong glutathione-dependent peroxidase activity representing the classical activities of zeta and theta/alpha class respectively. Interestingly, sll1545 has very low sequence and structural similarity with these classes. This is the first report of dichloroacetate degradation activity by any bacterial GST. Based on these results we classify sll1545 to a novel GST class, rho. The present data also indicate potential biotechnological and industrial applications of cyanobacterial GST in dichloroacetate-polluted areas.
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Affiliation(s)
- Tripti Pandey
- Department of Biochemistry, North-Eastern Hill University, Shillong 793022, India
| | - Gaurav Chhetri
- Department of Biochemistry, North-Eastern Hill University, Shillong 793022, India
| | - Ramesh Chinta
- Department of Biochemistry, North-Eastern Hill University, Shillong 793022, India
| | - Bijay Kumar
- Department of Biochemistry, North-Eastern Hill University, Shillong 793022, India
| | - Dev Bukhsh Singh
- Department of Biotechnology, Institute of Biosciences and Biotechnology, Chhatrapati Shahu Ji Maharaj University, Kanpur 208024, India
| | - Timir Tripathi
- Department of Biochemistry, North-Eastern Hill University, Shillong 793022, India
| | - Arvind Kumar Singh
- Department of Biochemistry, North-Eastern Hill University, Shillong 793022, India
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16
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Lee JY, Yang JG, Zhitnitsky D, Lewinson O, Rees DC. Structural basis for heavy metal detoxification by an Atm1-type ABC exporter. Science 2014; 343:1133-6. [PMID: 24604198 PMCID: PMC4151877 DOI: 10.1126/science.1246489] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Although substantial progress has been achieved in the structural analysis of exporters from the superfamily of adenosine triphosphate (ATP)-binding cassette (ABC) transporters, much less is known about how they selectively recognize substrates and how substrate binding is coupled to ATP hydrolysis. We have addressed these questions through crystallographic analysis of the Atm1/ABCB7/HMT1/ABCB6 ortholog from Novosphingobium aromaticivorans DSM 12444, NaAtm1, at 2.4 angstrom resolution. Consistent with a physiological role in cellular detoxification processes, functional studies showed that glutathione derivatives can serve as substrates for NaAtm1 and that its overexpression in Escherichia coli confers protection against silver and mercury toxicity. The glutathione binding site highlights the articulated design of ABC exporters, with ligands and nucleotides spanning structurally conserved elements to create adaptable interfaces accommodating conformational rearrangements during the transport cycle.
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Affiliation(s)
- Jonas Y. Lee
- Howard Hughes Medical Institute and Division of Chemistry and Chemical Engineering, Mail Code 114-96, California Institute of Technology, Pasadena, CA 91125, USA
| | - Janet G. Yang
- Howard Hughes Medical Institute and Division of Chemistry and Chemical Engineering, Mail Code 114-96, California Institute of Technology, Pasadena, CA 91125, USA
| | - Daniel Zhitnitsky
- Department of Microbiology, The Rappaport Family Institute for Research, Faculty of Medicine, The Technion-Israel Institute of Technology, Haifa, Israel
| | - Oded Lewinson
- Department of Microbiology, The Rappaport Family Institute for Research, Faculty of Medicine, The Technion-Israel Institute of Technology, Haifa, Israel
| | - Douglas C. Rees
- Howard Hughes Medical Institute and Division of Chemistry and Chemical Engineering, Mail Code 114-96, California Institute of Technology, Pasadena, CA 91125, USA
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Bocedi A, Fabrini R, Farrotti A, Stella L, Ketterman AJ, Pedersen JZ, Allocati N, Lau PCK, Grosse S, Eltis LD, Ruzzini A, Edwards TE, Morici L, Del Grosso E, Guidoni L, Bovi D, Lo Bello M, Federici G, Parker MW, Board PG, Ricci G. The impact of nitric oxide toxicity on the evolution of the glutathione transferase superfamily: a proposal for an evolutionary driving force. J Biol Chem 2013; 288:24936-47. [PMID: 23828197 DOI: 10.1074/jbc.m113.476135] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Glutathione transferases (GSTs) are protection enzymes capable of conjugating glutathione (GSH) to toxic compounds. During evolution an important catalytic cysteine residue involved in GSH activation was replaced by serine or, more recently, by tyrosine. The utility of these replacements represents an enigma because they yield no improvements in the affinity toward GSH or in its reactivity. Here we show that these changes better protect the cell from nitric oxide (NO) insults. In fact the dinitrosyl·diglutathionyl·iron complex (DNDGIC), which is formed spontaneously when NO enters the cell, is highly toxic when free in solution but completely harmless when bound to GSTs. By examining 42 different GSTs we discovered that only the more recently evolved Tyr-based GSTs display enough affinity for DNDGIC (KD < 10(-9) M) to sequester the complex efficiently. Ser-based GSTs and Cys-based GSTs show affinities 10(2)-10(4) times lower, not sufficient for this purpose. The NO sensitivity of bacteria that express only Cys-based GSTs could be related to the low or null affinity of their GSTs for DNDGIC. GSTs with the highest affinity (Tyr-based GSTs) are also over-represented in the perinuclear region of mammalian cells, possibly for nucleus protection. On the basis of these results we propose that GST evolution in higher organisms could be linked to the defense against NO.
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Affiliation(s)
- Alessio Bocedi
- Department of Chemical Sciences and Technologies, University of Rome, Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy
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18
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Kim J, Copley SD. The orphan protein bis-γ-glutamylcystine reductase joins the pyridine nucleotide disulfide reductase family. Biochemistry 2013; 52:2905-13. [PMID: 23560638 DOI: 10.1021/bi4003343] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Facile DNA sequencing became possible decades after many enzymes had been purified and characterized. Consequently, there are still "orphan" enyzmes for which activities are known but for which encoding genes have not been identified. Identification of the genes encoding orphan enzymes is important because it allows correct annotation of genes of unknown function or with misassigned function. Bis-γ-glutamylcystine reductase (GCR) is an orphan protein that was purified in 1988. This enzyme catalyzes the reduction of bis-γ-glutamylcystine. γ-Glutamylcysteine is the major low-molecular weight thiol in halobacteria. We purified GCR from Halobacterium sp. NRC-1 and identified the sequence of 23 tryptic peptides by nano-liquid chromatography electrospray ionization tandem mass spectrometry. These peptides cover 62% of the protein predicted to be encoded by a gene in Halobacterium sp. NRC-1 that is annotated as mercuric reductase. GCR and mercuric reductase activities were assayed using enzyme that was expressed in Escherichia coli and refolded from inclusion bodies. The enzyme had robust GCR activity but no mercuric reductase activity. The genomes of most, but not all, halobacteria for which whole genome sequences are available have close homologues of GCR, suggesting that there is more to be learned about the low-molecular weight thiols used in halobacteria.
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Affiliation(s)
- Juhan Kim
- Department of Molecular, Cellular and Developmental Biology and Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO 80309, USA
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19
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Jozefczak M, Remans T, Vangronsveld J, Cuypers A. Glutathione is a key player in metal-induced oxidative stress defenses. Int J Mol Sci 2012; 13:3145-3175. [PMID: 22489146 PMCID: PMC3317707 DOI: 10.3390/ijms13033145] [Citation(s) in RCA: 430] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Revised: 02/10/2012] [Accepted: 02/23/2012] [Indexed: 01/15/2023] Open
Abstract
Since the industrial revolution, the production, and consequently the emission of metals, has increased exponentially, overwhelming the natural cycles of metals in many ecosystems. Metals display a diverse array of physico-chemical properties such as essential versus non-essential and redox-active versus non-redox-active. In general, all metals can lead to toxicity and oxidative stress when taken up in excessive amounts, imposing a serious threat to the environment and human health. In order to cope with different kinds of metals, plants possess defense strategies in which glutathione (GSH; γ-glu-cys-gly) plays a central role as chelating agent, antioxidant and signaling component. Therefore, this review highlights the role of GSH in: (1) metal homeostasis; (2) antioxidative defense; and (3) signal transduction under metal stress. The diverse functions of GSH originate from the sulfhydryl group in cysteine, enabling GSH to chelate metals and participate in redox cycling.
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Affiliation(s)
- Marijke Jozefczak
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium; E-Mails: (M.J.); (T.R.); (J.V.)
| | - Tony Remans
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium; E-Mails: (M.J.); (T.R.); (J.V.)
| | - Jaco Vangronsveld
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium; E-Mails: (M.J.); (T.R.); (J.V.)
| | - Ann Cuypers
- Centre for Environmental Sciences, Hasselt University, Agoralaan Building D, 3590 Diepenbeek, Belgium; E-Mails: (M.J.); (T.R.); (J.V.)
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20
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Abstract
BACKGROUND Although traditionally cancer has been fought with the usual armamentarium of chemotherapy and high doses of directed radiation, lately there has been more attention devoted to combating cancer through nutritive means. In particular, certain phytochemicals including some vitamins, some minerals and a wide range of other bioactive nutrients have been found useful in the physiological battle against cancer. OBJECTIVE The objective of this article is to determine which vitamins, minerals and bioactive nutrients may be useful in combating cancer and to give therapeutic dosages of such when known. DATA SYNTHESIS The scientific literature is replete with research documenting the link between certain nutritional protocols and inhibition or protection against the disease of cancer. From the landmark article entitled The Causes of Cancer by Richard Doll and Richard Peto which was first commissioned as a report to the Office of Technology Assessment of the United States Congress to the American Cancer Societys Advisory Committee Guidelines on Diet, Nutrition and Cancer Prevention: Reducing the Risk of Cancer with Health Food Choices and Physical Activity, the nutritional literature continues to provide the necessary link for the clinician to justifiably advise patients regarding proper dietary habits in order reduce the patients risk of cancer. RESULTS Although there has been much research regarding the relationship between vitamins, minerals and other bioactive phytonutrients and cancer and protection against cancer, not all of the literature supports a strong and convincing link between the nutrient and cancer protection. This article differentiates the convincing evidence vs. the probable and the possible evidence of the link between the nutrient and its inhibitive effect on cancer. CONCLUSION Certain vitamins, minerals and bioactive phytonutrients can be used as a first line of therapeutic defense against cancer before chemotherapy and radiation treatment is commenced.
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Yang J, Rawat S, Stemmler TL, Rosen BP. Arsenic binding and transfer by the ArsD As(III) metallochaperone. Biochemistry 2010; 49:3658-66. [PMID: 20361763 DOI: 10.1021/bi100026a] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
ArsD is a metallochaperone that delivers trivalent metalloids [As(III) or Sb(III)] to the ArsA ATPase, the catalytic subunit of the ArsAB pump encoded by the arsRDABC operon of Escherichia coli plasmid R773. Interaction with ArsD increases the affinity of ArsA for As(III), conferring resistance to environmental concentrations of arsenic. Previous genetic analysis suggested that ArsD residues Cys12, Cys13, and Cys18 are involved in the transfer of As(III) to ArsA. Here X-ray absorption spectroscopy was used to show that As(III) is coordinated with three sulfur atoms, consistent with the three cysteine residues forming the As(III) binding site. Two single-tryptophan derivatives of ArsD exhibited quenching of intrinsic protein fluorescence upon binding of As(III) or Sb(III), which allowed estimation of the rates of binding and affinities for metalloids. Substitution of Cys12, Cys13, or Cys18 decreased the affinity for As(III) more than 10-fold. Reduced glutathione greatly increased the rate of binding of As(III) to ArsD but did not affect binding of As(III) to ArsA. This suggests that in vivo cytosolic As(III) might be initially bound to GSH and transferred to ArsD and then to ArsAB, which pumps the metalloid out of the cell. The As(III) chelator dimercaptosuccinic acid did not block the transfer from ArsD to ArsA, consistent with channeling of the metalloid from one protein to the other, as opposed to release and rebinding of the metalloid. Finally, transfer of As(III) from ArsD to ArsA occurred in the presence of MgATP at 23 degrees C but not at 4 degrees C. Neither MgADP nor MgATP-gamma-S could replace MgATP. These results suggest that transfer occurs with a conformation of ArsA that transiently forms during the catalytic cycle.
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Affiliation(s)
- Jianbo Yang
- Department of Biochemistry and Molecular Biology, Wayne State University, School of Medicine, Detroit, Michigan 48201, USA
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22
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Newton GL, Rawat M, La Clair JJ, Jothivasan VK, Budiarto T, Hamilton CJ, Claiborne A, Helmann JD, Fahey RC. Bacillithiol is an antioxidant thiol produced in Bacilli. Nat Chem Biol 2009; 5:625-7. [PMID: 19578333 PMCID: PMC3510479 DOI: 10.1038/nchembio.189] [Citation(s) in RCA: 214] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2008] [Accepted: 05/04/2009] [Indexed: 11/29/2022]
Abstract
Glutathione is a nearly ubiquitous low-molecular-weight thiol and antioxidant, although it is conspicuously absent from most Gram-positive bacteria. We identify here the structure of bacillithiol, a novel and abundant thiol produced by Bacillus species, Staphylococcus aureus, and Deinococcus radiodurans. Bacillithiol is the α-anomeric glycoside of l-cysteinyl-d-glucosamine with l-malic acid and likely functions as an antioxidant. Bacillithiol, like structurally similar mycothiol, may serve as a substitute for glutathione.
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Affiliation(s)
- Gerald L Newton
- Department of Chemistry and Biochemistry, University of California-San Diego, La Jolla, California, USA
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Marañón G, Manley W, Cayado P, García C, de la Muela MS, Vara E. Alterations in the glutathione metabolism could be implicated in the ischemia-induced small intestinal cell damage in horses. BMC Vet Res 2009; 5:10. [PMID: 19296836 PMCID: PMC2664797 DOI: 10.1186/1746-6148-5-10] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Accepted: 03/18/2009] [Indexed: 01/08/2023] Open
Abstract
Background Colic could be accompanied by changes in the morphology and physiology of organs and tissues, such as the intestine. This process might be, at least in part, due to the accumulation of oxidative damage induced by reactive oxygen (ROS) and reactive nitrogen species (RNS), secondary to intestinal ischemia. Glutathione (GSH), being the major intracellular thiol, provides protection against oxidative injury. The aim of this study was to investigate whether ischemia-induced intestinal injury could be related with alterations in GSH metabolism. Results Ischemia induced a significant increase in lipid hydroperoxides, nitric oxide and carbon monoxide, and a reduction in reduced glutathione, and adenosine triphosphate (ATP) content, as well as in methionine-adenosyl-transferase and methyl-transferase activities. Conclusion Our results suggest that ischemia induces harmful effects on equine small intestine, probably due to an increase in oxidative damage and proinflammatory molecules. This effect could be mediated, at least in part, by impairment in glutathione metabolism.
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Newton GL, Fahey RC. An N-acyl homolog of mycothiol is produced in marine actinomycetes. Arch Microbiol 2008; 190:547-57. [PMID: 18629474 PMCID: PMC2574923 DOI: 10.1007/s00203-008-0405-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2008] [Revised: 06/13/2008] [Accepted: 06/25/2008] [Indexed: 10/21/2022]
Abstract
Marine actinomycetes have generated much recent interest as a potentially valuable source of novel antibiotics. Like terrestrial actinomycetes the marine actinomycetes are shown here to produce mycothiol as their protective thiol. However, a novel thiol, U25, was produced by MAR2 strain CNQ703 upon progression into stationary phase when secondary metabolite production occurred and became the dominant thiol. MSH and U25 were maintained in a reduced state during early stationary phase, but become significantly oxidized after 10 days in culture. Isolation and structural analysis of the monobromobimane derivative identified U25 as a homolog of mycothiol in which the acetyl group attached to the nitrogen of cysteine is replaced by a propionyl residue. This N-propionyl-desacetyl-mycothiol was present in 13 of the 17 strains of marine actinomycetes examined, including five strains of Salinispora and representatives of the MAR2, MAR3, MAR4 and MAR6 groups. Mycothiol and its precursor, the pseudodisaccharide 1-O-(2-amino-2-deoxy-alpha-D-glucopyranosyl)-D-myo-inositol, were found in all strains. High levels of mycothiol S-conjugate amidase activity, a key enzyme in mycothiol-dependent detoxification, were found in most strains. The results demonstrate that major thiol/disulfide changes accompany secondary metabolite production and suggest that mycothiol-dependent detoxification is important at this developmental stage.
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Affiliation(s)
- Gerald L. Newton
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA e-mail: fax: 858-5344864
| | - Robert C. Fahey
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA e-mail: fax: 858-5344864
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Nossaman BD, Kadowitz PJ. Potential Benefits of Peroxynitrite. THE OPEN PHARMACOLOGY JOURNAL 2008; 2:31-53. [PMID: 19305646 PMCID: PMC2659344 DOI: 10.2174/1874143600802010031] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2008] [Revised: 03/24/2008] [Accepted: 04/29/2008] [Indexed: 12/14/2022]
Abstract
Peroxynitrite (PN) is generated by the reaction of nitric oxide (NO) and superoxide in one of the most rapid reactions in biology. Studies have reported that PN is a cytotoxic molecule that contributes to vascular injury in a number of disease states. However, it has become apparent that PN has beneficial effects including vasodilation, inhibition of platelet aggregation, inhibition of inflammatory cell adhesion, and protection against ischemia/reperfusion injury in the heart. It is our hypothesis that PN may serve to inactivate superoxide and prolong the actions of NO in the circulation. This manuscript reviews the beneficial effects of PN in the cardiovascular system.
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Affiliation(s)
- Bobby D. Nossaman
- Critical Care Medicine, Department of Anesthesiology, Ochsner Medical Center, 1514 Jefferson Highway, New Orleans, Louisiana 70121 USA
- Department of Pharmacology, Tulane University Medical Center, 1430 Tulane Avenue, New Orleans, Louisiana 70112-2699 USA
| | - Philip J. Kadowitz
- Department of Pharmacology, Tulane University Medical Center, 1430 Tulane Avenue, New Orleans, Louisiana 70112-2699 USA
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26
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Wiktelius E, Stenberg G. Novel class of glutathione transferases from cyanobacteria exhibit high catalytic activities towards naturally occurring isothiocyanates. Biochem J 2007; 406:115-23. [PMID: 17484723 PMCID: PMC1948994 DOI: 10.1042/bj20070328] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In the present paper, we report a novel class of GSTs (glutathione transferases), called the Chi class, originating from cyanobacteria and with properties not observed previously in prokaryotic enzymes. GSTs constitute a widespread multifunctional group of proteins, of which mammalian enzymes are the best characterized. Although GSTs have their origin in prokaryotes, few bacterial representatives have been characterized in detail, and the catalytic activities and substrate specificities observed have generally been very modest. The few well-studied bacterial GSTs have largely unknown physiological functions. Genome databases reveal that cyanobacteria have an extensive arsenal of glutathione-associated proteins. We have studied two cyanobacterial GSTs which are the first examples of bacterial enzymes that are as catalytically efficient as the best mammalian enzymes. GSTs from the thermophile Thermosynechococcus elongatus BP-1 and from Synechococcus elongatus PCC 6301 were found to catalyse the conjugation of naturally occurring plant-derived isothiocyanates to glutathione at high rates. The cyanobacterial GSTs studied are smaller than previously described members of this enzyme family, but display many of the typical structural features that are characteristics of GSTs. They are also active towards several classical substrates, but at the same moderate rates that have been observed for other GSTs derived from prokaryotes. The cloning, expression and characterization of two cyanobacterial GSTs are described. The possible significance of the observed catalytic properties is discussed in the context of physiological relevance and GST evolution.
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Affiliation(s)
- Eric Wiktelius
- Department of Biochemistry and Organic Chemistry, Biomedical Centre, Uppsala University, Box 576, SE-751 23 Uppsala, Sweden
| | - Gun Stenberg
- Department of Biochemistry and Organic Chemistry, Biomedical Centre, Uppsala University, Box 576, SE-751 23 Uppsala, Sweden
- To whom correspondence should be addressed (email )
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Site-directed Mutagenesis of Arginine 13 Residue in Human Glutathione S-Transferase P1-1. B KOREAN CHEM SOC 2007. [DOI: 10.5012/bkcs.2007.28.5.772] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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28
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Ganguli D, Kumar C, Bachhawat AK. The alternative pathway of glutathione degradation is mediated by a novel protein complex involving three new genes in Saccharomyces cerevisiae. Genetics 2006; 175:1137-51. [PMID: 17179087 PMCID: PMC1840075 DOI: 10.1534/genetics.106.066944] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Glutathione (GSH), L-gamma-glutamyl-L-cysteinyl-glycine, is the major low-molecular-weight thiol compound present in almost all eukaryotic cells. GSH degradation proceeds through the gamma-glutamyl cycle that is initiated, in all organisms, by the action of gamma-glutamyl transpeptidase. A novel pathway for the degradation of GSH that requires the participation of three previously uncharacterized genes is described in the yeast Saccharomyces cerevisiae. These genes have been named DUG1 (YFR044c), DUG2 (YBR281c), and DUG3 (YNL191w) (defective in utilization of glutathione). Although dipeptides and tripeptides with a normal peptide bond such as cys-gly or glu-cys-gly required the presence of only a functional DUG1 gene that encoded a protein belonging to the M20A metallohydrolase family, the presence of an unusual peptide bond such as in the dipeptide, gamma-glu-cys, or in GSH, required the participation of the DUG2 and DUG3 gene products as well. The DUG2 gene encodes a protein with a peptidase domain and a large WD40 repeat region, while the DUG3 gene encoded a protein with a glutamine amidotransferase domain. The Dug1p, Dug2p, and Dug3p proteins were found to form a degradosomal complex through Dug1p-Dug2p and Dug2p-Dug3p interactions. A model is proposed for the functioning of the Dug1p/Dug2p/Dug3p proteins as a specific GSH degradosomal complex.
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Abstract
Glutathione is one of the most abundant thiols present in cyanobacteria and proteobacteria, and in all mitochondria or chloroplast-bearing eukaryotes. In bacteria, in addition to its key role in maintaining the proper oxidation state of protein thiols, glutathione also serves a key function in protecting the cell from the action of low pH, chlorine compounds, and oxidative and osmotic stresses. Moreover, glutathione has emerged as a posttranslational regulator of protein function under conditions of oxidative stress, by the direct modification of proteins via glutathionylation. This review summarizes the biosynthesis and function of glutathione in bacteria from physiological and biotechnological standpoints.
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Affiliation(s)
- Lluis Masip
- Department of Chemical Engineering, Institute for Cell and Molecular Biology, University of Texas, Austin, 78712-0231, USA
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30
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Reliene R, Schiestl RH. Glutathione depletion by buthionine sulfoximine induces DNA deletions in mice. Carcinogenesis 2005; 27:240-4. [PMID: 16162646 DOI: 10.1093/carcin/bgi222] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Oxidative stress and genomic rearrangements play a role in cancer development. l-Buthionine-sulfoximine (BSO) induces oxidative stress in a cell by irreversibly inhibiting gamma-glutamylcysteine synthetase, an essential enzyme for the synthesis of glutathione (GSH). We postulated that oxidative stress induced by GSH depletion might lead to genomic rearrangements, such as DNA deletions, and that counteracting such pro-oxidant conditions by the exogenous antioxidant N-acetyl-L-cysteine (NAC), might suppress DNA deletions. Therefore, we determined the frequency of 70 kb DNA deletions and thiol levels in mouse fetuses exposed to BSO (alone or in combination with NAC) via drinking water given to female mice during gestation. BSO treatment resulted in a significantly increased frequency of DNA deletions and decreased concentrations of GSH and cysteine. An amount of 2 mM BSO treatment resulted in a 30% higher DNA deletion frequency, 45% lower GSH and 27% lower cysteine levels, when compared with the untreated control and 20 mM BSO treatment caused a 40% higher DNA deletion frequency, 70% lower GSH and 55% lower cysteine levels. In combination BSO and NAC resulted in reduced levels of GSH consistent with the effect of BSO; however, cysteine levels increased and the frequency of DNA deletions was within the normal range. Thus, NAC protected against genome rearrangements caused by GSH depletion. This study showed that lowering the concentrations of thiol antioxidants results in DNA deletions that may play a role in carcinogenesis.
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Affiliation(s)
- Ramune Reliene
- Department of Pathology, Geffen School of Medicine and School of Public Health, UCLA, Los Angeles, CA 90024, USA
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Ashida H, Sawa Y, Shibata H. Cloning, Biochemical and Phylogenetic Characterizations of γ-Glutamylcysteine Synthetase from Anabaena sp. PCC 7120. ACTA ACUST UNITED AC 2005; 46:557-62. [PMID: 15695431 DOI: 10.1093/pcp/pci056] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Gamma-glutamylcysteine synthetase (EC 6.3.2.2, gamma-GCS) catalyzes the first step of glutathione synthesis: l-Glu + l-Cys + ATP = gamma-l-glutamyl-l-cysteine (gamma-GC) + ADP + Pi. We have cloned the gene alr3351 of Anabaena sp. PCC 7120, expressed the recombinant enzyme in Escherichia coli, and characterized its product as gamma-GCS by analyzing gamma-GC production, ADP formation and Pi release. Apparent Km values for l-Glu, ATP and l-Cys were estimated to be 0.82, 0.23 and 0.14 mM, respectively. Glutathione and l-buthionine sulfoximine were inhibitors with Ki values of 6.5 and 29.3 mM, respectively. The molecular mass of Anabaena gamma-GCS was estimated to be 43.4 kDa by SDS-PAGE and matrix-assisted laser desorption/ionization time of flight mass spectrometry. The important sequence for the activity of plant gamma-GCS was found in alpha-proteobacterial gamma-GCSs but not in cyanobacterial enzymes, suggesting that the cyanobacterial gamma-GCS gene is not the primary progenitor for the plant genes.
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Affiliation(s)
- Hiroyuki Ashida
- Department of Molecular and Functional Genomics, Center for Integrated Research in Science, Shimane University, Matsue, Shimane, 690-8504 Japan
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32
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Park HJ, Cho HY, Kong KH. Purification and biochemical properties of glutathione S-transferase from Lactuca sativa. JOURNAL OF BIOCHEMISTRY AND MOLECULAR BIOLOGY 2005; 38:232-7. [PMID: 15826502 DOI: 10.5483/bmbrep.2005.38.2.232] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A glutathione S-transferase (GST) from Lactuca sativa was purified to electrophoretic homogeneity approximately 403-fold with a 9.6% activity yield by DEAE-Sephacel and glutathione (GSH)-Sepharose column chromatography. The molecular weight of the enzyme was determined to be approximately 23,000 by SDS-polyacrylamide gel electrophoresis and 48,000 by gel chromatography, indicating a homodimeric structure. The activity of the enzyme was significantly inhibited by ShexylGSH and S-(2,4-dinitrophenyl) glutathione. The enzyme displayed activity towards 1-chloro-2,4-dinitrobenzene, a general GST substrate and high activities towards ethacrynic acid. It also exhibited glutathione peroxidase activity toward cumene hydroperoxide.
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Affiliation(s)
- Hee-Joong Park
- Department of Chemistry, College of Natural Sciences, Chung-Ang University, Dongjak-ku, Seoul 156-756, Korea
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33
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Functional Studies of Tyrosine 108 Residue in the Active Site of Human Glutathione S-Transferase P1-1. B KOREAN CHEM SOC 2005. [DOI: 10.5012/bkcs.2005.26.3.433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Vickers TJ, Fairlamb AH. Trypanothione S-transferase activity in a trypanosomatid ribosomal elongation factor 1B. J Biol Chem 2004; 279:27246-56. [PMID: 15073172 PMCID: PMC3428924 DOI: 10.1074/jbc.m311039200] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Trypanothione is a thiol unique to the Kinetoplastida and has been shown to be a vital component of their antioxidant defenses. However, little is known as to the role of trypanothione in xenobiotic metabolism. A trypanothione S-transferase activity was detected in extracts of Leishmania major, L. infantum, L. tarentolae, Trypanosoma brucei, and Crithidia fasciculata, but not Trypanosoma cruzi. No glutathione S-transferase activity was detected in any of these parasites. Trypanothione S-transferase was purified from C. fasciculata and shown to be a hexadecameric complex of three subunits with a relative molecular weight of 650,000. This enzyme complex was specific for the thiols trypanothione and glutathionylspermidine and only used 1-chloro-2,4-dinitrobenzene from a range of glutathione S-transferase substrates. Peptide sequencing revealed that the three components were the alpha, beta, and gamma subunits of ribosomal eukaryotic elongation factor 1B (eEF1B). Partial dissociation of the complex suggested that the S-transferase activity was associated with the gamma subunit. Moreover, Cibacron blue was found to be a tight binding inhibitor and reactive blue 4 an irreversible time-dependent inhibitor that covalently modified only the gamma subunit. The rate of inactivation by reactive blue 4 was increased more than 600-fold in the presence of trypanothione, and Cibacron blue protected the enzyme from inactivation by 1-chloro-2,4-dinitrobenzene, confirming that these dyes interact with the active site region. Two eEF1Bgamma genes were cloned from C. fasciculata, but recombinant C. fasciculata eEF1Bgamma had no S-transferase activity, suggesting that eEF1Bgamma is unstable in the absence of the other subunits.
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Affiliation(s)
- Tim J. Vickers
- Division of Biological Chemistry and Molecular Microbiology, The Wellcome Trust Biocentre, School of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Alan H. Fairlamb
- Division of Biological Chemistry and Molecular Microbiology, The Wellcome Trust Biocentre, School of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
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35
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Site-directed Mutagenesis of Tyrosine 108 Residue in Human Glutathione S-Transferase P1-1. B KOREAN CHEM SOC 2003. [DOI: 10.5012/bkcs.2003.24.8.1188] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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36
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Li H, Xu H, Graham DE, White RH. Glutathione synthetase homologs encode alpha-L-glutamate ligases for methanogenic coenzyme F420 and tetrahydrosarcinapterin biosyntheses. Proc Natl Acad Sci U S A 2003; 100:9785-90. [PMID: 12909715 PMCID: PMC187843 DOI: 10.1073/pnas.1733391100] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2003] [Indexed: 11/18/2022] Open
Abstract
Proteins in the ATP-grasp superfamily of amide bond-forming ligases have evolved to function in a number of unrelated biosynthetic pathways. Previously identified homologs encoding glutathione synthetase, d-alanine:d-alanine ligase and the bacterial ribosomal protein S6:glutamate ligase have been vertically inherited within certain organismal lineages. Although members of this specificity-diverse superfamily share a common reaction mechanism, the nonoverlapping set of amino acid and peptide substrates recognized by each family provided few clues as to their evolutionary history. Two members of this family have been identified in the hyperthermophilic marine archaeon Methanococcus jannaschii and shown to catalyze the final reactions in two coenzyme biosynthetic pathways. The MJ0620 (mptN) locus encodes a tetrahydromethanopterin:alpha-l-glutamate ligase that forms tetrahydrosarcinapterin, a single carbon-carrying coenzyme. The MJ1001 (cofF) locus encodes a gamma-F420-2:alpha-l-glutamate ligase, which caps the gamma-glutamyl tail of the hydride carrier coenzyme F420. These two genes share a common ancestor with the ribosomal protein S6:glutamate ligase and a putative alpha-aminoadipate ligase, defining the first group of ATP-grasp enzymes with a shared amino acid substrate specificity. As in glutathione biosynthesis, two unrelated amino acid ligases catalyze sequential reactions in coenzyme F420 polyglutamate formation: a gamma-glutamyl ligase adds 1-3 l-glutamate residues and the ATP-grasp-type ligase described here caps the chain with a single alpha-linked l-glutamate residue. The analogous pathways for glutathione, F420, folate, and murein peptide biosyntheses illustrate convergent evolution of nonribosomal peptide biosynthesis through the recruitment of single-step amino acid ligases.
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Affiliation(s)
- Hong Li
- Department of Biochemistry (0308), Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
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37
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Missirlis F, Rahlfs S, Dimopoulos N, Bauer H, Becker K, Hilliker A, Phillips JP, Jäckle H. A putative glutathione peroxidase of Drosophila encodes a thioredoxin peroxidase that provides resistance against oxidative stress but fails to complement a lack of catalase activity. Biol Chem 2003; 384:463-72. [PMID: 12715897 DOI: 10.1515/bc.2003.052] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Cellular defense systems against reactive oxygen species (ROS) include thioredoxin reductase (TrxR) and glutathione reductase (GR). They generate sulfhydryl-reducing systems which are coupled to antioxidant enzymes, the thioredoxin and glutathione peroxidases (TPx and GPx). The fruit fly Drosophila lacks a functional GR, suggesting that the thioredoxin system is the major source for recycling glutathione. Whole genome in silico analysis identified two non-selenium containing putative GPx genes. We examined the biochemical characteristics of one of these gene products and found that it lacks GPx activity and functions as a TPx. Transgene-dependent overexpression of the newly identified Glutathione peroxidase homolog with thioredoxin peroxidase activity (Gtpx-1) gene increases resistance to experimentally induced oxidative stress, but does not compensate for the loss of catalase, an enzyme which, like GTPx-1, functions to eliminate hydrogen peroxide. The results suggest that GTPx-1 is part of the Drosophila Trx antioxidant defense system but acts in a genetically distinct pathway or in a different cellular compartment than catalase.
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Affiliation(s)
- Fanis Missirlis
- Abteilung Molekulare Entwicklungsbiologie, Max-Planck-Institut für biophysikalische Chemie, Am Fassberg, D-37077 Göttingen, Germany
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38
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Vergauwen B, Pauwels F, Vaneechoutte M, Van Beeumen JJ. Exogenous glutathione completes the defense against oxidative stress in Haemophilus influenzae. J Bacteriol 2003; 185:1572-81. [PMID: 12591874 PMCID: PMC148052 DOI: 10.1128/jb.185.5.1572-1581.2003] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Since they are equipped with several strategies by which they evade the antimicrobial defense of host macrophages, it is surprising that members of the genus Haemophilus appear to be deficient in common antioxidant systems that are well established to protect prokaryotes against oxidative stress. Among others, no genetic evidence for glutathione (gamma-Glu-Cys-Gly) (GSH) biosynthesis or for alkyl hydroperoxide reduction (e.g., the Ahp system characteristic or enteric bacteria) is apparent from the Haemophilus influenzae Rd genome sequence, suggesting that the organism relies on alternative systems to maintain redox homeostasis or to reduce small alkyl hydroperoxides. In this report we address this apparent paradox for the nontypeable H. influenzae type strain NCTC 8143. Instead of biosynthesis, we could show that this strain acquires GSH by importing the thiol tripeptide from the growth medium. Although such GSH accumulation had no effect on growth rates, the presence of cellular GSH protected against methylglyoxal, tert-butyl hydroperoxide (t-BuOOH), and S-nitrosoglutathione toxicity and regulated the activity of certain antioxidant enzymes. H. influenzae NCTC 8143 extracts were shown to contain GSH-dependent peroxidase activity with t-BuOOH as the peroxide substrate. The GSH-mediated protection against t-BuOOH stress is most probably catalyzed by the product of open reading frame HI0572 (Prx/Grx), which we isolated from a genomic DNA fragment that confers wild-type resistance to t-BuOOH toxicity in the Ahp-negative Escherichia coli strain TA4315 and that introduces GSH-dependent alkyl hydroperoxide reductase activity into naturally GSH peroxidase-negative E. coli. Finally, we demonstrated that cysteine is an essential amino acid for growth and that cystine, GSH, glutathione amide, and cysteinylglycine can be catabolized in order to complement cysteine deficiency.
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Affiliation(s)
- Bjorn Vergauwen
- Laboratory for Protein Biochemistry and Protein Engineering, Ghent University, Belgium
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39
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Mallick P, Boutz DR, Eisenberg D, Yeates TO. Genomic evidence that the intracellular proteins of archaeal microbes contain disulfide bonds. Proc Natl Acad Sci U S A 2002; 99:9679-84. [PMID: 12107280 PMCID: PMC124975 DOI: 10.1073/pnas.142310499] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Disulfide bonds have only rarely been found in intracellular proteins. That pattern is consistent with the chemically reducing environment inside the cells of well-studied organisms. However, recent experiments and new calculations based on genomic data of archaea provide striking contradictions to this pattern. Our results indicate that the intracellular proteins of certain hyperthermophilic archaea, especially the crenarchaea Pyrobaculum aerophilum and Aeropyrum pernix, are rich in disulfide bonds. This finding implicates disulfide bonding in stabilizing many thermostable proteins and points to novel chemical environments inside these microbes. These unexpected results illustrate the wealth of biochemical insights available from the growing reservoir of genomic data.
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Affiliation(s)
- Parag Mallick
- Department of Chemistry and Biochemistry and Department of Energy Center for Genomics and Proteomics, Molecular Biology Institute, and Howard Hughes Medical Institute, University of California, Los Angeles, CA 90095-1569, USA
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40
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Casey W, Anderson S, Fox T, Dold K, Colton H, Morgan K. Transcriptional and physiological responses of HepG2 cells exposed to diethyl maleate: time course analysis. Physiol Genomics 2002; 8:115-22. [PMID: 11875189 DOI: 10.1152/physiolgenomics.00064.2001] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Expression levels of 767 genes were measured in HepG2 cells at eight time points (0, 0.5, 1, 6, 12, 16, 20, and 24 h) following exposure to the oxidizing agent, diethyl maleate (DEM). DEM treatment caused an immediate and sustained loss of intracellular GSH, with a concomitant increase in GSSG. From 6-12 h after exposure, there was a substantial increase in the percentage of cells undergoing S phase arrest and apoptosis. Expression profiles of approximately 90% of the genes fell into one of five clusters generated using hierarchical-clustering software, indicating the well-ordered nature of the stress response. The directional movement and timing of induction for many genes matched closely the known physiological role of the proteins they encode. Inhibitors of the cell cycle (CDKN1, CDKN4D, ATM) were induced, whereas cyclins [proliferating cell nuclear antigen (PCNA), cyclin A, cyclin D1, cyclin K] were downregulated during the period from 6--20 h. Likewise, pro-apoptotic genes such as the caspases (CASP9, CASP3, CASP2) and apoptotic protease activating factor (APAF) were induced during the same period. Results of this study indicate that there is a good correlation between time-dependent physiological, biochemical, and gene expression data.
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Affiliation(s)
- Warren Casey
- Toxicogenomics, GlaxoSmithKline, Research Triangle Park, North Carolina 27709, USA.
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41
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Abstract
Glutathione metabolism is associated with oxygenic cyanobacteria and the oxygen-utilizing purple bacteria, but is absent in many other prokaryotes. This review focuses on novel thiols found in those bacteria lacking glutathione. Included are glutathione amide and its perthiol, produced by phototrophic purple sulfur bacteria and apparently involved in their sulfide metabolism. Among archaebacteria, coenzyme M (2-mercaptoethanesulfonic acid) and coenzyme B (7-mercaptoheptanoylthreonine phosphate) play central roles in the anaerobic production of CH4 and associated energy conversion by methanogens, whereas the major thiol in the aerobic phototrophic halobacteria is gamma-glutamylcysteine. The highly aerobic actinomycetes produce mycothiol, a conjugate of N-acetylcysteine with a pseudodisaccharide of glucosamine and myo-inositol, AcCys-GlcNalpha(1 --> 1)Ins, which appears to play an antioxidant role similar to glutathione. Ergothioneine, also produced by actinomycetes, remains a mystery despite many years of study. Available data on the biosynthesis and metabolism of these and other novel thiols is summarized and key areas for additional study are identified.
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Affiliation(s)
- R C Fahey
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, USA.
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42
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Affiliation(s)
- D A Sanders
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, USA
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43
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Shi ZZ, Osei-Frimpong J, Kala G, Kala SV, Barrios RJ, Habib GM, Lukin DJ, Danney CM, Matzuk MM, Lieberman MW. Glutathione synthesis is essential for mouse development but not for cell growth in culture. Proc Natl Acad Sci U S A 2000; 97:5101-6. [PMID: 10805773 PMCID: PMC25788 DOI: 10.1073/pnas.97.10.5101] [Citation(s) in RCA: 222] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Glutathione (GSH) is a major source of reducing equivalents in mammalian cells. To examine the role of GSH synthesis in development and cell growth, we generated mice deficient in GSH by a targeted disruption of the heavy subunit of gamma-glutamylcysteine synthetase (gammaGCS-HS(tm1)), an essential enzyme in GSH synthesis. Embryos homozygous for gammaGCS-HS(tm1) fail to gastrulate, do not form mesoderm, develop distal apoptosis, and die before day 8.5. Lethality results from apoptotic cell death rather than reduced cell proliferation. We also isolated cell lines from homozygous mutant blastocysts in medium containing GSH. These cells also grow indefinitely in GSH-free medium supplemented with N-acetylcysteine and have undetectable levels of GSH; further, they show no changes in mitochondrial morphology as judged by electron microscopy. These data demonstrate that GSH is required for mammalian development but dispensable in cell culture and that the functions of GSH, not GSH itself, are essential for cell growth.
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Affiliation(s)
- Z Z Shi
- Department of Pathology, Baylor College of Medicine, Houston, TX 77030, USA
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44
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Rea PA, Li ZS, Lu YP, Drozdowicz YM, Martinoia E. FROM VACUOLAR GS-X PUMPS TO MULTISPECIFIC ABC TRANSPORTERS. ACTA ACUST UNITED AC 1998; 49:727-760. [PMID: 15012252 DOI: 10.1146/annurev.arplant.49.1.727] [Citation(s) in RCA: 249] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
While the concept of H+-coupling has dominated studies of energy-dependent organic solute transport in plants for over two decades, recent studies have demonstrated the existence of a group of organic solute transporters, belonging to the ATP-binding cassette (ABC) superfamily, that are directly energized by MgATP rather than by a transmembrane H+-electrochemical potential difference. Originally identified in microbial and animal cells, the ABC superfamily is one of the largest and most widespread protein families known. Competent in the transport of a broad range of substances including sugars, peptides, alkaloids, inorganic anions, and lipids, all ABC transporters are constituted of one or two copies each of an integral membrane sector and cytosolically oriented ATP-binding domain. To date, two major subclasses, the multidrug resistance-associated proteins (MRPs) and multidrug resistance proteins (MDRs) (so named because of the phenotypes conferred by their animal prototypes), have been identified molecularly in plants. However, only the MRPs have been defined functionally. This review therefore focuses on the functional capabilities, energetics, organization, and regulation of the plant MRPs. Otherwise known as GS-X pumps, or glutathione-conjugate or multispecific organic anion Mg2+-ATPases, the MRPs are considered to participate in the transport of exogenous and endogenous amphipathic anions and glutathionated compounds from the cytosol into the vacuole. Encoded by a multigene family and possessing a unique domain organization, the types of processes that likely converge and depend on plant MRPs include herbicide detoxification, cell pigmentation, the alleviation of oxidative damage, and the storage of antimicrobial compounds. Additional functional capabilities might include channel regulation or activity, and/or the transport of heavy metal chelates. The identification of the MRPs, in particular, and the demonstration of a central role for ABC transporters, in general, in plant function not only provide fresh insights into the molecular basis of energy-dependent solute transport but also offer the prospect for manipulating and investigating many fundamental processes that have hitherto evaded analysis at the transport level.
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Affiliation(s)
- Philip A. Rea
- Plant Science Institute, Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104; e-mail: , Institut de Botanique, Universite de Neuchatel, 2007 Neuchatel, Switzerland
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Bornemann C, Jardine MA, Spies HS, Steenkamp DJ. Biosynthesis of mycothiol: elucidation of the sequence of steps in Mycobacterium smegmatis. Biochem J 1997; 325 ( Pt 3):623-9. [PMID: 9271081 PMCID: PMC1218604 DOI: 10.1042/bj3250623] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Several members of the Actinomycetales, including the medically important mycobacteria, produce 1-D-myo-inosityl-2-(N-acetyl-L-cysteinyl)amino-2-deoxy-alpha-D- glucop yranoside (trivial name mycothiol) as their principal low-molecular-mass thiol. The pseudo-disaccharide component of mycothiol, 1-D-myo-inosityl-2-amino-2-deoxy-alpha-D-glucopyranoside (alpha-D-GI), was synthesized by ligation of 1-D,L-2,3,4,5, 6-penta-O-acetyl-myo-inositol to 3,4,6-tri-O-acetyl-2-deoxy- 2-(2,4-dinitrophenylamino)-alpha-D-glu- copyranosyl bromide to give, in the first instance, an isomeric mixture of alpha- and beta-linked pseudo-disaccharides. The alpha-coupled D,D and D,L isomers, alpha-D-GI and alpha-L-GI respectively, were purified from the mixture by TLC, followed by removal of the protecting groups. A cell-free extract of Mycobacterium smegmatis catalysed the ligation of cysteine, acetate and alpha-D-GI in the presence of ATP and Mg2+ to form mycothiol, as judged by HPLC. When no acetate was added to the incubation mixture, an additional thiol accumulated. In the presence of [14C]acetate no radiolabel was recovered in this species, but only in mycothiol. The additional thiol was isolated as the bimane derivative, and 1H and 1H-1H COSY NMR spectra confirmed its identity as desacetylmycothiol. A more complete conversion of desacetylmycothiol into mycothiol was achieved in the presence of acetyl-S-CoA. These results indicate that the biosynthesis of mycothiol proceeds by the sequential addition of cysteine and acetate to alpha-D-GI. The inositol moiety appears to be an important determinant of specificity, since alpha-L-GI was poorly utilized.
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Affiliation(s)
- C Bornemann
- Department of Chemical Pathology, University of Cape Town Medical School, Observatory 7925, South Africa
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46
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Affiliation(s)
- S Vuilleumier
- Mikrobiologisches Institut, ETH Zürich, Switzerland.
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47
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Bartsch RG, Newton GL, Sherrill C, Fahey RC. Glutathione amide and its perthiol in anaerobic sulfur bacteria. J Bacteriol 1996; 178:4742-6. [PMID: 8755912 PMCID: PMC178251 DOI: 10.1128/jb.178.15.4742-4746.1996] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Chromatium species produced the novel biological thiol glutathione amide, gamma-L-glutamyl-L-cysteinylglycine amide (GASH), when grown photoheterotrophically. GASH was largely converted to the corresponding perthiol during photoautotrophic growth on sulfide, suggesting that GASH may have a function in anaerobic sulfide metabolism. This unprecedented form of glutathione metabolism was probably present in anaerobic ancestors of modern cyanobacteria and purple bacteria.
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Affiliation(s)
- R G Bartsch
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, 92093, USA
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Marrs KA. THE FUNCTIONS AND REGULATION OF GLUTATHIONE S-TRANSFERASES IN PLANTS. ACTA ACUST UNITED AC 1996; 47:127-158. [PMID: 15012285 DOI: 10.1146/annurev.arplant.47.1.127] [Citation(s) in RCA: 714] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Glutathione S-transferases (GSTs) play roles in both normal cellular metabolism as well as in the detoxification of a wide variety of xenobiotic compounds, and they have been intensively studied with regard to herbicide detoxification in plants. A newly discovered plant GST subclass has been implicated in numerous stress responses, including those arising from pathogen attack, oxidative stress, and heavy-metal toxicity. In addition, plant GSTs play a role in the cellular response to auxins and during the normal metabolism of plant secondary products like anthocyanins and cinnamic acid. This review presents the current knowledge about the functions of GSTs in regard to both herbicides and endogenous substrates. The catalytic mechanism of GST activity as well as the fate of glutathione S-conjugates are reviewed. Finally, a summary of what is known about the gene structure and regulation of plant GSTs is presented.
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Affiliation(s)
- Kathleen A. Marrs
- Department of Biological Sciences, Stanford University, Stanford California 94305-5020
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Newton GL, Arnold K, Price MS, Sherrill C, Delcardayre SB, Aharonowitz Y, Cohen G, Davies J, Fahey RC, Davis C. Distribution of thiols in microorganisms: mycothiol is a major thiol in most actinomycetes. J Bacteriol 1996; 178:1990-5. [PMID: 8606174 PMCID: PMC177895 DOI: 10.1128/jb.178.7.1990-1995.1996] [Citation(s) in RCA: 405] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Mycothiol [2-(N-acetylcysteinyl)amido-2-deoxy-alpha-D-glucopyranosyl- (1-->1)-myo-inositol] (MSH) has recently been identified as a major thiol in a number of actinomycetes (S. Sakuda, Z.-Y. Zhou, and Y. Yamada, Biosci. Biotech. Biochem. 58:1347-1348, 1994; H. S. C. Spies and D. J. Steenkamp, Eur. J. Biochem. 224:203-213, 1994; and G. L. Newton, C. A. Bewley, T. J. Dwyer, R. Horn, Y. Aharonowitz, G. Cohen, J. Davies, D. J. Faulkner, and R. C. Fahey, Eur. J. Biochem. 230:821-825, 1995). Since this novel thiol is more resistant than glutathione to heavy-metal ion-catalyzed oxidation, it seems likely to be the antioxidant thiol used by aerobic gram-positive bacteria that do not produce glutathione (GSH). In the present study we sought to define the spectrum of organisms that produce MSH. GSH was absent in all actinomycetes and some of the other gram-positive bacteria studied. Surprisingly, the streptococci and enterococci contained GSH, and some strains appeared to synthesize it rather than import it from the growth medium. MSH was found at significant levels in most actinomycetes examined. Among the actinobacteria four Micrococcus species produced MSH, but MSH was not found in representatives of the Arthrobacter, Agromyces, or Actinomyces genera. Of the nocardioforms examined, Nocardia, Rhodococcus, and Mycobacteria spp. all produced MSH. In addition to the established production of MSH by streptomycetes, we found that Micromonospora, Actinomadura, and Nocardiopsis spp. also synthesized MSH. Mycothiol production was not detected in Propionibacterium acnes or in representative species of the Listeria, Staphylococcus, Streptococcus, Enterococcus, Bacillus, and Clostridium genera. Examination of representatives of the cyanobacteria, purple bacteria, and spirochetes also gave negative results, as did tests of rat liver, bonito, Candida albicans, Neurospora crassa, and spinach leaves. The results, which indicate that MSH production is restricted to the actinomycetes, could have significant implications for the detection and treatment of infections with actinomycetes, especially those caused by mycobacteria.
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Affiliation(s)
- G L Newton
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla , California 92093, USA
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García P, Arca P, Evaristo Suárez J. Product of fosC, a gene from Pseudomonas syringae, mediates fosfomycin resistance by using ATP as cosubstrate. Antimicrob Agents Chemother 1995; 39:1569-73. [PMID: 7492106 PMCID: PMC162783 DOI: 10.1128/aac.39.7.1569] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Pseudomonas syringe PB-5123, a producer of fosfomycin, is resistant to high concentrations of the antibiotic. Two possible mechanisms of resistance have been detected: (i) impermeability to exogenous fosfomycin, even in the presence of sugar phosphate uptake inducers, and (ii) antibiotic phosphorylation. The gene responsible for this last activity, fosC, encodes a ca. 19,000-Da protein and is immediately followed by a second open reading frame, which shows sequence similarities to glutathione S-transferases. FosC uses ATP as a cosubstrate in an inactivation reaction that can be reversed with alkaline phosphatase. Other nucleotide triphosphates cannot be substituted for ATP in this reaction. No relationship between fosC and the previously described genes of fosfomycin resistance was found.
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Affiliation(s)
- P García
- Area de Microbiología, Facultad de Medicina, Universidad de Oviedo, Spain
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