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Bogetti X, Saxena S. Integrating Electron Paramagnetic Resonance Spectroscopy and Computational Modeling to Measure Protein Structure and Dynamics. Chempluschem 2024; 89:e202300506. [PMID: 37801003 DOI: 10.1002/cplu.202300506] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 10/05/2023] [Accepted: 10/06/2023] [Indexed: 10/07/2023]
Abstract
Electron paramagnetic resonance (EPR) has become a powerful probe of conformational heterogeneity and dynamics of biomolecules. In this Review, we discuss different computational modeling techniques that enrich the interpretation of EPR measurements of dynamics or distance restraints. A variety of spin labels are surveyed to provide a background for the discussion of modeling tools. Molecular dynamics (MD) simulations of models containing spin labels provide dynamical properties of biomolecules and their labels. These simulations can be used to predict EPR spectra, sample stable conformations and sample rotameric preferences of label sidechains. For molecular motions longer than milliseconds, enhanced sampling strategies and de novo prediction software incorporating or validated by EPR measurements are able to efficiently refine or predict protein conformations, respectively. To sample large-amplitude conformational transition, a coarse-grained or an atomistic weighted ensemble (WE) strategy can be guided with EPR insights. Looking forward, we anticipate an integrative strategy for efficient sampling of alternate conformations by de novo predictions, followed by validations by systematic EPR measurements and MD simulations. Continuous pathways between alternate states can be further sampled by WE-MD including all intermediate states.
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Affiliation(s)
- Xiaowei Bogetti
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, PA, 15260, USA
| | - Sunil Saxena
- Department of Chemistry, University of Pittsburgh, 219 Parkman Avenue, Pittsburgh, PA, 15260, USA
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2
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Matamá T, Costa C, Fernandes B, Araújo R, Cruz CF, Tortosa F, Sheeba CJ, Becker JD, Gomes A, Cavaco-Paulo A. Changing human hair fibre colour and shape from the follicle. J Adv Res 2023:S2090-1232(23)00350-8. [PMID: 37967812 DOI: 10.1016/j.jare.2023.11.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 09/21/2023] [Accepted: 11/12/2023] [Indexed: 11/17/2023] Open
Abstract
INTRODUCTION Natural hair curvature and colour are genetically determined human traits, that we intentionally change by applying thermal and chemical treatments to the fibre. Presently, those cosmetic methodologies act externally and their recurrent use is quite detrimental to hair fibre quality and even to our health. OBJECTIVES This work represents a disruptive concept to modify natural hair colour and curvature. We aim to model the fibre phenotype as it is actively produced in the follicle through the topical delivery of specific bioactive molecules to the scalp. METHODS Transcriptome differences between curly and straight hairs were identified by microarray. In scalp samples, the most variable transcripts were mapped by in situ hybridization. Then, by using appropriate cellular models, we screened a chemical library of 1200 generic drugs, searching for molecules that could lead to changes in either fibre colour or curvature. A pilot-scale, single-centre, investigator-initiated, prospective, blind, bilateral (split-scalp) placebo-controlled clinical study with the intervention of cosmetics was conducted to obtain a proof of concept (RNEC n.92938). RESULTS We found 85 genes transcribed significantly different between curly and straight hair, not previously associated with this human trait. Next, we mapped some of the most variable genes to the inner root sheath of follicles, reinforcing the role of this cell layer in fibre shape moulding. From the drug library screening, we selected 3 and 4 hits as modulators of melanin synthesis and gene transcription, respectively, to be further tested in 33 volunteers. The intentional specific hair change occurred: 8 of 14 volunteers exhibited colour changes, and 16 of 19 volunteers presented curvature modifications, by the end of the study. CONCLUSION The promising results obtained are the first step towards future cosmetics, complementary or alternative to current methodologies, taking hair styling to a new level: changing hair from the inside out.
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Affiliation(s)
- Teresa Matamá
- CEB - Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal; LABBELS - Associate Laboratory, 4710-057 Braga, Portugal.
| | - Cristiana Costa
- CEB - Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
| | - Bruno Fernandes
- CEB - Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
| | - Rita Araújo
- CBMA - Centre of Molecular and Environmental Biology, University of Minho, Campus of Gualtar, 4710-057, Braga, Portugal; CIBIO - Centro de Investigação em Biodiversidade e Recursos Genéticos, InBIO - Laboratório Associado, Campus de Vairão, Universidade do Porto, 4485-661 Vairão, Portugal
| | - Célia F Cruz
- CEB - Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal
| | - Francisco Tortosa
- Serviço de Anatomia Patológica, CHLN - Hospital de Santa Maria / Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal; Unidade de Anatomia Patológica, Hospital CUF Descobertas, Rua Mário Botas (Parque das Nações), 1998-018, Lisboa, Portugal
| | - Caroline J Sheeba
- ICVS - Life and Health Sciences Research Institute, University of Minho, 4710-057 Braga, Portugal; NIHR Central Commissioning Facility (CCF), Grange House, 15 Church Street, Twickenham, TW1 3NL, UK
| | - Jörg D Becker
- Instituto Gulbenkian de Ciência, Rua da Quinta Grande 6, Oeiras, 2780-156, Portugal; Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República, Oeiras, 2780-157, Portugal
| | - Andreia Gomes
- CBMA - Centre of Molecular and Environmental Biology, University of Minho, Campus of Gualtar, 4710-057, Braga, Portugal
| | - Artur Cavaco-Paulo
- CEB - Centre of Biological Engineering, University of Minho, 4710-057 Braga, Portugal; LABBELS - Associate Laboratory, 4710-057 Braga, Portugal; Solfarcos - Pharmaceutical and Cosmetic Solutions Ltd, Avenida Imaculada Conceição n. 589, 4700-034 Braga, Portugal.
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Bogetti X, Bogetti A, Casto J, Rule G, Chong L, Saxena S. Direct observation of negative cooperativity in a detoxification enzyme at the atomic level by Electron Paramagnetic Resonance spectroscopy and simulation. Protein Sci 2023; 32:e4770. [PMID: 37632831 PMCID: PMC10503414 DOI: 10.1002/pro.4770] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 07/14/2023] [Accepted: 08/23/2023] [Indexed: 08/28/2023]
Abstract
The catalytic activity of human glutathione S-transferase A1-1 (hGSTA1-1), a homodimeric detoxification enzyme, is dependent on the conformational dynamics of a key C-terminal helix α9 in each monomer. However, the structural details of how the two monomers interact upon binding of substrates is not well understood and the structure of the ligand-free state of the hGSTA1-1 homodimer has not been resolved. Here, we used a combination of electron paramagnetic resonance (EPR) distance measurements and weighted ensemble (WE) simulations to characterize the conformational ensemble of the ligand-free state at the atomic level. EPR measurements reveal a broad distance distribution between a pair of Cu(II) labels in the ligand-free state that gradually shifts and narrows as a function of increasing ligand concentration. These shifts suggest changes in the relative positioning of the two α9 helices upon ligand binding. WE simulations generated unbiased pathways for the seconds-timescale transition between alternate states of the enzyme, leading to the generation of atomically detailed structures of the ligand-free state. Notably, the simulations provide direct observations of negative cooperativity between the monomers of hGSTA1-1, which involve the mutually exclusive docking of α9 in each monomer as a lid over the active site. We identify key interactions between residues that lead to this negative cooperativity. Negative cooperativity may be essential for interaction of hGSTA1-1 with a wide variety of toxic substrates and their subsequent neutralization. More broadly, this work demonstrates the power of integrating EPR distances with WE rare-events sampling strategy to gain mechanistic information on protein function at the atomic level.
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Affiliation(s)
- Xiaowei Bogetti
- Department of ChemistryUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Anthony Bogetti
- Department of ChemistryUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Joshua Casto
- Department of ChemistryUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Gordon Rule
- Department of Biological SciencesCarnegie Mellon UniversityPittsburghPennsylvaniaUSA
| | - Lillian Chong
- Department of ChemistryUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Sunil Saxena
- Department of ChemistryUniversity of PittsburghPittsburghPennsylvaniaUSA
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4
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Yu L, Lee H, Rho SB, Park MK, Lee CH. Ethacrynic Acid: A Promising Candidate for Drug Repurposing as an Anticancer Agent. Int J Mol Sci 2023; 24:ijms24076712. [PMID: 37047688 PMCID: PMC10094867 DOI: 10.3390/ijms24076712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 03/28/2023] [Accepted: 03/30/2023] [Indexed: 04/07/2023] Open
Abstract
Ethacrynic acid (ECA) is a diuretic that inhibits Na-K-2Cl cotransporter (NKCC2) present in the thick ascending loop of Henle and muculo dens and is clinically used for the treatment of edema caused by excessive body fluid. However, its clinical use is limited due to its low bioavailability and side effects, such as liver damage and hearing loss at high doses. Despite this, ECA has recently emerged as a potential anticancer agent through the approach of drug repositioning, with a novel mechanism of action. ECA has been shown to regulate cancer hallmark processes such as proliferation, apoptosis, migration and invasion, angiogenesis, inflammation, energy metabolism, and the increase of inhibitory growth factors through various mechanisms. Additionally, ECA has been used as a scaffold for synthesizing a new material, and various derivatives have been synthesized. This review explores the potential of ECA and its derivatives as anticancer agents, both alone and in combination with adjuvants, by examining their effects on ten hallmarks of cancer and neuronal contribution to cancer. Furthermore, we investigated the trend of synthesis research of a series of ECA derivatives to improve the bioavailability of ECA. This review highlights the importance of ECA research and its potential to provide a cost-effective alternative to new drug discovery and development for cancer treatment.
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Affiliation(s)
- Lu Yu
- College of Pharmacy, Dongguk University, Seoul 04620, Republic of Korea
| | - Ho Lee
- Department of Cancer Biomedical Science, Graduate School of Cancer Science and Policy National Cancer Center, Goyang 10408, Republic of Korea
| | - Seung Bae Rho
- Department of Cancer Biomedical Science, Graduate School of Cancer Science and Policy National Cancer Center, Goyang 10408, Republic of Korea
| | - Mi Kyung Park
- College of Pharmacy, Dongguk University, Seoul 04620, Republic of Korea
- Department of Cancer Biomedical Science, Graduate School of Cancer Science and Policy National Cancer Center, Goyang 10408, Republic of Korea
| | - Chang Hoon Lee
- College of Pharmacy, Dongguk University, Seoul 04620, Republic of Korea
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A Key Role in Catalysis and Enzyme Thermostability of a Conserved Helix H5 Motif of Human Glutathione Transferase A1-1. Int J Mol Sci 2023; 24:ijms24043700. [PMID: 36835112 PMCID: PMC9959719 DOI: 10.3390/ijms24043700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 02/06/2023] [Accepted: 02/07/2023] [Indexed: 02/16/2023] Open
Abstract
Glutathione transferases (GSTs) are promiscuous enzymes whose main function is the detoxification of electrophilic compounds. These enzymes are characterized by structural modularity that underpins their exploitation as dynamic scaffolds for engineering enzyme variants, with customized catalytic and structural properties. In the present work, multiple sequence alignment of the alpha class GSTs allowed the identification of three conserved residues (E137, K141, and S142) at α-helix 5 (H5). A motif-directed redesign of the human glutathione transferase A1-1 (hGSTA1-1) was performed through site-directed mutagenesis at these sites, creating two single- and two double-point mutants (E137H, K141H, K141H/S142H, and E137H/K141H). The results showed that all the enzyme variants displayed enhanced catalytic activity compared to the wild-type enzyme hGSTA1-1, while the double mutant hGSTA1-K141H/S142H also showed improved thermal stability. X-ray crystallographic analysis revealed the molecular basis of the effects of double mutations on enzyme stability and catalysis. The biochemical and structural analysis presented here will contribute to a deeper understanding of the structure and function of alpha class GSTs.
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Kobzar O, Shulha Y, Buldenko V, Cherenok S, Silenko O, Kalchenko V, Vovk A. Inhibition of glutathione S-transferases by photoactive calix[4]arene α-ketophosphonic acids. Bioorg Med Chem Lett 2022; 77:129019. [DOI: 10.1016/j.bmcl.2022.129019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 09/20/2022] [Accepted: 10/03/2022] [Indexed: 11/02/2022]
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Schwartz M, Menetrier F, Heydel JM, Chavanne E, Faure P, Labrousse M, Lirussi F, Canon F, Mannervik B, Briand L, Neiers F. Interactions Between Odorants and Glutathione Transferases in the Human Olfactory Cleft. Chem Senses 2021; 45:645-654. [PMID: 32822468 DOI: 10.1093/chemse/bjaa055] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Xenobiotic metabolizing enzymes and other proteins, including odorant-binding proteins located in the nasal epithelium and mucus, participate in a series of processes modulating the concentration of odorants in the environment of olfactory receptors (ORs) and finely impact odor perception. These enzymes and transporters are thought to participate in odorant degradation or transport. Odorant biotransformation results in 1) changes in the odorant quantity up to their clearance and the termination of signaling and 2) the formation of new odorant stimuli (metabolites). Enzymes, such as cytochrome P450 and glutathione transferases (GSTs), have been proposed to participate in odorant clearance in insects and mammals as odorant metabolizing enzymes. This study aims to explore the function of GSTs in human olfaction. Using immunohistochemical methods, GSTs were found to be localized in human tissues surrounding the olfactory epithelium. Then, the activity of 2 members of the GST family toward odorants was measured using heterologously expressed enzymes. The interactions/reactions with odorants were further characterized using a combination of enzymatic techniques. Furthermore, the structure of the complex between human GSTA1 and the glutathione conjugate of an odorant was determined by X-ray crystallography. Our results strongly suggest the role of human GSTs in the modulation of odorant availability to ORs in the peripheral olfactory process.
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Affiliation(s)
- Mathieu Schwartz
- Université de Bourgogne-Franche Comté, CNRS, INRA, Centre des Sciences du Goût et de l'Alimentation, Dijon, France
| | - Franck Menetrier
- Université de Bourgogne-Franche Comté, CNRS, INRA, Centre des Sciences du Goût et de l'Alimentation, Dijon, France
| | - Jean-Marie Heydel
- Université de Bourgogne-Franche Comté, CNRS, INRA, Centre des Sciences du Goût et de l'Alimentation, Dijon, France
| | - Evelyne Chavanne
- Université de Bourgogne-Franche Comté, CNRS, INRA, Centre des Sciences du Goût et de l'Alimentation, Dijon, France
| | - Philippe Faure
- Université de Bourgogne-Franche Comté, CNRS, INRA, Centre des Sciences du Goût et de l'Alimentation, Dijon, France
| | - Marc Labrousse
- Laboratoire d'Anatomie, UFR Médecine de Reims, Université de Reims Champagne Ardenne, Reims, France
| | - Frédéric Lirussi
- Université de Bourgogne-Franche Comté, INSERM U1231, University Hospital of Dijon, Dijon, France
| | - Francis Canon
- Université de Bourgogne-Franche Comté, CNRS, INRA, Centre des Sciences du Goût et de l'Alimentation, Dijon, France
| | - Bengt Mannervik
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Loïc Briand
- Université de Bourgogne-Franche Comté, CNRS, INRA, Centre des Sciences du Goût et de l'Alimentation, Dijon, France
| | - Fabrice Neiers
- Université de Bourgogne-Franche Comté, CNRS, INRA, Centre des Sciences du Goût et de l'Alimentation, Dijon, France
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8
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García-Gutiérrez P, Zubillaga RA, Téllez-Plancarte A, Flores-López R, Camarillo-Cadena M, Landa A. Discovery of a new non-substrate inhibitor of the 26.5 kDa glutathione transferase from Taenia solium by virtual screening. J Mol Graph Model 2020; 100:107707. [PMID: 32854022 DOI: 10.1016/j.jmgm.2020.107707] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 07/09/2020] [Accepted: 07/15/2020] [Indexed: 12/29/2022]
Abstract
The inappropriate use of anthelmintics, such as praziquantel and albendazole, has generated resistance and the need to develop new drugs. Glutathione transferases, GSTs, are bisubstrate dimeric enzymes that constitute the main detoxification mechanism against electrophiles, drugs and oxidative damage in Taenia solium. Therefore, GSTs are important targets for the development of new anthelmintics. In this work, we reported a successful virtual screen aimed at the identification of novel inhibitors of a 26.5 kDa GST from T. solium (TsGST26). We found that a compound, i7, able to inhibit selectively TsGST26 concerning human GSTs, showing a non-competitive inhibition mechanism towards substrate glutathione with a Ki (GSH) of 55.7 μM and mixed inhibition towards the electrophilic substrate 1-chloro-2,4-dinitrobenzene with a Ki (CDNB) of 8.64 μM. These results are in agreement with those of docking simulations, which showed i7 binds a site adjacent to the electrophilic site and furthest from the glutathione site.
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Affiliation(s)
- Ponciano García-Gutiérrez
- Departamento de Química. Universidad Autónoma Metropolitana-Iztapalapa, Ciudad de México, C.P 09340, Mexico.
| | - Rafael A Zubillaga
- Departamento de Química. Universidad Autónoma Metropolitana-Iztapalapa, Ciudad de México, C.P 09340, Mexico
| | - Alexandro Téllez-Plancarte
- Departamento de Química. Universidad Autónoma Metropolitana-Iztapalapa, Ciudad de México, C.P 09340, Mexico
| | - Roberto Flores-López
- Departamento de Microbiología y Parasitología, Facultad de Medicina. Universidad Nacional Autónoma de México, Ciudad de México, C.P 04510, Mexico
| | - Menandro Camarillo-Cadena
- Departamento de Química. Universidad Autónoma Metropolitana-Iztapalapa, Ciudad de México, C.P 09340, Mexico
| | - Abraham Landa
- Departamento de Microbiología y Parasitología, Facultad de Medicina. Universidad Nacional Autónoma de México, Ciudad de México, C.P 04510, Mexico.
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9
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Googins MR, Woghiren-Afegbua AO, Calderon M, St Croix CM, Kiselyov KI, VanDemark AP. Structural and functional divergence of GDAP1 from the glutathione S-transferase superfamily. FASEB J 2020; 34:7192-7207. [PMID: 32274853 DOI: 10.1096/fj.202000110r] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 03/12/2020] [Accepted: 03/24/2020] [Indexed: 11/11/2022]
Abstract
Mutations in ganglioside-induced differentiation-associated protein 1 (GDAP1) alter mitochondrial morphology and result in several subtypes of the inherited peripheral neuropathy Charcot-Marie-Tooth disease; however, the mechanism by which GDAP1 functions has remained elusive. GDAP1 contains primary sequence homology to the GST superfamily; however, the question of whether GDAP1 is an active GST has not been clearly resolved. Here, we present biochemical evidence, suggesting that GDAP1 has lost the ability to bind glutathione without a loss of substrate binding activity. We have revealed that the α-loop, located within the H-site motif is the primary determinant for substrate binding. Using structural data of GDAP1, we have found that critical residues and configurations in the G-site which canonically interact with glutathione are altered in GDAP1, rendering it incapable of binding glutathione. Last, we have found that the overexpression of GDAP1 in HeLa cells results in a mitochondrial phenotype which is distinct from oxidative stress-induced mitochondrial fragmentation. This phenotype is dependent on the presence of the transmembrane domain, as well as a unique hydrophobic domain that is not found in canonical GSTs. Together, we data point toward a non-enzymatic role for GDAP1, such as a sensor or receptor.
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Affiliation(s)
- Matthew R Googins
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Michael Calderon
- Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA, USA
| | | | - Kirill I Kiselyov
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Andrew P VanDemark
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
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Atkins WM. Mechanisms of promiscuity among drug metabolizing enzymes and drug transporters. FEBS J 2020; 287:1306-1322. [PMID: 31663687 PMCID: PMC7138722 DOI: 10.1111/febs.15116] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 10/04/2019] [Accepted: 10/29/2019] [Indexed: 12/11/2022]
Abstract
Detoxication, or 'drug-metabolizing', enzymes and drug transporters exhibit remarkable substrate promiscuity and catalytic promiscuity. In contrast to substrate-specific enzymes that participate in defined metabolic pathways, individual detoxication enzymes must cope with substrates of vast structural diversity, including previously unencountered environmental toxins. Presumably, evolution selects for a balance of 'adequate' kcat /KM values for a wide range of substrates, rather than optimizing kcat /KM for any individual substrate. However, the structural, energetic, and metabolic properties that achieve this balance, and hence optimize detoxication, are not well understood. Two features of detoxication enzymes that are frequently cited as contributions to promiscuity include the exploitation of highly reactive versatile cofactors, or cosubstrates, and a high degree of flexibility within the protein structure. This review examines these intuitive mechanisms in detail and clarifies the contributions of the classic ligand binding models 'induced fit' (IF) and 'conformational selection' (CS) to substrate promiscuity. The available literature data for drug metabolizing enzymes and transporters suggest that IF is exploited by these promiscuous detoxication enzymes, as it is with substrate-specific enzymes, but the detoxication enzymes uniquely exploit 'IFs' to retain a wide range of substrates at their active sites. In contrast, whereas CS provides no catalytic advantage to substrate-specific enzymes, promiscuous enzymes may uniquely exploit it to recruit a wide range of substrates. The combination of CS and IF, for recruitment and retention of substrates, can potentially optimize the promiscuity of drug metabolizing enzymes and drug transporters.
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Affiliation(s)
- William M. Atkins
- Department of Medicinal ChemistryUniversity of WashingtonSeattleWAUSA
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11
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Sandamalika WMG, Priyathilaka TT, Liyanage DS, Lee S, Lim HK, Lee J. Molecular characterization of kappa class glutathione S-transferase from the disk abalone (Haliotis discus discus) and changes in expression following immune and stress challenges. FISH & SHELLFISH IMMUNOLOGY 2018; 77:252-263. [PMID: 29621633 DOI: 10.1016/j.fsi.2018.03.058] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2017] [Revised: 03/21/2018] [Accepted: 03/29/2018] [Indexed: 06/08/2023]
Abstract
Glutathione S-transferase (GST; EC 2.5.1.18) isoenzymes represent a complex group of proteins that are involved in phase II detoxification in several organisms. In this study, GST kappa (GSTκ) from the disk abalone (Haliotis discus discus; AbGSTκ) was characterized at both the transcriptional and functional levels to determine its potential capacity to perform as a detoxification agent under conditions of different stress. The predicted AbGSTκ protein consists of 227 amino acids, with a predicted molecular weight of 25.6 kDa and a theoretical isoelectric point (pI) of 7.78. In silico analysis reveals that AbGSTκ is a disulfide bond formation protein A (DsbA), consisting of a thioredoxin domain, GSH binding sites (G-sites), and a catalytic residue. In contrast, no hydrophobic ligand binding site (H-site), or signal peptides, were detected. AbGSTκ showed the highest sequence identity with the orthologue from pufferfish (Takifugu obscurus) (60.0%). In a phylogenetic tree, AbGSTκ clustered closely together with other fish GSTκs, and was evolutionarily distanced from other cytosolic GSTs. The predicted three-dimensional structure clearly demonstrates that the dimer adopts a butterfly-like shape. A tissue distribution analysis revealed that GSTκ was highly expressed in the digestive tract, suggesting it has detoxification ability. Depending on the tissue and time, AbGSTκ showed different expression patterns, and levels of expression, following challenge of the abalone with immune stimulants. Enzyme kinetics of the purified recombinant proteins demonstrated its conjugating ability using 1-Chloro-2,4-dinitrobenzene (CDNB) and glutathione (GSH) as substrates, and suggested it has a low affinity for both substrates. The optimum temperature and pH for the rAbGSTκ GSH: CDNB conjugating activity were found to be 35 °C and pH 8, respectively indicating that the abalone is well adapted to a wide range of environmental conditions. Cibacron blue (100 μM) was capable of completely inhibiting rAbGSTκ (100%) with an IC50 (half maximal inhibitory concentration) of 0.05 μM. A disk diffusion assay revealed that rAbGSTκ could significantly protect cells from H2O2, CdCl2, and ZnCl2. Altogether, this current study suggests that AbGSTκ is involved in detoxification and immunological host defense mechanisms and allows abalones to overcome stresses in order for them to have an increased chance of survival.
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Affiliation(s)
- W M Gayashani Sandamalika
- Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province 63243, Republic of Korea
| | - Thanthrige Thiunuwan Priyathilaka
- Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province 63243, Republic of Korea
| | - D S Liyanage
- Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province 63243, Republic of Korea
| | - Sukkyoung Lee
- Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province 63243, Republic of Korea
| | - Han-Kyu Lim
- Department of Marine and Fisheries Resources, College of Natural Sciences, Mokpo National University, Muan, Jeonnam 58554, Republic of Korea
| | - Jehee Lee
- Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju Self-Governing Province 63243, Republic of Korea; Marine Science Institute, Jeju National University, Jeju Self-Governing Province 63333, Republic of Korea.
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12
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Stoddard EG, Killinger BJ, Nair RN, Sadler NC, Volk RF, Purvine SO, Shukla AK, Smith JN, Wright AT. Activity-Based Probes for Isoenzyme- and Site-Specific Functional Characterization of Glutathione S-Transferases. J Am Chem Soc 2017; 139:16032-16035. [PMID: 29068682 DOI: 10.1021/jacs.7b07378] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Glutathione S-transferases (GSTs) comprise a diverse family of phase II drug metabolizing enzymes whose shared function is the conjugation of reduced glutathione (GSH) to endo- and xenobiotics. Although the conglomerate activity of these enzymes can be measured, the isoform-specific contribution to the metabolism of xenobiotics in complex biological samples has not been possible. We have developed two activity-based probes (ABPs) that characterize active GSTs in mammalian tissues. The GST active site is composed of a GSH binding "G site" and a substrate binding "H site". Therefore, we developed (1) a GSH-based photoaffinity probe (GSTABP-G) to target the "G site", and (2) an ABP designed to mimic a substrate molecule and have "H site" activity (GSTABP-H). The GSTABP-G features a photoreactive moiety for UV-induced covalent binding to GSTs and GSH-binding enzymes. The GSTABP-H is a derivative of a known mechanism-based GST inhibitor that binds within the active site and inhibits GST activity. Validation of probe targets and "G" and "H" site specificity was carried out using a series of competition experiments in the liver. Herein, we present robust tools for the characterization of enzyme- and active site-specific GST activity in mammalian model systems.
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Affiliation(s)
- Ethan G Stoddard
- Chemical Biology and Exposure Sciences, Biological Sciences Division, Pacific Northwest National Laboratory , 902 Battelle Boulevard, Richland, Washington 99352, United States
| | - Bryan J Killinger
- Chemical Biology and Exposure Sciences, Biological Sciences Division, Pacific Northwest National Laboratory , 902 Battelle Boulevard, Richland, Washington 99352, United States
| | - Reji N Nair
- Chemical Biology and Exposure Sciences, Biological Sciences Division, Pacific Northwest National Laboratory , 902 Battelle Boulevard, Richland, Washington 99352, United States
| | - Natalie C Sadler
- Chemical Biology and Exposure Sciences, Biological Sciences Division, Pacific Northwest National Laboratory , 902 Battelle Boulevard, Richland, Washington 99352, United States
| | - Regan F Volk
- Chemical Biology and Exposure Sciences, Biological Sciences Division, Pacific Northwest National Laboratory , 902 Battelle Boulevard, Richland, Washington 99352, United States
| | - Samuel O Purvine
- Chemical Biology and Exposure Sciences, Biological Sciences Division, Pacific Northwest National Laboratory , 902 Battelle Boulevard, Richland, Washington 99352, United States
| | - Anil K Shukla
- Chemical Biology and Exposure Sciences, Biological Sciences Division, Pacific Northwest National Laboratory , 902 Battelle Boulevard, Richland, Washington 99352, United States
| | - Jordan N Smith
- Chemical Biology and Exposure Sciences, Biological Sciences Division, Pacific Northwest National Laboratory , 902 Battelle Boulevard, Richland, Washington 99352, United States
| | - Aaron T Wright
- Chemical Biology and Exposure Sciences, Biological Sciences Division, Pacific Northwest National Laboratory , 902 Battelle Boulevard, Richland, Washington 99352, United States
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Identification of Potent Chloride Intracellular Channel Protein 1 Inhibitors from Traditional Chinese Medicine through Structure-Based Virtual Screening and Molecular Dynamics Analysis. BIOMED RESEARCH INTERNATIONAL 2017; 2017:4751780. [PMID: 29147652 PMCID: PMC5632872 DOI: 10.1155/2017/4751780] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 04/23/2017] [Accepted: 05/10/2017] [Indexed: 11/17/2022]
Abstract
Chloride intracellular channel 1 (CLIC1) is involved in the development of most aggressive human tumors, including gastric, colon, lung, liver, and glioblastoma cancers. It has become an attractive new therapeutic target for several types of cancer. In this work, we aim to identify natural products as potent CLIC1 inhibitors from Traditional Chinese Medicine (TCM) database using structure-based virtual screening and molecular dynamics (MD) simulation. First, structure-based docking was employed to screen the refined TCM database and the top 500 TCM compounds were obtained and reranked by X-Score. Then, 30 potent hits were achieved from the top 500 TCM compounds using cluster and ligand-protein interaction analysis. Finally, MD simulation was employed to validate the stability of interactions between each hit and CLIC1 protein from docking simulation, and Molecular Mechanics/Generalized Born Surface Area (MM-GBSA) analysis was used to refine the virtual hits. Six TCM compounds with top MM-GBSA scores and ideal-binding models were confirmed as the final hits. Our study provides information about the interaction between TCM compounds and CLIC1 protein, which may be helpful for further experimental investigations. In addition, the top 6 natural products structural scaffolds could serve as building blocks in designing drug-like molecules for CLIC1 inhibition.
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Mohana K, Achary A. Human cytosolic glutathione-S-transferases: quantitative analysis of expression, comparative analysis of structures and inhibition strategies of isozymes involved in drug resistance. Drug Metab Rev 2017; 49:318-337. [DOI: 10.1080/03602532.2017.1343343] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Krishnamoorthy Mohana
- Department of Biotechnology, Centre for Research, Kamaraj College of Engineering and Technology, Virudhunagar, India
| | - Anant Achary
- Department of Biotechnology, Centre for Research, Kamaraj College of Engineering and Technology, Virudhunagar, India
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15
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Axarli I, Muleta AW, Chronopoulou EG, Papageorgiou AC, Labrou NE. Directed evolution of glutathione transferases towards a selective glutathione-binding site and improved oxidative stability. Biochim Biophys Acta Gen Subj 2016; 1861:3416-3428. [PMID: 27612661 DOI: 10.1016/j.bbagen.2016.09.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 08/28/2016] [Accepted: 09/04/2016] [Indexed: 10/21/2022]
Abstract
BACKGROUND Glutathione transferases (GSTs) are a family of detoxification enzymes that catalyze the conjugation of glutathione (GSH) to electrophilic compounds. METHODS A library of alpha class GSTs was constructed by DNA shuffling using the DNA encoding the human glutathione transferase A1-1 (hGSTA1-1) and the rat glutathione transferase A1-1 (rGSTA1-1). RESULTS Activity screening of the library allowed the selection of a chimeric enzyme variant (GSTD4) that displayed high affinity towards GSH and GSH-Sepharose affinity adsorbent, higher kcat/Km and improved thermal stability, compared to the parent enzymes. The crystal structures of the GSTD4 enzyme in free form and in complex with GSH were determined to 1.6Å and 2.3Å resolution, respectively. Analysis of the GSTD4 structure showed subtle conformational changes in the GSH-binding site and in electron-sharing network that may contribute to the increased GSH affinity. The shuffled variant GSTD4 was further optimized for improved oxidative stability employing site-saturation mutagenesis. The Cys112Ser mutation confers optimal oxidative stability and kinetic properties in the GSTD4 enzyme. CONCLUSIONS DNA shuffling allowed the creation of a chimeric enzyme variant with improved properties, compared to the parent enzymes. X-ray crystallography shed light on how recombination of a specific segment from homologous GSTA1-1 together with point mutations gives rise to a new functionally competent enzyme with improved binding, catalytic properties and stability. GENERAL SIGNIFICANCE Such an engineered GST would be useful in biotechnology as affinity tool in affinity chromatography as well as a biocatalytic matrix for the construction of biochips or enzyme biosensors.
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Affiliation(s)
- Irine Axarli
- Laboratory of Enzyme Technology, Department of Biotechnology, School of Food, Biotechnology and Development, Agricultural University of Athens, 75 Iera Odos Street, GR-11855 Athens, Greece
| | - Abdi W Muleta
- Turku Centre for Biotechnology, BioCity, University of Turku and Åbo Akademi University, Turku 20521, Finland
| | - Evangelia G Chronopoulou
- Laboratory of Enzyme Technology, Department of Biotechnology, School of Food, Biotechnology and Development, Agricultural University of Athens, 75 Iera Odos Street, GR-11855 Athens, Greece
| | - Anastassios C Papageorgiou
- Turku Centre for Biotechnology, BioCity, University of Turku and Åbo Akademi University, Turku 20521, Finland
| | - Nikolaos E Labrou
- Laboratory of Enzyme Technology, Department of Biotechnology, School of Food, Biotechnology and Development, Agricultural University of Athens, 75 Iera Odos Street, GR-11855 Athens, Greece.
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16
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Al Khamici H, Brown LJ, Hossain KR, Hudson AL, Sinclair-Burton AA, Ng JPM, Daniel EL, Hare JE, Cornell BA, Curmi PMG, Davey MW, Valenzuela SM. Members of the chloride intracellular ion channel protein family demonstrate glutaredoxin-like enzymatic activity. PLoS One 2015; 10:e115699. [PMID: 25581026 PMCID: PMC4291220 DOI: 10.1371/journal.pone.0115699] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 11/26/2014] [Indexed: 01/07/2023] Open
Abstract
The Chloride Intracellular Ion Channel (CLIC) family consists of six evolutionarily conserved proteins in humans. Members of this family are unusual, existing as both monomeric soluble proteins and as integral membrane proteins where they function as chloride selective ion channels, however no function has previously been assigned to their soluble form. Structural studies have shown that in the soluble form, CLIC proteins adopt a glutathione S-transferase (GST) fold, however, they have an active site with a conserved glutaredoxin monothiol motif, similar to the omega class GSTs. We demonstrate that CLIC proteins have glutaredoxin-like glutathione-dependent oxidoreductase enzymatic activity. CLICs 1, 2 and 4 demonstrate typical glutaredoxin-like activity using 2-hydroxyethyl disulfide as a substrate. Mutagenesis experiments identify cysteine 24 as the catalytic cysteine residue in CLIC1, which is consistent with its structure. CLIC1 was shown to reduce sodium selenite and dehydroascorbate in a glutathione-dependent manner. Previous electrophysiological studies have shown that the drugs IAA-94 and A9C specifically block CLIC channel activity. These same compounds inhibit CLIC1 oxidoreductase activity. This work for the first time assigns a functional activity to the soluble form of the CLIC proteins. Our results demonstrate that the soluble form of the CLIC proteins has an enzymatic activity that is distinct from the channel activity of their integral membrane form. This CLIC enzymatic activity may be important for protecting the intracellular environment against oxidation. It is also likely that this enzymatic activity regulates the CLIC ion channel function.
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Affiliation(s)
- Heba Al Khamici
- School of Medical and Molecular Biosciences, University of Technology Sydney, Sydney, New South Wales 2007, Australia
| | - Louise J. Brown
- Department of Chemistry and Bimolecular Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Khondker R. Hossain
- School of Medical and Molecular Biosciences, University of Technology Sydney, Sydney, New South Wales 2007, Australia
- Bragg Institute, Australian Nuclear Science and Technology Organisation, Sydney, New South Wales 2234, Australia
| | - Amanda L. Hudson
- School of Medical and Molecular Biosciences, University of Technology Sydney, Sydney, New South Wales 2007, Australia
| | - Alxcia A. Sinclair-Burton
- School of Medical and Molecular Biosciences, University of Technology Sydney, Sydney, New South Wales 2007, Australia
| | - Jane Phui Mun Ng
- School of Medical and Molecular Biosciences, University of Technology Sydney, Sydney, New South Wales 2007, Australia
| | - Elizabeth L. Daniel
- Department of Chemistry and Bimolecular Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Joanna E. Hare
- Department of Chemistry and Bimolecular Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
| | - Bruce A. Cornell
- Surgical Diagnostics, Roseville, Sydney, New South Wales 2069, Australia
| | - Paul M. G. Curmi
- School of Physics, University of New South Wales, Sydney, New South Wales 2052, Australia
- Centre for Applied Medical Research, St Vincent's Hospital, Sydney, New South Wales 2010, Australia
| | - Mary W. Davey
- School of Medical and Molecular Biosciences, University of Technology Sydney, Sydney, New South Wales 2007, Australia
| | - Stella M. Valenzuela
- School of Medical and Molecular Biosciences, University of Technology Sydney, Sydney, New South Wales 2007, Australia
- Centre for Health Technologies, University of Technology Sydney, Sydney, New South Wales 2007, Australia
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17
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Ye J, Nadar SV, Li J, Rosen BP. Structure of Escherichia coli Grx2 in complex with glutathione: a dual-function hybrid of glutaredoxin and glutathione S-transferase. ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2014; 70:1907-13. [PMID: 25004967 PMCID: PMC4984262 DOI: 10.1107/s1399004714009250] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Accepted: 04/24/2014] [Indexed: 11/11/2022]
Abstract
The structure of glutaredoxin 2 (Grx2) from Escherichia coli co-crystallized with glutathione (GSH) was solved at 1.60 Å resolution. The structure of a mutant with the active-site residues Cys9 and Cys12 changed to serine crystallized in the absence of glutathione was solved to 2.4 Å resolution. Grx2 has an N-terminal domain characteristic of glutaredoxins, and the overall structure is congruent with the structure of glutathione S-transferases (GSTs). Purified Grx2 exhibited GST activity. Grx2, which is the physiological electron donor for arsenate reduction by E. coli ArsC, was docked with ArsC. The docked structure could be fitted with GSH bridging the active sites of the two proteins. It is proposed that Grx2 is a novel Grx/GST hybrid that functions in two steps of the ArsC catalytic cycle: as a GST it catalyzes glutathionylation of the ArsC-As(V) intermediate and as a glutaredoxin it catalyzes deglutathionylation of the ArsC-As(III)-SG intermediate.
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Affiliation(s)
- Jun Ye
- Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, People's Republic of China
| | - S Venkadesh Nadar
- Department of Cellular Biology and Pharmacology, Florida International University, Herbert Wertheim College of Medicine, Miami, FL 33199, USA
| | - Jiaojiao Li
- Department of Cellular Biology and Pharmacology, Florida International University, Herbert Wertheim College of Medicine, Miami, FL 33199, USA
| | - Barry P Rosen
- Department of Cellular Biology and Pharmacology, Florida International University, Herbert Wertheim College of Medicine, Miami, FL 33199, USA
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18
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Lin Y, Huang Y, Zheng W, Wang F, Habtemariam A, Luo Q, Li X, Wu K, Sadler PJ, Xiong S. Organometallic ruthenium anticancer complexes inhibit human glutathione-S-transferase π. J Inorg Biochem 2013; 128:77-84. [DOI: 10.1016/j.jinorgbio.2013.07.029] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 07/15/2013] [Accepted: 07/18/2013] [Indexed: 10/26/2022]
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19
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Musdal Y, Hegazy UM, Aksoy Y, Mannervik B. FDA-approved drugs and other compounds tested as inhibitors of human glutathione transferase P1-1. Chem Biol Interact 2013; 205:53-62. [DOI: 10.1016/j.cbi.2013.06.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Revised: 05/25/2013] [Accepted: 06/03/2013] [Indexed: 11/29/2022]
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20
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Bardai GK, Hales BF, Sunahara GI. Glyceryl trinitrate metabolism in the quail embryo by the glutathione S-transferases leads to a perturbation in redox status and embryotoxicity. Comp Biochem Physiol B Biochem Mol Biol 2013; 165:153-64. [DOI: 10.1016/j.cbpb.2013.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 04/03/2013] [Accepted: 04/04/2013] [Indexed: 10/27/2022]
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21
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Karpusas M, Axarli I, Chiniadis L, Papakyriakou A, Bethanis K, Scopelitou K, Clonis YD, Labrou NE. The interaction of the chemotherapeutic drug chlorambucil with human glutathione transferase A1-1: kinetic and structural analysis. PLoS One 2013; 8:e56337. [PMID: 23460799 PMCID: PMC3584069 DOI: 10.1371/journal.pone.0056337] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Accepted: 01/08/2013] [Indexed: 01/31/2023] Open
Abstract
Glutathione transferases (GSTs) are enzymes that contribute to cellular detoxification by catalysing the nucleophilic attack of glutathione (GSH) on the electrophilic centre of a number of xenobiotic compounds, including several chemotherapeutic drugs. In the present work we investigated the interaction of the chemotherapeutic drug chlorambucil (CBL) with human GSTA1-1 (hGSTA1-1) using kinetic analysis, protein crystallography and molecular dynamics. In the presence of GSH, CBL behaves as an efficient substrate for hGSTA1-1. The rate-limiting step of the catalytic reaction between CBL and GSH is viscosity-dependent and kinetic data suggest that product release is rate-limiting. The crystal structure of the hGSTA1-1/CBL-GSH complex was solved at 2.1 Å resolution by molecular replacement. CBL is bound at the H-site attached to the thiol group of GSH, is partially ordered and exposed to the solvent, making specific interactions with the enzyme. Molecular dynamics simulations based on the crystal structure indicated high mobility of the CBL moiety and stabilization of the C-terminal helix due to the presence of the adduct. In the absence of GSH, CBL is shown to be an alkylating irreversible inhibitor for hGSTA1-1. Inactivation of the enzyme by CBL followed a biphasic pseudo-first-order saturation kinetics with approximately 1 mol of CBL per mol of dimeric enzyme being incorporated. Structural analysis suggested that the modifying residue is Cys112 which is located at the entrance of the H-site. The results are indicative of a structural communication between the subunits on the basis of mutually exclusive modification of Cys112, indicating that the two enzyme active sites are presumably coordinated.
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Affiliation(s)
- Michael Karpusas
- Physics Laboratory, Department of Science, Agricultural University of Athens, Athens, Greece
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22
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Park AK, Moon JH, Jang EH, Park H, Ahn IY, Lee KS, Chi YM. The structure of a shellfish specific GST class glutathione S
-transferase from antarctic bivalve Laternula elliptica
reveals novel active site architecture. Proteins 2012; 81:531-7. [DOI: 10.1002/prot.24208] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2012] [Revised: 10/09/2012] [Accepted: 10/11/2012] [Indexed: 11/09/2022]
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23
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Human cytosolic glutathione transferases: structure, function, and drug discovery. Trends Pharmacol Sci 2012; 33:656-68. [DOI: 10.1016/j.tips.2012.09.007] [Citation(s) in RCA: 124] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Revised: 09/26/2012] [Accepted: 09/27/2012] [Indexed: 11/19/2022]
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24
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Chronopoulou EG, Papageorgiou AC, Markoglou A, Labrou NE. Inhibition of human glutathione transferases by pesticides: Development of a simple analytical assay for the quantification of pesticides in water. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.molcatb.2012.04.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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25
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Zhou H, Brock J, Liu D, Board PG, Oakley AJ. Structural Insights into the Dehydroascorbate Reductase Activity of Human Omega-Class Glutathione Transferases. J Mol Biol 2012; 420:190-203. [DOI: 10.1016/j.jmb.2012.04.014] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 04/09/2012] [Accepted: 04/11/2012] [Indexed: 11/30/2022]
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26
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Lea WA, Simeonov A. Differential scanning fluorometry signatures as indicators of enzyme inhibitor mode of action: case study of glutathione S-transferase. PLoS One 2012; 7:e36219. [PMID: 22558390 PMCID: PMC3340335 DOI: 10.1371/journal.pone.0036219] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 03/29/2012] [Indexed: 01/02/2023] Open
Abstract
Differential scanning fluorometry (DSF), also referred to as fluorescence thermal shift, is emerging as a convenient method to evaluate the stabilizing effect of small molecules on proteins of interest. However, its use in the mechanism of action studies has received far less attention. Herein, the ability of DSF to report on inhibitor mode of action was evaluated using glutathione S-transferase (GST) as a model enzyme that utilizes two distinct substrates and is known to be subject to a range of inhibition modes. Detailed investigation of the propensity of small molecule inhibitors to protect GST from thermal denaturation revealed that compounds with different inhibition modes displayed distinct thermal shift signatures when tested in the presence or absence of the enzyme's native co-substrate glutathione (GSH). Glutathione-competitive inhibitors produced dose-dependent thermal shift trendlines that converged at high compound concentrations. Inhibitors acting via the formation of glutathione conjugates induced a very pronounced stabilizing effect toward the protein only when GSH was present. Lastly, compounds known to act as noncompetitive inhibitors exhibited parallel concentration-dependent trends. Similar effects were observed with human GST isozymes A1-1 and M1-1. The results illustrate the potential of DSF as a tool to differentiate diverse classes of inhibitors based on simple analysis of co-substrate dependency of protein stabilization.
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Affiliation(s)
- Wendy A Lea
- NIH Chemical Genomics Center, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
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27
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Honaker MT, Acchione M, Sumida JP, Atkins WM. Ensemble perspective for catalytic promiscuity: calorimetric analysis of the active site conformational landscape of a detoxification enzyme. J Biol Chem 2011; 286:42770-42776. [PMID: 22002059 DOI: 10.1074/jbc.m111.304386] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Enzymological paradigms have shifted recently to acknowledge the biological importance of catalytic promiscuity. However, catalytic promiscuity is a poorly understood property, and no thermodynamic treatment has described the conformational landscape of promiscuous versus substrate-specific enzymes. Here, two structurally similar glutathione transferase (GST, glutathione S-transferase) isoforms with high specificity or high promiscuity are compared. Differential scanning calorimetry (DSC) indicates a reversible low temperature transition for the promiscuous GSTA1-1 that is not observed with substrate-specific GSTA4-4. This transition is assigned to rearrangement of the C terminus at the active site of GSTA1-1 based on the effects of ligands and mutations. Near-UV and far-UV circular dichroism indicate that this transition is due to repacking of tertiary contacts with the remainder of the subunit, rather than "unfolding" of the C terminus per se. Analysis of the DSC data using a modified Landau theory indicates that the local conformational landscape of the active site of GSTA1-1 is smooth, with barrierless transitions between states. The partition function of the C-terminal states is a broad unimodal distribution at all temperatures within this DSC transition. In contrast, the remainder of the GSTA1-1 subunit and the GSTA4-4 protein exhibit folded and unfolded macrostates with a significant energy barrier separating them. Their partition function includes a sharp unimodal distribution of states only at temperatures that yield either folded or unfolded macrostates. At intermediate temperatures the partition function includes a bimodal distribution. The barrierless rearrangement of the GSTA1-1 active site within a local smooth energy landscape suggests a thermodynamic basis for catalytic promiscuity.
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Affiliation(s)
- Matthew T Honaker
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98177-7610
| | - Mauro Acchione
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98177-7610
| | - John P Sumida
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98177-7610
| | - William M Atkins
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98177-7610.
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28
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Energetics of ligand binding to human glutathione transferase A1-1: Tyr-9 associated localisation of the C-terminal helix is ligand-dependent. Biophys Chem 2011; 156:153-8. [DOI: 10.1016/j.bpc.2011.04.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2011] [Revised: 04/05/2011] [Accepted: 04/05/2011] [Indexed: 11/19/2022]
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29
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Abstract
The glutathione transferases (GSTs) are one of the most important families of detoxifying enzymes in nature. The classic activity of the GSTs is conjugation of compounds with electrophilic centers to the tripeptide glutathione (GSH), but many other activities are now associated with GSTs, including steroid and leukotriene biosynthesis, peroxide degradation, double-bond cis-trans isomerization, dehydroascorbate reduction, Michael addition, and noncatalytic "ligandin" activity (ligand binding and transport). Since the first GST structure was determined in 1991, there has been an explosion in structural data across GSTs of all three families: the cytosolic GSTs, the mitochondrial GSTs, and the membrane-associated proteins in eicosanoid and glutathione metabolism (MAPEG family). In this review, the major insights into GST structure and function will be discussed.
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Affiliation(s)
- Aaron Oakley
- School of Chemistry, University of Wollongong, Wollongong, Australia.
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31
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Balogh LM, Atkins WM. Interactions of glutathione transferases with 4-hydroxynonenal. Drug Metab Rev 2011; 43:165-78. [PMID: 21401344 DOI: 10.3109/03602532.2011.558092] [Citation(s) in RCA: 263] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Electrophilic products of lipid peroxidation are important contributors to the progression of several pathological states. The prototypical α,β-unsaturated aldehyde, 4-hydroxynonenal (HNE), triggers cellular events associated with oxidative stress, which can be curtailed by the glutathione-dependent elimination of HNE. The glutathione transferases (GSTs) are a major determinate of the intracellular concentration of HNE and can influence susceptibility to toxic effects, particularly when HNE and GST levels are altered in disease states. In this article, we provide a brief summary of the cellular effects of HNE, followed by a review of its GST-catalyzed detoxification, with an emphasis on the structural attributes that play an important role in the interactions with alpha-class GSTs. Some of the key determining characteristics that impart high alkenal activity reside in the unique C-terminal interactions of the GSTA4-4 enzyme. Studies encompassing both kinetic and structural analyses of related isoforms will be highlighted, with additional attention to stereochemical aspects that demonstrate the capacity of GSTA4-4 to detoxify both enantiomers of the biologically relevant racemic mixture while generating a select set of diastereomeric products with subsequent implications. A summary of the literature that examines the interplay between GSTs and HNE in model systems relevant to oxidative stress will also be discussed to demonstrate the magnitude of importance of GSTs in the overall detoxification scheme.
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Affiliation(s)
- Larissa M Balogh
- Department of Pharmacokinetics, Dynamics, and Metabolism, Pfizer Global Research and Development, Pfizer Inc., Groton, CT 06340, USA.
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32
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Tuzmen C, Erman B. Identification of ligand binding sites of proteins using the Gaussian Network Model. PLoS One 2011; 6:e16474. [PMID: 21283550 PMCID: PMC3026835 DOI: 10.1371/journal.pone.0016474] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Accepted: 12/31/2010] [Indexed: 12/03/2022] Open
Abstract
The nonlocal nature of the protein-ligand binding problem is investigated via the Gaussian Network Model with which the residues lying along interaction pathways in a protein and the residues at the binding site are predicted. The predictions of the binding site residues are verified by using several benchmark systems where the topology of the unbound protein and the bound protein-ligand complex are known. Predictions are made on the unbound protein. Agreement of results with the bound complexes indicates that the information for binding resides in the unbound protein. Cliques that consist of three or more residues that are far apart along the primary structure but are in contact in the folded structure are shown to be important determinants of the binding problem. Comparison with known structures shows that the predictive capability of the method is significant.
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Affiliation(s)
- Ceren Tuzmen
- Center for Computational Biology and Bioinformatics, Koc University, Istanbul Turkey
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Balchin D, Fanucchi S, Achilonu I, Adamson RJ, Burke J, Fernandes M, Gildenhuys S, Dirr HW. Stability of the domain interface contributes towards the catalytic function at the H-site of class alpha glutathione transferase A1-1. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2010; 1804:2228-33. [DOI: 10.1016/j.bbapap.2010.09.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Revised: 08/26/2010] [Accepted: 09/02/2010] [Indexed: 11/25/2022]
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Balogh LM, Le Trong I, Kripps KA, Shireman LM, Stenkamp RE, Zhang W, Mannervik B, Atkins WM. Substrate specificity combined with stereopromiscuity in glutathione transferase A4-4-dependent metabolism of 4-hydroxynonenal. Biochemistry 2010; 49:1541-8. [PMID: 20085333 DOI: 10.1021/bi902038u] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Conjugation to glutathione (GSH) by glutathione transferase A4-4 (GSTA4-4) is a major route of elimination for the lipid peroxidation product 4-hydroxynonenal (HNE), a toxic compound that contributes to numerous diseases. Both enantiomers of HNE are presumed to be toxic, and GSTA4-4 has negligible stereoselectivity toward them, despite its high catalytic chemospecificity for alkenals. In contrast to the highly flexible, and substrate promiscuous, GSTA1-1 isoform that has poor catalytic efficiency with HNE, GSTA4-4 has been postulated to be a rigid template that is preorganized for HNE metabolism. However, the combination of high substrate chemoselectivity and low substrate stereoselectivity is intriguing. The mechanism by which GSTA4-4 achieves this combination is important, because it must metabolize both enantiomers of HNE to efficiently detoxify the biologically formed mixture. The crystal structures of GSTA4-4 and an engineered variant of GSTA1-1 with high catalytic efficiency toward HNE, cocrystallized with a GSH-HNE conjugate analogue, demonstrate that GSTA4-4 undergoes no enantiospecific induced fit; instead, the active site residue Arg15 is ideally located to interact with the 4-hydroxyl group of either HNE enantiomer. The results reveal an evolutionary strategy for achieving biologically useful stereopromiscuity toward a toxic racemate, concomitant with high catalytic efficiency and substrate specificity toward an endogenously formed toxin.
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Affiliation(s)
- Larissa M Balogh
- Department of Medicinal Chemistry, Box 357610, University of Washington, Seattle, Washington 98195, USA
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Quesada-Soriano I, Parker LJ, Primavera A, Casas-Solvas JM, Vargas-Berenguel A, Barón C, Morton CJ, Mazzetti AP, Lo Bello M, Parker MW, García-Fuentes L. Influence of the H-site residue 108 on human glutathione transferase P1-1 ligand binding: structure-thermodynamic relationships and thermal stability. Protein Sci 2010; 18:2454-70. [PMID: 19780048 DOI: 10.1002/pro.253] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The effect of the Y108V mutation of human glutathione S-transferase P1-1 (hGST P1-1) on the binding of the diuretic drug ethacrynic acid (EA) and its glutathione conjugate (EASG) was investigated by calorimetric, spectrofluorimetric, and crystallographic studies. The mutation Tyr 108 --> Val resulted in a 3D-structure very similar to the wild type (wt) enzyme, where both the hydrophobic ligand binding site (H-site) and glutathione binding site (G-site) are unchanged except for the mutation itself. However, due to a slight increase in the hydrophobicity of the H-site, as a consequence of the mutation, an increase in the entropy was observed. The Y108V mutation does not affect the affinity of EASG for the enzyme, which has a higher affinity (K(d) approximately 0.5 microM) when compared with those of the parent compounds, K(d) (EA) approximately 13 microM, K(d) (GSH) approximately 25 microM. The EA moiety of the conjugate binds in the H-site of Y108V mutant in a fashion completely different to those observed in the crystal structures of the EA or EASG wt complex structures. We further demonstrate that the Delta C(p) values of binding can also be correlated with the potential stacking interactions between ligand and residues located in the binding sites as predicted from crystal structures. Moreover, the mutation does not significantly affect the global stability of the enzyme. Our results demonstrate that calorimetric measurements maybe useful in determining the preference of binding (the binding mode) for a drug to a specific site of the enzyme, even in the absence of structural information.
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Affiliation(s)
- Indalecio Quesada-Soriano
- Physical Chemistry, Faculty of Experimental Sciences, University of Almería, La Cañada de San Urbano, 04120 Almería, Spain
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Dourado DFAR, Fernandes PA, Mannervik B, Ramos MJ. Glutathione Transferase A1-1: Catalytic Importance of Arginine 15. J Phys Chem B 2010; 114:1690-7. [DOI: 10.1021/jp908251z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Daniel F. A. R. Dourado
- REQUIMTE/Departamento de Química Faculdade de Ciências, Universidade do Porto Rua do Campo Alegre, 687, 4169-007 Porto, Portugal, and Department of Biochemistry and Organic Chemistry, Uppsala University, BMC Box 576, SE-75123 Uppsala, Sweden
| | - Pedro Alexandrino Fernandes
- REQUIMTE/Departamento de Química Faculdade de Ciências, Universidade do Porto Rua do Campo Alegre, 687, 4169-007 Porto, Portugal, and Department of Biochemistry and Organic Chemistry, Uppsala University, BMC Box 576, SE-75123 Uppsala, Sweden
| | - Bengt Mannervik
- REQUIMTE/Departamento de Química Faculdade de Ciências, Universidade do Porto Rua do Campo Alegre, 687, 4169-007 Porto, Portugal, and Department of Biochemistry and Organic Chemistry, Uppsala University, BMC Box 576, SE-75123 Uppsala, Sweden
| | - Maria João Ramos
- REQUIMTE/Departamento de Química Faculdade de Ciências, Universidade do Porto Rua do Campo Alegre, 687, 4169-007 Porto, Portugal, and Department of Biochemistry and Organic Chemistry, Uppsala University, BMC Box 576, SE-75123 Uppsala, Sweden
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Balogh LM, Le Trong I, Kripps KA, Tars K, Stenkamp RE, Mannervik B, Atkins WM. Structural analysis of a glutathione transferase A1-1 mutant tailored for high catalytic efficiency with toxic alkenals. Biochemistry 2009; 48:7698-704. [PMID: 19618965 DOI: 10.1021/bi900895b] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The specificity of human glutathione transferase (GST) A1-1 is drastically altered to favor alkenal substrates in the GIMFhelix mutant designed to mimic first-sphere interactions utilized by GSTA4-4. This redesign serves as a model for improving our understanding of the structural determinants that contribute to the distinct specificities of alpha class GSTs. Herein we report the first crystal structures of GIMFhelix, both in complex with GSH and in apo form at 1.98 and 2.38 A resolution. In contrast to the preorganized hydrophobic binding pocket that accommodates alkenals in GSTA4-4, GSTA1-1 includes a dynamic alpha9 helix that undergoes a ligand-dependent localization to complete the active site. Comparisons of the GIMFhelix structures with previously reported structures show a striking similarity with the GSTA4-4 active site obtained within an essentially GSTA1-1 scaffold and reveal the alpha9 helix assumes a similar localized structure regardless of active site occupancy in a manner resembling that of GSTA4-4. However, we cannot fully account for all the structural elements important in GSTA4-4 within the mutant's active site. The contribution of Phe10 to the Tyr212-Phe10-Phe220 network prevents complete C-terminal closure and demonstrates that the presence of Phe10 within the context of a GSTA4-4-like active site may ultimately hinder Phe220, a key C-terminal residue, from effectively contributing to the active site. In total, these results illustrate the remaining structural differences presumably reflected in the previously reported catalytic efficiencies of GIMFhelix and GSTA4-4 and emphasize the F10P mutation as being necessary to completely accomplish the transformation to a highly specific GST from the more promiscuous GSTA1-1 enzyme.
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Affiliation(s)
- Larissa M Balogh
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195, USA
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Dourado D, Fernandes P, Mannervik B, Ramos M. Glutathione Transferase: New Model for Glutathione Activation. Chemistry 2008; 14:9591-8. [DOI: 10.1002/chem.200800946] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Kinsley N, Sayed Y, Mosebi S, Armstrong RN, Dirr HW. Characterization of the binding of 8-anilinonaphthalene sulfonate to rat class Mu GST M1-1. Biophys Chem 2008; 137:100-4. [PMID: 18703268 DOI: 10.1016/j.bpc.2008.07.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2008] [Revised: 07/26/2008] [Accepted: 07/28/2008] [Indexed: 10/21/2022]
Abstract
Molecular docking and ANS-displacement experiments indicated that 8-anilinonaphthalene sulfonate (ANS) binds the hydrophobic site (H-site) in the active site of dimeric class Mu rGST M1-1. The naphthalene moiety provides most of the van der Waals contacts at the ANS-binding interface while the anilino group is able to sample different rotamers. The energetics of ANS binding were studied by isothermal titration calorimetry (ITC) over the temperature range of 5-30 degrees C. Binding is both enthalpically and entropically driven and displays a stoichiometry of one ANS molecule per subunit (or H-site). ANS binding is linked to the uptake of 0.5 protons at pH 6.5. Enthalpy of binding depends linearly upon temperature yielding a DeltaC(p) of -80+/-4 cal K(-1) mol(-1) indicating the burial of solvent-exposed nonpolar surface area upon ANS-protein complex formation. While ion-pair interactions between the sulfonate moiety of ANS and protein cationic groups may be significant for other ANS-binding proteins, the binding of ANS to rGST M1-1 is primarily hydrophobic in origin. The binding properties are compared with those of other GSTs and ANS-binding proteins.
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Affiliation(s)
- Nichole Kinsley
- Protein Structure-Function Research Unit, School of Molecular and Cell Biology, University of the Wiwatersrand, Johannesburg 2050, South Africa
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41
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Ji X, Pal A, Kalathur R, Hu X, Gu Y, Saavedra JE, Buzard GS, Srinivasan A, Keefer LK, Singh SV. Structure-Based Design of Anticancer Prodrug PABA/NO. DRUG DESIGN DEVELOPMENT AND THERAPY 2008; 2:123-130. [PMID: 19662104 PMCID: PMC2721280 DOI: 10.2147/dddt.s3931] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Glutathione S-transferase (GST) is a superfamily of detoxification enzymes, represented by GSTα, GSTμ, GSTπ, etc. GSTα is the predominant isoform of GST in human liver, playing important roles for our well being. GSTπ is overexpressed in many forms of cancer, thus presenting an opportunity for selective targeting of cancer cells. Our structure-based design of prodrugs intended to release cytotoxic levels of nitric oxide in GSTπ-overexpressing cancer cells yielded PABA/NO, which exhibited anticancer activity both in vitro and in vivo with a potency similar to that of cisplatin. Here, we present the details on structural modification, molecular modeling, and enzymatic characterization for the design of PABA/NO. The design was efficient because it was on the basis of the reaction mechanism and the structures of related GST isozymes at both the ground state and the transition state. The ground-state structures outlined the shape and property of the substrate-binding site in different isozymes, and the structural information at the transition-state indicated distinct conformations of the Meisenheimer complex of prodrugs in the active site of different isozymes, providing guidance for the modifications of the molecular structure of the prodrug molecules. Two key alterations of a GSTα-selective compound led to the GSTπ-selective PABA/NO.
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Affiliation(s)
- Xinhua Ji
- Macromolecular Crystallography Laboratory, National Cancer Institute, National Institutes of Health, Frederick, MD 21702, USA
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42
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Balogh LM, Roberts AG, Shireman LM, Greene RJ, Atkins WM. The stereochemical course of 4-hydroxy-2-nonenal metabolism by glutathione S-transferases. J Biol Chem 2008; 283:16702-10. [PMID: 18424441 DOI: 10.1074/jbc.m801725200] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
4-Hydroxy-2-nonenal (HNE) is a toxic aldehyde generated during lipid peroxidation and has been implicated in a variety of pathological states associated with oxidative stress. Glutathione S-transferase (GST) A4-4 is recognized as one of the predominant enzymes responsible for the metabolism of HNE. However, substrate and product stereoselectivity remain to be fully explored. The results from a product formation assay indicate that hGSTA4-4 exhibits a modest preference for the biotransformation of S-HNE in the presence of both enantiomers. Liquid chromatography mass spectrometry analyses using the racemic and enantioisomeric HNE substrates explicitly demonstrate that hGSTA4-4 conjugates glutathione to both HNE enantiomers in a completely stereoselective manner that is not maintained in the spontaneous reaction. Compared with other hGST isoforms, hGSTA4-4 shows the highest degree of stereoselectivity. NMR experiments in combination with simulated annealing structure determinations enabled the determination of stereochemical configurations for the GSHNE diastereomers and are consistent with an hGSTA4-4-catalyzed nucleophilic attack that produces only the S-configuration at the site of conjugation, regardless of substrate chirality. In total these results indicate that hGSTA4-4 exhibits an intriguing combination of low substrate stereoselectivity with strict product stereoselectivity. This behavior allows for the detoxification of both HNE enantiomers while generating only a select set of GSHNE diastereomers with potential stereochemical implications concerning their effects and fates in biological tissues.
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Affiliation(s)
- Larissa M Balogh
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195-7610, USA
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Blanchette B, Feng X, Singh BR. Marine glutathione S-transferases. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2007; 9:513-42. [PMID: 17682821 DOI: 10.1007/s10126-007-9034-0] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2007] [Accepted: 06/07/2007] [Indexed: 05/16/2023]
Abstract
The aquatic environment is generally affected by the presence of environmental xenobiotic compounds. One of the major xenobiotic detoxifying enzymes is glutathione S-transferase (GST), which belongs to a family of multifunctional enzymes involved in catalyzing nucleophilic attack of the sulfur atom of glutathione (gamma-glutamyl-cysteinylglycine) to an electrophilic group on metabolic products or xenobiotic compounds. Because of the unique nature of the aquatic environment and the possible pollution therein, the biochemical evolution in terms of the nature of GSTs could by uniquely expressed. The full complement of GSTs has not been studied in marine organisms, as very few aquatic GSTs have been fully characterized. The focus of this article is to present an overview of the GST superfamily and their critical role in the survival of organisms in the marine environment, emphasizing the critical roles of GSTs in the detoxification of marine organisms and the unique characteristics of their GSTs compared to those from non-marine organisms.
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Affiliation(s)
- Brian Blanchette
- Department of Chemistry and Biochemistry, University of Massachusetts Dartmouth, Dartmouth, MA 02747, USA
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Hou L, Honaker MT, Shireman LM, Balogh LM, Roberts AG, Ng KC, Nath A, Atkins WM. Functional Promiscuity Correlates with Conformational Heterogeneity in A-class Glutathione S-Transferases. J Biol Chem 2007; 282:23264-74. [PMID: 17561509 DOI: 10.1074/jbc.m700868200] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The structurally related glutathione S-transferase isoforms GSTA1-1 and GSTA4-4 differ greatly in their relative catalytic promiscuity. GSTA1-1 is a highly promiscuous detoxification enzyme. In contrast, GSTA4-4 exhibits selectivity for congeners of the lipid peroxidation product 4-hydroxynonenal. The contribution of protein dynamics to promiscuity has not been studied. Therefore, hydrogen/deuterium exchange mass spectrometry (H/DX) and fluorescence lifetime distribution analysis were performed with glutathione S-transferases A1-1 and A4-4. Differences in local dynamics of the C-terminal helix were evident as expected on the basis of previous studies. However, H/DX demonstrated significantly greater solvent accessibility throughout most of the GSTA1-1 sequence compared with GSTA4-4. A Phe-111/Tyr-217 aromatic-aromatic interaction in A4-4, which is not present in A1-1, was hypothesized to increase core packing. "Swap" mutants that eliminate this interaction from A4-4 or incorporate it into A1-1 yield H/DX behavior that is intermediate between the wild type templates. In addition, the single Trp-21 residue of each isoform was exploited to probe the conformational heterogeneity at the intrasubunit domain-domain interface. Excited state fluorescence lifetime distribution analysis indicates that this core residue is more conformationally heterogeneous in GSTA1-1 than in GSTA4-4, and this correlates with greater stability toward urea denaturation for GSTA4-4. The fluorescence distribution and urea sensitivity of the mutant proteins were intermediate between the wild type templates. The results suggest that the differences in protein dynamics of these homologs are global. The results suggest also the possible importance of extensive conformational plasticity to achieve high levels of functional promiscuity, possibly at the cost of stability.
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Affiliation(s)
- Liming Hou
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195-7610, USA
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Maeda DY, Mahajan SS, Atkins WM, Zebala JA. Bivalent inhibitors of glutathione S-transferase: the effect of spacer length on isozyme selectivity. Bioorg Med Chem Lett 2006; 16:3780-3. [PMID: 16675217 DOI: 10.1016/j.bmcl.2006.04.041] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2006] [Revised: 04/17/2006] [Accepted: 04/17/2006] [Indexed: 10/24/2022]
Abstract
Glutathione S-transferases (GSTs) are cytosolic enzymes that catalyze the conjugation of glutathione with a variety of exogenous and endogenous electrophiles. High affinity, isozyme-specific inhibitors of GST are required for use as pharmacological tools as well as potential therapeutics. The design of selective inhibitors is hindered due to the broad substrate binding capabilities of the GST enzymes. GSTs are dimeric enzymes, and therefore offer a unique discriminator for achieving inhibitor selectivity: the distance between binding sites on each monomer unit as a function of its quaternary organization. Bivalent analogs of the non-selective GST inhibitor ethacrynic acid were prepared, and selectivity for the GST A1-1 isozyme over GST P1-1 (IC50 values of 13.7 vs 1022 nM, respectively) was achieved through the optimization of the spacer length between the ethacrynic acid ligand domains.
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46
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O'Sullivan SM, McCarthy RM, Vargo MA, Colman RF, Sheehan D. Chemical modification at subunit 1 of rat kidney Alpha class glutathione transferase with 2,3,5,6-tetrachloro-1,4-benzoquinone: Close structural connectivity between glutathione conjugation activity and non-substrate ligand binding. Biochem Pharmacol 2006; 71:1629-36. [PMID: 16620786 DOI: 10.1016/j.bcp.2006.03.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2005] [Revised: 03/02/2006] [Accepted: 03/03/2006] [Indexed: 11/28/2022]
Abstract
2, 3, 5, 6-Tetrachloro-1, 4-benzoquinone (TCBQ) is a metabolite of pentachlorophenol known to react with cysteines of glutathione transferases (GSTs). TCBQ treatment of rat kidney rGSTA1-2 and rGSTA1-1 abolishes 70-80% conjugation of glutathione (GSH) to 1-chloro-2, 4-dinitrobenzene and results in strongly correlated quenching of intrinsic fluorescence of Trp-20 (R>0.96). rGSTA2-2 is only inhibited by 25%. Approximately 70% (rGSTA1-1) and 60% (rGSTA1-2) conjugation activity is abolished at TCBQ: GST stoichiometries near 1:1. The inactivation follows a Kitz/Wilson model with K(D) of 4.77+/-2.5microM for TCBQ and k(3) for inactivation of 0.036+/-0.01min(-1). A single tryptic peptide labelled with TCBQ was isolated from kidney rGSTA1-2 containing Cys-17 which we identify as the site of modification. Treatment with more than stoichiometric amounts of TCBQ modified other residues but resulted in only modest further inhibition of catalysis. We interpret these findings in terms of localised steric effects on the relatively rigid alpha-helix 1 adjacent to the catalytic site of subunit 1 possibly affecting the Alpha class-specific alpha-helix 9 which acts as a "lid" on the hydrophobic part of the active site. Homology modelling of rGSTA1-1 modified at Cys-17 of one subunit revealed only modest structural perturbations in the second subunit and tends to exclude global structural effects.
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Affiliation(s)
- Siobhan M O'Sullivan
- Proteomics Research Group, Department of Biochemistry, University College Cork, Lee Maltings, Prospect Row, Mardyke, Cork, Ireland
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Alves C, Kuhnert D, Sayed Y, Dirr H. The intersubunit lock-and-key motif in human glutathione transferase A1-1: role of the key residues Met51 and Phe52 in function and dimer stability. Biochem J 2006; 393:523-8. [PMID: 16190865 PMCID: PMC1360702 DOI: 10.1042/bj20051066] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The dimeric structure of certain cytosolic GSTs (glutathione S-transferases) is stabilized by a hydrophobic lock-and-key motif at their subunit interface. In hGSTA1-1 (human class Alpha GST with two type-1 subunits), the key consists of two residues, Met51 and Phe52, that fit into a hydrophobic cavity (lock) in the adjacent subunit. SEC (size-exclusion chromatography)-HPLC, far-UV CD and tryptophan fluorescence of the M51A and M51A/F52S mutants indicated the non-disruptive nature of these mutations on the global structure. While the M51A mutant retained 80% of wild-type activity, the activity of the M51A/F52S was markedly diminished, indicating the importance of Phe52 in maintaining the correct conformation at the active site. The M51A and M51A/F52S mutations altered the binding of ANS (8-anilinonaphthalene-l-sulphonic acid) at the H-site by destabilizing helix 9 in the C-terminal region. Data from urea unfolding studies show that the dimer is destabilized by both mutations and that the dimer dissociates to aggregation-prone monomers at low urea concentrations before global unfolding. Although not essential for the assembly of the dimeric structure of hGSTA1-1, both Met51 and Phe52 in the intersubunit lock-and-key motif play important structural roles in maintaining the catalytic and ligandin functions and stability of the GST dimer.
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Affiliation(s)
- Carla S. Alves
- Protein Structure–Function Research Unit, School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg 2050, South Africa
| | - Diane C. Kuhnert
- Protein Structure–Function Research Unit, School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg 2050, South Africa
| | - Yasien Sayed
- Protein Structure–Function Research Unit, School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg 2050, South Africa
| | - Heini W. Dirr
- Protein Structure–Function Research Unit, School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg 2050, South Africa
- To whom correspondence should be addressed (email )
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Tars K, Larsson AK, Shokeer A, Olin B, Mannervik B, Kleywegt GJ. Structural basis of the suppressed catalytic activity of wild-type human glutathione transferase T1-1 compared to its W234R mutant. J Mol Biol 2005; 355:96-105. [PMID: 16298388 DOI: 10.1016/j.jmb.2005.10.049] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2005] [Revised: 10/14/2005] [Accepted: 10/15/2005] [Indexed: 11/18/2022]
Abstract
The crystal structures of wild-type human theta class glutathione-S-transferase (GST) T1-1 and its W234R mutant, where Trp234 was replaced by Arg, were solved both in the presence and absence of S-hexyl-glutathione. The W234R mutant was of interest due to its previously observed enhanced catalytic activity compared to the wild-type enzyme. GST T1-1 from rat and mouse naturally contain Arg in position 234, with correspondingly high catalytic efficiency. The overall structure of GST T1-1 is similar to that of GST T2-2, as expected from their 53% sequence identity at the protein level. Wild-type GST T1-1 has the side-chain of Trp234 occupying a significant portion of the active site. This bulky residue prevents efficient binding of both glutathione and hydrophobic substrates through steric hindrance. The wild-type GST T1-1 crystal structure, obtained from co-crystallization experiments with glutathione and its derivatives, showed no electron density for the glutathione ligand. However, the structure of GST T1-1 mutant W234R showed clear electron density for S-hexyl-glutathione after co-crystallization. In contrast to Trp234 in the wild-type structure, the side-chain of Arg234 in the mutant does not occupy any part of the substrate-binding site. Instead, Arg234 is pointing in a different direction and, in addition, interacts with the carboxylate group of glutathione. These findings explain our earlier observation that the W234R mutant has a markedly improved catalytic activity with most substrates tested to date compared to the wild-type enzyme. GST T1-1 catalyzes detoxication reactions as well as reactions that result in toxic products, and our findings therefore suggest that humans have gained an evolutionary advantage by a partially disabled active site.
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Affiliation(s)
- Kaspars Tars
- Department of Cell and Molecular Biology, Uppsala University, Biomedical Centre, Box 590, SE-751 24, Uppsala, Sweden.
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49
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Ivarsson Y, Mannervik B. Regio- and enantioselectivities in epoxide conjugations are modulated by residue 210 in Mu class glutathione transferases. Protein Eng Des Sel 2005; 18:607-16. [PMID: 16251220 DOI: 10.1093/protein/gzi064] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The homologous human glutathione transferases (GSTs) M1-1 and M2-2 have similar catalytic activities with many electrophilic substrates, but differ strikingly in their conjugation of epoxides with glutathione. Residue 210, Thr in GST M2-2 and Ser in GST M1-1, is a key active-site component in determining the activity profile with epoxide substrates. This residue is hypervariable in Mu class GSTs, suggesting that it has special significance in the evolution of new functions. The present study shows that minor modifications of this residue can have major consequences for the enzyme-catalyzed epoxide conjugations. In general, a Ser at position 210 gives the highest catalytic efficiency, but the relatively high activity with an Ala placed on this position demonstrates that a hydroxyl group is not required. In contrast, a Thr residue suppresses the activity with epoxides by several orders of magnitude without major effects on the activity with alternative GST substrates. Residue 210 influences both the regio- and enantioselectivity with chiral and prochiral epoxides of stilbene and styrene and influences the distribution of isomeric glutathione conjugates. Thus, residue 210 contributes to both stereoselective recognition of the substrates and to partitioning of the isomeric reactants to the alternative transition states leading to separate chiral products.
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Affiliation(s)
- Ylva Ivarsson
- Department of Biochemistry, Uppsala University, Biomedical Center, Box 576, SE-751 23 Uppsala, Sweden
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Misquitta SA, Colman RF. Communication between the two active sites of glutathione S-transferase A1-1, probed using wild-type-mutant heterodimers. Biochemistry 2005; 44:8608-19. [PMID: 15952767 DOI: 10.1021/bi050449a] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
To study the communication between the two active sites of dimeric glutathione S-transferase A1-1, we used heterodimers containing one wild-type (WT) active site and one active site with a single mutation at either Tyr9, Arg15, or Arg131. Tyr9 and Arg15 are part of the active site of the same subunit, while Arg131 contributes to the active site of the opposite subunit. The V(max) values of Tyr9 and Arg15 mutant enzymes were less than 2% that of WT, indicating their importance in catalysis. In contrast, V(max) values of Arg131 mutant enzymes were about 50-90% of that of WT enzyme while K(m)(GSH) values were approximately 3-8 times that of WT, suggesting that Arg131 plays a role in glutathione binding. The mutant enzyme (with a His(6) tag) and the WT enzyme (without a His(6) tag) were used to construct heterodimers (WT-Y9F, WT-Y9T, WT-R15Q, WT-R131M, WT-R131Q, and WT-R131E) by incubation of a mixture of wild-type and mutant enzyme at pH 7.5 in buffer containing 1,6-hexanediol, followed by dialysis against buffer lacking the organic solvent. The resultant heterodimers were separated from the wild-type and mutant homodimers using chromatography on nickel-nitrilotriacetic acid agarose. The V(max) values of all heterodimers were lower than expected for independent active sites. Our experiments demonstrate that mutation of an amino acid residue in one active site affects the activity in the other active site. Modeling studies show that key amino acid residues and water molecules connect the two active sites. This connectivity is responsible for the cross-talk between the active sites.
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Affiliation(s)
- Stephanie A Misquitta
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
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