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Engineering a Pseudo-26-kDa Schistosoma Glutathione Transferase from bovis/ haematobium for Structure, Kinetics, and Ligandin Studies. Biomolecules 2021; 11:biom11121844. [PMID: 34944488 PMCID: PMC8699318 DOI: 10.3390/biom11121844] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/25/2021] [Accepted: 11/25/2021] [Indexed: 12/25/2022] Open
Abstract
Glutathione transferases (GSTs) are the main detoxification enzymes in schistosomes. These parasitic enzymes tend to be upregulated during drug treatment, with Schistosoma haematobium being one of the species that mainly affect humans. There is a lack of complete sequence information on the closely related bovis and haematobium 26-kDa GST isoforms in any database. Consequently, we engineered a pseudo-26-kDa S. bovis/haematobium GST (Sbh26GST) to understand structure–function relations and ligandin activity towards selected potential ligands. Sbh26GST was overexpressed in Escherichia coli as an MBP-fusion protein, purified to homogeneity and catalyzed 1-chloro-2,4-dinitrobenzene-glutathione (CDNB-GSH) conjugation activity, with a specific activity of 13 μmol/min/mg. This activity decreased by ~95% in the presence of bromosulfophthalein (BSP), which showed an IC50 of 27 µM. Additionally, enzyme kinetics revealed that BSP acts as a non-competitive inhibitor relative to GSH. Spectroscopic studies affirmed that Sbh26GST adopts the canonical GST structure, which is predominantly α-helical. Further extrinsic 8-anilino-1-naphthalenesulfonate (ANS) spectroscopy illustrated that BSP, praziquantel (PZQ), and artemisinin (ART) might preferentially bind at the dimer interface or in proximity to the hydrophobic substrate-binding site of the enzyme. The Sbh26GST-BSP interaction is both enthalpically and entropically driven, with a stoichiometry of one BSP molecule per Sbh26GST dimer. Enzyme stability appeared enhanced in the presence of BSP and GSH. Induced fit ligand docking affirmed the spectroscopic, thermodynamic, and molecular modelling results. In conclusion, BSP is a potent inhibitor of Sbh26GST and could potentially be rationalized as a treatment for schistosomiasis.
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Alqarni MH, Foudah AI, Muharram MM, Labrou NE. The Interaction of Human Glutathione Transferase GSTA1-1 with Reactive Dyes. Molecules 2021; 26:molecules26082399. [PMID: 33924269 PMCID: PMC8074892 DOI: 10.3390/molecules26082399] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 04/05/2021] [Accepted: 04/16/2021] [Indexed: 11/16/2022] Open
Abstract
Human glutathione transferase A1-1 (hGSTA1-1) contributes to developing resistance to anticancer drugs and, therefore, is promising in terms of drug-design targets for coping with this phenomenon. In the present study, the interaction of anthraquinone and diazo dichlorotriazine dyes (DCTD) with hGSTA1-1 was investigated. The anthraquinone dye Procion blue MX-R (PBMX-R) appeared to interact with higher affinity and was selected for further study. The enzyme was specifically and irreversibly inactivated by PBMX-R, following a biphasic pseudo-first-order saturation kinetics, with approximately 1 mol of inhibitor per mol of the dimeric enzyme being incorporated. Molecular modeling and protein chemistry data suggested that the modified residue is the Cys112, which is located at the entrance of the solvent channel at the subunits interface. The results suggest that negative cooperativity exists upon PBMX-R binding, indicating a structural communication between the two subunits. Kinetic inhibition analysis showed that the dye is a competitive inhibitor towards glutathione (GSH) and mixed-type inhibitor towards 1-chloro-2,4-dinitrobenzene (CDNB). The present study results suggest that PBMX-R is a useful probe suitable for assessing by kinetic means the drugability of the enzyme in future drug-design efforts.
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Affiliation(s)
- Mohammed Hamed Alqarni
- Department of Pharmacognosy, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Alkharj 11942, Saudi Arabia;
- Correspondence: (M.H.A.); (N.E.L.)
| | - Ahmed Ibrahim Foudah
- Department of Pharmacognosy, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Alkharj 11942, Saudi Arabia;
| | - Magdy Mohamed Muharram
- Department of Pharmaceutics, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Alkharj 11942, Saudi Arabia;
- Department of Microbiology, College of Science, Al-Azhar University, Nasr City, Cairo 11884, Egypt
| | - 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
- Correspondence: (M.H.A.); (N.E.L.)
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3
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Mandic-Maravic V, Mitkovic-Voncina M, Pljesa-Ercegovac M, Savic-Radojevic A, Djordjevic M, Pekmezovic T, Grujicic R, Ercegovac M, Simic T, Lecic-Tosevski D, Pejovic-Milovancevic M. Autism Spectrum Disorders and Perinatal Complications-Is Oxidative Stress the Connection? Front Psychiatry 2019; 10:675. [PMID: 31681027 PMCID: PMC6798050 DOI: 10.3389/fpsyt.2019.00675] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 08/21/2019] [Indexed: 12/22/2022] Open
Abstract
Background: Autism spectrum disorders (ASD) are complex psychiatric disorders, with gene environment interaction being in the basis of their etiology. The association of perinatal complications and ASD is well established. Recent findings suggested that oxidative stress and polymorphism in genes encoding antioxidant enzymes might be involved in the development of ASD. Glutathione transferases (GSTs) have an important role in the antioxidant defense system. We aimed to establish whether the predictive effects of prenatal and perinatal complications (as possible oxidative stress inducers) on ASD risk are dependent on GST polymorphisms. Methods: The study included 113 ASD cases and 114 age- and sex group-matched healthy controls. All participants were genotyped for GSTA1, GSTM1, GSTT1, and GSTP1 polymorphisms. The questionnaire regarding prenatal and perinatal risk factors and complications was administered for all the subjects in the study. Results: The evaluated perinatal complications as a group significantly increased the risk of ASD [odds ratio (OR) = 9.415; p = 0.000], as well as individual perinatal complications, such as prematurity (OR = 11.42; p = 0.001), neonatal jaundice (OR = 8.774; p = 0.000), respiratory distress syndrome (OR = 4.835; p = 0.047), and the use of any medication during pregnancy (OR = 2.413; p = 0.03). In logistic regression model, adding GST genotypes did not modify the significant effects found for prematurity and neonatal jaundice as risk factors in ASD. However, there was a significant interaction of GST genotype with medication use during pregnancy and the use of tocolytics during pregnancy, which was predictive of ASD risk only in carriers of GSTM1-null, as opposed to carriers of GSTM1-active genotype. Conclusion: Specific perinatal complications may be significant risk factors for ASD. GSTM1 genotype may serve as a moderator of the effect of some prenatal factors on the risk of ASD such as using medication during pregnancy. It may be speculated that different oxidative stress-related genetic and environmental factors could lead to development of ASD. Apart from etiological mechanisms, possible therapeutic implications in ASD are also discussed.
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Affiliation(s)
- Vanja Mandic-Maravic
- Institute of Mental Health, Belgrade, Serbia.,Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Marija Mitkovic-Voncina
- Institute of Mental Health, Belgrade, Serbia.,Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Marija Pljesa-Ercegovac
- Faculty of Medicine, University of Belgrade, Belgrade, Serbia.,Institute of Medical and Clinical Biochemistry, Belgrade, Serbia
| | - Ana Savic-Radojevic
- Faculty of Medicine, University of Belgrade, Belgrade, Serbia.,Institute of Medical and Clinical Biochemistry, Belgrade, Serbia
| | - Miroslav Djordjevic
- Faculty of Medicine, University of Belgrade, Belgrade, Serbia.,University Children's Hospital, Belgrade, Serbia
| | - Tatjana Pekmezovic
- Faculty of Medicine, University of Belgrade, Belgrade, Serbia.,Institute of Epidemiology, Belgrade, Serbia
| | | | - Marko Ercegovac
- Faculty of Medicine, University of Belgrade, Belgrade, Serbia
| | - Tatjana Simic
- Faculty of Medicine, University of Belgrade, Belgrade, Serbia.,Institute of Medical and Clinical Biochemistry, Belgrade, Serbia.,Serbian Academy of Sciences and Arts, Belgrade, Serbia
| | - Dusica Lecic-Tosevski
- Institute of Mental Health, Belgrade, Serbia.,Serbian Academy of Sciences and Arts, Belgrade, Serbia
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4
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Kolawole AO. Interaction of Aldehyde dehydrogenase with acetaminophen as examined by spectroscopies and molecular docking. Biochem Biophys Rep 2017; 10:198-207. [PMID: 28955748 PMCID: PMC5614660 DOI: 10.1016/j.bbrep.2017.03.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 03/08/2017] [Accepted: 03/28/2017] [Indexed: 12/14/2022] Open
Abstract
The interaction of acetaminophen, a non-substrate anionic ligand, with Aldehyde Dehydrogenase was studied by fluorescence, UV-Vis absorption, and circular dichroism spectroscopies under simulated physiological conditions. The fluorescence spectra and data generated showed that acetaminophen binding to ALDH is purely dynamic quenching mechanism. The acetaminophen-ALDH is kinetically rapid reversible interaction with a binding constant, Ka, of 4.91×103 L mol-1. There was an existence of second binding site of ALDH for acetaminophen at saturating acetaminophen concentration. The binding sites were non-cooperative. The thermodynamic parameters obtained suggest that Van der Waal force and hydrogen bonding played a major role in the binding of acetaminophen to ALDH. The interaction caused perturbation of the ALDH structures with an obvious reduction in the α-helix. The binding distance of 4.43 nm was obtained between Acetaminophen and ALDH. Using Ficoll 400 as macro-viscosogen and glycerol as micro-viscosogen, Stoke-Einstein empirical plot demonstrated that acetaminophen-ALDH binding was diffusion controlled. Molecular docking showed the participation of some amino acids in the complex formation with -5.3 kcal binding energy. With these, ALDH might not an excipient detoxifier of acetaminophen but could be involved in its pegylation/encapsulation.
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2,2′-Dihydroxybenzophenones and their carbonyl N-analogues as inhibitor scaffolds for MDR-involved human glutathione transferase isoenzyme A1-1. Bioorg Med Chem 2014; 22:3957-70. [DOI: 10.1016/j.bmc.2014.06.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 05/20/2014] [Accepted: 06/04/2014] [Indexed: 12/21/2022]
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6
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Achilonu I, Siganunu TP, Dirr HW. Purification and characterisation of recombinant human eukaryotic elongation factor 1 gamma. Protein Expr Purif 2014; 99:70-7. [DOI: 10.1016/j.pep.2014.04.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 04/02/2014] [Accepted: 04/03/2014] [Indexed: 11/17/2022]
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7
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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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8
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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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9
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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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10
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Andujar-Sánchez M, Jara-Perez V, Cobos ES, Cámara-Artigas A. A thermodynamic characterization of the interaction of 8-anilino-1-naphthalenesulfonic acid with native globular proteins: the effect of the ligand dimerization in the analysis of the binding isotherms. J Mol Recognit 2010; 24:548-56. [DOI: 10.1002/jmr.1065] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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11
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Arginine 15 stabilizes an SNAr reaction transition state and the binding of anionic ligands at the active site of human glutathione transferase A1-1. Biophys Chem 2010; 146:118-25. [DOI: 10.1016/j.bpc.2009.11.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2009] [Revised: 11/12/2009] [Accepted: 11/12/2009] [Indexed: 11/22/2022]
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12
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Kapoli P, Axarli IA, Platis D, Fragoulaki M, Paine M, Hemingway J, Vontas J, Labrou NE. Engineering sensitive glutathione transferase for the detection of xenobiotics. Biosens Bioelectron 2008; 24:498-503. [DOI: 10.1016/j.bios.2008.06.037] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2008] [Revised: 06/10/2008] [Accepted: 06/24/2008] [Indexed: 11/28/2022]
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13
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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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14
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Muslu N, Dogruer ZN, Eskandari G, Atici A, Kul S, Atik U. Are glutathione S-transferase gene polymorphisms linked to neonatal jaundice? Eur J Pediatr 2008; 167:57-61. [PMID: 17318621 DOI: 10.1007/s00431-007-0425-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2006] [Accepted: 01/15/2007] [Indexed: 10/23/2022]
Abstract
Glutathione S-transferases (GSTs) are a major group of phase II detoxification enzymes involved in the metabolism of both endogenous and xenobiotic compounds. In addition to their catalytic function in detoxification, GSTs participate in binding to nonsubstrate ligands such as bilirubin. Ligandin, which is one of the principal hepatic-binding proteins, is also a member of the GST family. The aim of the present study was to investigate the possible relationship between neonatal jaundice and the GST gene polymorphisms. The study cohort consisted of a patient group of 116 newborns (plasma bilirubin levels > or = 15 mg/dl) and a control group of 54 newborns (plasma bilirubin levels <13 mg/dl). In the patient group, the null genotype frequencies in GSTM1 and GSTT1 were 52.6 and 19%, respectively; in the control group, these were 63 and 27.8%, respectively. The frequencies of GSTM1 and GSTT1 were similar in the patient and control groups (p > 0.05). Total bilirubin levels were found to be significantly higher in patients with the GSTM1 null genotype than in patients with the GSTM1 wild genotype (p = 0.042). There was no statistically significant difference in total bilirubin levels between patients with the null GSTT1 genotype and those with the wild GSTT1 genotype. It is conceivable that there is a relation between GSTM1 gene polymorphism and total bilirubin levels in neonatal jaundice. We suggest that GSTM1 gene polymorphisms may affect ligandin functions in hepatocytes, which are important in bilirubin transportation. Consequently, patients with the GSTM1 null genotype may have higher total levels of bilirubin.
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Affiliation(s)
- Necati Muslu
- Department of Biochemistry, Mersin University Medical Faculty, Mersin, Turkey.
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15
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Piromjitpong J, Wongsantichon J, Ketterman A. Differences in the subunit interface residues of alternatively spliced glutathione transferases affects catalytic and structural functions. Biochem J 2007; 401:635-44. [PMID: 16938097 PMCID: PMC1770856 DOI: 10.1042/bj20060603] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
GSTs (glutathione transferases) are multifunctional widespread enzymes. Currently there are 13 identified classes within this family. Previously most structural characterization has been reported for mammalian Alpha, Mu and Pi class GSTs. In the present study we characterize two enzymes from the insect-specific Delta class, adGSTD3-3 and adGSTD4-4. These two proteins are alternatively spliced products from the same gene and have very similar tertiary structures. Several major contributions to the dimer interface area can be separated into three regions: conserved electrostatic interactions in region 1, hydrophobic interactions in region 2 and an ionic network in region 3. The four amino acid side chains studied in region 1 interact with each other as a planar rectangle. These interactions are highly conserved among the GST classes, Delta, Sigma and Theta. The hydrophobic residues in region 2 are not only subunit interface residues but also active site residues. Overall these three regions provide important contributions to stabilization and folding of the protein. In addition, decreases in yield as well as catalytic activity changes, suggest that the mutations in these regions can disrupt the active site conformation which decreases binding affinity, alters kinetic constants and alters substrate specificity. Several of these residues have only a slight effect on the initial folding of each subunit but have more influence on the dimerization process as well as impacting upon appropriate active site conformation. The results also suggest that even splicing products from the same gene may have specific features in the subunit interface area that would preclude heterodimerization.
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Affiliation(s)
- Juthamart Piromjitpong
- Institute of Molecular Biology and Genetics, Mahidol University, Salaya Campus, Nakhon Pathom 73170, Thailand
| | - Jantana Wongsantichon
- Institute of Molecular Biology and Genetics, Mahidol University, Salaya Campus, Nakhon Pathom 73170, Thailand
| | - Albert J. Ketterman
- Institute of Molecular Biology and Genetics, Mahidol University, Salaya Campus, Nakhon Pathom 73170, Thailand
- To whom correspondence should be addressed (email )
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16
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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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17
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Wongsantichon J, Ketterman A. An intersubunit lock-and-key 'clasp' motif in the dimer interface of Delta class glutathione transferase. Biochem J 2006; 394:135-44. [PMID: 16225458 PMCID: PMC1386011 DOI: 10.1042/bj20050915] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Structural investigations of a GST (glutathione transferase), adGSTD4-4, from the malaria vector Anopheles dirus show a novel lock-and-key 'Clasp' motif in the dimer interface of the Delta class enzyme. This motif also appears to be highly conserved across several insect GST classes, but differs from a previously reported mammalian lock-and-key motif. The aromatic 'key' residue not only inserts into a hydrophobic pocket, the 'lock', of the neighbouring subunit, but also acts as part of the 'lock' for the other subunit 'key'. The 'key' residues from both subunits show aromatic ring stacking with each other in a pi-pi interaction, generating a 'Clasp' in the middle of the subunit interface. Enzyme catalytic and structural characterizations revealed that single amino acid replacements in this 'Clasp' motif impacted on catalytic efficiencies, substrate selectivity and stability. Substitutions to the 'key' residue create strong positive co-operativity for glutathione binding, with a Hill coefficient approaching 2. The lock-and-key motif in general and especially the 'Clasp' motif with the pi-pi interaction appear to play a pivotal role in subunit communication between active sites, as well as in stabilizing the quaternary structure. Evidence of allosteric effects suggests an important role for this particular intersubunit architecture in regulating catalytic activity through conformational transitions of subunits. The observation of co-operativity in the mutants also implies that glutathione ligand binding and dimerization are linked. Quaternary structural changes of all mutants suggest that subunit assembly or dimerization basically manipulates subunit communication.
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Affiliation(s)
- Jantana Wongsantichon
- Institute of Molecular Biology and Genetics, Mahidol University, Salaya Campus, 25/25 Phutthamonthol Road 4, Salaya, Nakhon Pathom 73170, Thailand
| | - Albert J. Ketterman
- Institute of Molecular Biology and Genetics, Mahidol University, Salaya Campus, 25/25 Phutthamonthol Road 4, Salaya, Nakhon Pathom 73170, Thailand
- To whom correspondence should be addressed (email )
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Wongsantichon J, Yuvaniyama J, Ketterman AJ. Crystallization and preliminary X-ray crystallographic analysis of a highly stable mutant V107A of glutathione transferase from Anopheles dirus in complex with glutathione. Acta Crystallogr Sect F Struct Biol Cryst Commun 2006; 62:310-2. [PMID: 16511331 PMCID: PMC2197175 DOI: 10.1107/s1744309106006580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2005] [Accepted: 02/22/2006] [Indexed: 11/10/2022]
Abstract
An engineered mutant V107A of the dimeric glutathione transferase enzyme from Anopheles dirus (adgstD4-4) was cocrystallized with glutathione substrate using the hanging-drop vapour-diffusion method. The crystal diffracted to 2.47 A resolution in space group P3(2)21 (unit-cell parameters a = b = 49.4, c = 272.4 A). Although the crystal morphology differed from that previously obtained for the wild-type enzyme, the crystal packing was the same. At 318 K, the engineered mutant showed an enzyme stability that was increased by about 32-fold, while possessing a similar catalytic function to the wild type. Structural determination will provide valuable understanding of the role of Val107. This residue is in the dimeric interface and appears to contribute towards enhancing the physical properties of the entire protein.
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Affiliation(s)
- Jantana Wongsantichon
- Institute of Molecular Biology and Genetics, Mahidol University, Salaya Campus, Nakorn Pathom 73170, Thailand
| | - Jirundon Yuvaniyama
- Department of Biochemistry and Center for Excellence in Protein Structure and Function, Faculty of Science, Mahidol University, Rama 6 Road, Phayathai, Bangkok 10400, Thailand
| | - Albert J. Ketterman
- Institute of Molecular Biology and Genetics, Mahidol University, Salaya Campus, Nakorn Pathom 73170, Thailand
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Celej MS, Dassie SA, Freire E, Bianconi ML, Fidelio GD. Ligand-induced thermostability in proteins: thermodynamic analysis of ANS-albumin interaction. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2005; 1750:122-33. [PMID: 15972267 DOI: 10.1016/j.bbapap.2005.05.003] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2004] [Revised: 05/03/2005] [Accepted: 05/03/2005] [Indexed: 10/25/2022]
Abstract
A comparative thermodynamic study of the interaction of anilinonaphthalene sulfonate (ANS) derivatives with bovine serum albumin (BSA) was performed by using differential scanning calorimetry (DSC) and isothermal titration calorimetry (ITC). The chemically related ligands, 1,8-ANS and 2,6-ANS, present a similar affinity for BSA with different binding energetics. The analysis of the binding driving forces suggests that not only hydrophobic effect but also electrostatic interactions are relevant, even though they have been extensively used as probes for non-polar domains in proteins. Ligand association leads to an increase in protein thermostability, indicating that both dyes interact mainly with native BSA. ITC data show that 1,8-ANS and 2,6-ANS have a moderate affinity for BSA, with an association constant of around 1-9x10(5) M(-1) for the high-affinity site. Ligand binding is disfavoured by conformational entropy. The theoretical model used to simulate DSC data satisfactorily reproduces experimental thermograms, validating this approach as one which provides new insights into the interaction between one or more ligands with a protein. By comparison with 1,8-ANS, 2,6-ANS appears as a more "inert" probe to assess processes which involve conformational changes in proteins.
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Affiliation(s)
- M Soledad Celej
- Departamento de Química Biológica-CIQUIBIC, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Haya de la Torre y Medina Allende, Ciudad Universitaria, 5000, Córdoba, Argentina
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Kuhnert DC, Sayed Y, Mosebi S, Sayed M, Sewell T, Dirr HW. Tertiary Interactions Stabilise the C-terminal Region of Human Glutathione Transferase A1-1: a Crystallographic and Calorimetric Study. J Mol Biol 2005; 349:825-38. [PMID: 15893769 DOI: 10.1016/j.jmb.2005.04.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2005] [Revised: 04/13/2005] [Accepted: 04/14/2005] [Indexed: 11/21/2022]
Abstract
The C-terminal region in class Alpha glutathione transferase A1-1 (GSTA1-1), which forms an amphipathic alpha-helix (helix 9), is known to contribute to the catalytic and non-substrate ligand-binding functions of the enzyme. The region in the apo protein is proposed to be disordered which, upon ligand binding at the active-site, becomes structured and localised. Because Ile219 plays a pivotal role in the stability and localisation of the region, the role of tertiary interactions mediated by Ile219 in determining the conformation and dynamics of the C-terminal region were studied. Ligand-binding microcalorimetric and X-ray structural data were obtained to characterise ligand binding at the active-site and the associated localisation of the C-terminal region. In the crystal structure of the I219A hGSTA1-1.S-hexylglutathione complex, the C-terminal region of one chain is mobile and not observed (unresolved electron density), whereas the corresponding region of the other chain is localised and structured as a result of crystal packing interactions. In solution, the mutant C-terminal region of both chains in the complex is mobile and delocalised resulting in a hydrated, less hydrophobic active-site and a reduction in the affinity of the protein for S-hexylglutathione. Complete dehydration of the active-site, important for maintaining the highly reactive thiolate form of glutathione, requires the binding of ligands and the subsequent localisation of the C-terminal region. Thermodynamic data demonstrate that the mobile C-terminal region in apo hGSTA1-1 is structured and does not undergo ligand-induced folding. Its close proximity to the surface of the wild-type protein is indicated by the concurrence between the observed heat capacity change of complex formation and the type and amount of surface area that becomes buried at the ligand-protein interface when the C-terminal region in the apo protein assumes the same localised structure as that observed in the wild-type complex.
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Affiliation(s)
- Diane C Kuhnert
- Protein Structure-Function Research Programme, School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg 2050, South Africa
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Axarli I, Rigden D, Labrou N. Characterization of the ligandin site of maize glutathione S-transferase I. Biochem J 2005; 382:885-93. [PMID: 15196053 PMCID: PMC1133964 DOI: 10.1042/bj20040298] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2004] [Revised: 05/25/2004] [Accepted: 06/11/2004] [Indexed: 11/17/2022]
Abstract
Cytosolic GSTs (glutathione S-transferases) are a major reserve of high-capacity binding proteins and exhibit ligand-binding properties for a large variety of compounds. In the present study, the binding of two non-substrate anthraquinone dyes VBAR (Vilmafix Blue A-R) and CB3GA (Cibacron Blue 3GA) to maize (Zea mays) GST I was investigated. The results showed that the enzyme was specifically and irreversible inactivated by VBAR with a K(d) of 35.5+/-2.2 microM and a k(3) of 0.47 min(-1). Proteolytic cleavage of the VBAR-modified enzyme and subsequent separation of peptides gave only one modified peptide. Sequencing of the modified peptide revealed the target site of VBAR reaction to be Lys(41). CB3GA binds reversibly to GST I and behaves as a competitive inhibitor towards CDNB (1-chloro-2,4-dinitrobenzene) and glutathione. CB3GA binding to GST I is accompanied by a characteristic spectral change in the absorption at positive maximum (670 nm) which exhibited a hyperbolic dependence on dye concentration with a K(d) of 12.1+/-0.5 microM. Site-directed mutagenesis of selected residues (Trp(12), Phe(35), Lys(41), Asn(49), Gln(53), Ser(67) and Ile(118)) was employed, and the mutated enzymes were assessed for CB3GA binding. These results, together with molecular-modelling studies, established that the ligandin-binding site of GST I is located mainly in the hydrophobic binding site. The ability of VBAR to specifically inactivate GST I was exploited further to demonstrate the specific binding of several plant hormones and flavonoids to GST I. The inactivation of other GST isoenzymes by VBAR was also investigated, and it was concluded that VBAR may have wide applicability as an affinity label for probing structure-function relationships of GST isoenzymes.
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Affiliation(s)
- Irine A. Axarli
- *Laboratory of Enzyme Technology, Department of Agricultural Biotechnology, Agricultural University of Athens, Iera Odos 75, 11855-Athens, Greece
| | - Daniel J. Rigden
- †School of Biological Sciences, University of Liverpool, Liverpool L69 7ZB, U.K
| | - Nikolaos E. Labrou
- *Laboratory of Enzyme Technology, Department of Agricultural Biotechnology, Agricultural University of Athens, Iera Odos 75, 11855-Athens, Greece
- To whom correspondence should be addressed (email )
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Kolobe D, Sayed Y, Dirr H. Characterization of bromosulphophthalein binding to human glutathione S-transferase A1-1: thermodynamics and inhibition kinetics. Biochem J 2005; 382:703-9. [PMID: 15147239 PMCID: PMC1133828 DOI: 10.1042/bj20040056] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2004] [Revised: 05/12/2004] [Accepted: 05/18/2004] [Indexed: 11/17/2022]
Abstract
In addition to their catalytic functions, GSTs (glutathione S-transferases) bind a wide variety of structurally diverse non-substrate ligands. This ligandin function is known to result in the inhibition of catalytic function. The interaction between hGSTA1-1 (human class Alpha GST with two type 1 subunits) and a non-substrate anionic ligand, BSP (bromosulphophthalein), was studied by isothermal titration calorimetry and inhibition kinetics. The binding isotherm is biphasic, best described by a set of two independent sites: a high-affinity site and a low-affinity site(s). The binding stoichiometries for these sites are 1 and 3 molecules of BSP respectively. BSP binds to the high-affinity site 80 times more tightly (K(d)=0.12 microM) than it does to the low-affinity site(s) (K(d)=9.1 microM). Binding at these sites is enthalpically and entropically favourable, with no linkage to protonation events. Temperature- and salt-dependent studies indicate the significance of hydrophobic interactions in the binding of BSP, and that the low-affinity site(s) displays low specificity towards the anion. Binding of BSP results in the release of ordered water molecules at these hydrophobic sites, which more than offsets unfavourable entropic changes during binding. BSP inhibition studies show that the binding of BSP to its high-affinity site does not inhibit hGSTA1-1. This site, located near Trp-20, may be related to the buffer-binding site observed in GSTP1-1. The low-affinity-binding site(s) for BSP is most probably located at or near the active site of hGSTA1-1. Binding to this site(s) results in non-competitive inhibition with respect to CDNB (1-chloro-2,4-dinitrobenzene) (K(i)(BSP)=16.8+/-1.9 microM). Given the properties of the H site and the relatively small size of the electrophilic substrate CDNB, it is plausible that the active site of the enzyme can simultaneously accommodate both BSP and CDNB. This would explain the non-competitive behaviour of certain inhibitors that bind the active site (e.g. BSP).
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Affiliation(s)
- Doris Kolobe
- Protein Structure–Function Research Programme, School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg 2050, South Africa
| | - Yasien Sayed
- Protein Structure–Function Research Programme, School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg 2050, South Africa
| | - Heini W. Dirr
- Protein Structure–Function Research Programme, 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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Yassin Z, Ortiz-Salmerón E, García-Maroto F, Barón C, García-Fuentes L. Implications of the ligandin binding site on the binding of non-substrate ligands to Schistosoma japonicum-glutathione transferase. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2004; 1698:227-37. [PMID: 15134656 DOI: 10.1016/j.bbapap.2003.12.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2003] [Revised: 10/31/2003] [Accepted: 12/01/2003] [Indexed: 10/26/2022]
Abstract
The binding interactions between dimeric glutathione transferase from Schistosoma japonicum (Sj26GST) and bromosulfophthalein (BS) or 8-anilino-1-naphthalene sulfonate (ANS) were characterised by fluorescence spectroscopy and isothermal titration calorimetry (ITC). Both ligands inhibit the enzymatic activity of Sj26GST in a non-competitive form. A stoichiometry of 1 molecule of ligand per mole of dimeric enzyme was obtained for the binding of these ligands. The affinity of BS is higher (K(d)=3.2 microM) than that for ANS (K(d)=195 microM). The thermodynamic parameters obtained by calorimetric titrations are pH-independent in the range of 5.5 to 7.5. The interaction process is enthalpically driven at all the studied temperatures. This enthalpic contribution is larger for the ANS anion than for BS. The strongly favourable enthalpic contribution for the binding of ANS to Sj26GST is compensated by a negative entropy change, due to enthalpy-entropy compensation. DeltaG degrees remains almost invariant over the temperature range studied. The free energy change for the binding of BS to Sj26GST is also favoured by entropic contributions at temperatures below 32 degrees C, thus indicating a strong hydrophobic interaction. Heat capacity change obtained for BS (DeltaC(p) degrees =(-580.3+/-54.2) cal x K(-1) mol(-1)) is twofold larger (in absolute value) than for ANS (DeltaC(p) degrees =(-294.8+/-15.8) cal x K(-1) mol(-1)). Taking together the thermodynamic parameters obtained for these inhibitors, it can be argued that the possible hydrophobic interactions in the binding of these inhibitors to L-site must be accompanied by other interactions whose contribution is enthalpic. Therefore, the non-substrate binding site (designed as ligandin) on Sj26GST may not be fully hydrophobic.
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Affiliation(s)
- Zeyad Yassin
- Department of Physical Chemistry, Biochemistry and Inorganic Chemistry, Faculty of Experimental Sciences, University of Almería, La Cañada de San Urbano, Almería, 04120, Spain
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