1
|
Cardwell PA, Del Moro C, Murphy MP, Lapthorn AJ, Hartley RC. Human mitochondrial glutathione transferases: Kinetic parameters and accommodation of a mitochondria-targeting group in substrates. Bioorg Med Chem 2024; 104:117712. [PMID: 38593670 DOI: 10.1016/j.bmc.2024.117712] [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: 01/06/2024] [Revised: 04/01/2024] [Accepted: 04/01/2024] [Indexed: 04/11/2024]
Abstract
Glutathione-S-transferases are key to the cellular detoxification of xenobiotics and products of oxidative damage. GSTs catalyse the reaction of glutathione (GSH) with electrophiles to form stable thioether adducts. GSTK1-1 is the main GST isoform in the mitochondrial matrix, but the GSTA1-1 and GSTA4-4 isoforms are also thought to be in the mitochondria with their distribution altering in transformed cells, thus potentially providing a cancer specific target. A mitochondria-targeted version of the GST substrate 1-chloro-2,4-dinitrobenzene (CDNB), MitoCDNB, has been used to manipulate the mitochondrial GSH pool. To finesse this approach to target particular GST isoforms in the context of cancer, here we have determined the kcat/Km for the human isoforms of GSTK1-1, GSTA1-1 and GSTA4-4 with respect to GSH and CDNB. We show how the rate of the GST-catalysed reaction between GSH and CDNB analogues can be modified by both the electron withdrawing substituents, and by the position of the mitochondria-targeting triphenylphosphonium on the chlorobenzene ring to tune the activity of mitochondria-targeted substrates. These findings can now be exploited to selectively disrupt the mitochondrial GSH pools of cancer cells expressing particular GST isoforms.
Collapse
Affiliation(s)
- Patrick A Cardwell
- School of Chemistry, Joseph Black Building, University Avenue, University of Glasgow, Glasgow G12 8QQ, UK.
| | - Carlo Del Moro
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0XY, UK
| | - Michael P Murphy
- MRC Mitochondrial Biology Unit, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0XY, UK
| | - Adrian J Lapthorn
- School of Chemistry, Joseph Black Building, University Avenue, University of Glasgow, Glasgow G12 8QQ, UK
| | - Richard C Hartley
- School of Chemistry, Joseph Black Building, University Avenue, University of Glasgow, Glasgow G12 8QQ, UK.
| |
Collapse
|
2
|
Scian M, Paço L, Murphree TA, Shireman LM, Atkins WM. Reversibility and Low Commitment to Forward Catalysis in the Conjugation of Lipid Alkenals by Glutathione Transferase A4-4. Biomolecules 2023; 13:biom13020329. [PMID: 36830698 PMCID: PMC9953347 DOI: 10.3390/biom13020329] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 01/31/2023] [Accepted: 02/06/2023] [Indexed: 02/11/2023] Open
Abstract
High concentrations of electrophilic lipid alkenals formed during oxidative stress are implicated in cytotoxicity and disease. However, low concentrations of alkenals are required to induce antioxidative stress responses. An established clearance pathway for lipid alkenals includes conjugation to glutathione (GSH) via Michael addition, which is catalyzed mainly by glutathione transferase isoform A4 (GSTA4-4). Based on the ability of GSTs to catalyze hydrolysis or retro-Michael addition of GSH conjugates, and the antioxidant function of low concentrations of lipid alkenals, we hypothesize that GSTA4-4 contributes a homeostatic role in lipid metabolism. Enzymatic kinetic parameters for retro-Michael addition with trans-2-Nonenal (NE) reveal the chemical competence of GSTA4-4 in this putative role. The forward GSTA4-4-catalyzed Michael addition occurs with the rapid exchange of the C2 proton of NE in D2O as observed by NMR. The isotope exchange was completely dependent on the presence of GSH. The overall commitment to catalysis, or the ratio of first order kcat,f for 'forward' Michael addition to the first order kcat,ex for H/D exchange is remarkably low, approximately 3:1. This behavior is consistent with the possibility that GSTA4-4 is a regulatory enzyme that contributes to steady-state levels of lipid alkenals, rather than a strict 'one way' detoxication enzyme.
Collapse
|
3
|
Komarov IV, Tolstanova G, Kuznietsova H, Dziubenko N, Yanchuk PI, Shtanova LY, Veselsky SP, Garmanchuk LV, Khranovska N, Gorbach O, Dovbynchuk T, Borysko P, Babii O, Schober T, Ulrich AS, Afonin S. Towards in vivo photomediated delivery of anticancer peptides: Insights from pharmacokinetic and -dynamic data. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 2022; 233:112479. [PMID: 35660309 DOI: 10.1016/j.jphotobiol.2022.112479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 05/13/2022] [Accepted: 05/17/2022] [Indexed: 06/15/2023]
Abstract
An in vivo study of a photoswitchable cytotoxic peptide LMB040 has been undertaken on a chemically induced hepatocellular carcinoma model in immunocompetent rats. We analysed the pharmacokinetic profile of the less toxic photoform ("ring-closed" dithienylethene) of the compound in tumors, plasma, and healthy liver. Accordingly, the peptide can reach a tumor concentration sufficiently high to exert a cytotoxic effect upon photoconversion into the more active ("ring-open") photoform. Tissue morphology, histology, redox state of the liver, and hepatic biochemical parameters in blood serum were analysed upon treatment with (i) the less active photoform, (ii) the in vivo light-activated alternative photoform, and (iii) compared with a reference chemotherapeutic 5-fluorouracil. We found that application of the less toxic form followed by a delayed in vivo photoconversion into the more toxic ring-open form of LMB040 led to a higher overall survival of the animals, and signs of enhanced immune response were observed compared to the untreated animals.
Collapse
Affiliation(s)
- Igor V Komarov
- Taras Shevchenko National University of Kyiv, Kyiv, Ukraine; Lumobiotics, Karlsruhe, Germany; Enamine, Kyiv, Ukraine.
| | | | - Halyna Kuznietsova
- Taras Shevchenko National University of Kyiv, Kyiv, Ukraine; Enamine, Kyiv, Ukraine
| | | | | | | | | | | | | | | | | | | | - Oleg Babii
- Lumobiotics, Karlsruhe, Germany; Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Tim Schober
- Lumobiotics, Karlsruhe, Germany; Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Anne S Ulrich
- Karlsruhe Institute of Technology, Karlsruhe, Germany; Institute of Organic Chemistry of Karlsruhe KIT, Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany..
| | - Sergii Afonin
- Karlsruhe Institute of Technology, Karlsruhe, Germany.
| |
Collapse
|
4
|
Mannervik B, Ismail A, Lindström H, Sjödin B, Ing NH. Glutathione Transferases as Efficient Ketosteroid Isomerases. Front Mol Biosci 2021; 8:765970. [PMID: 34881290 PMCID: PMC8645602 DOI: 10.3389/fmolb.2021.765970] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 11/01/2021] [Indexed: 01/01/2023] Open
Abstract
In addition to their well-established role in detoxication, glutathione transferases (GSTs) have other biological functions. We are focusing on the ketosteroid isomerase activity, which appears to contribute to steroid hormone biosynthesis in mammalian tissues. A highly efficient GST A3-3 is present in some, but not all, mammals. The alpha class enzyme GST A3-3 in humans and the horse shows the highest catalytic efficiency with kcat/Km values of approximately 107 M-1s-1, ranking close to the most active enzymes known. The expression of GST A3-3 in steroidogenic tissues suggests that the enzyme has evolved to support the activity of 3β-hydroxysteroid dehydrogenase, which catalyzes the formation of 5-androsten-3,17-dione and 5-pregnen-3,20-dione that are substrates for the double-bond isomerization catalyzed by GST A3-3. The dehydrogenase also catalyzes the isomerization, but its kcat of approximately 1 s-1 is 200-fold lower than the kcat values of human and equine GST A3-3. Inhibition of GST A3-3 in progesterone-producing human cells suppress the formation of the hormone. Glutathione serves as a coenzyme contributing a thiolate as a base in the isomerase mechanism, which also involves the active-site Tyr9 and Arg15. These conserved residues are necessary but not sufficient for the ketosteroid isomerase activity. A proper assortment of H-site residues is crucial to efficient catalysis by forming the cavity binding the hydrophobic substrate. It remains to elucidate why some mammals, such as rats and mice, lack GSTs with the prominent ketosteroid isomerase activity found in certain other species. Remarkably, the fruit fly Drosophila melanogaster, expresses a GSTE14 with notable steroid isomerase activity, even though Ser14 has evolved as the active-site residue corresponding to Tyr9 in the mammalian alpha class.
Collapse
Affiliation(s)
- Bengt Mannervik
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Aram Ismail
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Helena Lindström
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Birgitta Sjödin
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Nancy H. Ing
- Department of Animal Science, Texas A&M AgriLife Research, Texas A&M University, College Station, TX, United States
| |
Collapse
|
5
|
Stetska VO, Dovbynchuk TV, Makedon YS, Dziubenko NV. The effect of water-soluble pristine C60 fullerene on 6-OHDA-induced Parkinson’s disease in rats. REGULATORY MECHANISMS IN BIOSYSTEMS 2021. [DOI: 10.15421/022182] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Oxidative stress is thought to be one of the mechanisms that leads to the dysfunction and degeneration of dopaminergic neurons in Parkinson’s disease pathogenesis and presumed to be underway during the prodromal phase. Therefore, therapy, which is effective against pre-motor symptoms, might be effective in preventing or delaying the development and progression of Parkinson’s disease. The aim of our study was to investigate the therapeutic efficiency of pristine C60 fullerene aqueous solution (C60FAS) during Parkinson’s disease in rats. The unilateral dopamine deficiency was induced in male Wistar rats (220–250 g) by stereotaxic microinjection of neurotoxin 6-hydroxydopamine (6-OHDA, 12 μg). C60FAS was injected to rats intraperitoneally daily for 10 days (0.65 mg/kg per day). The percentage of destroyed dopaminergic neurons was determined by the apomorphine test and by IHC staining of tyrosine hydroxylase-positive neurons in substantia nigra. We evaluated the rat body weight, the water and food intake, Open Field behavioural test, the level of biochemical antioxidant system, the activity of peritoneal macrophages. Levels of spontaneous and carbachol-stimulated colon motility were estimated by ballonographic method in vivo. C60FAS showed a positive tendency to increase the number of tyrosine hydroxylase-positive cells in the midbrain, which was associated with more profound improvement in apomorphine-rotation behaviour and slight relief of the anxiety level in Open Field test. Furthermore, C60FAS treatment increased the index of stimulated distal colon motor activity while it did not have a significant effect on water content in feces and total gastrointestinal transit time. C60FAS treatment did not affect water intake behaviour or body weight changes while it induced an increase of glutathione level and decrease activity of glutathione peroxidase in the brain as well as an increase in activity of peritoneal macrophages in 6-OHDA-Parkinson’s disease rats. These findings confirmed the potential therapeutic effectiveness of water-soluble pristine C60 fullerene in Parkinson’s disease pathogenesis, though there is ground for caution because of its systemic mild toxic effect.
Collapse
|
6
|
Kuznietsova H, Dziubenko N, Herheliuk T, Prylutskyy Y, Tauscher E, Ritter U, Scharff P. Water-Soluble Pristine C 60 Fullerene Inhibits Liver Alterations Associated with Hepatocellular Carcinoma in Rat. Pharmaceutics 2020; 12:pharmaceutics12090794. [PMID: 32842595 PMCID: PMC7559840 DOI: 10.3390/pharmaceutics12090794] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 08/15/2020] [Accepted: 08/19/2020] [Indexed: 12/11/2022] Open
Abstract
Excessive production of reactive oxygen species is the main cause of hepatocellular carcinoma (HCC) initiation and progression. Water-soluble pristine C60 fullerene is a powerful and non-toxic antioxidant, therefore, its effect under rat HCC model and its possible mechanisms were aimed to be discovered. Studies on HepG2 cells (human HCC) demonstrated C60 fullerene ability to inhibit cell growth (IC50 = 108.2 μmol), to induce apoptosis, to downregulate glucose-6-phosphate dehydrogenase, to upregulate vimentin and p53 expression and to alter HepG2 redox state. If applied to animals experienced HCC in dose of 0.25 mg/kg per day starting at liver cirrhosis stage, C60 fullerene improved post-treatment survival similar to reference 5-fluorouracil (31 and 30 compared to 17 weeks) and inhibited metastasis unlike the latter. Furthermore, C60 fullerene substantially attenuated liver injury and fibrosis, decreased liver enzymes, and normalized bilirubin and redox markers (elevated by 1.7–7.7 times under HCC). Thus, C60 fullerene ability to inhibit HepG2 cell growth and HCC development and metastasis and to improve animal survival was concluded. C60 fullerene cytostatic action might be realized through apoptosis induction and glucose-6-phosphate dehydrogenase downregulation in addition to its antioxidant activity.
Collapse
Affiliation(s)
- Halyna Kuznietsova
- Institute of Biology and Medicine, Taras Shevchenko National University of Kyiv, Volodymyrska str., 64, 01601 Kyiv, Ukraine; (N.D.); (T.H.); (Y.P.)
- Correspondence: (H.K.); (U.R.); Tel.: +38-095-277-4370 (H.K.); +49-3677-69-3603 (U.R.)
| | - Natalia Dziubenko
- Institute of Biology and Medicine, Taras Shevchenko National University of Kyiv, Volodymyrska str., 64, 01601 Kyiv, Ukraine; (N.D.); (T.H.); (Y.P.)
| | - Tetiana Herheliuk
- Institute of Biology and Medicine, Taras Shevchenko National University of Kyiv, Volodymyrska str., 64, 01601 Kyiv, Ukraine; (N.D.); (T.H.); (Y.P.)
| | - Yuriy Prylutskyy
- Institute of Biology and Medicine, Taras Shevchenko National University of Kyiv, Volodymyrska str., 64, 01601 Kyiv, Ukraine; (N.D.); (T.H.); (Y.P.)
| | - Eric Tauscher
- Institute of Chemistry and Biotechnology, Technical University of Ilmenau, Weimarer str. 25, 98693 Ilmenau, Germany; (E.T.); (P.S.)
| | - Uwe Ritter
- Institute of Chemistry and Biotechnology, Technical University of Ilmenau, Weimarer str. 25, 98693 Ilmenau, Germany; (E.T.); (P.S.)
- Correspondence: (H.K.); (U.R.); Tel.: +38-095-277-4370 (H.K.); +49-3677-69-3603 (U.R.)
| | - Peter Scharff
- Institute of Chemistry and Biotechnology, Technical University of Ilmenau, Weimarer str. 25, 98693 Ilmenau, Germany; (E.T.); (P.S.)
| |
Collapse
|
7
|
Moharana TR, Rao NM. Substrate structure and computation guided engineering of a lipase for omega-3 fatty acid selectivity. PLoS One 2020; 15:e0231177. [PMID: 32271820 PMCID: PMC7145112 DOI: 10.1371/journal.pone.0231177] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 03/17/2020] [Indexed: 11/19/2022] Open
Abstract
Enrichment of omega-3 fatty acids (ɷ-3 FAs) in natural oils is important to realize their health benefits. Lipases are promising catalysts to perform this enrichment, however, fatty acid specificity of lipases is poor. We attempted to improve the fatty acid selectivity of a lipase from Geobacillus thermoleovorans (GTL) by two approaches. In a semi-rational approach, amino acid positions critical for binding were identified by docking the substrate to the GTL and best substitutes at these positions were identified by site saturation mutagenesis followed by screening to obtain a variant of GTL (CM-GTL). In the second approach based on rational design, a variant of GTL was designed (DM-GTL) wherein the active site was narrowed by incorporating two heavier amino acids in the lining of acyl-binding pocket to hinder access to bulky ɷ-3 FAs. The affinities DM-GTL with designed substrates were evaluated in silico. Both, CM-GTL and DM-GTL have shown excellent ability to discriminate against the ɷ-3 FAs during hydrolysis of oils. Engineering the binding pocket of an enzyme of a complex substrate, such as a triglyceride, by incorporating the information on substrate structure and computationally derived binding modes, has resulted in designing two efficient lipase variants with improved substrate selectivity.
Collapse
|
8
|
Water-Soluble Pristine C 60 Fullerenes Inhibit Liver Fibrotic Alteration and Prevent Liver Cirrhosis in Rats. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:8061246. [PMID: 32148657 PMCID: PMC7044474 DOI: 10.1155/2020/8061246] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 01/11/2020] [Accepted: 01/20/2020] [Indexed: 02/07/2023]
Abstract
Liver cirrhosis is an outcome of a wide range of liver chronic diseases. It is attributed to oxidative stress; therefore, antioxidant usage could be a promising treatment of that. So, exploring the impact of effective free radical scavenger pristine C60 fullerenes on liver fibrosis and cirrhosis and their ability to interact with main growth factor receptors involved in liver fibrogenesis was aimed to be discovered. We used N-diethylnitrosamine/carbon tetrachloride-induced simulations of rat liver fibrosis (10 weeks) and cirrhosis (15 weeks). Pristine C60 fullerene aqueous colloid solution (C60FAS) was injected daily at a dose of 0.25 mg/kg throughout the experiment. Liver morphology and functional and redox states were assessed. C60 fullerenes' ability to interact with epidermal, vasoendothelial, platelet-derived, and fibroblast growth factor receptors (EGFR, VEGFR, PDGFR, and FGFR, respectively) was estimated by computational modeling. We observed that C60FAS reduced the severity of fibrosis in fibrotic rats (0.75 vs. 3.0 points according to Ishak score), attenuated the hepatocyte injury, normalized elevated blood serum alkaline phosphatase (ALP) and lactate dehydrogenase (LDH), and mitigated oxidative stress manifestation in liver tissue restoring its redox balance. When applied to cirrhotic animals, C60FAS reduced connective tissue deposition as well (2.4 vs. 5.4 points according to Ishak score), diminished ALP and LDH (by 16% and 61%), and normalized conjugated and nonconjugated bilirubin, restoring the liver function. Altered liver lipid and protein peroxides and glutathione peroxidase activity were also leveled. Within a computer simulation, it was shown that C60 fullerenes can block hinge prohibiting ATP binding for EGFR and FGFR and thus blocking associated signal pathways. This ability in addition to their antioxidant properties may contribute to C60 fullerene's antifibrotic action. Thus, C60FAS may have a substantial therapeutic potential as an inhibitor of liver fibrosis and cirrhosis.
Collapse
|
9
|
Byelinska I, Kuznietsova H, Dziubenko N, Lynchak O, Rybalchenko T, Prylutskyy Y, Kyzyma O, Ivankov O, Rybalchenko V, Ritter U. Effect of С60 fullerenes on the intensity of colon damage and hematological signs of ulcerative colitis in rats. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2018; 93:505-517. [DOI: 10.1016/j.msec.2018.08.033] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 07/06/2018] [Accepted: 08/11/2018] [Indexed: 02/07/2023]
|
10
|
Musdal Y, Govindarajan S, Mannervik B. Exploring sequence-function space of a poplar glutathione transferase using designed information-rich gene variants. Protein Eng Des Sel 2017; 30:543-549. [PMID: 28967959 PMCID: PMC5914380 DOI: 10.1093/protein/gzx045] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2017] [Accepted: 08/15/2017] [Indexed: 01/19/2023] Open
Abstract
Exploring the vicinity around a locus of a protein in sequence space may identify homologs with enhanced properties, which could become valuable in biotechnical and other applications. A rational approach to this pursuit is the use of ‘infologs’, i.e. synthetic sequences with specific substitutions capturing maximal sequence information derived from the evolutionary history of the protein family. Ninety-five such infolog genes of poplar glutathione transferase were synthesized and expressed in Escherichia coli, and the catalytic activities of the proteins determined with alternative substrates. Sequence–activity relationships derived from the infologs were used to design a second set of 47 infologs in which 90% of the members exceeded wild-type properties. Two mutants, C2 (V55I/E95D/D108E/A160V) and G5 (F13L/C70A/G122E), were further functionally characterized. The activities of the infologs with the alternative substrates 1-chloro-2,4-dinitrobenzene and phenethyl isothiocyanate, subject to different chemistries, were positively correlated, indicating that the examined mutations were affecting the overall catalytic competence without major shift in substrate discrimination. By contrast, the enhanced protein expressivity observed in many of the mutants were not similarly correlated with the activities. In conclusion, small libraries of well-defined infologs can be used to systematically explore sequence space to optimize proteins in multidimensional functional space.
Collapse
Affiliation(s)
- Yaman Musdal
- Department of Neurochemistry, Arrhenius Laboratories, Stockholm University, Svante Arrhenius väg 16B, SE-10691 Stockholm, Sweden
| | | | - Bengt Mannervik
- Department of Neurochemistry, Arrhenius Laboratories, Stockholm University, Svante Arrhenius väg 16B, SE-10691 Stockholm, Sweden
| |
Collapse
|
11
|
Mazari AMA, Mannervik B. Drosophila GSTs display outstanding catalytic efficiencies with the environmental pollutants 2,4,6-trinitrotoluene and 2,4-dinitrotoluene. Biochem Biophys Rep 2015; 5:141-145. [PMID: 28955816 PMCID: PMC5600427 DOI: 10.1016/j.bbrep.2015.12.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 11/20/2015] [Accepted: 12/01/2015] [Indexed: 12/03/2022] Open
Abstract
The nitroaromatic explosive 2,4,6-trinitrotoluene (TNT) and the related 2,4-dinitrotoluene (DNT) are toxic environmental pollutants. The biotransformation and detoxication of these persistent compounds in higher organisms are of great significance from a health perspective as well as for the biotechnological challenge of bioremediation of contaminated soil. We demonstrate that different human glutathione transferases (GSTs) and GSTs from the fruit fly Drosophila melanogaster are catalysts of the biotransformation of TNT and DNT. The human GSTs had significant but modest catalytic activities with both DNT and TNT. However, D. melanogaster GSTE6 and GSTE7 displayed outstanding high activities with both substrates. The explosive TNT is a carcinogenic environmental pollutant spread world-wide. TNT and the related DNT can be detoxified by conjugation with cellular glutathione. Previously studied plant glutathione transferases display modest activity with TNT. We found that human GSTs from four classes have low activity with TNT and DNT. By contrast Drosophila GSTE6 and GSTE7 displayed outstanding TNT and DNT activities.
Collapse
Affiliation(s)
- Aslam M A Mazari
- Department of Neurochemistry, Stockholm University, SE-10691 Stockholm, Sweden
| | - Bengt Mannervik
- Department of Neurochemistry, Stockholm University, SE-10691 Stockholm, Sweden
| |
Collapse
|
12
|
Role of CRD-BP in the growth of human basal cell carcinoma cells. J Invest Dermatol 2014; 134:1718-1724. [PMID: 24468749 PMCID: PMC4041658 DOI: 10.1038/jid.2014.17] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 12/18/2013] [Accepted: 12/19/2013] [Indexed: 12/22/2022]
Abstract
Although the number of new cases of Basal Cell Carcinoma (BCC) has increased rapidly in the last few decades, the molecular basis of its pathogenesis is not completely understood. Activation of Hedgehog (Hh) signaling pathway has been shown to be a key factor driving the development of BCC. The Wnt/β-catenin signaling pathway was also shown to be activated in BCCs and to perhaps modulate the activity of Hh pathway. We have previously identified a novel mechanism by which Wnt signaling regulates the transcriptional outcome of Hh signaling pathway. We demonstrated that CRD-BP, a direct target of the Wnt/β-catenin signaling, binds to GLI1 mRNA, stabilizes it, and consequently upregulates its levels (mRNA and protein) and activities. We hypothesized that Wnt-induced and CRD-BP-dependent regulation of GLI1 expression and activities is important to the development of BCC. In this study, we show that CRD-BP is over-expressed in BCC and that its expression positively correlates with the activation of both Wnt and Hh signaling pathways. We also describe the generation and characterization of a human BCC cell line. This cell line was utilized to demonstrate the importance of CRD-BP-dependent regulation of GLI1 expression and activities in the development of BCC.
Collapse
|
13
|
Suplatov D, Kirilin E, Takhaveev V, Švedas V. Zebra: a web server for bioinformatic analysis of diverse protein families. J Biomol Struct Dyn 2013; 32:1752-8. [DOI: 10.1080/07391102.2013.834514] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
14
|
Honaker MT, Acchione M, Zhang W, Mannervik B, Atkins WM. Enzymatic detoxication, conformational selection, and the role of molten globule active sites. J Biol Chem 2013; 288:18599-611. [PMID: 23649628 DOI: 10.1074/jbc.m112.445767] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The role of conformational ensembles in enzymatic reactions remains unclear. Discussion concerning "induced fit" versus "conformational selection" has, however, ignored detoxication enzymes, which exhibit catalytic promiscuity. These enzymes dominate drug metabolism and determine drug-drug interactions. The detoxication enzyme glutathione transferase A1-1 (GSTA1-1), exploits a molten globule-like active site to achieve remarkable catalytic promiscuity wherein the substrate-free conformational ensemble is broad with barrierless transitions between states. A quantitative index of catalytic promiscuity is used to compare engineered variants of GSTA1-1 and the catalytic promiscuity correlates strongly with characteristics of the thermodynamic partition function, for the substrate-free enzymes. Access to chemically disparate transition states is encoded by the substrate-free conformational ensemble. Pre-steady state catalytic data confirm an extension of the conformational selection model, wherein different substrates select different starting conformations. The kinetic liability of the conformational breadth is minimized by a smooth landscape. We propose that "local" molten globule behavior optimizes detoxication enzymes.
Collapse
Affiliation(s)
- Matthew T Honaker
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195-7610, USA
| | | | | | | | | |
Collapse
|
15
|
Espinoza HM, Shireman LM, McClain V, Atkins W, Gallagher EP. Cloning, expression and analysis of the olfactory glutathione S-transferases in coho salmon. Biochem Pharmacol 2012; 85:839-48. [PMID: 23261526 DOI: 10.1016/j.bcp.2012.11.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Revised: 11/21/2012] [Accepted: 11/27/2012] [Indexed: 12/11/2022]
Abstract
The glutathione S-transferases (GSTs) provide cellular protection by detoxifying xenobiotics, maintaining redox status, and modulating secondary messengers, all of which are critical to maintaining olfaction in salmonids. Here, we characterized the major coho salmon olfactory GSTs (OlfGSTs), namely omega, pi, and rho subclasses. OlfGST omega contained an open reading frame of 720bp and encoded a protein of 239 amino acids. OlfGST pi and OlfGST rho contained open reading frames of 627 and 681nt, respectively, and encoded proteins of 208 and 226 amino acids. Whole-protein mass spectrometry yielded molecular weights of 29,950, 23,354, and 26,655Da, respectively, for the GST omega, pi, and rho subunits. Homology modeling using four protein-structure prediction algorithms suggest that the active sites in all three OlfGST isoforms resembled counterparts in other species. The olfactory GSTs conjugated prototypical GST substrates, but only OlfGST rho catalyzed the demethylation of the pesticide methyl parathion. OlfGST pi and rho exhibited thiol oxidoreductase activity toward 2-hydroxyethyl disulfide (2-HEDS) and conjugated 4-hydroxynonenal (HNE), a toxic aldehyde with neurodegenerative properties. The kinetic parameters for OlfGST pi conjugation of HNE were K(M)=0.16 ± 0.06mM and V(max)=0.5 ± 0.1μmolmin⁻¹mg⁻¹, whereas OlfGST rho was more efficient at catalyzing HNE conjugation (K(M)=0.022 ± 0.008 mM and V(max)=0.47 ± 0.05μmolmin⁻¹mg⁻¹). Our findings indicate that the peripheral olfactory system of coho expresses GST isoforms that detoxify certain electrophiles and pesticides and that help maintain redox status and signal transduction.
Collapse
Affiliation(s)
- Herbert M Espinoza
- Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, United States
| | | | | | | | | |
Collapse
|
16
|
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.
Collapse
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.
| |
Collapse
|
17
|
Norrgård MA, Mannervik B. Engineering GST M2-2 for High Activity with Indene 1,2-Oxide and Indication of an H-Site Residue Sustaining Catalytic Promiscuity. J Mol Biol 2011; 412:111-20. [DOI: 10.1016/j.jmb.2011.07.039] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Revised: 07/05/2011] [Accepted: 07/19/2011] [Indexed: 11/28/2022]
|
18
|
Norrgård MA, Hellman U, Mannervik B. Cys-X scanning for expansion of active-site residues and modulation of catalytic functions in a glutathione transferase. J Biol Chem 2011; 286:16871-8. [PMID: 21454564 DOI: 10.1074/jbc.m111.230078] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We propose Cys-X scanning as a semisynthetic approach to engineer the functional properties of recombinant proteins. As in the case of Ala scanning, key residues in the primary structure are identified, and one of them is replaced by Cys via site-directed mutagenesis. The thiol of the residue introduced is subsequently modified by alternative chemical reagents to yield diverse Cys-X mutants of the protein. This chemical approach is orthogonal to Ala or Cys scanning and allows the expansion of the repertoire of amino acid side chains far beyond those present in natural proteins. In its present application, we have introduced Cys-X residues in human glutathione transferase (GST) M2-2, replacing Met-212 in the substrate-binding site. To achieve selectivity of the modifications, the Cys residues in the wild-type enzyme were replaced by Ala. A suite of simple substitutions resulted in a set of homologous Met derivatives ranging from normethionine to S-heptyl-cysteine. The chemical modifications were validated by HPLC and mass spectrometry. The derivatized mutant enzymes were assayed with alternative GST substrates representing diverse chemical reactions: aromatic substitution, epoxide opening, transnitrosylation, and addition to an ortho-quinone. The Cys substitutions had different effects on the alternative substrates and differentially enhanced or suppressed catalytic activities depending on both the Cys-X substitution and the substrate assayed. As a consequence, the enzyme specificity profile could be changed among the alternative substrates. The procedure lends itself to large-scale production of Cys-X modified protein variants.
Collapse
Affiliation(s)
- Malena A Norrgård
- Department of Biochemistry and Organic Chemistry, Uppsala University, SE-75123 Uppsala, Sweden
| | | | | |
Collapse
|
19
|
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.
Collapse
Affiliation(s)
- Larissa M Balogh
- Department of Pharmacokinetics, Dynamics, and Metabolism, Pfizer Global Research and Development, Pfizer Inc., Groton, CT 06340, USA.
| | | |
Collapse
|
20
|
The quest for molecular quasi-species in ligand-activity space and its application to directed enzyme evolution. FEBS Lett 2010; 584:2565-71. [DOI: 10.1016/j.febslet.2010.04.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2010] [Accepted: 04/12/2010] [Indexed: 11/20/2022]
|
21
|
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.
Collapse
Affiliation(s)
- Larissa M Balogh
- Department of Medicinal Chemistry, Box 357610, University of Washington, Seattle, Washington 98195, USA
| | | | | | | | | | | | | | | |
Collapse
|
22
|
Shokeer A, Mannervik B. Minor modifications of the C-terminal helix reschedule the favored chemical reactions catalyzed by theta class glutathione transferase T1-1. J Biol Chem 2009; 285:5639-45. [PMID: 20022951 DOI: 10.1074/jbc.m109.074757] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Adaptive responses to novel toxic challenges provide selective advantages to organisms in evolution. Glutathione transferases (GSTs) play a pivotal role in the cellular defense because they are main contributors to the inactivation of genotoxic compounds of exogenous as well as of endogenous origins. GSTs are promiscuous enzymes catalyzing a variety of chemical reactions with numerous alternative substrates. Despite broad substrate acceptance, individual GSTs display pronounced selectivities such that only a limited number of substrates are transformed with high catalytic efficiency. The present study shows that minor structural changes in the C-terminal helix of mouse GST T1-1 induce major changes in the substrate-activity profile of the enzyme to favor novel chemical reactions and to suppress other reactions catalyzed by the parental enzyme.
Collapse
Affiliation(s)
- Abeer Shokeer
- Department of Biochemistry and Organic Chemistry, Uppsala University, Biomedical Center, Box 576, SE-75123 Uppsala, Sweden
| | | |
Collapse
|
23
|
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.
Collapse
Affiliation(s)
- Larissa M Balogh
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195, USA
| | | | | | | | | | | | | |
Collapse
|
24
|
Singh SP, Zimniak L, Zimniak P. The human hGSTA5 gene encodes an enzymatically active protein. Biochim Biophys Acta Gen Subj 2009; 1800:16-22. [PMID: 19664689 DOI: 10.1016/j.bbagen.2009.07.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2009] [Revised: 07/23/2009] [Accepted: 07/29/2009] [Indexed: 12/24/2022]
Abstract
BACKGROUND Of the five human Alpha-class glutathione transferases, expression of hGSTA5 has not been experimentally documented, even though in silico the hGSTA5 sequence can be assembled into a mRNA and translated. The present work was undertaken to determine whether hGSTA5 is functional. METHODS Human K562 cells were transfected with the hGSTA5 gene driven by the CMV promoter, and hGSTA5 cDNA was recovered from mature mRNA by reverse transcription. The cDNA was used in bacterial and eukaryotic protein expression systems. The resulting protein, after purification by glutathione affinity chromatography where appropriate, was tested for glutathione transferase activity. RESULTS Human K562 cells transfected with the hGSTA5 gene under control of a CMV promoter produced a fully spliced mRNA which, after reverse transcription and expression in E. coli, yielded a protein that catalyzed the conjugation of the lipid peroxidation product 4-hydroxynonenal to glutathione. Similarly, transfection of human HEK-293 cells with the hGSTA5 gene driven by the CMV promoter led to an elevated 4-hydroxynonenal-conjugating activity in the cell lysate. In addition, translation of hGSTA5 cDNA in a cell-free eukaryotic system gave rise to a protein with 4-hydroxynonenal-conjugating activity. CONCLUSIONS hGSTA5 can be processed to a mature mRNA which is translation-competent, producing a catalytically active enzyme. GENERAL SIGNIFICANCE Because a functional gene would not be maintained in the absence of selective pressure, we conclude that the native hGSTA5 promoter is active but has a spatially or temporally restricted expression pattern, and/or is expressed only under specific (patho)physiological conditions.
Collapse
Affiliation(s)
- Sharda P Singh
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | | | | |
Collapse
|
25
|
Emergence of a novel highly specific and catalytically efficient enzyme from a naturally promiscuous glutathione transferase. Biochim Biophys Acta Gen Subj 2008; 1780:1458-63. [PMID: 18706975 DOI: 10.1016/j.bbagen.2008.07.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Accepted: 07/12/2008] [Indexed: 11/21/2022]
Abstract
Redesign of glutathione transferases (GSTs) has led to enzymes with remarkably enhanced catalytic properties. Exchange of substrate-binding residues in GST A1-1 created a GST A4-4 mimic, called GIMFhelix, with >300-fold improved activity with nonenal and suppressed activity with other substrates. In the present investigation GIMFhelix was compared with the naturally-evolved GSTs A1-1 and A4-4 by determining catalytic efficiencies with nine alternative substrates. The enzymes can be represented by vectors in multidimensional substrate-activity space, and the vectors of GIMFhelix and GST A1-1, expressed in kcat/Km values for the alternative substrates, are essentially orthogonal. By contrast, the vectors of GIMFhelix and GST A4-4 have approximately similar lengths and directions. The broad substrate acceptance of GST A1-1 contrasts with the high selectivity of GST A4-4 and GIMFhelix for alkenal substrates. Multivariate analysis demonstrated that among the diverse substrates used, nonenal, cumene hydroperoxide, and androstenedione are major determinants in the portrayal of the three enzyme variants. These GST substrates represent diverse chemistries of naturally occurring substrates undergoing Michael addition, hydroperoxide reduction, and steroid double-bond isomerization, respectively. In terms of function, GIMFhelix is a novel enzyme compared to its progenitor GST A1-1 in spite of 94% amino-acid sequence identity between the enzymes. The redesign of GST A1-1 into GIMFhelix therefore serves as an illustration of divergent evolution leading to novel enzymes by minor structural modifications in the active site. Notwithstanding low sequence identity (60%), GIMFhelix is functionally an isoenzyme of GST A4-4.
Collapse
|
26
|
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.
Collapse
Affiliation(s)
- Larissa M Balogh
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195-7610, USA
| | | | | | | | | |
Collapse
|
27
|
Kurtovic S, Grehn L, Karlsson A, Hellman U, Mannervik B. Glutathione transferase activity with a novel substrate mimics the activation of the prodrug azathioprine. Anal Biochem 2008; 375:339-44. [DOI: 10.1016/j.ab.2007.12.033] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2007] [Revised: 12/21/2007] [Accepted: 12/26/2007] [Indexed: 10/22/2022]
|
28
|
Kurtovic S, Shokeer A, Mannervik B. Diverging catalytic capacities and selectivity profiles with haloalkane substrates of chimeric alpha class glutathione transferases. Protein Eng Des Sel 2008; 21:329-41. [DOI: 10.1093/protein/gzn010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
29
|
Kurtovic S, Modén O, Shokeer A, Mannervik B. Structural Determinants of Glutathione Transferases with Azathioprine Activity Identified by DNA Shuffling of Alpha Class Members. J Mol Biol 2008; 375:1365-79. [DOI: 10.1016/j.jmb.2007.11.034] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2007] [Accepted: 11/13/2007] [Indexed: 10/22/2022]
|
30
|
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.
Collapse
Affiliation(s)
- Liming Hou
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195-7610, USA
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Frova C. Glutathione transferases in the genomics era: new insights and perspectives. ACTA ACUST UNITED AC 2006; 23:149-69. [PMID: 16839810 DOI: 10.1016/j.bioeng.2006.05.020] [Citation(s) in RCA: 322] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2006] [Revised: 05/12/2006] [Accepted: 05/12/2006] [Indexed: 11/23/2022]
Abstract
In the last decade the tumultuous development of "omics" greatly improved our ability to understand protein structure, function and evolution, and to define their roles and networks in complex biological processes. This fast accumulating knowledge holds great potential for biotechnological applications, from the development of biomolecules with novel properties of industrial and medical importance, to the creation of transgenic organisms with new, favorable characteristics. This review focuses on glutathione transferases (GSTs), an ancient protein superfamily with multiple roles in all eukaryotic organisms, and attempts to give an overview of the new insights and perspectives provided by omics into the biology of these proteins. Among the aspects considered are the redefinition of GST subfamilies, their evolution in connection with structurally related families, present and future biotechnological outcomes.
Collapse
Affiliation(s)
- Carla Frova
- Department of Biomolecular Sciences and Biotechnology, University of Milano, Via Celoria 26, 20133 Milano, Italy.
| |
Collapse
|
32
|
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.
Collapse
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 )
| |
Collapse
|
33
|
Lian HY, Jiang Y, Zhang H, Jones GW, Perrett S. The yeast prion protein Ure2: Structure, function and folding. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2006; 1764:535-45. [PMID: 16427819 DOI: 10.1016/j.bbapap.2005.11.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2005] [Revised: 11/28/2005] [Accepted: 11/29/2005] [Indexed: 11/23/2022]
Abstract
The Saccharomyces cerevisiae protein Ure2 functions as a regulator of nitrogen metabolism and as a glutathione-dependent peroxidase. Ure2 also has the characteristics of a prion, in that it can undergo a heritable conformational change to an aggregated state; the prion form of Ure2 loses the regulatory function, but the enzymatic function appears to be maintained. A number of factors are found to affect the prion properties of Ure2, including mutation and expression levels of molecular chaperones, and the effect of these factors on structure and stability are being investigated. The relationship between structure, function and folding for the yeast prion Ure2 are discussed.
Collapse
Affiliation(s)
- Hui-Yong Lian
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101, China
| | | | | | | | | |
Collapse
|
34
|
Parikh MR, Matsumura I. Site-saturation mutagenesis is more efficient than DNA shuffling for the directed evolution of beta-fucosidase from beta-galactosidase. J Mol Biol 2005; 352:621-8. [PMID: 16095606 PMCID: PMC2014722 DOI: 10.1016/j.jmb.2005.07.020] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2005] [Revised: 06/30/2005] [Accepted: 07/11/2005] [Indexed: 11/29/2022]
Abstract
Protein engineers use a variety of mutagenic strategies to adapt enzymes to novel substrates. Directed evolution techniques (random mutagenesis and high-throughput screening) offer a systematic approach to the management of protein complexity. This sub-discipline was galvanized by the invention of DNA shuffling, a procedure that randomly recombines point mutations in vitro. In one influential study, Escherichia coli beta-galactosidase (BGAL) variants with enhanced beta-fucosidase activity (tenfold increase in k(cat)/K(M) in reactions with the novel para-nitrophenyl-beta-d-fucopyranoside substrate; 39-fold decrease in reactivity with the "native"para-nitrophenyl-beta-d-galactopyranoside substrate) were evolved in seven rounds of DNA shuffling and screening. Here, we show that a single round of site-saturation mutagenesis and screening enabled the identification of beta-fucosidases that are significantly more active (180-fold increase in k(cat)/K(M) in reactions with the novel substrate) and specific (700,000-fold inversion of specificity) than the best variants in the previous study. Site-saturation mutagenesis thus proved faster, less resource-intensive and more effective than DNA shuffling for this particular evolutionary pathway.
Collapse
Affiliation(s)
| | - Ichiro Matsumura
- *Corresponding author. E-mail address of the corresponding author:
| |
Collapse
|
35
|
Ayyadevara S, Engle MR, Singh SP, Dandapat A, Lichti CF, Benes H, Shmookler Reis RJ, Liebau E, Zimniak P. Lifespan and stress resistance of Caenorhabditis elegans are increased by expression of glutathione transferases capable of metabolizing the lipid peroxidation product 4-hydroxynonenal. Aging Cell 2005; 4:257-71. [PMID: 16164425 DOI: 10.1111/j.1474-9726.2005.00168.x] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Caenorhabditis elegans expresses a glutathione transferase (GST) belonging to the Pi class, for which we propose the name CeGSTP2-2. CeGSTP2-2 (the product of the gst-10 gene) has the ability to conjugate the lipid peroxidation product 4-hydroxynonenal (4-HNE). Transgenic C. elegans strains were generated in which the 5'-flanking region and promoter of gst-10 were placed upstream of gst-10 and mGsta4 cDNAs, respectively. mGsta4 encodes the murine mGSTA4-4, an enzyme with particularly high catalytic efficiency for 4-HNE. The localization of both transgenes was similar to that of native CeGSTP2-2. The 4-HNE-conjugating activity in worm lysates increased in the order: control<mGsta4 transgenic<gst-10 transgenic; and the amount of 4-HNE-protein adducts decreased in the same order, indicating that the transgenic enzymes were active and effective in limiting electrophilic damage by 4-HNE. Stress resistance and lifespan were measured in transgenic animals (five independent lines each) and were compared with two independent control lines. Resistance to paraquat, heat shock, ultraviolet irradiation and hydrogen peroxide was greater in transgenic strains. Median lifespan of mGsta4 and gst-10 transgenic strains vs. control strains was increased by 13% and 22%, respectively. In addition to the cause-effect relationship between GST expression and lifespan observed in the transgenic lines, correlative evidence was also obtained in a series of congenic lines of C. elegans in which lifespan paralleled the 4-HNE-conjugating activity in whole-animal lysates. We conclude that electrophilic damage by 4-HNE may contribute to organismal aging.
Collapse
Affiliation(s)
- Srinivas Ayyadevara
- Department of Pharmacology & Toxicology, University of Arkansas for Medical Sciences, and Central Arkansas Veterans Healthcare System, Little Rock, AR 72205, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
36
|
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.
Collapse
Affiliation(s)
- Diane C Kuhnert
- Protein Structure-Function Research Programme, School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg 2050, South Africa
| | | | | | | | | | | |
Collapse
|
37
|
Udomsinprasert R, Bogoyevitch M, Ketterman A. Reciprocal regulation of glutathione S-transferase spliceforms and the Drosophila c-Jun N-terminal kinase pathway components. Biochem J 2005; 383:483-90. [PMID: 15250826 PMCID: PMC1133741 DOI: 10.1042/bj20040519] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In mammalian systems, detoxification enzymes of the GST (glutathione S-transferase) family regulate JNK (c-Jun N-terminal kinase) signal transduction by interaction with JNK itself or other proteins upstream in the JNK pathway. In the present study, we have studied GSTs and their interaction with components of the JNK pathway from Diptera. We have evaluated the effects of four Delta class Anopheles dirus GSTs, GSTD1-1, GSTD2-2, GSTD3-3 and GSTD4-4, on the activity of full-length recombinant Drosophila HEP (mitogen-activated protein kinase kinase 7; where HEP stands for hemipterous) and the Drosophila JNK, as well as the reciprocal effect of these kinases on GST activity. Interestingly, even though these four GSTs are alternatively spliced products of the same gene and share >60% identity, they exerted different effects on JNK activity. GSTD1-1 inhibited JNK activity, whereas the other three GST isoforms activated JNK. GSTD2-2, GSTD3-3 and GSTD4-4 were inhibited 50-80% by HEP or JNK but GSTD1-1 was not inhibited by JNK. However, there were some similarities in the actions of HEP and JNK on these GSTs. For example, binding constants for HEP or JNK inhibiting a GST were similar (20-70 nM). Furthermore, after incubation of the GSTs with JNK, both JNK and the GSTs changed catalytic properties. The substrate specificities of both GSTs and JNK were also altered after their co-incubation. In addition, glutathione modulated the effects of JNK on GST activity. These results emphasize that different GST spliceforms possess different properties, both in their catalytic function and in their regulation of signalling through the JNK pathway.
Collapse
Affiliation(s)
- Rungrutai Udomsinprasert
- *Institute of Molecular Biology and Genetics, Mahidol University, Salaya Campus, Nakorn Pathom 73170, Thailand
| | - Marie A. Bogoyevitch
- †Cell Signalling Laboratory, Biochemistry and Molecular Biology, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia
| | - Albert J. Ketterman
- *Institute of Molecular Biology and Genetics, Mahidol University, Salaya Campus, Nakorn Pathom 73170, Thailand
- To whom correspondence should be addressed (email )
| |
Collapse
|
38
|
Dirr HW, Little T, Kuhnert DC, Sayed Y. A conserved N-capping motif contributes significantly to the stabilization and dynamics of the C-terminal region of class Alpha glutathione S-transferases. J Biol Chem 2005; 280:19480-7. [PMID: 15757902 DOI: 10.1074/jbc.m413608200] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Helix 9, the major structural element in the C-terminal region of class Alpha glutathione transferases, forms part of the active site of these enzymes where its dynamic properties modulate both catalytic and ligandin functions. A conserved aspartic acid N-capping motif for helix 9 was identified by sequence alignments of the C-terminal regions of class Alpha glutathione S-transferases (GSTs) and an analysis by the helix-coil algorithm AGADIR. The contribution of the N-capping motif to the stability and dynamics of the region was investigated by replacing the N-cap residue Asp-209 with a glycine in human glutathione S-transferase A1-1 (hGST A1-1) and in a peptide corresponding to its C-terminal region. Far-UV circular dichroism and AGADIR analyses indicate that, in the absence of tertiary interactions, the wild-type peptide displays a low intrinsic tendency to form a helix and that this tendency is reduced significantly by the Asp-to-Gly mutation. Disruption of the N-capping motif of helix 9 in hGST A1-1 alters the conformational dynamics of the C-terminal region and, consequently, the features of the H-site to which hydrophobic substrates (e.g. 1-chloro-2,4-dinitrobenzene (CDNB)) and nonsubstrates (e.g. 8-anilino-1-naphthalene sulfonate (ANS)) bind. Isothermal calorimetric and fluorescence data for complex formation between ANS and protein suggest that the D209G-induced perturbation in the C-terminal region prevents normal ligand-induced localization of the region at the active site, resulting in a less hydrophobic and more solvent-exposed H-site. Therefore, the catalytic efficiency of the enzyme with CDNB is diminished due to a lowered affinity for the electrophilic substrate and a lower stabilization of the transition state.
Collapse
Affiliation(s)
- Heini W Dirr
- Protein Structure-Function Research Programme, School of Molecular and Cell Biology, University of the Witwatersrand, Johannesburg, South Africa.
| | | | | | | |
Collapse
|
39
|
Hederos S, Baltzer L. Nucleophile selectivity in the acyl transfer reaction of a designed enzyme. Biopolymers 2005; 79:292-9. [PMID: 16108014 DOI: 10.1002/bip.20351] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The acyl transfer reaction of S-glutathionyl benzoate (GSB) is catalyzed by a rationally designed mutant of human glutathione transferase A1-1, A216H. The catalyzed reaction proceeds via the formation of an acyl intermediate and has been studied in the presence of nitrogen, oxygen, and sulfur nucleophiles to determine the selectivity with regards to nucleophile structure. Methanol was previously shown to react with the acyl intermediate and form the corresponding ester, methylbenzoate, under a significant rate enhancement. In the present investigation, the dependence on nucleophile structure and reactivity has been investigated. Ethane thiol gave rise to a larger rate enhancement in the enzyme-catalyzed reaction than ethanol, whereas ethylamine did not increase the reaction rate. The reactivities toward the acyl intermediate of primary and secondary alcohols with similar pKa values depended on the structure of the aliphatic chain, and 1-propanol was the most efficient alcohol. The reactivity of the oxygen nucleophiles was also found to depend strongly on pKa as 2,2,2-trifluoroethanol, with a pKa of 12.4, was the most efficient nucleophile of all that were tested. Saturation kinetics was observed in the case of 1-propanol, indicating a second binding site in the active site of A216H. The nucleophile selectivity of A216H provides the knowledge base needed for the further reengineering of A216H towards alternative substrate specificities.
Collapse
Affiliation(s)
- Sofia Hederos
- IFM Chemistry, Division of Organic Chemistry, Linköping University SE-581 83, Linköping, Sweden
| | | |
Collapse
|
40
|
Bornscheuer UT, Kazlauskas RJ. Untreue Enzyme in der Biokatalyse: mit alten Enzymen zu neuen Bindungen und Synthesewegen. Angew Chem Int Ed Engl 2004. [DOI: 10.1002/ange.200460416] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
41
|
Bornscheuer UT, Kazlauskas RJ. Catalytic Promiscuity in Biocatalysis: Using Old Enzymes to Form New Bonds and Follow New Pathways. Angew Chem Int Ed Engl 2004; 43:6032-40. [PMID: 15523680 DOI: 10.1002/anie.200460416] [Citation(s) in RCA: 428] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Biocatalysis has expanded rapidly in the last decades with the discoveries of highly stereoselective enzymes with broad substrate specificity. A new frontier for biocatalysis is broad reaction specificity, where enzymes catalyze alternate reactions. Although often under-appreciated, catalytic promiscuity has a natural role in evolution and occasionally in the biosynthesis of secondary metabolites. Examples of catalytic promiscuity with current or potential applications in synthesis are reviewed here. Combined with protein engineering, the catalytic promiscuity of enzymes may broadly extend their usefulness in organic synthesis.
Collapse
Affiliation(s)
- Uwe T Bornscheuer
- Institute of Chemistry and Biochemistry, Department of Technical Chemistry and Biotechnology, Greifswald University, Soldmannstrasse 16, 17487 Greifswald, Germany.
| | | |
Collapse
|
42
|
Hederos S, Broo KS, Jakobsson E, Kleywegt GJ, Mannervik B, Baltzer L. Incorporation of a single His residue by rational design enables thiol-ester hydrolysis by human glutathione transferase A1-1. Proc Natl Acad Sci U S A 2004; 101:13163-7. [PMID: 15333749 PMCID: PMC516542 DOI: 10.1073/pnas.0403045101] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2004] [Indexed: 11/18/2022] Open
Abstract
A strategy for rational enzyme design is reported and illustrated by the engineering of a protein catalyst for thiol-ester hydrolysis. Five mutants of human glutathione (GSH; gamma-Glu-Cys-Gly) transferase A1-1 were designed in the search for a catalyst and to provide a set of proteins from which the reaction mechanism could be elucidated. The single mutant A216H catalyzed the hydrolysis of the S-benzoyl ester of GSH under turnover conditions with a k(cat)/K(M) of 156 M(-1) x min(-1), and a catalytic proficiency of >10(7) M(-1) when compared with the first-order rate constant of the uncatalyzed reaction. The wild-type enzyme did not hydrolyze the substrate, and thus, the introduction of a single histidine residue transformed the wild-type enzyme into a turnover system for thiol-ester hydrolysis. By kinetic analysis of single, double, and triple mutants, as well as from studies of reaction products, it was established that the enzyme A216H catalyzes the hydrolysis of the thiol-ester substrate by a mechanism that includes an acyl intermediate at the side chain of Y9. Kinetic measurements and the crystal structure of the A216H GSH complex provided compelling evidence that H216 acts as a general-base catalyst. The introduction of a single His residue into human GSH transferase A1-1 created an unprecedented enzymatic function, suggesting a strategy that may be of broad applicability in the design of new enzymes. The protein catalyst has the hallmarks of a native enzyme and is expected to catalyze various hydrolytic, as well as transesterification, reactions.
Collapse
Affiliation(s)
- Sofia Hederos
- Department of Chemistry, IFM, Linköping University, SE-581 83 Linköping, Sweden
| | | | | | | | | | | |
Collapse
|
43
|
Kato T, Miyakawa H, Ishibashi M. Frequency and significance of anti-glutathione S-transferase autoantibody (anti-GST A1-1) in autoimmune hepatitis. J Autoimmun 2004; 22:211-6. [PMID: 15041041 DOI: 10.1016/j.jaut.2004.01.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2003] [Revised: 01/07/2004] [Accepted: 01/14/2004] [Indexed: 10/26/2022]
Abstract
Several phase I and phase II multi-drug metabolizing enzymes, such as CYP2D6, 3A4, and UGTA1, were reported to act as immunotargets in a subset of autoimmune hepatitis and hepatic autoimmunity. However, it is uncertain whether glutathione S-transferase (GST) A1-1, one of the phase II multi-drug metabolizing enzymes, is also an immunotarget in autoimmune hepatitis. So, in the present study, we investigated the frequency and significance of anti-GST A1-1 in sera from patients with autoimmune hepatitis. A total of 74 serum samples from patients with autoimmune hepatitis were examined in the present study. As controls, 20 serum samples from patients with primary biliary cirrhosis, 10 serum samples from patients with primary sclerosing cholangitis, 40 serum samples from patients with liver cirrhosis type B and C, 32 serum samples from patients with systemic lupus erythematosus, and 20 serum samples from normal controls were used. Anti-GST A1-1 antibody was determined by immunoblotting using the recombinant full-length GST A1-1 protein as the antigen. The immunofluorescent staining pattern of anti-GST A1-1 was investigated using rat liver and kidney sections. We compared clinicopathologic findings between anti-GST A1-1-positive and -negative autoimmune hepatitis patients. Anti-GST A1-1 was detected in 12 (16%) of 74 patients with autoimmune hepatitis, however, it was not detected in any control serum samples except for two patients with primary biliary cirrhosis. The immunofluorescence staining pattern of anti-GST A1-1 was found to be unique and different from those of anti-mitochondrial antibody or anti-liver-kidney microsome type 1 antibody. Anti-GST A1-1 coexisted with other autoantibodies such as anti-nuclear or anti-smooth muscle antibodies, but did not coexist with anti-soluble liver antigen/liver pancreas. Anti-GST A1-1-positive autoimmune hepatitis patients had severe clinical features and a poor prognosis compared with anti-GST A1-1-negative patients. These findings suggested that despite the low frequency, anti-GST A1-1 might be the marker of an early progression in autoimmune hepatitis.
Collapse
Affiliation(s)
- Takashi Kato
- Fourth Department of Internal Medicine, Teikyo University School of Medicine, 3-8-3 Mizonokuchi, Takatsu-ku, Kawasaki-shi, Kanagawa 213-8507, Japan
| | | | | |
Collapse
|
44
|
Wongtrakul J, Udomsinprasert R, Ketterman AJ. Non-active site residues Cys69 and Asp150 affected the enzymatic properties of glutathione S-transferase AdGSTD3-3. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2003; 33:971-979. [PMID: 14505690 DOI: 10.1016/s0965-1748(03)00103-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
To elucidate how non-active site residues support the catalytic function, five selected residues of AdGSTD3-3 isoenzyme were changed to AdGSTD1-1 residues by means of site-directed mutagenesis. Analysis of the kinetic parameters indicated that Cys69Gln and Asp150Ser showed marked differences in Vmax and Km compared with the wild type enzyme. Both residues were characterized further by replacement with several amino acids. Both the Cys69 and Asp150 mutants showed differences with several GST substrates and inhibitors including affecting the interactions with pyrethroid insecticides. Cys69 and Asp150 mutants possessed a decreased half-life relative to the wild type enzyme. The Asp150 mutation appears to affect neighboring residues that support two important structural motifs, the N-capping box and the hydrophobic staple motif. The Cys69 mutants appeared to have subtle conformational changes near the active site residues resulting in different conformations and also directly affecting the active site region. The results show the importance of the cumulative effects of residues remote from the active site and demonstrate that minute changes in tertiary structure play a role in modulating enzyme activity.
Collapse
Affiliation(s)
- Jeerang Wongtrakul
- Institute of Molecular Biology and Genetics, Mahidol University, Salaya Campus, Nakhon Pathom 73170, Thailand
| | | | | |
Collapse
|
45
|
Rowe LA, Geddie ML, Alexander OB, Matsumura I. A comparison of directed evolution approaches using the beta-glucuronidase model system. J Mol Biol 2003; 332:851-60. [PMID: 12972256 DOI: 10.1016/s0022-2836(03)00972-0] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Protein engineers can alter the properties of enzymes by directing their evolution in vitro. Many methods to generate molecular diversity and to identify improved clones have been developed, but experimental evolution remains as much an art as a science. We previously used DNA shuffling (sexual recombination) and a histochemical screen to direct the evolution of Escherichia coli beta-glucuronidase (GUS) variants with improved beta-galactosidase (BGAL) activity. Here, we employ the same model evolutionary system to test the efficiencies of several other techniques: recursive random mutagenesis (asexual), combinatorial cassette mutagenesis (high-frequency recombination) and a versatile high-throughput microplate screen. GUS variants with altered specificity evolved in each trial, but different combinations of mutagenesis and screening techniques effected the fixation of different beneficial mutations. The new microplate screen identified a broader set of mutations than the previously employed X-gal colony screen. Recursive random mutagenesis produced essentially asexual populations, within which beneficial mutations drove each other into extinction (clonal interference); DNA shuffling and combinatorial cassette mutagenesis led instead to the accumulation of beneficial mutations within a single allele. These results explain why recombinational approaches generally increase the efficiency of laboratory evolution.
Collapse
Affiliation(s)
- Lori A Rowe
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322, USA
| | | | | | | |
Collapse
|
46
|
Abstract
Recent developments to modify enzymes for use in organic synthesis have targeted several areas. These include altering the reaction mechanism of the enzyme to catalyse new reactions, switching substrate specificity, expanding substrate specificity, and improving substrate specificity, such as enantioselectivity in kinetic resolutions. Such modifications can be achieved either by rational redesign, which requires knowledge of the enzyme structure, or by random mutagenesis methods followed by screening. Both strategies of enzyme engineering can be successful and are very useful for improving the utility of enzymes for applied catalysis. Several examples illustrating these concepts in a variety of enzyme classes have appeared recently.
Collapse
Affiliation(s)
- Karl Hult
- Department of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Center, SE-106 91 Stockholm, Sweden.
| | | |
Collapse
|
47
|
Dixon DP, McEwen AG, Lapthorn AJ, Edwards R. Forced evolution of a herbicide detoxifying glutathione transferase. J Biol Chem 2003; 278:23930-5. [PMID: 12692133 DOI: 10.1074/jbc.m303620200] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Plant Tau class glutathione transferases (GSTUs) detoxify diphenylether herbicides such as fluorodifen, determining their selectivity in crops and weeds. Using reconstructive PCR, a series of mutant GSTUs were generated from in vitro recombination and mutagenesis of the maize sequences ZmGSTU1 and ZmGSTU2 (with the prefix Zm designating Zea mays L.). A screen of 5000 mutant GSTUs identified seven enzymes with enhanced fluorodifen detoxifying activity. The best performing enhanced fluorodifen detoxifying mutant (EFD) had activity 19-fold higher than the parent enzymes, with a single point mutation conferring this enhancement. Further mutagenesis of this residue generated an EFD with a 29-fold higher catalytic efficiency toward fluorodifen as compared with the parents but with unaltered catalysis toward other substrates. When expressed in Arabidopsis thaliana, the optimized EFD, but not the parent enzymes, conferred enhanced tolerance to fluorodifen. Molecular modeling predicts that the serendipitous mutation giving the improvement in detoxification is due to the removal of an unfavorable interaction together with the introduction of a favorable change in conformation of residues 107-119, which contribute to herbicide binding.
Collapse
Affiliation(s)
- David P Dixon
- Crop Protection Group, School of Biological and Biomedical Sciences, University of Durham, South Road, Durham DH1 3LE, United Kingdom
| | | | | | | |
Collapse
|
48
|
Ibarra CA, Chowdhury P, Petrich JW, Atkins WM. The anomalous pKa of Tyr-9 in glutathione S-transferase A1-1 catalyzes product release. J Biol Chem 2003; 278:19257-65. [PMID: 12637518 PMCID: PMC1945185 DOI: 10.1074/jbc.m301566200] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The pKa of the catalytic Tyr-9 in glutathione S-transferase (GST) A1-1 is lowered from 10.3 to approximately 8.1 in the apoenzyme and approximately 9.0 with a GSH conjugate bound at the active site. However, a clear functional role for the unusual Tyr-9 pKa has not been elucidated. GSTA1-1 also includes a dynamic C terminus that undergoes a ligand-dependent disorder-to-order transition. Previous studies suggest a functional link between Tyr-9 ionization and C-terminal dynamics. Here we directly probe the role of Tyr-9 ionization in ligand binding and C-terminal conformation. An engineered mutant of rGSTA1-1, W21F/F222W, which contains a single Trp at the C terminus, was used as a fluorescent reporter of pH-dependent C-terminal dynamics. This mutant exhibited a pH-dependent change in Trp-222 emission properties consistent with changes in C-terminal solvation or conformation. The apparent pKa values for the conformational transition were 7.9 +/- 0.1 and 9.3 +/- 0.1 for the apoenzyme and ligand-bound enzyme, respectively, in excellent agreement with the pKa for Tyr-9 in these states. The Y9F/W21F/F222W mutant, however, exhibited no such pH-dependent changes. Time-resolved fluorescence anisotropy studies revealed a ligand-dependent, Tyr-9-dependent, change in the order parameter of Trp-222. However, no pH dependence was observed. In equilibrium and pre-steady-state ligand binding studies, product conjugate had a decreased equilibrium binding affinity (KD), concomitant with increased binding and dissociation rates, at higher pH values. Furthermore, the recovered pKa values for the pH-dependent microscopic rate constants ranged from 7.7 to 8.4, also in agreement with the pKa of Tyr-9. In contrast, the Y9F/W21F/F222W mutant had no pH-dependent transition in KD or rate constants for ligand binding or dissociation. The combined results indicate that the macroscopic populations of "open" and "closed" states of the C terminus are not determined solely by the ionization state of Tyr-9. However, the rates of transition between these states are faster for the ionized Tyr-9. The ionized Tyr-9 states provide a parallel pathway for product dissociation, which is kinetically and thermodynamically favored. In silico kinetic models further support the functional role for the parallel dissociation pathway provided by ionized Tyr-9.
Collapse
Affiliation(s)
- Catherine A. Ibarra
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195-7610
| | - Pramit Chowdhury
- Department of Chemistry, Iowa State University, Ames, Iowa 50011
| | - Jacob W. Petrich
- Department of Chemistry, Iowa State University, Ames, Iowa 50011
| | - William M. Atkins
- Department of Medicinal Chemistry, University of Washington, Seattle, Washington 98195-7610
- ¶To whom correspondence should be addressed: Dept. of Medicinal Chemistry, Box 357610, University of Washington, Seattle, WA 98195-7610. Tel.: 206-685-0379l; Fax: 206-685-3252; E-mail:
| |
Collapse
|
49
|
Ivarsson Y, Mackey AJ, Edalat M, Pearson WR, Mannervik B. Identification of residues in glutathione transferase capable of driving functional diversification in evolution. A novel approach to protein redesign. J Biol Chem 2003; 278:8733-8. [PMID: 12486119 DOI: 10.1074/jbc.m211776200] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Evolution of protein function can be driven by positive selection of advantageous nonsynonymous codon mutations that arise following gene duplication. By observing the presence and degree of site-specific positive selection for change between divergent paralogs, residue positions responsible for functional changes can be identified. We applied this analysis to genes encoding Mu class glutathione transferases, which differ widely in substrate specificities. Approximately 3% of the amino acid residue positions, both near to and distant from the active site, are under statistically significant positive selection for change. Relevant human glutathione transferase (GST) M1-1 and GST M2-2 codons were mutated. A chemically conservative threonine to serine mutation in GST M2-2 elicited a 1,000-fold increase in specific activity with the GST M1-1-specific substrate trans-stilbene oxide and a 30-fold increase with the alternative epoxide substrates styrene oxide and nitrophenyl glycidol. The reverse mutation in GST M1-1 resulted in reciprocal decreases in activity. Thus, identification of hypervariable codon positions can be a powerful aid in the redesign of protein function, lessening the requirement for extensive mutagenesis or structural knowledge and sometimes suggesting mutations that would otherwise be considered functionally conservative.
Collapse
Affiliation(s)
- Ylva Ivarsson
- Department of Biochemistry, Uppsala University, Biomedical Center, Box 576, Sweden
| | | | | | | | | |
Collapse
|
50
|
Micaloni C, Kong GKW, Mazzetti AP, Nuccetelli M, Antonini G, Stella L, McKinstry WJ, Polekhina G, Rossjohn J, Federici G, Ricci G, Parker MW, Lo Bello M. Engineering a new C-terminal tail in the H-site of human glutathione transferase P1-1: structural and functional consequences. J Mol Biol 2003; 325:111-22. [PMID: 12473455 DOI: 10.1016/s0022-2836(02)01178-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We have sought the structural basis for the differing substrate specificities of human glutathione transferase P1-1 (class Pi) and human glutathione transferase A1-1 (class Alpha) by adding an extra helix (helix 9), found in the electrophilic substrate-binding site (H-site) of the human class Alpha enzyme, at the C terminus of the human class Pi enzyme. This class Pi-chimera (CODA) was expressed in Escherichia coli, purified and characterized by kinetic and crystallographic approaches. The presence of the newly engineered tail in the H-site of the human Pi enzyme alters its catalytic properties towards those exhibited by the human Alpha enzyme, as assessed using cumene hydroperoxide (diagnostic for class Alpha enzymes) and ethacrynic acid (diagnostic for class Pi) as co-substrates. There is a change of substrate selectivity in the latter case, as the k(cat)/K(m)(EA) value decreases about 70-fold, compared to that of class Pi. With 1-chloro-2,4-dinitrobenzene as co-substrate there is a loss of catalytic activity to about 2% with respect to that of the Pi enzyme. Crystallographic and kinetic studies of the class Pi-chimera provide important clues to explain these altered catalytic properties. The new helix forms many complimentary interactions with the rest of the protein and re-models the original electrophilic substrate-binding site towards one that is more enclosed, albeit flexible. Of particular note are the interactions between Glu205 of the new tail and the catalytic residues, Tyr7 and Tyr108, and the thiol moiety of glutathione (GSH). These interactions may provide an explanation of the more than one unit increase in the pK(a) value of the GSH thiolate and affect both the turnover number and GSH binding, using 1-chloro-2,4-dinitrobenzene as co-substrate. The data presented are consistent with the engineered tail adopting a highly mobile or disordered state in the apo form of the enzyme.
Collapse
Affiliation(s)
- Chiara Micaloni
- Department of Biology, University of Rome Tor Vergata, Via della Ricerca Scientifica snc, 00133 Rome, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|