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Roy PK, Paul A, Lalchhuanawmi S, Babu NK, Singh S. Pyridoxal kinase gene deletion leads to impaired growth, deranged redox metabolism and cell cycle arrest in Leishmania donovani. Biochimie 2024; 222:72-86. [PMID: 38403043 DOI: 10.1016/j.biochi.2024.02.009] [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: 09/14/2023] [Revised: 02/19/2024] [Accepted: 02/22/2024] [Indexed: 02/27/2024]
Abstract
Pyridoxal kinase (PdxK) is a vitamin B6 salvage pathway enzyme which produces pyridoxal phosphate. We have investigated the impact of PdxK deletion in Leishmania donovani on parasite survivability, infectivity and cellular metabolism. LdPdxK mutants were generated by gene replacement strategy. All mutants showed significant reduction in growth in comparison to wild type. For PdxK mediated biochemical perturbations, only heterozygous mutants and complementation mutants were used as the growth of null mutants were compromised. Heterozygous mutant showed reduction invitro infectivity and higher cytosolic and mitochondrial ROS levels. Glutathione levels decreased significantly in heterozygous mutant indicating its involvement in cellular oxidative metabolism. Pyridoxal kinase gene deletion resulted in reduced ATP levels in parasites and arrest at G0/G1 phase of cell cycle. All these perturbations were rescued by PdxK gene complementation. This is the first report to confirm that LdPdxK plays an indispensable role in cell survival, pathogenicity, redox metabolism and cell cycle progression of L. donovani parasites. These results provide substantial evidence supporting PdxK as a therapeutic target for the development of specific antileishmanial drug candidates.
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Affiliation(s)
- Pradyot Kumar Roy
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, S.A.S. Nagar, Mohali, 160062, Punjab, India
| | - Anindita Paul
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, S.A.S. Nagar, Mohali, 160062, Punjab, India
| | - Sandra Lalchhuanawmi
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, S.A.S. Nagar, Mohali, 160062, Punjab, India
| | - Neerupudi Kishore Babu
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, S.A.S. Nagar, Mohali, 160062, Punjab, India
| | - Sushma Singh
- Department of Biotechnology, National Institute of Pharmaceutical Education and Research, S.A.S. Nagar, Mohali, 160062, Punjab, India.
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Nawaz A, Priya B, Singh K, Ali V. Unveiling the role of serine o-acetyltransferase in drug resistance and oxidative stress tolerance in Leishmania donovani through the regulation of thiol-based redox metabolism. Free Radic Biol Med 2024; 213:371-393. [PMID: 38272324 DOI: 10.1016/j.freeradbiomed.2024.01.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 12/25/2023] [Accepted: 01/22/2024] [Indexed: 01/27/2024]
Abstract
Understanding the unique metabolic pathway of L. donovani is crucial for comprehending its biology under oxidative stress conditions. The de novo cysteine biosynthetic pathway of L. donovani is absent in humans and its product, cysteine regulates the downstream components of trypanothione-based thiol metabolism, important for maintaining cellular redox homeostasis. The role of serine o-acetyl transferase (SAT), the first enzyme of this pathway remains unexplored. In order to investigate the role of SAT protein, we cloned SAT gene into pXG-GFP+ vector for episomal expression of SAT in Amphotericin B sensitive L. donovani promastigotes. The SAT overexpression was confirmed by SAT enzymatic assay, GFP fluorescence, immunoblotting and PCR. Our study unveiled an upregulated expression of both LdSAT and LdCS of cysteine biosynthetic pathway and other downstream thiol pathway proteins in LdSAT-OE promastigotes. Additionally, there was an increase in enzymatic activities of LdSAT and LdCS proteins in LdSAT-OE, which was found similar to the Amp B resistant parasites, indicating a potential role of SAT protein in modulating drug resistance. We observed that the overexpression of SAT in Amp B sensitive parasites increases tolerance to drug pressure and oxidative stress via trypanothione-dependent antioxidant mechanism. Moreover, the in vitro J774A.1 macrophage infectivity assessment showed that SAT overexpression augments parasite infectivity. In LdSAT-OE promastigotes, antioxidant enzyme activities like APx and SOD were upregulated, intracellular reactive oxygen species were reduced with a corresponding increase in thiol level, emphasizing SAT's role in stress tolerance and enhanced infectivity. Additionally, the ROS mediated upregulation in the expression of LdSAT, LdCS, LdTryS and LdcTXNPx proteins reveals an essential cross talk between SAT and proteins of thiol metabolism in combating oxidative stress and maintaining redox homeostasis. Taken together, our results provide the first insight into the role of SAT protein in parasite infectivity and survival under drug pressure and oxidative stress.
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Affiliation(s)
- Afreen Nawaz
- ICMR - Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Patna, Bihar, 800007, India
| | - Bhawna Priya
- ICMR - Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Patna, Bihar, 800007, India
| | - Kuljit Singh
- Infectious Diseases Division, CSIR - Indian Institute of Integrative Medicine, Jammu, 180001, India
| | - Vahab Ali
- ICMR - Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Patna, Bihar, 800007, India.
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3
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Ihnatenko I, Müller MJ, Orban OCF, Lindhof JC, Benítez D, Ortíz C, Dibello E, Seidl LL, Comini MA, Kunick C. The indole motif is essential for the antitrypanosomal activity of N5-substituted paullones. PLoS One 2023; 18:e0292946. [PMID: 38032881 PMCID: PMC10688702 DOI: 10.1371/journal.pone.0292946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 10/02/2023] [Indexed: 12/02/2023] Open
Abstract
Severe infections with potentially fatal outcomes are caused by parasites from the genera Trypanosoma and Leishmania (class Kinetoplastea). The diseases affect people of remote areas in the tropics and subtropics with limited access to adequate health care. Besides insufficient diagnostics, treatment options are limited, with tenuous developments in recent years. Therefore, new antitrypanosomal antiinfectives are required to fight these maladies. In the presented approach, new compounds were developed and tested on the target trypanothione synthetase (TryS). This enzyme is crucial to the kinetoplastids' unique trypanothione-based thiol redox metabolism and thus for pathogen survival. Preceding studies have shown that N5-substituted paullones display antitrypanosomal activity as well as TryS inhibition. Herein, this compound class was further examined regarding the structure-activity relationships (SAR). Diverse benzazepinone derivatives were designed and tested in cell-based assays on bloodstream Trypanosoma brucei brucei (T. b. brucei) and intracellular amastigotes of Leishmania infantum (L. infantum) as well as in enzyme-based assays on L. infantum TryS (LiTryS) and T. b. brucei TryS (TbTryS). While an exchange of just the substituent in the 9-position of paullones led to potent inhibitors on LiTryS and T. b. brucei parasites, new compounds lacking the indole moiety showed a total loss of activity in both assays. Conclusively, the indole as part of the paullone structure is pivotal for keeping the TryS inhibitory and antitrypanosomal activity of this substance class.
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Affiliation(s)
- Irina Ihnatenko
- Institute of Medicinal and Pharmaceutical Chemistry, TU Braunschweig, Braunschweig, Germany
- PVZ-Center of Pharmaceutical Engineering, TU Braunschweig, Braunschweig, Germany
| | - Marco J Müller
- Institute of Medicinal and Pharmaceutical Chemistry, TU Braunschweig, Braunschweig, Germany
- PVZ-Center of Pharmaceutical Engineering, TU Braunschweig, Braunschweig, Germany
| | - Oliver C F Orban
- Institute of Medicinal and Pharmaceutical Chemistry, TU Braunschweig, Braunschweig, Germany
- PVZ-Center of Pharmaceutical Engineering, TU Braunschweig, Braunschweig, Germany
| | - Jens C Lindhof
- Institute of Medicinal and Pharmaceutical Chemistry, TU Braunschweig, Braunschweig, Germany
- PVZ-Center of Pharmaceutical Engineering, TU Braunschweig, Braunschweig, Germany
| | - Diego Benítez
- Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Cecilia Ortíz
- Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Estefanía Dibello
- Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
- Laboratorio de Síntesis Orgánica, Departamento de Química Orgánica, Facultad de Química, Universidad de la República, Montevideo, Uruguay
| | - Leonardo L Seidl
- Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Marcelo A Comini
- Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Conrad Kunick
- Institute of Medicinal and Pharmaceutical Chemistry, TU Braunschweig, Braunschweig, Germany
- PVZ-Center of Pharmaceutical Engineering, TU Braunschweig, Braunschweig, Germany
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4
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Jamabo M, Mahlalela M, Edkins AL, Boshoff A. Tackling Sleeping Sickness: Current and Promising Therapeutics and Treatment Strategies. Int J Mol Sci 2023; 24:12529. [PMID: 37569903 PMCID: PMC10420020 DOI: 10.3390/ijms241512529] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 07/27/2023] [Accepted: 08/03/2023] [Indexed: 08/13/2023] Open
Abstract
Human African trypanosomiasis is a neglected tropical disease caused by the extracellular protozoan parasite Trypanosoma brucei, and targeted for eradication by 2030. The COVID-19 pandemic contributed to the lengthening of the proposed time frame for eliminating human African trypanosomiasis as control programs were interrupted. Armed with extensive antigenic variation and the depletion of the B cell population during an infectious cycle, attempts to develop a vaccine have remained unachievable. With the absence of a vaccine, control of the disease has relied heavily on intensive screening measures and the use of drugs. The chemotherapeutics previously available for disease management were plagued by issues such as toxicity, resistance, and difficulty in administration. The approval of the latest and first oral drug, fexinidazole, is a major chemotherapeutic achievement for the treatment of human African trypanosomiasis in the past few decades. Timely and accurate diagnosis is essential for effective treatment, while poor compliance and resistance remain outstanding challenges. Drug discovery is on-going, and herein we review the recent advances in anti-trypanosomal drug discovery, including novel potential drug targets. The numerous challenges associated with disease eradication will also be addressed.
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Affiliation(s)
- Miebaka Jamabo
- Biotechnology Innovation Centre, Rhodes University, Makhanda 6139, South Africa; (M.J.); (M.M.)
| | - Maduma Mahlalela
- Biotechnology Innovation Centre, Rhodes University, Makhanda 6139, South Africa; (M.J.); (M.M.)
| | - Adrienne L. Edkins
- Department of Biochemistry and Microbiology, Biomedical Biotechnology Research Centre (BioBRU), Rhodes University, Makhanda 6139, South Africa;
| | - Aileen Boshoff
- Biotechnology Innovation Centre, Rhodes University, Makhanda 6139, South Africa; (M.J.); (M.M.)
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Discovery of novel Leishmania major trypanothione synthetase inhibitors by high-throughput screening. Biochem Biophys Res Commun 2022; 637:308-313. [DOI: 10.1016/j.bbrc.2022.11.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 11/15/2022] [Indexed: 11/18/2022]
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Ali V, Behera S, Nawaz A, Equbal A, Pandey K. Unique thiol metabolism in trypanosomatids: Redox homeostasis and drug resistance. ADVANCES IN PARASITOLOGY 2022; 117:75-155. [PMID: 35878950 DOI: 10.1016/bs.apar.2022.04.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Trypanosomatids are mainly responsible for heterogeneous parasitic diseases: Leishmaniasis, Sleeping sickness, and Chagas disease and control of these diseases implicates serious challenges due to the emergence of drug resistance. Redox-active biomolecules are the endogenous substances in organisms, which play important role in the regulation of redox homeostasis. The redox-active substances like glutathione, trypanothione, cysteine, cysteine persulfides, etc., and other inorganic intermediates (hydrogen peroxide, nitric oxide) are very useful as defence mechanism. In the present review, the suitability of trypanothione and other essential thiol molecules of trypanosomatids as drug targets are described in Leishmania and Trypanosoma. We have explored the role of tryparedoxin, tryparedoxin peroxidase, ascorbate peroxidase, superoxide dismutase, and glutaredoxins in the anti-oxidant mechanism and drug resistance. Up-regulation of some proteins in trypanothione metabolism helps the parasites in survival against drug pressure (sodium stibogluconate, Amphotericin B, etc.) and oxidative stress. These molecules accept electrons from the reduced trypanothione and donate their electrons to other proteins, and these proteins reduce toxic molecules, neutralize reactive oxygen, or nitrogen species; and help parasites to cope with oxidative stress. Thus, a better understanding of the role of these molecules in drug resistance and redox homeostasis will help to target metabolic pathway proteins to combat Leishmaniasis and trypanosomiases.
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Affiliation(s)
- Vahab Ali
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, ICMR-Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Patna, Bihar, India.
| | - Sachidananda Behera
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, ICMR-Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Patna, Bihar, India
| | - Afreen Nawaz
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, ICMR-Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Patna, Bihar, India
| | - Asif Equbal
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, ICMR-Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Patna, Bihar, India; Department of Botany, Araria College, Purnea University, Purnia, Bihar, India
| | - Krishna Pandey
- Department of Clinical Medicine, ICMR-Rajendra Memorial Research Institute of Medical Sciences (RMRIMS), Patna, Bihar, India
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Benítez D, Franco J, Sardi F, Leyva A, Durán R, Choi G, Yang G, Kim T, Kim N, Heo J, Kim K, Lee H, Choi I, Radu C, Shum D, No JH, Comini MA. Drug-like molecules with anti-trypanothione synthetase activity identified by high throughput screening. J Enzyme Inhib Med Chem 2022; 37:912-929. [PMID: 35306933 PMCID: PMC8942522 DOI: 10.1080/14756366.2022.2045590] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Trypanothione synthetase (TryS) catalyses the synthesis of N1,N8-bis(glutathionyl)spermidine (trypanothione), which is the main low molecular mass thiol supporting several redox functions in trypanosomatids. TryS attracts attention as molecular target for drug development against pathogens causing severe and fatal diseases in mammals. A drug discovery campaign aimed to identify and characterise new inhibitors of TryS with promising biological activity was conducted. A large compound library (n = 51,624), most of them bearing drug-like properties, was primarily screened against TryS from Trypanosoma brucei (TbTryS). With a true-hit rate of 0.056%, several of the TbTryS hits (IC50 from 1.2 to 36 µM) also targeted the homologue enzyme from Leishmania infantum and Trypanosoma cruzi (IC50 values from 2.6 to 40 µM). Calmidazolium chloride and Ebselen stand out for their multi-species anti-TryS activity at low µM concentrations (IC50 from 2.6 to 13.8 µM). The moieties carboxy piperidine amide and amide methyl thiazole phenyl were identified as novel TbTryS inhibitor scaffolds. Several of the TryS hits presented one-digit µM EC50 against T. cruzi and L. donovani amastigotes but proved cytotoxic against the human osteosarcoma and macrophage host cells (selectivity index ≤ 3). In contrast, seven hits showed a significantly higher selectivity against T. b. brucei (selectivity index from 11 to 182). Non-invasive redox assays confirmed that Ebselen, a multi-TryS inhibitor, induces an intracellular oxidative milieu in bloodstream T. b. brucei. Kinetic and mass spectrometry analysis revealed that Ebselen is a slow-binding inhibitor that modifies irreversible a highly conserved cysteine residue from the TryS’s synthetase domain. The most potent TbTryS inhibitor (a singleton containing an adamantine moiety) exerted a non-covalent, non-competitive (with any of the substrates) inhibition of the enzyme. These data feed the drug discovery pipeline for trypanosomatids with novel and valuable information on chemical entities with drug potential.
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Affiliation(s)
- Diego Benítez
- Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Jaime Franco
- Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Florencia Sardi
- Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Alejandro Leyva
- Analytical Biochemistry and Proteomics Unit, Institut Pasteur de Montevideo, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - Rosario Durán
- Analytical Biochemistry and Proteomics Unit, Institut Pasteur de Montevideo, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - Gahee Choi
- Host-Parasite Research Laboratory, Institut Pasteur Korea, Gyeonggi-do, Republic of Korea
| | - Gyongseon Yang
- Host-Parasite Research Laboratory, Institut Pasteur Korea, Gyeonggi-do, Republic of Korea
| | - Taehee Kim
- Assay Development and Screening, Institut Pasteur Korea, Gyeonggi-do, Republic of Korea
| | - Namyoul Kim
- Assay Development and Screening, Institut Pasteur Korea, Gyeonggi-do, Republic of Korea
| | - Jinyeong Heo
- Assay Development and Screening, Institut Pasteur Korea, Gyeonggi-do, Republic of Korea
| | - Kideok Kim
- Automation and Logistics Management, Institut Pasteur Korea, Gyeonggi-do, Republic of Korea
| | - Honggun Lee
- Automation and Logistics Management, Institut Pasteur Korea, Gyeonggi-do, Republic of Korea
| | - Inhee Choi
- Medicinal Chemistry, Institut Pasteur Korea, Gyeonggi-do, Republic of Korea
| | - Constantin Radu
- Automation and Logistics Management, Institut Pasteur Korea, Gyeonggi-do, Republic of Korea
| | - David Shum
- Assay Development and Screening, Institut Pasteur Korea, Gyeonggi-do, Republic of Korea
| | - Joo Hwan No
- Host-Parasite Research Laboratory, Institut Pasteur Korea, Gyeonggi-do, Republic of Korea
| | - Marcelo A Comini
- Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
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8
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Dibello E, Comini MA, Benítez D. A Simple, Robust, and Affordable Bioluminescent Assay for Drug Screening Against Infective African Trypanosomes. Methods Mol Biol 2022; 2524:149-162. [PMID: 35821469 DOI: 10.1007/978-1-0716-2453-1_11] [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] [Indexed: 06/15/2023]
Abstract
This chapter introduces a simple and robust in vitro viability assay to screen bioactive small molecules (e.g., natural, synthetic) against the monomorphic and infective (bloodstream) form of Trypanosoma brucei brucei. The assay relies on a bioluminescent transgenic parasite harboring a genetically encoded copy of a thermostable redshifted firefly luciferase from Photinus pyralis.The major advantages of the assay are simplicity and cost efficiency, along with excellent quality parameters. The bioassay allows estimating parasite numbers and viability (and metabolic state) as a function of bioluminescence (BL) signal. Parasites are grown in the presence of the molecules of interest in a 96-well microplate, and 24 h later, BL is determined with a simple protocol lacking washing steps, using cost-efficient reagents with a reasonable readout time for high-throughput applications.
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Affiliation(s)
- Estefania Dibello
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
- Laboratorio de Síntesis Orgánica, Departamento de Química Orgánica, Facultad de Química, Universidad de la República, Montevideo, Uruguay
| | - Marcelo A Comini
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay.
| | - Diego Benítez
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay.
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9
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Alice JI, Bellera CL, Benítez D, Comini MA, Duchowicz PR, Talevi A. Ensemble learning application to discover new trypanothione synthetase inhibitors. Mol Divers 2021; 25:1361-1373. [PMID: 34264440 DOI: 10.1007/s11030-021-10265-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 06/24/2021] [Indexed: 11/28/2022]
Abstract
Trypanosomatid-caused diseases are among the neglected infectious diseases with the highest disease burden, affecting about 27 million people worldwide and, in particular, socio-economically vulnerable populations. Trypanothione synthetase (TryS) is considered one of the most attractive drug targets within the thiol-polyamine metabolism of typanosomatids, being unique, essential and druggable. Here, we have compiled a dataset of 401 T. brucei TryS inhibitors that includes compounds with inhibitory data reported in the literature, but also in-house acquired data. QSAR classifiers were derived and validated from such dataset, using publicly available and open-source software, thus assuring the portability of the obtained models. The performance and robustness of the resulting models were substantially improved through ensemble learning. The performance of the individual models and the model ensembles was further assessed through retrospective virtual screening campaigns. At last, as an application example, the chosen model-ensemble has been applied in a prospective virtual screening campaign on DrugBank 5.1.6 compound library. All the in-house scripts used in this study are available on request, whereas the dataset has been included as supplementary material.
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Affiliation(s)
- Juan I Alice
- Laboratorio de Investigación y Desarrollo de Bioactivos (LIDeB), Facultad de Ciencias Exactas, Universidad Nacional de La Plata (UNLP), La Plata, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), CCT La Plata, La Plata, Argentina
| | - Carolina L Bellera
- Laboratorio de Investigación y Desarrollo de Bioactivos (LIDeB), Facultad de Ciencias Exactas, Universidad Nacional de La Plata (UNLP), La Plata, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), CCT La Plata, La Plata, Argentina
| | - Diego Benítez
- Group Redox Biology of Trypanosomes, Institut Pasteur Montevideo, Montevideo, Uruguay
| | - Marcelo A Comini
- Group Redox Biology of Trypanosomes, Institut Pasteur Montevideo, Montevideo, Uruguay
| | - Pablo R Duchowicz
- Facultad de Ciencias Exactas, Universidad Nacional de La Plata (UNLP)-Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), La Plata, Argentina
| | - Alan Talevi
- Laboratorio de Investigación y Desarrollo de Bioactivos (LIDeB), Facultad de Ciencias Exactas, Universidad Nacional de La Plata (UNLP), La Plata, Buenos Aires, Argentina. .,Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), CCT La Plata, La Plata, Argentina.
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10
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Ortíz C, Moraca F, Laverriere M, Jordan A, Hamilton N, Comini MA. Glucose 6-Phosphate Dehydrogenase from Trypanosomes: Selectivity for Steroids and Chemical Validation in Bloodstream Trypanosoma brucei. Molecules 2021; 26:E358. [PMID: 33445584 PMCID: PMC7826790 DOI: 10.3390/molecules26020358] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 01/07/2021] [Accepted: 01/09/2021] [Indexed: 11/17/2022] Open
Abstract
Glucose 6-phosphate dehydrogenase (G6PDH) fulfills an essential role in cell physiology by catalyzing the production of NADPH+ and of a precursor for the de novo synthesis of ribose 5-phosphate. In trypanosomatids, G6PDH is essential for in vitro proliferation, antioxidant defense and, thereby, drug resistance mechanisms. So far, 16α-brominated epiandrosterone represents the most potent hit targeting trypanosomal G6PDH. Here, we extended the investigations on this important drug target and its inhibition by using a small subset of androstane derivatives. In Trypanosoma cruzi, immunofluorescence revealed a cytoplasmic distribution of G6PDH and the absence of signal in major organelles. Cytochemical assays confirmed parasitic G6PDH as the molecular target of epiandrosterone. Structure-activity analysis for a set of new (dehydro)epiandrosterone derivatives revealed that bromination at position 16α of the cyclopentane moiety yielded more potent T. cruzi G6PDH inhibitors than the corresponding β-substituted analogues. For the 16α brominated compounds, the inclusion of an acetoxy group at position 3 either proved detrimental or enhanced the activity of the epiandrosterone or the dehydroepiandrosterone derivatives, respectively. Most derivatives presented single digit μM EC50 against infective T. brucei and the killing mechanism involved an early thiol-redox unbalance. This data suggests that infective African trypanosomes lack efficient NADPH+-synthesizing pathways, beyond the Pentose Phosphate, to maintain thiol-redox homeostasis.
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Affiliation(s)
- Cecilia Ortíz
- Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo 11400, Uruguay;
| | - Francesca Moraca
- Dipartimento di Biotecnologie, Chimica e Farmacia, Università degli Studi di Siena, Via Aldo Moro 2, 53100 Siena, Italy;
| | - Marc Laverriere
- Instituto de Investigaciones Biotecnológicas, Instituto Tecnológico de Chascomus (IIB-INTECH, UNSAM-CONICET), Av. General Paz 5445, INTI, San Martín 1650, Pcia de Buenos Aires, Argentina;
| | - Allan Jordan
- Drug Discovery Unit, Cancer Research UK Manchester Institute, University of Manchester, Alderley Park, Macclesfield SK10 4TG, UK; (A.J.); (N.H.)
| | - Niall Hamilton
- Drug Discovery Unit, Cancer Research UK Manchester Institute, University of Manchester, Alderley Park, Macclesfield SK10 4TG, UK; (A.J.); (N.H.)
| | - Marcelo A. Comini
- Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo 11400, Uruguay;
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11
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Piñeyro MD, Arias D, Parodi-Talice A, Guerrero S, Robello C. Trypanothione Metabolism as Drug Target for Trypanosomatids. Curr Pharm Des 2021; 27:1834-1846. [PMID: 33308115 DOI: 10.2174/1381612826666201211115329] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 10/01/2020] [Accepted: 10/08/2020] [Indexed: 11/22/2022]
Abstract
Chagas Disease, African sleeping sickness, and leishmaniasis are neglected diseases caused by pathogenic trypanosomatid parasites, which have a considerable impact on morbidity and mortality in poor countries. The available drugs used as treatment have high toxicity, limited access, and can cause parasite drug resistance. Long-term treatments, added to their high toxicity, result in patients that give up therapy. Trypanosomatids presents a unique trypanothione based redox system, which is responsible for maintaining the redox balance. Therefore, inhibition of these essential and exclusive parasite's metabolic pathways, absent from the mammalian host, could lead to the development of more efficient and safe drugs. The system contains different redox cascades, where trypanothione and tryparedoxins play together a central role in transferring reduced power to different enzymes, such as 2-Cys peroxiredoxins, non-selenium glutathione peroxidases, ascorbate peroxidases, glutaredoxins and methionine sulfoxide reductases, through NADPH as a source of electrons. There is sufficient evidence that this complex system is essential for parasite survival and infection. In this review, we explore what is known in terms of essentiality, kinetic and structural data, and the development of inhibitors of enzymes from this trypanothione-based redox system. The recent advances and limitations in the development of lead inhibitory compounds targeting these enzymes have been discussed. The combination of molecular biology, bioinformatics, genomics, and structural biology is fundamental since the knowledge of unique features of the trypanothione-dependent system will provide tools for rational drug design in order to develop better treatments for these diseases.
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Affiliation(s)
| | - Diego Arias
- Instituto de Agrobiotecnologia del Litoral y Facultad de Bioquimica y Ciencias Biologicas, CONICET-UNL, Santa F, Argentina
| | | | - Sergio Guerrero
- Instituto de Agrobiotecnologia del Litoral y Facultad de Bioquimica y Ciencias Biologicas, CONICET-UNL, Santa F, Argentina
| | - Carlos Robello
- Unidad de Biologia Molecular, Instituto Pasteur Montevideo, Montevideo, Uruguay
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12
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Medeiros A, Benítez D, Korn RS, Ferreira VC, Barrera E, Carrión F, Pritsch O, Pantano S, Kunick C, de Oliveira CI, Orban OCF, Comini MA. Mechanistic and biological characterisation of novel N5-substituted paullones targeting the biosynthesis of trypanothione in Leishmania. J Enzyme Inhib Med Chem 2020; 35:1345-1358. [PMID: 32588679 PMCID: PMC7717452 DOI: 10.1080/14756366.2020.1780227] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Trypanothione synthetase (TryS) produces N1,N8-bis(glutathionyl)spermidine (or trypanothione) at the expense of ATP. Trypanothione is a metabolite unique and essential for survival and drug-resistance of trypanosomatid parasites. In this study, we report the mechanistic and biological characterisation of optimised N5-substituted paullone analogues with anti-TryS activity. Several of the new derivatives retained submicromolar IC50 against leishmanial TryS. The binding mode to TryS of the most potent paullones has been revealed by means of kinetic, biophysical and molecular modelling approaches. A subset of analogues showed an improved potency (EC50 0.5–10 µM) and selectivity (20–35) against the clinically relevant stage of Leishmania braziliensis (mucocutaneous leishmaniasis) and L. infantum (visceral leishmaniasis). For a selected derivative, the mode of action involved intracellular depletion of trypanothione. Our findings shed light on the molecular interaction of TryS with rationally designed inhibitors and disclose a new set of compounds with on-target activity against different Leishmania species.
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Affiliation(s)
- Andrea Medeiros
- Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay.,Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Diego Benítez
- Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Ricarda S Korn
- Institut für Medizinische und Pharmazeutische Chemie, Technische Universität Braunschweig, Braunschweig, Germany
| | | | - Exequiel Barrera
- Biomolecular Simulations Group, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Federico Carrión
- Protein Biophysics Unit, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Otto Pritsch
- Protein Biophysics Unit, Institut Pasteur de Montevideo, Montevideo, Uruguay.,Departamento de Inmunobiología, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Sergio Pantano
- Biomolecular Simulations Group, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Conrad Kunick
- Institut für Medizinische und Pharmazeutische Chemie, Technische Universität Braunschweig, Braunschweig, Germany
| | | | - Oliver C F Orban
- Institut für Medizinische und Pharmazeutische Chemie, Technische Universität Braunschweig, Braunschweig, Germany
| | - Marcelo A Comini
- Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
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13
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Ebersoll S, Bogacz M, Günter LM, Dick TP, Krauth-Siegel RL. A tryparedoxin-coupled biosensor reveals a mitochondrial trypanothione metabolism in trypanosomes. eLife 2020; 9:53227. [PMID: 32003744 PMCID: PMC7046469 DOI: 10.7554/elife.53227] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 01/29/2020] [Indexed: 12/12/2022] Open
Abstract
Trypanosomes have a trypanothione redox metabolism that provides the reducing equivalents for numerous essential processes, most being mediated by tryparedoxin (Tpx). While the biosynthesis and reduction of trypanothione are cytosolic, the molecular basis of the thiol redox homeostasis in the single mitochondrion of these parasites has remained largely unknown. Here we expressed Tpx-roGFP2, roGFP2-hGrx1 or roGFP2 in either the cytosol or mitochondrion of Trypanosoma brucei. We show that the novel Tpx-roGFP2 is a superior probe for the trypanothione redox couple and that the mitochondrial matrix harbors a trypanothione system. Inhibition of trypanothione biosynthesis by the anti-trypanosomal drug Eflornithine impairs the ability of the cytosol and mitochondrion to cope with exogenous oxidative stresses, indicating a direct link between both thiol systems. Tpx depletion abolishes the cytosolic, but only partially affects the mitochondrial sensor response to H2O2. This strongly suggests that the mitochondrion harbors some Tpx and, another, as yet unidentified, oxidoreductase.
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Affiliation(s)
| | - Marta Bogacz
- Biochemie-Zentrum der Universität Heidelberg, Heidelberg, Germany
| | - Lina M Günter
- Biochemie-Zentrum der Universität Heidelberg, Heidelberg, Germany
| | - Tobias P Dick
- Division of Redox Regulation, DKFZ-ZMBH Alliance, German Cancer Research Center (DKFZ), Heidelberg, Germany
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14
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Benítez D, Dibello E, Bonilla M, Comini MA. A simple, robust, and affordable bioluminescent assay for drug discovery against infective African trypanosomes. Drug Dev Res 2020; 83:253-263. [PMID: 31958156 DOI: 10.1002/ddr.21634] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 11/28/2019] [Accepted: 12/17/2019] [Indexed: 12/22/2022]
Abstract
African trypanosomiasis is a major problem for human and animal health in endemic countries, where it threatens millions of people and affects economic development. New drugs are needed to overcome the toxicity, administration, low efficacy, and resistance issues of the current chemotherapy. Robust, simple, and economical high-throughput, whole-cell-based assays are required to accelerate the identification of novel chemical entities. With this aim, we generated a bioluminescent cell line of the bloodstream stage of Trypanosoma brucei brucei and established a screening assay. Trypanosomes were stably transfected to constitutively express a thermostable red-shifted luciferase. The growth phenotype and drug sensitivity of the reporter cell line were essentially identical to that of the parental cell line. The endogenous luciferase activity, measured by a simple bioluminescence assay, proved to be proportional to parasite number and metabolic status. The assay, optimized to detect highly potent compounds in a 96-well-plate format, was validated by screening a small compound library (inter-assay values for Z' factor and coefficient variation were 0.77 and 5.8%, respectively). With a hit-confirmation ratio of ~97%, the assay was potent enough to identify several hits with EC50 ≤ 10 μM. Preliminary tests indicated that the assay can be scaled up to a 384-well-plate format without compromising its robustness. In summary, we have generated reporter trypanosomes and a simple, robust, and affordable bioluminescence screening assay with great potential to speed up the early-phase drug discovery against African trypanosomes.
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Affiliation(s)
- Diego Benítez
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Estefania Dibello
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay.,Laboratorio de Síntesis Orgánica, Departamento de Química Orgánica, Facultad de Química, Universidad de la República, Montevideo, Uruguay
| | - Mariana Bonilla
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay.,Laboratorio de Fisicoquímica Biológica y Laboratorio de Enzimología, Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Marcelo A Comini
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
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15
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Talevi A, Carrillo C, Comini M. The Thiol-polyamine Metabolism of Trypanosoma cruzi: Molecular Targets and Drug Repurposing Strategies. Curr Med Chem 2019; 26:6614-6635. [PMID: 30259812 DOI: 10.2174/0929867325666180926151059] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 07/23/2018] [Accepted: 09/10/2018] [Indexed: 12/18/2022]
Abstract
Chagas´ disease continues to be a challenging and neglected public health problem in many American countries. The etiologic agent, Trypanosoma cruzi, develops intracellularly in the mammalian host, which hinders treatment efficacy. Progress in the knowledge of parasite biology and host-pathogen interaction has not been paralleled by the development of novel, safe and effective therapeutic options. It is then urgent to seek for novel therapeutic candidates and to implement drug discovery strategies that may accelerate the discovery process. The most appealing targets for pharmacological intervention are those essential for the pathogen and, whenever possible, absent or significantly different from the host homolog. The thiol-polyamine metabolism of T. cruzi offers interesting candidates for a rational design of selective drugs. In this respect, here we critically review the state of the art of the thiolpolyamine metabolism of T. cruzi and the pharmacological potential of its components. On the other hand, drug repurposing emerged as a valid strategy to identify new biological activities for drugs in clinical use, while significantly shortening the long time and high cost associated with de novo drug discovery approaches. Thus, we also discuss the different drug repurposing strategies available with a special emphasis in their applications to the identification of drug candidates targeting essential components of the thiol-polyamine metabolism of T. cruzi.
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Affiliation(s)
- Alan Talevi
- Medicinal Chemistry, Department of Biological Sciences, Faculty of Exact Sciences, University of La Plata, La Plata, Argentina
| | - Carolina Carrillo
- Instituto de Ciencias y Tecnología Dr. César Milstein (ICT Milstein) - CONICET. Ciudad Autónoma de Buenos Aires, Argentina
| | - Marcelo Comini
- Institut Pasteur de Montevideo, Mataojo 2020, Montevideo 11400, Uruguay
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16
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Rub A, Shaker K, Kashif M, Arish M, Dukhyil AAB, Alshehri BM, Alaidarous MA, Banawas S, Amir K. Repurposing Glyburide as Antileishmanial Agent to Fight Against Leishmaniasis. Protein Pept Lett 2019; 26:371-376. [PMID: 30827222 DOI: 10.2174/0929866526666190301114012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 02/06/2019] [Accepted: 02/13/2019] [Indexed: 02/07/2023]
Abstract
BACKGROUND Leishmaniasis is caused by a protozoan parasite, Leishmania. It is common in more than 98 countries throughout the world. Due to insufficient availability of antileishmanial chemotherapeutics, it is an urgent need to search for new molecules which have better efficacy, low toxicity and are available at low cost. OBJECTIVES There is a high rate of diabetic cases throughout the world that is why we planned to test the antileishmanial activity of glyburide, an effective sugar lowering drug used for the treatment of diabetes. In this study, glyburide showed a significant decrease in the parasite growth and survival in vitro in a dose-dependent manner. METHODS Anti-leishmanial activity of glyburide was checked by culturing Leishmania donovani promastigotes in the presence of glyburide in a dose and time dependent manner. Docking study against Leishmania donovani-Trypanothione synthetase (LdTrySyn) protein was performed using Autodock Vina tool. RESULTS Growth reversibility assay shows that growth of treated parasite was not reversed when transferred to fresh culture media after 7 days. Moreover, docking studies show efficient interactions of glyburide with key residues in the catalytic site of Leishmania donovani- Trypanothione synthetase (LdTrySyn), a very important leishmanial enzyme involved in parasite's survival by detoxification of Nitric Oxide (NO) species, generated by the mammalian host as a defense molecule. Thus this study proves that the drug-repurposing is a beneficial strategy for identification of new and potent antileishmanial molecules. CONCLUSION The results suggest that glyburide binds to LdTrySyn and inhibits its activity which further leads to the altered parasite morphology and inhibition of parasite growth. Glyburide may also be used in combination with other anti-leishmanial drugs to potentiate the response of the chemotherapy. Overall this study provides information about combination therapy as well as a single drug treatment for the infected patients suffering from diabetes. This study also provides raw information for further in vivo disease model studies to confirm the hypothesis.
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Affiliation(s)
- Abdur Rub
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Majmaah University, Al Majmaah 11952, Saudi Arabia.,Infection and Immunity Lab, Department of Biotechnology, Jamia Millia Islamia (A Central University), New Delhi 110025, India
| | - Kamal Shaker
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Majmaah University, Al Majmaah 11952, Saudi Arabia
| | - Mohammad Kashif
- Infection and Immunity Lab, Department of Biotechnology, Jamia Millia Islamia (A Central University), New Delhi 110025, India
| | - Mohd Arish
- Infection and Immunity Lab, Department of Biotechnology, Jamia Millia Islamia (A Central University), New Delhi 110025, India
| | - Abdul Aziz Bin Dukhyil
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Majmaah University, Al Majmaah 11952, Saudi Arabia
| | - Bader Mohammed Alshehri
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Majmaah University, Al Majmaah 11952, Saudi Arabia
| | - Mohammed A Alaidarous
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Majmaah University, Al Majmaah 11952, Saudi Arabia
| | - Saeed Banawas
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Majmaah University, Al Majmaah 11952, Saudi Arabia
| | - Khwaja Amir
- Department of Basic Medical Sciences, College of Medicine, Majmaah University, Al Majmaah 11952, Saudi Arabia
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17
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Currier RB, Ulrich K, Leroux AE, Dirdjaja N, Deambrosi M, Bonilla M, Ahmed YL, Adrian L, Antelmann H, Jakob U, Comini MA, Krauth-Siegel RL. An essential thioredoxin-type protein of Trypanosoma brucei acts as redox-regulated mitochondrial chaperone. PLoS Pathog 2019; 15:e1008065. [PMID: 31557263 PMCID: PMC6783113 DOI: 10.1371/journal.ppat.1008065] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 10/08/2019] [Accepted: 09/02/2019] [Indexed: 12/22/2022] Open
Abstract
Most known thioredoxin-type proteins (Trx) participate in redox pathways, using two highly conserved cysteine residues to catalyze thiol-disulfide exchange reactions. Here we demonstrate that the so far unexplored Trx2 from African trypanosomes (Trypanosoma brucei) lacks protein disulfide reductase activity but functions as an effective temperature-activated and redox-regulated chaperone. Immunofluorescence microscopy and fractionated cell lysis revealed that Trx2 is located in the mitochondrion of the parasite. RNA-interference and gene knock-out approaches showed that depletion of Trx2 impairs growth of both mammalian bloodstream and insect stage procyclic parasites. Procyclic cells lacking Trx2 stop proliferation under standard culture conditions at 27°C and are unable to survive prolonged exposure to 37°C, indicating that Trx2 plays a vital role that becomes augmented under heat stress. Moreover, we found that Trx2 contributes to the in vivo infectivity of T. brucei. Remarkably, a Trx2 version, in which all five cysteines were replaced by serine residues, complements for the wildtype protein in conditional knock-out cells and confers parasite infectivity in the mouse model. Characterization of the recombinant protein revealed that Trx2 can coordinate an iron sulfur cluster and is highly sensitive towards spontaneous oxidation. Moreover, we discovered that both wildtype and mutant Trx2 protect other proteins against thermal aggregation and preserve their ability to refold upon return to non-stress conditions. Activation of the chaperone function of Trx2 appears to be triggered by temperature-mediated structural changes and inhibited by oxidative disulfide bond formation. Our studies indicate that Trx2 acts as a novel chaperone in the unique single mitochondrion of T. brucei and reveal a new perspective regarding the physiological function of thioredoxin-type proteins in trypanosomes.
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Affiliation(s)
- Rachel B. Currier
- Biochemie-Zentrum der Universität Heidelberg (BZH), Heidelberg, Germany
| | - Kathrin Ulrich
- Biochemie-Zentrum der Universität Heidelberg (BZH), Heidelberg, Germany
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | | | - Natalie Dirdjaja
- Biochemie-Zentrum der Universität Heidelberg (BZH), Heidelberg, Germany
| | - Matías Deambrosi
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Mariana Bonilla
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
- Laboratorio de Fisicoquímica Biológica, Instituto de Química Biológica, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | | | - Lorenz Adrian
- Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research–UFZ, Leipzig, Germany
- Fachgebiet Geobiotechnologie, Technische Universität Berlin, Berlin, Germany
| | - Haike Antelmann
- Institut für Biologie-Mikrobiologie, Freie Universität Berlin, Berlin, Germany
| | - Ursula Jakob
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Marcelo A. Comini
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
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18
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Ulrich K, Jakob U. The role of thiols in antioxidant systems. Free Radic Biol Med 2019; 140:14-27. [PMID: 31201851 PMCID: PMC7041647 DOI: 10.1016/j.freeradbiomed.2019.05.035] [Citation(s) in RCA: 223] [Impact Index Per Article: 44.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 04/04/2019] [Accepted: 05/31/2019] [Indexed: 02/07/2023]
Abstract
The sulfur biochemistry of the thiol group endows cysteines with a number of highly specialized and unique features that enable them to serve a variety of different functions in the cell. Typically highly conserved in proteins, cysteines are predominantly found in functionally or structurally crucial regions, where they act as stabilizing, catalytic, metal-binding and/or redox-regulatory entities. As highly abundant low molecular weight thiols, cysteine thiols and their oxidized disulfide counterparts are carefully balanced to maintain redox homeostasis in various cellular compartments, protect organisms from oxidative and xenobiotic stressors and partake actively in redox-regulatory and signaling processes. In this review, we will discuss the role of protein thiols as scavengers of hydrogen peroxide in antioxidant enzymes, use thiol peroxidases to exemplify how protein thiols contribute to redox signaling, provide an overview over the diverse set of low molecular weight thiol-based redox systems found in biology, and illustrate how thiol-based redox systems have evolved not only to protect against but to take full advantage of a world full of molecular oxygen.
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Affiliation(s)
- Kathrin Ulrich
- Department of Molecular, Cellular, and Developmental Biology, University of Michgan, Ann Arbor, MI, 48109, USA
| | - Ursula Jakob
- Department of Molecular, Cellular, and Developmental Biology, University of Michgan, Ann Arbor, MI, 48109, USA; Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, 48109, USA.
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19
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Osorio-Méndez JF, Cevallos AM. Discovery and Genetic Validation of Chemotherapeutic Targets for Chagas' Disease. Front Cell Infect Microbiol 2019; 8:439. [PMID: 30666299 PMCID: PMC6330712 DOI: 10.3389/fcimb.2018.00439] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Accepted: 12/10/2018] [Indexed: 01/06/2023] Open
Abstract
There is an urgent need to develop new treatments for Chagas' disease. To identify drug targets, it is important to understand the basic biology of Trypanosoma cruzi, in particular with respect to the biological pathways or proteins that are essential for its survival within the host. This review provides a streamlined approach for identifying drug targets using freely available chemogenetic databases and outlines the relevant characteristics of an ideal chemotherapeutic target. Among those are their essentiality, druggability, availability of structural information, and selectivity. At the moment only 16 genes have been found as essential by gene disruption in T. cruzi. At the TDR Targets database, a chemogenomics resource for neglected diseases, information about published structures for these genes was only found for three of these genes, and annotation of validated inhibitors was found in two. These inhibitors have activity against the parasitic stages present in the host. We then analyzed three of the pathways that are considered promising in the search for new targets: (1) Ergosterol biosynthesis, (2) Resistance to oxidative stress, (3) Synthesis of surface glycoconjugates. We have annotated all the genes that participate in them, identified those that are considered as druggable, and incorporated evidence from either Trypanosoma brucei, and Leishmania spp. that supports the hypothesis that these pathways are essential for T. cruzi survival.
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Affiliation(s)
- Juan Felipe Osorio-Méndez
- Laboratorio de Microbiología y Biología Molecular, Programa de Medicina, Corporación Universitaria Empresarial Alexander von Humboldt, Armenia, Colombia.,Grupo de Estudio en Parasitología Molecular, Centro de Investigaciones Biomédicas, Universidad del Quindío, Armenia, Colombia
| | - Ana María Cevallos
- Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
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20
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Mesías AC, Sasoni N, Arias DG, Pérez Brandán C, Orban OCF, Kunick C, Robello C, Comini MA, Garg NJ, Zago MP. Trypanothione synthetase confers growth, survival advantage and resistance to anti-protozoal drugs in Trypanosoma cruzi. Free Radic Biol Med 2019; 130:23-34. [PMID: 30359758 PMCID: PMC6331241 DOI: 10.1016/j.freeradbiomed.2018.10.436] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 10/09/2018] [Accepted: 10/20/2018] [Indexed: 01/29/2023]
Abstract
BACKGROUND Chagas cardiomyopathy, caused by Trypanosoma cruzi infection, continues to be a neglected illness, and has a major impact on global health. The parasite undergoes several stages of morphological and biochemical changes during its life cycle, and utilizes an elaborated antioxidant network to overcome the oxidants barrier and establish infection in vector and mammalian hosts. Trypanothione synthetase (TryS) catalyzes the biosynthesis of glutathione-spermidine adduct trypanothione (T(SH)2) that is the principal intracellular thiol-redox metabolite in trypanosomatids. METHODS AND RESULTS We utilized genetic overexpression (TryShi) and pharmacological inhibition approaches to examine the role of TryS in T. cruzi proliferation, tolerance to oxidative stress and resistance to anti-protozoal drugs. Our data showed the expression and activity of TryS was increased in all morphological stages of TryShi (vs. control) parasites. In comparison to controls, the TryShi epimastigotes (insect stage) recorded shorter doubling time, and both epimastigotes and infective trypomastigotes of TryShi exhibited 36-71% higher resistance to H2O2 (50-1000 μM) and heavy metal (1-500 μM) toxicity. Treatment with TryS inhibitors (5-30 μM) abolished the proliferation and survival advantages against H2O2 pressure in a dose-dependent manner in both TryShi and control parasites. Further, epimastigote and trypomastigote forms of TryShi (vs. control) T. cruzi tolerated higher doses of benznidazole and nifurtimox, the drugs currently administered for acute Chagas disease treatment. CONCLUSIONS TryS is essential for proliferation and survival of T. cruzi under normal and oxidant stress conditions, and provides an advantage to the parasite to develop resistance against currently used anti-trypanosomal drugs. TryS indispensability has been chemically validated with inhibitors that may be useful for drug combination therapy against Chagas disease.
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Affiliation(s)
- Andrea C Mesías
- Instituto de Patología Experimental, Universidad Nacional de Salta - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Salta, Argentina
| | - Natalia Sasoni
- Instituto de Agrobiotecnología del Litoral, Universidad Nacional del Litoral - CONICET, Santa Fe, Argentina
| | - Diego G Arias
- Instituto de Agrobiotecnología del Litoral, Universidad Nacional del Litoral - CONICET, Santa Fe, Argentina
| | - Cecilia Pérez Brandán
- Instituto de Patología Experimental, Universidad Nacional de Salta - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Salta, Argentina
| | - Oliver C F Orban
- Technische Universität Braunschweig, Institut für Medizinische und Pharmazeutische Chemie, Beethovenstraße 55, D-38106 Braunschweig, Germany
| | - Conrad Kunick
- Technische Universität Braunschweig, Institut für Medizinische und Pharmazeutische Chemie, Beethovenstraße 55, D-38106 Braunschweig, Germany
| | - Carlos Robello
- Unidad de Biología Molecular, Institut Pasteur de Montevideo, and Departamento de Bioquímica, Facultad de Medicina, Uruguay
| | - Marcelo A Comini
- Redox Biology of Trypanosomes - Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Nisha J Garg
- Departments of Microbiology and Immunology and Pathology, Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, USA.
| | - M Paola Zago
- Instituto de Patología Experimental, Universidad Nacional de Salta - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Salta, Argentina.
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21
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Manta B, Bonilla M, Fiestas L, Sturlese M, Salinas G, Bellanda M, Comini MA. Polyamine-Based Thiols in Trypanosomatids: Evolution, Protein Structural Adaptations, and Biological Functions. Antioxid Redox Signal 2018; 28:463-486. [PMID: 29048199 DOI: 10.1089/ars.2017.7133] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
SIGNIFICANCE Major pathogenic enterobacteria and protozoan parasites from the phylum Euglenozoa, such as trypanosomatids, are endowed with glutathione (GSH)-spermidine (Sp) derivatives that play important roles in signaling and metal and thiol-redox homeostasis. For some Euglenozoa lineages, the GSH-Sp conjugates represent the main redox cosubstrates around which entire new redox systems have evolved. Several proteins underwent molecular adaptations to synthesize and utilize the new polyamine-based thiols. Recent Advances: The genomes of closely related organisms have recently been sequenced, which allows mining and analysis of gene sequences that belong to these peculiar redox systems. Similarly, the three-dimensional structures of several of these proteins have been solved, which allows for comparison with their counterparts in classical redox systems that rely on GSH/glutaredoxin and thioredoxin. CRITICAL ISSUES The evolutionary and structural aspects related to the emergence and use of GSH-Sp conjugates in Euglenozoa are reviewed focusing on unique structural specializations that proteins developed to use N1,N8-bisglutathionylspermidine (trypanothione) as redox cosubstrate. An updated overview on the biochemical and biological significance of the major enzymatic activities is also provided. FUTURE DIRECTIONS A thiol-redox system strictly dependent on trypanothione is a feature unique to trypanosomatids. The physicochemical properties of the polyamine-GSH conjugates were a major driving force for structural adaptation of proteins that use these thiols as ligand and redox cofactor. In fact, the structural differences of indispensable components of this system can be exploited toward selective drug development. Future research should clarify whether additional cellular processes are regulated by the trypanothione system. Antioxid. Redox Signal. 28, 463-486.
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Affiliation(s)
- Bruno Manta
- 1 Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo , Montevideo, Uruguay .,2 Laboratorio de Fisicoquímica Biológica, Instituto de Química Biológica , Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Mariana Bonilla
- 1 Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo , Montevideo, Uruguay .,2 Laboratorio de Fisicoquímica Biológica, Instituto de Química Biológica , Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
| | - Lucía Fiestas
- 1 Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo , Montevideo, Uruguay
| | - Mattia Sturlese
- 3 Department of Chemical Sciences, Università degli Studi di Padova , Padova, Italy
| | - Gustavo Salinas
- 4 Worm Biology Lab, Institut Pasteur de Montevideo , Montevideo, Uruguay .,5 Departamento de Biociencias, Facultad de Química, Universidad de la República , Montevideo, Uruguay
| | - Massimo Bellanda
- 3 Department of Chemical Sciences, Università degli Studi di Padova , Padova, Italy
| | - Marcelo A Comini
- 1 Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo , Montevideo, Uruguay
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Franco J, Scarone L, Comini MA. Drugs and Drug Resistance in African and American Trypanosomiasis. ANNUAL REPORTS IN MEDICINAL CHEMISTRY 2018. [DOI: 10.1016/bs.armc.2018.08.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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23
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Polyamine-based analogs and conjugates as antikinetoplastid agents. Eur J Med Chem 2017; 139:982-1015. [DOI: 10.1016/j.ejmech.2017.08.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 07/24/2017] [Accepted: 08/04/2017] [Indexed: 12/12/2022]
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Ulrich K, Finkenzeller C, Merker S, Rojas F, Matthews K, Ruppert T, Krauth-Siegel RL. Stress-Induced Protein S-Glutathionylation and S-Trypanothionylation in African Trypanosomes-A Quantitative Redox Proteome and Thiol Analysis. Antioxid Redox Signal 2017; 27:517-533. [PMID: 28338335 PMCID: PMC5567454 DOI: 10.1089/ars.2016.6947] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
AIMS Trypanosomatids have a unique trypanothione-based thiol redox metabolism. The parasite-specific dithiol is synthesized from glutathione and spermidine, with glutathionylspermidine as intermediate catalyzed by trypanothione synthetase. In this study, we address the oxidative stress response of African trypanosomes with special focus on putative protein S-thiolation. RESULTS Challenging bloodstream Trypanosoma brucei with diamide, H2O2 or hypochlorite results in distinct levels of reversible overall protein S-thiolation. Quantitative proteome analyses reveal 84 proteins oxidized in diamide-stressed parasites. Fourteen of them, including several essential thiol redox proteins and chaperones, are also enriched when glutathione/glutaredoxin serves as a reducing system indicating S-thiolation. In parasites exposed to H2O2, other sets of proteins are modified. Only three proteins are S-thiolated under all stress conditions studied in accordance with a highly specific response. H2O2 causes primarily the formation of free disulfides. In contrast, in diamide-treated cells, glutathione, glutathionylspermidine, and trypanothione are almost completely protein bound. Remarkably, the total level of trypanothione is decreased, whereas those of glutathione and glutathionylspermidine are increased, indicating partial hydrolysis of protein-bound trypanothione. Depletion of trypanothione synthetase exclusively induces protein S-glutathionylation. Total mass analyses of a recombinant peroxidase treated with T(SH)2 and either diamide or hydrogen peroxide verify protein S-trypanothionylation as stable modification. INNOVATION Our data reveal for the first time that trypanosomes employ protein S-thiolation when exposed to exogenous and endogenous oxidative stresses and trypanothione, despite its dithiol character, forms protein-mixed disulfides. CONCLUSION The stress-specific responses shown here emphasize protein S-trypanothionylation and S-glutathionylation as reversible protection mechanism in these parasites. Antioxid. Redox Signal. 27, 517-533.
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Affiliation(s)
- Kathrin Ulrich
- 1 Biochemie-Zentrum der Universität Heidelberg (BZH) , Heidelberg, Germany
| | | | - Sabine Merker
- 2 Zentrum für Molekularbiologie der Universität Heidelberg (ZMBH) , Heidelberg, Germany
| | - Federico Rojas
- 3 Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh , Edinburgh, United Kingdom
| | - Keith Matthews
- 3 Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh , Edinburgh, United Kingdom
| | - Thomas Ruppert
- 2 Zentrum für Molekularbiologie der Universität Heidelberg (ZMBH) , Heidelberg, Germany
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Previti S, Ettari R, Cosconati S, Amendola G, Chouchene K, Wagner A, Hellmich UA, Ulrich K, Krauth-Siegel RL, Wich PR, Schmid I, Schirmeister T, Gut J, Rosenthal PJ, Grasso S, Zappalà M. Development of Novel Peptide-Based Michael Acceptors Targeting Rhodesain and Falcipain-2 for the Treatment of Neglected Tropical Diseases (NTDs). J Med Chem 2017; 60:6911-6923. [PMID: 28763614 DOI: 10.1021/acs.jmedchem.7b00405] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
This paper describes the development of a class of peptide-based inhibitors as novel antitrypanosomal and antimalarial agents. The inhibitors are based on a characteristic peptide sequence for the inhibition of the cysteine proteases rhodesain of Trypanosoma brucei rhodesiense and falcipain-2 of Plasmodium falciparum. We exploited the reactivity of novel unsaturated electrophilic functions such as vinyl-sulfones, -ketones, -esters, and -nitriles. The Michael acceptors inhibited both rhodesain and falcipain-2, at nanomolar and micromolar levels, respectively. In particular, the vinyl ketone 3b has emerged as a potent rhodesain inhibitor (k2nd = 67 × 106 M-1 min-1), endowed with a picomolar binding affinity (Ki = 38 pM), coupled with a single-digit micromolar activity against Trypanosoma brucei brucei (EC50 = 2.97 μM), thus being considered as a novel lead compound for the discovery of novel effective antitrypanosomal agents.
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Affiliation(s)
- Santo Previti
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina , Viale Annunziata, 98168 Messina, Italy
| | - Roberta Ettari
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina , Viale Annunziata, 98168 Messina, Italy
| | - Sandro Cosconati
- DiSTABiF, University of Campania Luigi Vanvitelli , Via Vivaldi 43, 81100 Caserta, Italy
| | - Giorgio Amendola
- DiSTABiF, University of Campania Luigi Vanvitelli , Via Vivaldi 43, 81100 Caserta, Italy
| | - Khawla Chouchene
- Laboratoire de Chimie des Substances Naturelles UR/11-ES-74, Faculté des Sciences de Sfax, Université de Sfax , Route de l'aeroport, 3000 Sfax, Tunisia
| | - Annika Wagner
- Institute of Pharmacy and Biochemistry, University of Mainz , Johann-Joachim-Becherweg 30, DE 55128 Mainz, Germany.,Centre for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt , Max-von-Laue-Strasse 9, DE 60438 Frankfurt am Main, Germany
| | - Ute A Hellmich
- Institute of Pharmacy and Biochemistry, University of Mainz , Johann-Joachim-Becherweg 30, DE 55128 Mainz, Germany.,Centre for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt , Max-von-Laue-Strasse 9, DE 60438 Frankfurt am Main, Germany
| | - Kathrin Ulrich
- Biochemistry Center, Heidelberg University , Im Neuenheimer Feld 328, DE 69120 Heidelberg, Germany
| | - R Luise Krauth-Siegel
- Biochemistry Center, Heidelberg University , Im Neuenheimer Feld 328, DE 69120 Heidelberg, Germany
| | - Peter R Wich
- Institute of Pharmacy and Biochemistry, University of Mainz , Staudingerweg 5, DE 55128 Mainz, Germany
| | - Ira Schmid
- Institute of Pharmacy and Biochemistry, University of Mainz , Staudingerweg 5, DE 55128 Mainz, Germany
| | - Tanja Schirmeister
- Institute of Pharmacy and Biochemistry, University of Mainz , Staudingerweg 5, DE 55128 Mainz, Germany
| | - Jiri Gut
- Department of Medicine, San Francisco General Hospital, University of California , 1001 Potrero Avenue, San Francisco, California 94110, United States
| | - Philip J Rosenthal
- Department of Medicine, San Francisco General Hospital, University of California , 1001 Potrero Avenue, San Francisco, California 94110, United States
| | - Silvana Grasso
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina , Viale Annunziata, 98168 Messina, Italy
| | - Maria Zappalà
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina , Viale Annunziata, 98168 Messina, Italy
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Singh K, Ali V, Pratap Singh K, Gupta P, Suman SS, Ghosh AK, Bimal S, Pandey K, Das P. Deciphering the interplay between cysteine synthase and thiol cascade proteins in modulating Amphotericin B resistance and survival of Leishmania donovani under oxidative stress. Redox Biol 2017; 12:350-366. [PMID: 28288415 PMCID: PMC5349463 DOI: 10.1016/j.redox.2017.03.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 03/03/2017] [Indexed: 12/13/2022] Open
Abstract
Leishmania donovani is the causative organism of the neglected human disease known as visceral leishmaniasis which is often fatal, if left untreated. The cysteine biosynthesis pathway of Leishmania may serve as a potential drug target because it is different from human host and regulates downstream components of redox metabolism of the parasites; essential for their survival, pathogenicity and drug resistance. However, despite the apparent dependency of redox metabolism of cysteine biosynthesis pathway, the role of L. donovani cysteine synthase (LdCS) in drug resistance and redox homeostasis has been unexplored. Herein, we report that over-expression of LdCS in Amphotericin B (Amp B) sensitive strain (S1-OE) modulates resistance towards oxidative stress and drug pressure. We observed that antioxidant enzyme activities were up-regulated in S1-OE parasites and these parasites alleviate intracellular reactive oxygen species (ROS) efficiently by maintaining the reduced thiol pool. In contrast to S1-OE parasites, Amp B sensitive strain (S1) showed higher levels of ROS which was positively correlated with the protein carbonylation levels and negatively correlated with cell viability. Moreover, further investigations showed that LdCS over-expression also augments the ROS-primed induction of LdCS-GFP as well as endogenous LdCS and thiol pathway proteins (LdTryS, LdTryR and LdcTXN) in L. donovani parasites; which probably aids in stress tolerance and drug resistance. In addition, the expression of LdCS was found to be up-regulated in Amp B resistant isolates and during infective stationary stages of growth and consistent with these observations, our ex vivo infectivity studies confirmed that LdCS over-expression enhances the infectivity of L. donovani parasites. Our results reveal a novel crosstalk between LdCS and thiol metabolic pathway proteins and demonstrate the crucial role of LdCS in drug resistance and redox homeostasis of Leishmania. Over-expression of CS in L. donovani modulates oxidative stress & Amp B resistance. Over-expressing parasite possess higher thiol to counteract the oxidative stress. Over-expressing parasites showed increased activity of TXNPx, GST, SOD, and APx. Expression/activity of LdCS is up-regulated in Amp B resistant clinical isolates. Ex vivo results confirm that LdCS over-expression enhance the parasites infectivity. Over-expressing parasites survived long time under oxidative stress conditions.
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Affiliation(s)
- Kuljit Singh
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna 800007, India; Department of Biotechnology, National Institute of Pharmaceutical Education and Research, EPIP Complex, Hajipur 844102, India
| | - Vahab Ali
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna 800007, India; Department of Biotechnology, National Institute of Pharmaceutical Education and Research, EPIP Complex, Hajipur 844102, India.
| | - Krishn Pratap Singh
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna 800007, India
| | - Parool Gupta
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna 800007, India
| | - Shashi S Suman
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna 800007, India
| | - Ayan K Ghosh
- Department of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna 800007, India
| | - Sanjiva Bimal
- Department of Immunology, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna 800007, India
| | - Krishna Pandey
- Department of Clinical Medicine, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna 800007, India
| | - Pradeep Das
- Department of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna 800007, India
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Franco J, Medeiros A, Benítez D, Perelmuter K, Serra G, Comini MA, Scarone L. In vitro activity and mode of action of distamycin analogues against African trypanosomes. Eur J Med Chem 2016; 126:776-788. [PMID: 27951486 DOI: 10.1016/j.ejmech.2016.12.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Revised: 10/29/2016] [Accepted: 12/01/2016] [Indexed: 12/14/2022]
Abstract
Distamycin, a natural polyamide containing three heterocycle rings with a polar end, has inspired several groups to prepare synthetic analogues, which proved to have anti-trypanosomal and anti-tumoral activity. We describe the synthesis of bi and tri thiazoles amides that harbor different substitutions at their ends and the evaluation of their anti-Trypanosoma brucei activity. The most active compound 10b showed better biological activity (EC50 310 nM and selectivity index 16) than the control drug nifurtimox (EC50 15 μM and selectivity index 10). Studies on the mode of action show that the parasiticidal activity of 10b originates from disruption of lysosomal homeostasis, which is followed by release of redox active iron, an increase in oxidizing species and collapse of cell membrane integrity. In this respect, our study suggests that non-charged lipophylic distamycins destabilize cell membranes.
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Affiliation(s)
- Jaime Franco
- Laboratorio de Química Farmacéutica, Departamento de Química Orgánica, Facultad de Química, Universidad de la República, Montevideo, Uruguay; Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Andrea Medeiros
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay; Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Diego Benítez
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Karen Perelmuter
- Cell Biology Unit, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Gloria Serra
- Laboratorio de Química Farmacéutica, Departamento de Química Orgánica, Facultad de Química, Universidad de la República, Montevideo, Uruguay
| | - Marcelo A Comini
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay.
| | - Laura Scarone
- Laboratorio de Química Farmacéutica, Departamento de Química Orgánica, Facultad de Química, Universidad de la República, Montevideo, Uruguay.
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Singh K, Singh KP, Equbal A, Suman SS, Zaidi A, Garg G, Pandey K, Das P, Ali V. Interaction between cysteine synthase and serine O-acetyltransferase proteins and their stage specific expression in Leishmania donovani. Biochimie 2016; 131:29-44. [PMID: 27638321 DOI: 10.1016/j.biochi.2016.09.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 09/05/2016] [Accepted: 09/05/2016] [Indexed: 01/14/2023]
Abstract
Leishmania possess a unique trypanothione redox metabolism with undebated roles in protection from oxidative damage and drug resistance. The biosynthesis of trypanothione depends on l-cysteine bioavailability which is regulated by cysteine biosynthesis pathway. The de novo cysteine biosynthesis pathway is comprised of serine O-acetyltransferase (SAT) and cysteine synthase (CS) enzymes which sequentially mediate two consecutive steps of cysteine biosynthesis, and is absent in mammalian host. However, despite the apparent dependency of redox metabolism on cysteine biosynthesis pathway, the role of SAT and CS in redox homeostasis has been unexplored in Leishmania parasites. Herein, we have characterized CS and SAT to investigate their interaction and relative abundance of these proteins in promastigote vs. amastigote growth stages of L. donovani. CS and SAT genes of L. donovani (LdCS and LdSAT) were cloned, expressed, and fusion proteins purified to homogeneity with affinity column chromatography. Purified LdCS contains PLP as cofactor and showed optimum enzymatic activity at pH 7.5. Enzyme kinetics showed that LdCS catalyses the synthesis of cysteine using O-acetylserine and sulfide with a Km of 15.86 mM and 0.17 mM, respectively. Digitonin fractionation and indirect immunofluorescence microscopy showed that LdCS and LdSAT are localized in the cytoplasm of promastigotes. Size exclusion chromatography, co-purification, pull down and immuno-precipitation assays demonstrated a stable complex formation between LdCS and LdSAT proteins. Furthermore, LdCS and LdSAT proteins expression/activity was upregulated in amastigote growth stage of the parasite. Thus, the stage specific differential expression of LdCS and LdSAT suggests that it may have a role in the redox homeostasis of Leishmania.
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Affiliation(s)
- Kuljit Singh
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna, 800007, India; Department of Biotechnology, National Institute of Pharmaceutical Education and Research, EPIP Complex, Hajipur, 844102, India
| | - Krishn Pratap Singh
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna, 800007, India
| | - Asif Equbal
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna, 800007, India
| | - Shashi S Suman
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna, 800007, India
| | - Amir Zaidi
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna, 800007, India
| | - Gaurav Garg
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna, 800007, India; Department of Biotechnology, National Institute of Pharmaceutical Education and Research, EPIP Complex, Hajipur, 844102, India
| | - Krishna Pandey
- Department of Clinical Medicine, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna, 800007, India
| | - Pradeep Das
- Department of Molecular Biology, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna, 800007, India
| | - Vahab Ali
- Laboratory of Molecular Biochemistry and Cell Biology, Department of Biochemistry, Rajendra Memorial Research Institute of Medical Sciences, Agamkuan, Patna, 800007, India; Department of Biotechnology, National Institute of Pharmaceutical Education and Research, EPIP Complex, Hajipur, 844102, India.
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5-Substituted 3-chlorokenpaullone derivatives are potent inhibitors of Trypanosoma brucei bloodstream forms. Bioorg Med Chem 2016; 24:3790-800. [DOI: 10.1016/j.bmc.2016.06.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 06/09/2016] [Accepted: 06/11/2016] [Indexed: 01/31/2023]
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Identification of Novel Chemical Scaffolds Inhibiting Trypanothione Synthetase from Pathogenic Trypanosomatids. PLoS Negl Trop Dis 2016; 10:e0004617. [PMID: 27070550 PMCID: PMC4829233 DOI: 10.1371/journal.pntd.0004617] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2015] [Accepted: 03/18/2016] [Indexed: 11/30/2022] Open
Abstract
Background The search for novel chemical entities targeting essential and parasite-specific pathways is considered a priority for neglected diseases such as trypanosomiasis and leishmaniasis. The thiol-dependent redox metabolism of trypanosomatids relies on bis-glutathionylspermidine [trypanothione, T(SH)2], a low molecular mass cosubstrate absent in the host. In pathogenic trypanosomatids, a single enzyme, trypanothione synthetase (TryS), catalyzes trypanothione biosynthesis, which is indispensable for parasite survival. Thus, TryS qualifies as an attractive drug target candidate. Methodology/Principal Finding A library composed of 144 compounds from 7 different families and several singletons was screened against TryS from three major pathogen species (Trypanosoma brucei, Trypanosoma cruzi and Leishmania infantum). The screening conditions were adjusted to the TryS´ kinetic parameters and intracellular concentration of substrates corresponding to each trypanosomatid species, and/or to avoid assay interference. The screening assay yielded suitable Z’ and signal to noise values (≥0.85 and ~3.5, respectively), and high intra-assay reproducibility. Several novel chemical scaffolds were identified as low μM and selective tri-tryp TryS inhibitors. Compounds displaying multi-TryS inhibition (N,N'-bis(3,4-substituted-benzyl) diamine derivatives) and an N5-substituted paullone (MOL2008) halted the proliferation of infective Trypanosoma brucei (EC50 in the nM range) and Leishmania infantum promastigotes (EC50 = 12 μM), respectively. A bis-benzyl diamine derivative and MOL2008 depleted intracellular trypanothione in treated parasites, which confirmed the on-target activity of these compounds. Conclusions/Significance Novel molecular scaffolds with on-target mode of action were identified as hit candidates for TryS inhibition. Due to the remarkable species-specificity exhibited by tri-tryp TryS towards the compounds, future optimization and screening campaigns should aim at designing and detecting, respectively, more potent and broad-range TryS inhibitors. Parasites from the genus Trypanosoma and Leishmania are etiologic agents for a group of neglected diseases with high morbidity and mortality rates in the developing world. Inasmuch as vaccine development is hampered by the successful mechanisms employed by the pathogens to evade the host immune response, chemotherapy remains as a safe option to fight these diseases. However, new drugs with better pharmacological performance (i.e. safety, efficacy and ease of administration) than those in current use are urgently needed. The thiol-redox metabolism of trypanosomatids offers an excellent opportunity for the development of more selective and efficacious medicines because it depends on a molecule, trypanothione (a bis-glutathionyl derivative of spermidine), unique and indispensable to the pathogens. Here we report the identification of novel inhibitors of trypanothione synthetase from three major trypanosomatid species of medical and veterinary relevance. Although highly conserved in sequence, trypanothione synthetases display significant species-specifity towards compounds, pointing to structural differences as determinants of ligand selectivity. Most of the active compounds presented two-digit μM inhibitory activity and serve as primary scaffolds to develop more potent inhibitors. Among them, N,N'-bis(benzyl)-substituted diamine and paullone derivatives are interesting candidates because of their potent and/or selective anti-trypanosomal and anti-trypanothione synthetase activity.
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Leroux AE, Krauth-Siegel RL. Thiol redox biology of trypanosomatids and potential targets for chemotherapy. Mol Biochem Parasitol 2016; 206:67-74. [DOI: 10.1016/j.molbiopara.2015.11.003] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Revised: 11/09/2015] [Accepted: 11/18/2015] [Indexed: 02/08/2023]
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Alberca LN, Sbaraglini ML, Balcazar D, Fraccaroli L, Carrillo C, Medeiros A, Benitez D, Comini M, Talevi A. Discovery of novel polyamine analogs with anti-protozoal activity by computer guided drug repositioning. J Comput Aided Mol Des 2016; 30:305-21. [PMID: 26891837 DOI: 10.1007/s10822-016-9903-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 02/12/2016] [Indexed: 12/01/2022]
Abstract
Chagas disease is a parasitic infection caused by the protozoa Trypanosoma cruzi that affects about 6 million people in Latin America. Despite its sanitary importance, there are currently only two drugs available for treatment: benznidazole and nifurtimox, both exhibiting serious adverse effects and limited efficacy in the chronic stage of the disease. Polyamines are ubiquitous to all living organisms where they participate in multiple basic functions such as biosynthesis of nucleic acids and proteins, proliferation and cell differentiation. T. cruzi is auxotroph for polyamines, which are taken up from the extracellular medium by efficient transporters and, to a large extent, incorporated into trypanothione (bis-glutathionylspermidine), the major redox cosubstrate of trypanosomatids. From a 268-compound database containing polyamine analogs with and without inhibitory effect on T. cruzi we have inferred classificatory models that were later applied in a virtual screening campaign to identify anti-trypanosomal compounds among drugs already used for other therapeutic indications (i.e. computer-guided drug repositioning) compiled in the DrugBank and Sweetlead databases. Five of the candidates identified with this strategy were evaluated in cellular models from different pathogenic trypanosomatids (T. cruzi wt, T. cruzi PAT12, T. brucei and Leishmania infantum), and in vitro models of aminoacid/polyamine transport assays and trypanothione synthetase inhibition assay. Triclabendazole, sertaconazole and paroxetine displayed inhibitory effects on the proliferation of T. cruzi (epimastigotes) and the uptake of putrescine by the parasite. They also interfered with the uptake of others aminoacids and the proliferation of infective T. brucei and L. infantum (promastigotes). Trypanothione synthetase was ruled out as molecular target for the anti-parasitic activity of these compounds.
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Affiliation(s)
- Lucas N Alberca
- Laboratory of Bioactive Compounds Research and Development (LIDeB), Medicinal Chemistry, Department of Biological Science, Exact Sciences College, National University of La Plata (UNLP), Argentina, 47 & 115, B1900AJI, La Plata, Buenos Aires, Argentina
| | - María L Sbaraglini
- Laboratory of Bioactive Compounds Research and Development (LIDeB), Medicinal Chemistry, Department of Biological Science, Exact Sciences College, National University of La Plata (UNLP), Argentina, 47 & 115, B1900AJI, La Plata, Buenos Aires, Argentina
| | - Darío Balcazar
- Instituto de Ciencias y Tecnología Dr. César Milstein (ICT Milstein), Argentinean National Council of Scientific and Technical Research (CONICET), Buenos Aires, Argentina
| | - Laura Fraccaroli
- Instituto de Ciencias y Tecnología Dr. César Milstein (ICT Milstein), Argentinean National Council of Scientific and Technical Research (CONICET), Buenos Aires, Argentina
| | - Carolina Carrillo
- Instituto de Ciencias y Tecnología Dr. César Milstein (ICT Milstein), Argentinean National Council of Scientific and Technical Research (CONICET), Buenos Aires, Argentina
| | - Andrea Medeiros
- Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, 11400, Montevideo, Uruguay
| | - Diego Benitez
- Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, 11400, Montevideo, Uruguay
| | - Marcelo Comini
- Laboratory Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, 11400, Montevideo, Uruguay
| | - Alan Talevi
- Laboratory of Bioactive Compounds Research and Development (LIDeB), Medicinal Chemistry, Department of Biological Science, Exact Sciences College, National University of La Plata (UNLP), Argentina, 47 & 115, B1900AJI, La Plata, Buenos Aires, Argentina.
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Achcar F, Fadda A, Haanstra JR, Kerkhoven EJ, Kim DH, Leroux AE, Papamarkou T, Rojas F, Bakker BM, Barrett MP, Clayton C, Girolami M, Krauth-Siegel RL, Matthews KR, Breitling R. The silicon trypanosome: a test case of iterative model extension in systems biology. Adv Microb Physiol 2014; 64:115-43. [PMID: 24797926 DOI: 10.1016/b978-0-12-800143-1.00003-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The African trypanosome, Trypanosoma brucei, is a unicellular parasite causing African Trypanosomiasis (sleeping sickness in humans and nagana in animals). Due to some of its unique properties, it has emerged as a popular model organism in systems biology. A predictive quantitative model of glycolysis in the bloodstream form of the parasite has been constructed and updated several times. The Silicon Trypanosome is a project that brings together modellers and experimentalists to improve and extend this core model with new pathways and additional levels of regulation. These new extensions and analyses use computational methods that explicitly take different levels of uncertainty into account. During this project, numerous tools and techniques have been developed for this purpose, which can now be used for a wide range of different studies in systems biology.
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Affiliation(s)
- Fiona Achcar
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Abeer Fadda
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Jurgen R Haanstra
- Department of Pediatrics, Centre for Liver Digestive and Metabolic Diseases, and Systems Biology Centre for Energy Metabolism and Ageing, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands; Department of Molecular Cell Physiology, Faculty of Earth and Life Sciences, VU University Amsterdam, Amsterdam, The Netherlands
| | - Eduard J Kerkhoven
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, and Glasgow Polyomics, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom; Systems and Synthetic Biology Group, Department of Chemical and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Dong-Hyun Kim
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, and Glasgow Polyomics, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | | | - Theodore Papamarkou
- The Department of Statistical Science and The Centre for Computational Statistics and Machine Learning University College London, London, United Kingdom
| | - Federico Rojas
- Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, Ashworth Laboratories, University of Edinburgh, Edinburgh, United Kingdom
| | - Barbara M Bakker
- Department of Pediatrics, Centre for Liver Digestive and Metabolic Diseases, and Systems Biology Centre for Energy Metabolism and Ageing, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Michael P Barrett
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, and Glasgow Polyomics, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Christine Clayton
- Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Mark Girolami
- The Department of Statistical Science and The Centre for Computational Statistics and Machine Learning University College London, London, United Kingdom
| | | | - Keith R Matthews
- Centre for Immunity, Infection and Evolution, Institute for Immunology and Infection Research, School of Biological Sciences, Ashworth Laboratories, University of Edinburgh, Edinburgh, United Kingdom
| | - Rainer Breitling
- Manchester Institute of Biotechnology, Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom.
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Sousa AF, Gomes-Alves AG, Benítez D, Comini MA, Flohé L, Jaeger T, Passos J, Stuhlmann F, Tomás AM, Castro H. Genetic and chemical analyses reveal that trypanothione synthetase but not glutathionylspermidine synthetase is essential for Leishmania infantum. Free Radic Biol Med 2014; 73:229-38. [PMID: 24853758 DOI: 10.1016/j.freeradbiomed.2014.05.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 05/12/2014] [Accepted: 05/13/2014] [Indexed: 11/23/2022]
Abstract
Trypanothione is a unique and essential redox metabolite of trypanosomatid parasites, the biosynthetic pathway of which is regarded as a promising target for antiparasitic drugs. Synthesis of trypanothione occurs by the consecutive conjugation of two glutathione molecules to spermidine. Both reaction steps are catalyzed by trypanothione synthetase (TRYS), a molecule known to be essential in Trypanosoma brucei. However, other trypanosomatids (including some Leishmania species and Trypanosoma cruzi) potentially express one additional enzyme, glutathionylspermidine synthetase (GSPS), capable of driving the first step of trypanothione synthesis yielding glutathionylspermidine. Because this monothiol can substitute for trypanothione in some reactions, the possibility existed that TRYS was redundant in parasites harboring GSPS. To clarify this issue, the functional relevance of both GSPS and TRYS was investigated in Leishmania infantum (Li). Employing a gene-targeting approach, we generated a gsps(-/-) knockout line, which was viable and capable of replicating in both life cycle stages of the parasite, thus demonstrating the superfluous role of LiGSPS. In contrast, elimination of both LiTRYS alleles was not possible unless parasites were previously complemented with an episomal copy of the gene. Retention of extrachromosomal LiTRYS in the trys(-/-)/+TRYS line after several passages in culture further supported the essentiality of this gene for survival of L. infantum (including its clinically relevant stage), hence ruling out the hypothesis of functional complementation by LiGSPS. Chemical targeting of LiTRYS with a drug-like compound was shown to also lead to parasite death. Overall, this study disqualifies GSPS as a target for drug development campaigns and, by genetic and chemical evidence, validates TRYS as a chemotherapeutic target in a parasite endowed with GSPS and, thus, probably along the entire trypanosomatid lineage.
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Affiliation(s)
- André F Sousa
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150-180 Porto, Portugal
| | - Ana G Gomes-Alves
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150-180 Porto, Portugal
| | - Diego Benítez
- Laboratory of Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, CP 11400 Montevideo, Uruguay
| | - Marcelo A Comini
- Laboratory of Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, CP 11400 Montevideo, Uruguay
| | - Leopold Flohé
- Departamento de Bioquímica, Universidad de la República, CP 11800 Montevideo, Uruguay, and Department of Molecular Medicine, Università degli Studi di Padova, 35131 Padova, Italy
| | - Timo Jaeger
- German Center for Infection Research, 38124 Braunschweig, Germany
| | - Joana Passos
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150-180 Porto, Portugal
| | | | - Ana M Tomás
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150-180 Porto, Portugal; ICBAS - Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, 4099-003 Porto, Portugal
| | - Helena Castro
- IBMC - Instituto de Biologia Molecular e Celular, Universidade do Porto, 4150-180 Porto, Portugal.
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Maiwald F, Benítez D, Charquero D, Dar MA, Erdmann H, Preu L, Koch O, Hölscher C, Loaëc N, Meijer L, Comini MA, Kunick C. 9- and 11-Substituted 4-azapaullones are potent and selective inhibitors of African trypanosoma. Eur J Med Chem 2014; 83:274-83. [PMID: 24973661 DOI: 10.1016/j.ejmech.2014.06.020] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 06/04/2014] [Accepted: 06/10/2014] [Indexed: 10/25/2022]
Abstract
Trypanosomes from the "brucei" complex are pathogenic parasites endemic in sub-Saharan Africa and causative agents of severe diseases in humans and livestock. In order to identify new antitrypanosomal chemotypes against African trypanosomes, 4-azapaullones carrying α,β-unsaturated carbonyl chains in 9- or 11-position were synthesized employing a procedure with a Heck reaction as key step. Among the so prepared compounds, 5a and 5e proved to be potent antiparasitic agents with antitrypanosomal activity in the submicromolar range.
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Affiliation(s)
- Franziska Maiwald
- Technische Universität Braunschweig, Institut für Medizinische und Pharmazeutische Chemie, Beethovenstraße 55, D-38106 Braunschweig, Germany
| | - Diego Benítez
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, CP 11400 Montevideo, Uruguay
| | - Diego Charquero
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, CP 11400 Montevideo, Uruguay
| | - Mahin Abad Dar
- Forschungszentrum Borstel, Forschungsgruppe Infektionsimmunologie, Parkallee 22, D-23845 Borstel, Germany
| | - Hanna Erdmann
- Forschungszentrum Borstel, Forschungsgruppe Infektionsimmunologie, Parkallee 22, D-23845 Borstel, Germany
| | - Lutz Preu
- Technische Universität Braunschweig, Institut für Medizinische und Pharmazeutische Chemie, Beethovenstraße 55, D-38106 Braunschweig, Germany
| | - Oliver Koch
- Technische Universität Dortmund, Department of Chemistry and Chemical Biology, Technische Universität Dortmund, Otto-Hahn-Straße 6, 44227 Dortmund, Germany
| | - Christoph Hölscher
- Forschungszentrum Borstel, Forschungsgruppe Infektionsimmunologie, Parkallee 22, D-23845 Borstel, Germany
| | - Nadège Loaëc
- ManRos Therapeutics, Perharidy Research Center, 29680 Roscoff, France
| | - Laurent Meijer
- ManRos Therapeutics, Perharidy Research Center, 29680 Roscoff, France
| | - Marcelo A Comini
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Mataojo 2020, CP 11400 Montevideo, Uruguay.
| | - Conrad Kunick
- Technische Universität Braunschweig, Institut für Medizinische und Pharmazeutische Chemie, Beethovenstraße 55, D-38106 Braunschweig, Germany.
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Hiller C, Nissen A, Benítez D, Comini MA, Krauth-Siegel RL. Cytosolic peroxidases protect the lysosome of bloodstream African trypanosomes from iron-mediated membrane damage. PLoS Pathog 2014; 10:e1004075. [PMID: 24722489 PMCID: PMC3983053 DOI: 10.1371/journal.ppat.1004075] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 03/02/2014] [Indexed: 01/23/2023] Open
Abstract
African trypanosomes express three virtually identical non-selenium glutathione peroxidase (Px)-type enzymes which preferably detoxify lipid-derived hydroperoxides. As shown previously, bloodstream Trypanosoma brucei lacking the mitochondrial Px III display only a weak and transient proliferation defect whereas parasites that lack the cytosolic Px I and Px II undergo extremely fast lipid peroxidation and cell lysis. The phenotype can completely be rescued by supplementing the medium with the α-tocopherol derivative Trolox. The mechanism underlying the rapid cell death remained however elusive. Here we show that the lysosome is the origin of the cellular injury. Feeding the px I–II knockout parasites with Alexa Fluor-conjugated dextran or LysoTracker in the presence of Trolox yielded a discrete lysosomal staining. Yet upon withdrawal of the antioxidant, the signal became progressively spread over the whole cell body and was completely lost, respectively. T. brucei acquire iron by endocytosis of host transferrin. Supplementing the medium with iron or transferrin induced, whereas the iron chelator deferoxamine and apo-transferrin attenuated lysis of the px I–II knockout cells. Immunofluorescence microscopy with MitoTracker and antibodies against the lysosomal marker protein p67 revealed that disintegration of the lysosome precedes mitochondrial damage. In vivo experiments confirmed the negligible role of the mitochondrial peroxidase: Mice infected with px III knockout cells displayed only a slightly delayed disease development compared to wild-type parasites. Our data demonstrate that in bloodstream African trypanosomes, the lysosome, not the mitochondrion, is the primary site of oxidative damage and cytosolic trypanothione/tryparedoxin-dependent peroxidases protect the lysosome from iron-induced membrane peroxidation. This process appears to be closely linked to the high endocytic rate and distinct iron acquisition mechanisms of the infective stage of T. brucei. The respective knockout of the cytosolic px I–II in the procyclic insect form resulted in cells that were fully viable in Trolox-free medium. In many cell types, mitochondria are the main source of intracellular reactive oxygen species but iron-induced oxidative lysosomal damage has been described as well. African trypanosomes are the causative agents of human sleeping sickness and the cattle disease Nagana. The parasites are obligate extracellular pathogens that multiply in the bloodstream and body fluids of their mammalian hosts and as procyclic forms in their insect vector, the tsetse fly. Bloodstream Trypanosoma brucei in which the genes for cytosolic lipid hydroperoxide-detoxifying peroxidases have been knocked out undergo an extremely rapid membrane peroxidation and lyse within less than two hours when they are cultured without an exogenous antioxidant. Here we show that the primary site of intracellular damage is the single terminal lysosome of the parasites. Disintegration of the lysosome clearly precedes damage of the mitochondrion and parasite death. Iron, acquired by the endocytosis of iron-loaded host transferrin, induces cell lysis. Contrary to the cytosolic enzymes, the respective mitochondrial peroxidase is dispensable for both in vitro proliferation and mouse infectivity. This is the first report demonstrating that cytosolic thiol peroxidases are responsible for protecting the lysosome of a cell.
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Affiliation(s)
- Corinna Hiller
- Biochemie-Zentrum der Universität Heidelberg (BZH), Heidelberg, Germany
| | - Amrei Nissen
- Biochemie-Zentrum der Universität Heidelberg (BZH), Heidelberg, Germany
| | - Diego Benítez
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Marcelo A. Comini
- Group Redox Biology of Trypanosomes, Institut Pasteur de Montevideo, Montevideo, Uruguay
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Saudagar P, Dubey VK. Molecular mechanisms of in vitro betulin-induced apoptosis of Leishmania donovani. Am J Trop Med Hyg 2014; 90:354-60. [PMID: 24420777 DOI: 10.4269/ajtmh.13-0320] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Although leishmanial infections of humans occur globally, the major health impact lies in developing nations, thus, leishmaniases remain "neglected" diseases for new drugs development. Multidrug resistance has been documented in most countries where leishmaniases is endemic. Betulin is a widely available and affordable natural product exerting leishmanicidal activity at micromolar concentration. In this study, the molecular mechanisms of death that contribute to the anti-leishmanial activity of betulin are investigated. In promastigotes, betulin stimulated reactive oxygen species generation at micromolar concentrations in Leishmania. Apoptosis was observed in betulin-treated promastigotes using flow cytometric analysis of treated cells stained with annexin V-FITC and propidium iodide. Furthermore, betulin treatment of promastigotes led to mitochondrial membrane damage, activation of caspase-like proteases, and DNA fragmentation in Leishmania donovani promastigotes. Betulin treatment of amastigotes cultured within macrophages, resulted in a reduced number of amastigotes, with no substantive cytotoxic damage to the host macrophage cells at leishmanicidal drug concentrations.
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Affiliation(s)
- Prakash Saudagar
- Department of Biotechnology, Indian Institute of Technology Guwahati, Assam, India
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38
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Saudagar P, Saha P, Saikia AK, Dubey VK. Molecular mechanism underlying antileishmanial effect of oxabicyclo[3.3.1]nonanones: inhibition of key redox enzymes of the pathogen. Eur J Pharm Biopharm 2013; 85:569-77. [PMID: 24002022 DOI: 10.1016/j.ejpb.2013.08.014] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Revised: 06/20/2013] [Accepted: 08/28/2013] [Indexed: 10/26/2022]
Abstract
We report oxabicyclo[3.3.1]nonanones as inhibitors of key redox enzymes, trypanothione synthetase (TryS), and trypanothione reductase (TryR) of Leishmania. Further, detailed cellular effects of 4-(4,4,8-Trimethyl-7-oxo-3-oxabicyclo[3.3.1]non-2-yl)-benzoic acid methyl ester, a oxabicyclo[3.3.1]nonanones, on the parasite were investigated. As these compounds inhibit key redox enzymes (TryR amd TryS), treatment of these compounds resulted in increased reactive oxygen species (ROS), mitochondrial membrane damage, activation of caspase like proteases, and DNA damage that finally leads to apoptosis. Although the compound has modest IC50 value against parasite (4.9±0.4 μM), they identify a novel chemical space to design and develop drugs based on these compounds against the Leishmania parasite. This is first report of oxabicyclo[3.3.1]nonanones as antileishmanial.
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Affiliation(s)
- Prakash Saudagar
- Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati, India
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Leroux AE, Haanstra JR, Bakker BM, Krauth-Siegel RL. Dissecting the catalytic mechanism of Trypanosoma brucei trypanothione synthetase by kinetic analysis and computational modeling. J Biol Chem 2013; 288:23751-64. [PMID: 23814051 PMCID: PMC3745322 DOI: 10.1074/jbc.m113.483289] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
In pathogenic trypanosomes, trypanothione synthetase (TryS) catalyzes the synthesis of both glutathionylspermidine (Gsp) and trypanothione (bis(glutathionyl)spermidine (T(SH)2)). Here we present a thorough kinetic analysis of Trypanosoma brucei TryS in a newly developed phosphate buffer system at pH 7.0 and 37 °C, mimicking the physiological environment of the enzyme in the cytosol of bloodstream parasites. Under these conditions, TryS displays Km values for GSH, ATP, spermidine, and Gsp of 34, 18, 687, and 32 μm, respectively, as well as Ki values for GSH and T(SH)2 of 1 mm and 360 μm, respectively. As Gsp hydrolysis has a Km value of 5.6 mm, the in vivo amidase activity is probably negligible. To obtain deeper insight in the molecular mechanism of TryS, we have formulated alternative kinetic models, with elementary reaction steps represented by linear kinetic equations. The model parameters were fitted to the extensive matrix of steady-state data obtained for different substrate/product combinations under the in vivo-like conditions. The best model describes the full kinetic profile and is able to predict time course data that were not used for fitting. This system's biology approach to enzyme kinetics led us to conclude that (i) TryS follows a ter-reactant mechanism, (ii) the intermediate Gsp dissociates from the enzyme between the two catalytic steps, and (iii) T(SH)2 inhibits the enzyme by remaining bound at its product site and, as does the inhibitory GSH, by binding to the activated enzyme complex. The newly detected concerted substrate and product inhibition suggests that TryS activity is tightly regulated.
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Affiliation(s)
- Alejandro E Leroux
- Biochemie-Zentrum der Universität Heidelberg, D-69120 Heidelberg, Germany
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40
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Gupta SK, Kosti I, Plaut G, Pivko A, Tkacz ID, Cohen-Chalamish S, Biswas DK, Wachtel C, Waldman Ben-Asher H, Carmi S, Glaser F, Mandel-Gutfreund Y, Michaeli S. The hnRNP F/H homologue of Trypanosoma brucei is differentially expressed in the two life cycle stages of the parasite and regulates splicing and mRNA stability. Nucleic Acids Res 2013; 41:6577-94. [PMID: 23666624 PMCID: PMC3711420 DOI: 10.1093/nar/gkt369] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Trypanosomes are protozoan parasites that cycle between a mammalian host (bloodstream form) and an insect host, the Tsetse fly (procyclic stage). In trypanosomes, all mRNAs are trans-spliced as part of their maturation. Genome-wide analysis of trans-splicing indicates the existence of alternative trans-splicing, but little is known regarding RNA-binding proteins that participate in such regulation. In this study, we performed functional analysis of the Trypanosoma brucei heterogeneous nuclear ribonucleoproteins (hnRNP) F/H homologue, a protein known to regulate alternative splicing in metazoa. The hnRNP F/H is highly expressed in the bloodstream form of the parasite, but is also functional in the procyclic form. Transcriptome analyses of RNAi-silenced cells were used to deduce the RNA motif recognized by this protein. A purine rich motif, AAGAA, was enriched in both the regulatory regions flanking the 3′ splice site and poly (A) sites of the regulated genes. The motif was further validated using mini-genes carrying wild-type and mutated sequences in the 3′ and 5′ UTRs, demonstrating the role of hnRNP F/H in mRNA stability and splicing. Biochemical studies confirmed the binding of the protein to this proposed site. The differential expression of the protein and its inverse effects on mRNA level in the two lifecycle stages demonstrate the role of hnRNP F/H in developmental regulation.
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Affiliation(s)
- Sachin Kumar Gupta
- Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan 52900, Israel
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41
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Trypanothione: A unique bis-glutathionyl derivative in trypanosomatids. Biochim Biophys Acta Gen Subj 2013; 1830:3199-216. [DOI: 10.1016/j.bbagen.2013.01.013] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 01/11/2013] [Accepted: 01/16/2013] [Indexed: 11/21/2022]
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42
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Koch O, Cappel D, Nocker M, Jäger T, Flohé L, Sotriffer CA, Selzer PM. Molecular dynamics reveal binding mode of glutathionylspermidine by trypanothione synthetase. PLoS One 2013; 8:e56788. [PMID: 23451087 PMCID: PMC3581523 DOI: 10.1371/journal.pone.0056788] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Accepted: 01/15/2013] [Indexed: 11/19/2022] Open
Abstract
The trypanothione synthetase (TryS) catalyses the two-step biosynthesis of trypanothione from spermidine and glutathione and is an attractive new drug target for the development of trypanocidal and antileishmanial drugs, especially since the structural information of TryS from Leishmania major has become available. Unfortunately, the TryS structure was solved without any of the substrates and lacks loop regions that are mechanistically important. This contribution describes docking and molecular dynamics simulations that led to further insights into trypanothione biosynthesis and, in particular, explains the binding modes of substrates for the second catalytic step. The structural model essentially confirm previously proposed binding sites for glutathione, ATP and two Mg2+ ions, which appear identical for both catalytic steps. The analysis of an unsolved loop region near the proposed spermidine binding site revealed a new pocket that was demonstrated to bind glutathionylspermidine in an inverted orientation. For the second step of trypanothione synthesis glutathionylspermidine is bound in a way that preferentially allows N1-glutathionylation of N8-glutathionylspermidine, classifying N8-glutathionylspermidine as the favoured substrate. By inhibitor docking, the binding site for N8-glutathionylspermidine was characterised as druggable.
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Affiliation(s)
- Oliver Koch
- MSD Animal Health Innovation GmbH, Schwabenheim, Germany
- MOLISA GmbH, Magdeburg, Germany
- * E-mail: (OK); (PMS)
| | - Daniel Cappel
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Würzburg, Germany
| | - Monika Nocker
- Institute of Pharmacy and Food Chemistry, University of Würzburg, Würzburg, Germany
| | | | | | | | - Paul M. Selzer
- MSD Animal Health Innovation GmbH, Schwabenheim, Germany
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
- Wellcome Trust Centre for Molecular Parasitology and Division of Infection & Immunity, Faculty of Biomedical & Life Sciences, University of Glasgow, Glasgow, United Kingdom
- * E-mail: (OK); (PMS)
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Mashiyama ST, Koupparis K, Caffrey CR, McKerrow JH, Babbitt PC. A global comparison of the human and T. brucei degradomes gives insights about possible parasite drug targets. PLoS Negl Trop Dis 2012; 6:e1942. [PMID: 23236535 PMCID: PMC3516576 DOI: 10.1371/journal.pntd.0001942] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 10/23/2012] [Indexed: 01/26/2023] Open
Abstract
We performed a genome-level computational study of sequence and structure similarity, the latter using crystal structures and models, of the proteases of Homo sapiens and the human parasite Trypanosoma brucei. Using sequence and structure similarity networks to summarize the results, we constructed global views that show visually the relative abundance and variety of proteases in the degradome landscapes of these two species, and provide insights into evolutionary relationships between proteases. The results also indicate how broadly these sequence sets are covered by three-dimensional structures. These views facilitate cross-species comparisons and offer clues for drug design from knowledge about the sequences and structures of potential drug targets and their homologs. Two protease groups (“M32” and “C51”) that are very different in sequence from human proteases are examined in structural detail, illustrating the application of this global approach in mining new pathogen genomes for potential drug targets. Based on our analyses, a human ACE2 inhibitor was selected for experimental testing on one of these parasite proteases, TbM32, and was shown to inhibit it. These sequence and structure data, along with interactive versions of the protein similarity networks generated in this study, are available at http://babbittlab.ucsf.edu/resources.html. Human African trypanosomiasis (HAT) is caused by the protozoan parasite Trypanosoma brucei. HAT is fatal unless treated, yet the current treatment itself can cause death. New treatments are urgently needed. Our study focuses on proteases, which are enzymes that break down proteins. Because of their roles in many centrally important biological processes, proteases are targets for drugs to treat a variety of diseases including parasite infection. The recent explosion of protein sequence and structure information in public databases has made surveys of proteins on a genomic scale possible. However, collecting specific data of interest from diverse databases and synthesizing them in a way that is easy to interpret can be difficult. We used T. brucei and human protease sequences, crystal structures, and models to create network views that show how proteases cluster by similarity. Such views are valuable not only for understanding the evolution of the protein repertoire in each species, but also can give important clues for drug design. Two T. brucei protease groups (“M32” and “C51”) that are very different in sequence from human proteases were examined in structural detail. Based on our analyses, a human ACE2 inhibitor was selected for experimental testing on one of these parasite proteases, TbM32, and was shown to inhibit it.
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Affiliation(s)
- Susan T. Mashiyama
- Department of Bioengineering and Therapeutic Sciences, California Institute for Quantitative Biomedical Research (QB3), University of California San Francisco, San Francisco, California, United States of America
- Center for Discovery and Innovation in Parasitic Diseases, and Department of Pathology, QB3, University of California San Francisco, San Francisco, California, United States of America
| | - Kyriacos Koupparis
- Center for Discovery and Innovation in Parasitic Diseases, and Department of Pathology, QB3, University of California San Francisco, San Francisco, California, United States of America
| | - Conor R. Caffrey
- Center for Discovery and Innovation in Parasitic Diseases, and Department of Pathology, QB3, University of California San Francisco, San Francisco, California, United States of America
| | - James H. McKerrow
- Center for Discovery and Innovation in Parasitic Diseases, and Department of Pathology, QB3, University of California San Francisco, San Francisco, California, United States of America
- * E-mail: (JHM); (PCB)
| | - Patricia C. Babbitt
- Department of Bioengineering and Therapeutic Sciences, California Institute for Quantitative Biomedical Research (QB3), University of California San Francisco, San Francisco, California, United States of America
- * E-mail: (JHM); (PCB)
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Fiorillo A, Colotti G, Boffi A, Baiocco P, Ilari A. The crystal structures of the tryparedoxin-tryparedoxin peroxidase couple unveil the structural determinants of Leishmania detoxification pathway. PLoS Negl Trop Dis 2012; 6:e1781. [PMID: 22928053 PMCID: PMC3424247 DOI: 10.1371/journal.pntd.0001781] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Accepted: 07/03/2012] [Indexed: 12/20/2022] Open
Abstract
Leishmaniasis is a neglected disease caused by Leishmania, an intracellular protozoan parasite which possesses a unique thiol metabolism based on trypanothione. Trypanothione is used as a source of electrons by the tryparedoxin/tryparedoxin peroxidase system (TXN/TXNPx) to reduce the hydroperoxides produced by macrophages during infection. This detoxification pathway is not only unique to the parasite but is also essential for its survival; therefore, it constitutes a most attractive drug target. Several forms of TXNPx, with very high sequence identity to one another, have been found in Leishmania strains, one of which has been used as a component of a potential anti-leishmanial polyprotein vaccine. The structures of cytosolic TXN and TXNPx from L. major (LmTXN and LmTXNPx) offer a unique opportunity to study peroxide reduction in Leishmania parasites at a molecular level, and may provide new tools for multienzyme inhibition-based drug discovery. Structural analyses bring out key structural features to elucidate LmTXN and LmTXNPx function. LmTXN displays an unusual N-terminal α-helix which allows the formation of a stable domain-swapped dimer. In LmTXNPx, crystallized in reducing condition, both the locally unfolded (LU) and fully folded (FF) conformations, typical of the oxidized and reduced protein respectively, are populated. The structural analysis presented here points to a high flexibility of the loop that includes the peroxidatic cysteine which facilitates Cys52 to form an inter-chain disulfide bond with the resolving cysteine (Cys173), thereby preventing over-oxidation which would inactivate the enzyme. Analysis of the electrostatic surface potentials of both LmTXN and LmTXNPx unveils the structural elements at the basis of functionally relevant interaction between the two proteins. Finally, the structural analysis of TXNPx allows us to identify the position of the epitopes that make the protein antigenic and therefore potentially suitable to be used in an anti-leishmanial polyprotein vaccine. Leishmania spp. are protozoa responsible for Leishmaniases, neglected diseases killing up to 60,000 people every year. Current therapies rely mainly on antimonial drugs that are inadequate due to poor drug efficacy and safety, combined with increasing drug resistance. To overcome these problems, there is an urgent need to find new and more affordable drugs. Leishmania reduces the hydrogen peroxide produced by macrophages during the infection by means of the tryparedoxin/tryparedoxin peroxidase couple. The two enzymes are potentially suitable drug targets since they are both necessary for parasite survival and absent in the human host. To understand the molecular basis of peroxide reduction in the Leishmania parasites, we have solved the X-ray crystal structures of both enzymes. Structural analyses highlight oligomerization of the two proteins and allow the regions responsible for their interaction to be identified. Moreover, based on the X-ray structures and on electronic microscopy data present in literature for the homologous proteins from Trypanosoma brucei, we have generated a model of interaction between tryparedoxin and tryparedoxin peroxidase from L. major. From the X-ray structure and from this model, we have identified the epitopes of tryparedoxin peroxidase, which is part of a potential threecomponent vaccine that is presently being studied in animal models and in human.
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Affiliation(s)
- Annarita Fiorillo
- Dipartimento di Scienze Biochimiche, University Sapienza, Rome, Italy
| | - Gianni Colotti
- Istituto di Biologia e Patologia Molecolari, CNR, Rome, Italy
- * E-mail: (AI), (GC)
| | - Alberto Boffi
- Dipartimento di Scienze Biochimiche, University Sapienza, Rome, Italy
- Istituto di Biologia e Patologia Molecolari, CNR, Rome, Italy
- Istituto Pasteur, Fondazione Cenci Bolognetti, Dipartimento di Scienze Biochimiche, Università di Roma “Sapienza”, Rome, Italy
| | - Paola Baiocco
- Dipartimento di Scienze Biochimiche, University Sapienza, Rome, Italy
| | - Andrea Ilari
- Istituto di Biologia e Patologia Molecolari, CNR, Rome, Italy
- * E-mail: (AI), (GC)
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Abstract
SIGNIFICANCE Parasitic infections continue to be a major problem for global human health. Vaccines are practically not available and chemotherapy is highly unsatisfactory. One approach toward a novel antiparasitic drug development is to unravel pathways that may be suited as future targets. Parasitic organisms show a remarkable diversity with respect to the nature and functions of their main low-molecular-mass antioxidants and many of them developed pathways that do not have a counterpart in their mammalian hosts. RECENT ADVANCES Work of the last years disclosed the individual antioxidants employed by parasites and their distinct pathways. Entamoeba, Trichomonas, and Giardia directly use cysteine as main low-molecular-mass thiol but have divergent cysteine metabolisms. Malarial parasites rely exclusively on cysteine uptake and generate glutathione (GSH) as main free thiol as do metazoan parasites. Trypanosomes and Leishmania have a unique trypanothione-based thiol metabolism but employ individual mechanisms for their cysteine supply. In addition, some trypanosomatids synthesize ovothiol A and/or ascorbate. Various essential parasite enzymes such as trypanothione synthetase and trypanothione reductase in Trypanosomatids and the Schistosoma thioredoxin GSH reductase are currently intensively explored as drug target molecules. CRITICAL ISSUES Essentiality is a prerequisite but not a sufficient property of an enzyme to become a suited drug target. The availability of an appropriate in vivo screening system and many other factors are equally important. FUTURE DIRECTIONS The current organism-wide RNA-interference and proteome analyses are supposed to reveal many more interesting candidates for future drug development approaches directed against the parasite antioxidant defense systems.
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Flohé L. The trypanothione system and its implications in the therapy of trypanosomatid diseases. Int J Med Microbiol 2012; 302:216-20. [PMID: 22889611 DOI: 10.1016/j.ijmm.2012.07.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Biosynthesis and the use of trypanothione, a redox metabolite of parasitic trypanosomatids, are reviewed here with special emphasis on the development of trypanocidal drugs. This metabolic system is unique to and essential for the protozoal parasites. Selective inhibition of key elements of trypanothione metabolism, therefore, promises eradication of the parasites without affecting the host. Considering the metabolic importance and drugability of system components, inhibition of the enzymes for regeneration and de novo synthesis of trypanothione is rated as the most promising approach, while related peroxidases and redoxins are disregarded as targets because of limited chances to achieve selective inhibition. The organizational need to exploit the accumulating knowledge of trypanosomatid metabolism for medical practice is briefly addressed.
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Affiliation(s)
- Leopold Flohé
- Department of Chemistry, Otto-von-Guericke-Universität, Universitätsplatz 2, 39106 Magdeburg, Germany.
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Raj I, Kumar S, Gourinath S. The narrow active-site cleft ofO-acetylserine sulfhydrylase fromLeishmania donovaniallows complex formation with serine acetyltransferases with a range of C-terminal sequences. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2012; 68:909-19. [DOI: 10.1107/s0907444912016459] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Accepted: 04/16/2012] [Indexed: 05/26/2023]
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Saudagar P, Dubey VK. Cloning, expression, characterization and inhibition studies on trypanothione synthetase, a drug target enzyme, from Leishmania donovani. Biol Chem 2012; 392:1113-22. [PMID: 22050226 DOI: 10.1515/bc.2011.222] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Trypanothione synthetase, a validated drug target, synthesizes trypanothione from glutathione and spermidine. Here we report the gene cloning, expression, characterization and inhibition studies of trypanothione synthetase from Leishmania donovani (LdTryS). The purified recombinant LdTryS enzyme obeyed Michaelis-Menten kinetics. High substrate inhibition was observed with glutathione (K(m)=33.24 μm, k(cat)=1.3 s(-1), K(i)=866 μm). The enzyme shows simple hyperbolic kinetics with fixed glutathione concentration and with other substrates limiting K(m) values for Mg. ATP and spermidine of 14.2 μm and 139.6 μm, respectively. LdTryS was also screened for inhibitors. Tomatine, conessine, uvaol and betulin were identified as inhibitors of the enzyme and were tested for leishmanicidal activity. Finally, the effect of LdTryS inhibitors on redox homeostasis of the parasite gives a broader picture of their action against leishmaniasis.
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Affiliation(s)
- Prakash Saudagar
- Department of Biotechnology, Indian Institute of Technology Guwahati, Assam-781039, India
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Olin-Sandoval V, González-Chávez Z, Berzunza-Cruz M, Martínez I, Jasso-Chávez R, Becker I, Espinoza B, Moreno-Sánchez R, Saavedra E. Drug target validation of the trypanothione pathway enzymes through metabolic modelling. FEBS J 2012; 279:1811-33. [DOI: 10.1111/j.1742-4658.2012.08557.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Induction of oxidative stress in Trypanosoma brucei by the antitrypanosomal dihydroquinoline OSU-40. Antimicrob Agents Chemother 2012; 56:2428-34. [PMID: 22314522 DOI: 10.1128/aac.06386-11] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Dihydroquinoline derivative OSU-40 (1-benzyl-1,2-dihydro-2,2,4-trimethylquinolin-6-yl acetate) is selectively potent against Trypanosma brucei rhodesiense in vitro (50% inhibitory concentration [IC(50)], 14 nM; selectivity index, 1,700) and has been proposed to cause the formation of reactive oxygen species (ROS) in African trypanosomes (J. Fotie et al., J. Med. Chem. 53:966-982, 2010). In the present study, we sought to provide further support for the hypothesis that OSU-40 kills trypanosomes through oxidative stress. Inducible RNA interference (RNAi) was applied to downregulate key enzymes in parasite antioxidant defense, including T. brucei trypanothione synthetase (TbTryS) and superoxide dismutase B (TbSODB). Both TbTryS RNAi-induced and TbSODB RNAi-induced cells showed impaired growth and increased sensitivity toward OSU-40 by 2.4-fold and 3.4-fold, respectively. Decreased expression of key parasite antioxidant enzymes was thus associated with increased sensitivity to OSU-40, consistent with the hypothesis that OSU-40 acts through oxidative stress. Finally, the dose-dependent formation of free radicals was observed after incubation of T. brucei with OSU-40 utilizing electron spin resonance (ESR) spectroscopy. These data support the notion that the mode of antitrypanosomal action for this class of compounds is to induce oxidative stress.
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