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González-Matos M, Aguado ME, Izquierdo M, Monzote L, González-Bacerio J. Compounds with potentialities as novel chemotherapeutic agents in leishmaniasis at preclinical level. Exp Parasitol 2024; 260:108747. [PMID: 38518969 DOI: 10.1016/j.exppara.2024.108747] [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: 12/15/2023] [Revised: 02/27/2024] [Accepted: 03/19/2024] [Indexed: 03/24/2024]
Abstract
Leishmaniasis are neglected infectious diseases caused by kinetoplastid protozoan parasites from the genus Leishmania. These sicknesses are present mainly in tropical regions and almost 1 million new cases are reported each year. The absence of vaccines, as well as the high cost, toxicity or resistance to the current drugs determines the necessity of new treatments against these pathologies. In this review, several compounds with potentialities as new antileishmanial drugs are presented. The discussion is restricted to the preclinical level and molecules are organized according to their chemical nature, source and molecular targets. In this manner, we present antimicrobial peptides, flavonoids, withanolides, 8-aminoquinolines, compounds from Leish-Box, pyrazolopyrimidines, and inhibitors of tubulin polymerization/depolymerization, topoisomerase IB, proteases, pteridine reductase, N-myristoyltransferase, as well as enzymes involved in polyamine metabolism, response against oxidative stress, signaling pathways, and sterol biosynthesis. This work is a contribution to the general knowledge of these compounds as antileishmanial agents.
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Affiliation(s)
- Maikel González-Matos
- Center for Protein Studies, Faculty of Biology, University of Havana, Calle 25 #455 Entre I y J, Vedado, La Habana, Cuba
| | - Mirtha Elisa Aguado
- Center for Protein Studies, Faculty of Biology, University of Havana, Calle 25 #455 Entre I y J, Vedado, La Habana, Cuba
| | - Maikel Izquierdo
- Center for Protein Studies, Faculty of Biology, University of Havana, Calle 25 #455 Entre I y J, Vedado, La Habana, Cuba
| | - Lianet Monzote
- Department of Parasitology, Center for Research, Diagnosis and Reference, Tropical Medicine Institute "Pedro Kourí", Autopista Novia Del Mediodía Km 6½, La Lisa, La Habana, Cuba.
| | - Jorge González-Bacerio
- Center for Protein Studies, Faculty of Biology, University of Havana, Calle 25 #455 Entre I y J, Vedado, La Habana, Cuba; Department of Biochemistry, Faculty of Biology, University of Havana, Calle 25 #455 Entre I y J, Vedado, La Habana, Cuba.
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2
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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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3
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Mohammadi-Ghalehbin B, Shiran JA, Gholizadeh N, Razzaghi-Asl N. Synthesis, antileishmanial activity and molecular modeling of new 1-aryl/alkyl-3-benzoyl/cyclopropanoyl thiourea derivatives. Mol Divers 2023; 27:1531-1545. [PMID: 36001225 DOI: 10.1007/s11030-022-10508-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Accepted: 07/27/2022] [Indexed: 11/27/2022]
Abstract
Due to the lack of effective vaccine(s) against leishmania and also pharmacokinetics issues of current drugs, it is necessary to discover new antileishmanial agents. Within this particular study, a series of novel 1-aryl/alkyl-3-benzoyl/cyclopropanoyl thiourea derivatives were synthesized (yields 69-84%) and evaluated as antileishmanial compounds (1-11). Synthetic derivatives were subjected to in vitro antileishmanial assessment against Leishmania major promastigotes by colorimetric MTT assay. Compounds 3 (IC50 38.54 µg/mL), 5 (IC50 84.75 µg/mL) and 10 (IC50 70.31 µg/mL) exhibited higher activities after 48 h but were less potent than amphotericin B (IC50 0.19 µg/mL). Antileishmanial activities indicated priority of 5-methyl-4-phenyl thiazole over furyl methyl substituents and 4-phenyl thiazole on thiourea nitrogen. N-myristoyltransferase (NMT) was selected as a validated L. major target for molecular docking studies. In silico results indicated the contribution of hydrophobic, π-stacking and H-bond interactions in binding to target. Most of the synthesized derivatives had lower binding affinities to human NMT (hNMT) than leishmanial enzyme. Docking conformations of top-ranked selective binders (compounds 3 and 5) were subjected to 50 ns MD simulations inside L. major HMT (LmNMT) active site. MD trajectories were used to extract RMSD, RMSF, Rg and durability of intramolecular/intermolecular H-bonds of the complex. It was observed that compound 3 escaped from LmNMT binding site during simulation period and no stable complex could be envisaged. Unlike 3, compound 5 attained stable binding conformation with converged stability parameters. Although mechanistic details for antileishmanial effects of synthesized derivatives are to be explored, current results may be implicated in further structure-guided approach toward potent antileishmanial agents.
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Affiliation(s)
- Behnam Mohammadi-Ghalehbin
- Department of Microbiology and Parasitology, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran
- Research Center for Zoonoses, Parasitic and Microbial Diseases, Ardabil University of Medical Sciences, Ardabil, Iran
| | - Jafar Abbasi Shiran
- Department of Medicinal Chemistry, School of Pharmacy, Ardabil University of Medical Sciences, 5618953141, Ardabil, Iran
| | - Nastaran Gholizadeh
- Students Research Committee, School of Pharmacy, Ardabil University of Medical Sciences, Ardabil, Iran
| | - Nima Razzaghi-Asl
- Department of Medicinal Chemistry, School of Pharmacy, Ardabil University of Medical Sciences, 5618953141, Ardabil, Iran.
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Ji Z, Nagar R, Duncan SM, Sampaio Guther ML, Ferguson MAJ. Identification of the glycosylphosphatidylinositol-specific phospholipase A2 (GPI-PLA2) that mediates GPI fatty acid remodeling in Trypanosoma brucei. J Biol Chem 2023; 299:105016. [PMID: 37414151 PMCID: PMC10457582 DOI: 10.1016/j.jbc.2023.105016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 06/28/2023] [Accepted: 06/30/2023] [Indexed: 07/08/2023] Open
Abstract
The biosynthesis of glycosylphosphatidylinositol (GPI)-anchored proteins (GPI-APs) in the parasitic protozoan Trypanosoma brucei involves fatty acid remodeling of the GPI precursor molecules before they are transferred to protein in the endoplasmic reticulum. The genes encoding the requisite phospholipase A2 and A1 activities for this remodeling have thus far been elusive. Here, we identify a gene, Tb927.7.6110, that encodes a protein that is both necessary and sufficient for GPI-phospholipase A2 (GPI-PLA2) activity in the procyclic form of the parasite. The predicted protein product belongs to the alkaline ceramidase, PAQR receptor, Per1, SID-1, and TMEM8 (CREST) superfamily of transmembrane hydrolase proteins and shows sequence similarity to Post-GPI-Attachment to Protein 6 (PGAP6), a GPI-PLA2 that acts after transfer of GPI precursors to protein in mammalian cells. We show the trypanosome Tb927.7.6110 GPI-PLA2 gene resides in a locus with two closely related genes Tb927.7.6150 and Tb927.7.6170, one of which (Tb927.7.6150) most likely encodes a catalytically inactive protein. The absence of GPI-PLA2 in the null mutant procyclic cells not only affected fatty acid remodeling but also reduced GPI anchor sidechain size on mature GPI-anchored procyclin glycoproteins. This reduction in GPI anchor sidechain size was reversed upon the re-addition of Tb927.7.6110 and of Tb927.7.6170, despite the latter not encoding GPI precursor GPI-PLA2 activity. Taken together, we conclude that Tb927.7.6110 encodes the GPI-PLA2 of GPI precursor fatty acid remodeling and that more work is required to assess the roles and essentiality of Tb927.7.6170 and the presumably enzymatically inactive Tb927.7.6150.
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Affiliation(s)
- Zhe Ji
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Rupa Nagar
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Samuel M Duncan
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Maria Lucia Sampaio Guther
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Michael A J Ferguson
- Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dundee, United Kingdom.
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Preliminary Structure-Activity Relationship Study of the MMV Pathogen Box Compound MMV675968 (2,4-Diaminoquinazoline) Unveils Novel Inhibitors of Trypanosoma brucei brucei. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27196574. [PMID: 36235118 PMCID: PMC9571290 DOI: 10.3390/molecules27196574] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 09/23/2022] [Accepted: 09/26/2022] [Indexed: 11/06/2022]
Abstract
New drugs are urgently needed for the treatment of human African trypanosomiasis (HAT). In line with our quest for novel inhibitors of trypanosomes, a small library of analogs of the antitrypanosomal hit (MMV675968) available at MMV as solid materials was screened for antitrypanosomal activity. In silico exploration of two potent antitrypanosomal structural analogs (7-MMV1578647 and 10-MMV1578445) as inhibitors of dihydrofolate reductase (DHFR) was achieved, together with elucidation of other antitrypanosomal modes of action. In addition, they were assessed in vitro for tentative inhibition of DHFR in a crude trypanosome extract. Their ADMET properties were also predicted using dedicated software. Overall, the two diaminoquinazoline analogs displayed approximately 40-fold and 60-fold more potency and selectivity in vitro than the parent hit, respectively (MMV1578445 (10): IC50 = 0.045 µM, SI = 1737; MMV1578467 (7): IC50 = 0.06 µM; SI = 412). Analogs 7 and 10 were also strong binders of the DHFR enzyme in silico, in all their accessible protonation states, and interacted with key DHFR ligand recognition residues Val32, Asp54, and Ile160. They also exhibited significant activity against trypanosome protein isolate. MMV1578445 (10) portrayed fast and irreversible trypanosome growth arrest between 4–72 h at IC99. Analogs 7 and 10 induced in vitro ferric iron reduction and DNA fragmentation or apoptosis induction, respectively. The two potent analogs endowed with predicted suitable physicochemical and ADMET properties are good candidates for further deciphering their potential as starting points for new drug development for HAT.
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Morales JF, Chuguransky S, Alberca LN, Alice JI, Goicoechea S, Ruiz ME, Bellera CL, Talevi A. Positive Predictive Value Surfaces as a Complementary Tool to Assess the Performance of Virtual Screening Methods. Mini Rev Med Chem 2021; 20:1447-1460. [PMID: 32072906 DOI: 10.2174/1871525718666200219130229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 10/28/2019] [Accepted: 10/29/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND Since their introduction in the virtual screening field, Receiver Operating Characteristic (ROC) curve-derived metrics have been widely used for benchmarking of computational methods and algorithms intended for virtual screening applications. Whereas in classification problems, the ratio between sensitivity and specificity for a given score value is very informative, a practical concern in virtual screening campaigns is to predict the actual probability that a predicted hit will prove truly active when submitted to experimental testing (in other words, the Positive Predictive Value - PPV). Estimation of such probability is however, obstructed due to its dependency on the yield of actives of the screened library, which cannot be known a priori. OBJECTIVE To explore the use of PPV surfaces derived from simulated ranking experiments (retrospective virtual screening) as a complementary tool to ROC curves, for both benchmarking and optimization of score cutoff values. METHODS The utility of the proposed approach is assessed in retrospective virtual screening experiments with four datasets used to infer QSAR classifiers: inhibitors of Trypanosoma cruzi trypanothione synthetase; inhibitors of Trypanosoma brucei N-myristoyltransferase; inhibitors of GABA transaminase and anticonvulsant activity in the 6 Hz seizure model. RESULTS Besides illustrating the utility of PPV surfaces to compare the performance of machine learning models for virtual screening applications and to select an adequate score threshold, our results also suggest that ensemble learning provides models with better predictivity and more robust behavior. CONCLUSION PPV surfaces are valuable tools to assess virtual screening tools and choose score thresholds to be applied in prospective in silico screens. Ensemble learning approaches seem to consistently lead to improved predictivity and robustness.
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Affiliation(s)
- Juan F Morales
- Laboratory of Bioactive Research and Development (LIDeB), Department of Biological Sciences, Faculty of Exact Sciences, University of La Plata (UNLP) - 47 & 115, La Plata (1900), Buenos Aires, Argentina
| | - Sara Chuguransky
- Laboratory of Bioactive Research and Development (LIDeB), Department of Biological Sciences, Faculty of Exact Sciences, University of La Plata (UNLP) - 47 & 115, La Plata (1900), Buenos Aires, Argentina
| | - Lucas N Alberca
- Laboratory of Bioactive Research and Development (LIDeB), Department of Biological Sciences, Faculty of Exact Sciences, University of La Plata (UNLP) - 47 & 115, La Plata (1900), Buenos Aires, Argentina
| | - Juan I Alice
- Laboratory of Bioactive Research and Development (LIDeB), Department of Biological Sciences, Faculty of Exact Sciences, University of La Plata (UNLP) - 47 & 115, La Plata (1900), Buenos Aires, Argentina
| | - Sofía Goicoechea
- Laboratory of Bioactive Research and Development (LIDeB), Department of Biological Sciences, Faculty of Exact Sciences, University of La Plata (UNLP) - 47 & 115, La Plata (1900), Buenos Aires, Argentina
| | - María E Ruiz
- Laboratory of Bioactive Research and Development (LIDeB), Department of Biological Sciences, Faculty of Exact Sciences, University of La Plata (UNLP) - 47 & 115, La Plata (1900), Buenos Aires, Argentina
| | - Carolina L Bellera
- Laboratory of Bioactive Research and Development (LIDeB), Department of Biological Sciences, Faculty of Exact Sciences, University of La Plata (UNLP) - 47 & 115, La Plata (1900), Buenos Aires, Argentina
| | - Alan Talevi
- Laboratory of Bioactive Research and Development (LIDeB), Department of Biological Sciences, Faculty of Exact Sciences, University of La Plata (UNLP) - 47 & 115, La Plata (1900), Buenos Aires, Argentina
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7
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Rashidi S, Tuteja R, Mansouri R, Ali-Hassanzadeh M, Shafiei R, Ghani E, Karimazar M, Nguewa P, Manzano-Román R. The main post-translational modifications and related regulatory pathways in the malaria parasite Plasmodium falciparum: An update. J Proteomics 2021; 245:104279. [PMID: 34089893 DOI: 10.1016/j.jprot.2021.104279] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 05/18/2021] [Accepted: 05/27/2021] [Indexed: 12/14/2022]
Abstract
There are important challenges when investigating individual post-translational modifications (PTMs) or protein interaction network and delineating if PTMs or their changes and cross-talks are involved during infection, disease initiation or as a result of disease progression. Proteomics and in silico approaches now offer the possibility to complement each other to further understand the regulatory involvement of these modifications in parasites and infection biology. Accordingly, the current review highlights key expressed or altered proteins and PTMs are invisible switches that turn on and off the function of most of the proteins. PTMs include phosphorylation, glycosylation, ubiquitylation, palmitoylation, myristoylation, prenylation, acetylation, methylation, and epigenetic PTMs in P. falciparum which have been recently identified. But also other low-abundant or overlooked PTMs that might be important for the parasite's survival, infectivity, antigenicity, immunomodulation and pathogenesis. We here emphasize the PTMs as regulatory pathways playing major roles in the biology, pathogenicity, metabolic pathways, survival, host-parasite interactions and the life cycle of P. falciparum. Further validations and functional characterizations of such proteins might confirm the discovery of therapeutic targets and might most likely provide valuable data for the treatment of P. falciparum, the main cause of severe malaria in human.
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Affiliation(s)
- Sajad Rashidi
- Department of Parasitology and Mycology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Renu Tuteja
- Parasite Biology Group, ICGEB, P. O. Box 10504, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Reza Mansouri
- Department of Immunology, Faculty of Medicine, Shahid Sadoughi University of Medical Sciences and Health Services, Yazd, Iran
| | - Mohammad Ali-Hassanzadeh
- Department of Immunology, School of Medicine, Jiroft University of Medical Sciences, Jiroft, Iran
| | - Reza Shafiei
- Vector-borne Diseases Research Center, North Khorasan University of Medical Sciences, Bojnurd, Iran
| | - Esmaeel Ghani
- Endocrinology and Metabolism Research Center, Hormozgan University of Medical Sciences, Bandar Abbas, Iran
| | - Mohammadreza Karimazar
- Department of Parasitology and Mycology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Paul Nguewa
- University of Navarra, ISTUN Instituto de Salud Tropical, Department of Microbiology and Parasitology, IdiSNA (Navarra Institute for Health Research), c/Irunlarrea 1, 31008 Pamplona, Spain.
| | - Raúl Manzano-Román
- Proteomics Unit, Cancer Research Centre (IBMCC/CSIC/USAL/IBSAL), 37007, Salamanca, Spain.
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8
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Pandey M, Huang Y, Lim TK, Lin Q, He CY. Flagellar targeting of an arginine kinase requires a conserved lipidated protein intraflagellar transport (LIFT) pathway in Trypanosoma brucei. J Biol Chem 2020; 295:11326-11336. [PMID: 32587088 DOI: 10.1074/jbc.ra120.014287] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/18/2020] [Indexed: 12/31/2022] Open
Abstract
Both intraflagellar transport (IFT) and lipidated protein intraflagellar transport (LIFT) pathways are essential for cilia/flagella biogenesis, motility, and sensory functions. In the LIFT pathway, lipidated cargoes are transported into the cilia through the coordinated actions of cargo carrier proteins such as Unc119 or PDE6δ, as well as small GTPases Arl13b and Arl3 in the cilium. Our previous studies have revealed a single Arl13b ortholog in the evolutionarily divergent Trypanosoma brucei, the causative agent of African sleeping sickness. TbArl13 catalyzes two TbArl3 homologs, TbArl3A and TbArl3C, suggesting the presence of a conserved LIFT pathway in these protozoan parasites. Only a single homolog to the cargo carrier protein Unc119 has been identified in T. brucei genome, but its function in lipidated protein transport has not been characterized. In this study, we exploited the proximity-based biotinylation approach to identify binding partners of TbUnc119. We showed that TbUnc119 binds to a flagellar arginine kinase TbAK3 in a myristoylation-dependent manner and is responsible for its targeting to and enrichment in the flagellum. Interestingly, only TbArl3A, but not TbArl3C interacted with TbUnc119 in a GTP-dependent manner, suggesting functional specialization of Arl3-GTPases in T. brucei These results establish the function of TbUnc119 as a myristoylated cargo carrier and support the presence of a conserved LIFT pathway in T. brucei.
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Affiliation(s)
- Maneesha Pandey
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Yameng Huang
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Teck Kwang Lim
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Qingsong Lin
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Cynthia Y He
- Department of Biological Sciences, National University of Singapore, Singapore
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Manzano-Román R, Fuentes M. Relevance and proteomics challenge of functional posttranslational modifications in Kinetoplastid parasites. J Proteomics 2020; 220:103762. [PMID: 32244008 DOI: 10.1016/j.jprot.2020.103762] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 03/06/2020] [Accepted: 03/23/2020] [Indexed: 02/06/2023]
Abstract
Protozoan parasitic infections are health, social and economic issues impacting both humans and animals, with significant morbidity and mortality worldwide. Protozoan parasites have complicated life cycles with both intracellular and extracellular forms. As a consequence, protozoan adapt to changing environments in part through a dynamic enzyme-catalyzed process leading to reversible posttranslational modifications (PTMs). The characterization by proteomics approaches reveals the critical role of the PTMs of the proteins involved in host-pathogen interaction. The complexity of PTMs characterization is increased by the high diversity, stoichiometry, dynamic and also co-existence of several PTMs in the same moieties which crosstalk between them. Here, we review how to understand the complexity and the essential role of PTMs crosstalk in order to provide a new hallmark for vaccines developments, immunotherapies and personalized medicine. In addition, the importance of these motifs in the biology and biological cycle of kinetoplastid parasites is highlighted with key examples showing the potential to act as targets against protozoan diseases.
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Affiliation(s)
- R Manzano-Román
- Proteomics Unit, Cancer Research Centre (IBMCC/CSIC/USAL/IBSAL), 37007, Salamanca, Spain..
| | - M Fuentes
- Proteomics Unit, Cancer Research Centre (IBMCC/CSIC/USAL/IBSAL), 37007, Salamanca, Spain.; Proteomics Unit, Cancer Research Centre (IBMCC/CSIC/USAL/IBSAL), 37007 Salamanca, Spain; Department of Medicine and General Cytometry Service-Nucleus, Cancer Research Centre (IBMCC/CSIC/USAL/IBSAL), 37007, Salamanca, Spain
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10
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Kersten C, Fleischer E, Kehrein J, Borek C, Jaenicke E, Sotriffer C, Brenk R. How To Design Selective Ligands for Highly Conserved Binding Sites: A Case Study Using N-Myristoyltransferases as a Model System. J Med Chem 2019; 63:2095-2113. [PMID: 31423787 DOI: 10.1021/acs.jmedchem.9b00586] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A model system of two related enzymes with conserved binding sites, namely N-myristoyltransferase from two different organisms, was studied to decipher the driving forces that lead to selective inhibition in such cases. Using a combination of computational and experimental tools, two different selectivity-determining features were identified. For some ligands, a change in side-chain flexibility appears to be responsible for selective inhibition. Remarkably, this was observed for residues orienting their side chains away from the ligands. For other ligands, selectivity is caused by interfering with a water molecule that binds more strongly to the off-target than to the target. On the basis of this finding, a virtual screen for selective compounds was conducted, resulting in three hit compounds with the desired selectivity profile. This study delivers a guideline on how to assess selectivity-determining features in proteins with conserved binding sites and to translate this knowledge into the design of selective inhibitors.
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Affiliation(s)
- Christian Kersten
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg-Universität Mainz, Staudingerweg 5, 55128 Mainz, Germany.,Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5020 Bergen, Norway
| | - Edmond Fleischer
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg-Universität Mainz, Staudingerweg 5, 55128 Mainz, Germany
| | - Josef Kehrein
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5020 Bergen, Norway.,Institute of Pharmacy and Food Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Christoph Borek
- Institute of Pharmacy and Biochemistry, Johannes Gutenberg-Universität Mainz, Staudingerweg 5, 55128 Mainz, Germany
| | - Elmar Jaenicke
- Institute of Molecular Biophysics, Johannes Gutenberg University, Jakob-Welder-Weg 26, 55128 Mainz, Germany
| | - Christoph Sotriffer
- Institute of Pharmacy and Food Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Ruth Brenk
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5020 Bergen, Norway
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11
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de Pablos LM, Ferreira TR, Dowle AA, Forrester S, Parry E, Newling K, Walrad PB. The mRNA-bound Proteome of Leishmania mexicana: Novel Genetic Insight into an Ancient Parasite. Mol Cell Proteomics 2019; 18:1271-1284. [PMID: 30948621 PMCID: PMC6601212 DOI: 10.1074/mcp.ra118.001307] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Revised: 02/23/2019] [Indexed: 01/08/2023] Open
Abstract
Leishmania parasite infections, termed the leishmaniases, cause significant global infectious disease burden. The lifecycle of the parasite embodies three main stages that require precise coordination of gene regulation to survive environmental shifts between sandfly and mammalian hosts. Constitutive transcription in kinetoplastid parasites means that gene regulation is overwhelmingly reliant on post-transcriptional mechanisms, yet strikingly few Leishmania trans-regulators are known. Using optimized crosslinking and deep, quantified mass spectrometry, we present a comprehensive analysis of 1400 mRNA binding proteins (mRBPs) and whole cell proteomes from the three main Leishmania lifecycle stages. Supporting the validity, although the crosslinked RBPome is magnitudes more enriched, the protein identities of the crosslinked and non-crosslinked RBPomes were nearly identical. Moreover, multiple candidate RBPs were endogenously tagged and found to associate with discrete mRNA target pools in a stage-specific manner. Results indicate that in L. mexicana parasites, mRNA levels are not a strong predictor of the whole cell expression or RNA binding potential of encoded proteins. Evidence includes a low correlation between transcript and corresponding protein expression and stage-specific variation in protein expression versus RNA binding potential. Unsurprisingly, RNA binding protein enrichment correlates strongly with relative replication efficiency of the specific lifecycle stage. Our study is the first to quantitatively define and compare the mRBPome of multiple stages in kinetoplastid parasites. It provides novel, in-depth insight into the trans-regulatory mRNA:Protein (mRNP) complexes that drive Leishmania parasite lifecycle progression.
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Affiliation(s)
| | | | - Adam A Dowle
- §Metabolomics and Proteomics Lab, Bioscience Technology Facility, and
| | | | - Ewan Parry
- From the ‡Centre for Immunology and Infection
| | - Katherine Newling
- ¶Genomics and Bioinformatics Lab, Bioscience Technology Facility, Department of Biology, University of York, UK
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12
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Veale CGL. Unpacking the Pathogen Box-An Open Source Tool for Fighting Neglected Tropical Disease. ChemMedChem 2019; 14:386-453. [PMID: 30614200 DOI: 10.1002/cmdc.201800755] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Indexed: 12/13/2022]
Abstract
The Pathogen Box is a 400-strong collection of drug-like compounds, selected for their potential against several of the world's most important neglected tropical diseases, including trypanosomiasis, leishmaniasis, cryptosporidiosis, toxoplasmosis, filariasis, schistosomiasis, dengue virus and trichuriasis, in addition to malaria and tuberculosis. This library represents an ensemble of numerous successful drug discovery programmes from around the globe, aimed at providing a powerful resource to stimulate open source drug discovery for diseases threatening the most vulnerable communities in the world. This review seeks to provide an in-depth analysis of the literature pertaining to the compounds in the Pathogen Box, including structure-activity relationship highlights, mechanisms of action, related compounds with reported activity against different diseases, and, where appropriate, discussion on the known and putative targets of compounds, thereby providing context and increasing the accessibility of the Pathogen Box to the drug discovery community.
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Affiliation(s)
- Clinton G L Veale
- School of Chemistry and Physics, Pietermaritzburg Campus, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, South Africa
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13
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Harrison JR, Brand S, Smith V, Robinson DA, Thompson S, Smith A, Davies K, Mok N, Torrie LS, Collie I, Hallyburton I, Norval S, Simeons FRC, Stojanovski L, Frearson JA, Brenk R, Wyatt PG, Gilbert IH, Read KD. A Molecular Hybridization Approach for the Design of Potent, Highly Selective, and Brain-Penetrant N-Myristoyltransferase Inhibitors. J Med Chem 2018; 61:8374-8389. [PMID: 30207721 PMCID: PMC6167002 DOI: 10.1021/acs.jmedchem.8b00884] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Crystallography has guided the hybridization of two series of Trypanosoma brucei N-myristoyltransferase (NMT) inhibitors, leading to a novel highly selective series. The effect of combining the selectivity enhancing elements from two pharmacophores is shown to be additive and has led to compounds that have greater than 1000-fold selectivity for TbNMT vs HsNMT. Further optimization of the hybrid series has identified compounds with significant trypanocidal activity capable of crossing the blood-brain barrier. By using CF-1 mdr1a deficient mice, we were able to demonstrate full cures in vivo in a mouse model of stage 2 African sleeping sickness. This and previous work provides very strong validation for NMT as a drug target for human African trypanosomiasis in both the peripheral and central nervous system stages of disease.
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Affiliation(s)
- Justin R Harrison
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences , University of Dundee , Dundee , DD1 5EH , United Kingdom
| | - Stephen Brand
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences , University of Dundee , Dundee , DD1 5EH , United Kingdom
| | - Victoria Smith
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences , University of Dundee , Dundee , DD1 5EH , United Kingdom
| | - David A Robinson
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences , University of Dundee , Dundee , DD1 5EH , United Kingdom
| | - Stephen Thompson
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences , University of Dundee , Dundee , DD1 5EH , United Kingdom
| | - Alasdair Smith
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences , University of Dundee , Dundee , DD1 5EH , United Kingdom
| | - Kenneth Davies
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences , University of Dundee , Dundee , DD1 5EH , United Kingdom
| | - Ngai Mok
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences , University of Dundee , Dundee , DD1 5EH , United Kingdom
| | - Leah S Torrie
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences , University of Dundee , Dundee , DD1 5EH , United Kingdom
| | - Iain Collie
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences , University of Dundee , Dundee , DD1 5EH , United Kingdom
| | - Irene Hallyburton
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences , University of Dundee , Dundee , DD1 5EH , United Kingdom
| | - Suzanne Norval
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences , University of Dundee , Dundee , DD1 5EH , United Kingdom
| | - Frederick R C Simeons
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences , University of Dundee , Dundee , DD1 5EH , United Kingdom
| | - Laste Stojanovski
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences , University of Dundee , Dundee , DD1 5EH , United Kingdom
| | - Julie A Frearson
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences , University of Dundee , Dundee , DD1 5EH , United Kingdom
| | - Ruth Brenk
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences , University of Dundee , Dundee , DD1 5EH , United Kingdom
| | - Paul G Wyatt
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences , University of Dundee , Dundee , DD1 5EH , United Kingdom
| | - Ian H Gilbert
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences , University of Dundee , Dundee , DD1 5EH , United Kingdom
| | - Kevin D Read
- Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, Division of Biological Chemistry and Drug Discovery, School of Life Sciences , University of Dundee , Dundee , DD1 5EH , United Kingdom
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14
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Bayliss T, Robinson DA, Smith VC, Brand S, McElroy SP, Torrie LS, Mpamhanga C, Norval S, Stojanovski L, Brenk R, Frearson JA, Read KD, Gilbert IH, Wyatt PG. Design and Synthesis of Brain Penetrant Trypanocidal N-Myristoyltransferase Inhibitors. J Med Chem 2017; 60:9790-9806. [PMID: 29125744 PMCID: PMC5734605 DOI: 10.1021/acs.jmedchem.7b01255] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
N-Myristoyltransferase (NMT) represents a promising drug target within the parasitic protozoa Trypanosoma brucei (T. brucei), the causative agent for human African trypanosomiasis (HAT) or sleeping sickness. We have previously validated T. brucei NMT as a promising druggable target for the treatment of HAT in both stages 1 and 2 of the disease. We report on the use of the previously reported DDD85646 (1) as a starting point for the design of a class of potent, brain penetrant inhibitors of T. brucei NMT.
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Affiliation(s)
- Tracy Bayliss
- Drug Discovery Unit, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - David A Robinson
- Drug Discovery Unit, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Victoria C Smith
- Drug Discovery Unit, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Stephen Brand
- Drug Discovery Unit, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Stuart P McElroy
- Drug Discovery Unit, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Leah S Torrie
- Drug Discovery Unit, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Chido Mpamhanga
- Drug Discovery Unit, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Suzanne Norval
- Drug Discovery Unit, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Laste Stojanovski
- Drug Discovery Unit, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Ruth Brenk
- Drug Discovery Unit, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Julie A Frearson
- Drug Discovery Unit, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Kevin D Read
- Drug Discovery Unit, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Ian H Gilbert
- Drug Discovery Unit, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
| | - Paul G Wyatt
- Drug Discovery Unit, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
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15
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Wright MH, Paape D, Price HP, Smith DF, Tate EW. Global Profiling and Inhibition of Protein Lipidation in Vector and Host Stages of the Sleeping Sickness Parasite Trypanosoma brucei. ACS Infect Dis 2016; 2:427-441. [PMID: 27331140 PMCID: PMC4906374 DOI: 10.1021/acsinfecdis.6b00034] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Indexed: 01/05/2023]
Abstract
The enzyme N-myristoyltransferase (NMT) catalyzes the essential fatty acylation of substrate proteins with myristic acid in eukaryotes and is a validated drug target in the parasite Trypanosoma brucei, the causative agent of African trypanosomiasis (sleeping sickness). N-Myristoylation typically mediates membrane localization of proteins and is essential to the function of many. However, only a handful of proteins are experimentally validated as N-myristoylated in T. brucei. Here, we perform metabolic labeling with an alkyne-tagged myristic acid analogue, enabling the capture of lipidated proteins in insect and host life stages of T. brucei. We further compare this with a longer chain palmitate analogue to explore the chain length-specific incorporation of fatty acids into proteins. Finally, we combine the alkynyl-myristate analogue with NMT inhibitors and quantitative chemical proteomics to globally define N-myristoylated proteins in the clinically relevant bloodstream form parasites. This analysis reveals five ARF family small GTPases, calpain-like proteins, phosphatases, and many uncharacterized proteins as substrates of NMT in the parasite, providing a global view of the scope of this important protein modification and further evidence for the crucial and pleiotropic role of NMT in the cell.
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Affiliation(s)
- Megan H. Wright
- Department of Chemistry, Imperial College London, London SW7 2AZ, United Kingdom
| | - Daniel Paape
- Centre for Immunology and Infection, Department
of Biology, University of York, York YO10 5DD, United Kingdom
| | - Helen P. Price
- Centre for Immunology and Infection, Department
of Biology, University of York, York YO10 5DD, United Kingdom
| | - Deborah F. Smith
- Centre for Immunology and Infection, Department
of Biology, University of York, York YO10 5DD, United Kingdom
| | - Edward W. Tate
- Department of Chemistry, Imperial College London, London SW7 2AZ, United Kingdom
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16
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Herrera LJ, Brand S, Santos A, Nohara LL, Harrison J, Norcross NR, Thompson S, Smith V, Lema C, Varela-Ramirez A, Gilbert IH, Almeida IC, Maldonado RA. Validation of N-myristoyltransferase as Potential Chemotherapeutic Target in Mammal-Dwelling Stages of Trypanosoma cruzi. PLoS Negl Trop Dis 2016; 10:e0004540. [PMID: 27128971 PMCID: PMC4851402 DOI: 10.1371/journal.pntd.0004540] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 02/22/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Trypanosoma cruzi causes Chagas disease, an endemic and debilitating illness in Latin America. Lately, owing to extensive population movements, this neglected tropical disease has become a global health concern. The two clinically available drugs for the chemotherapy of Chagas disease have rather high toxicity and limited efficacy in the chronic phase of the disease, and may induce parasite resistance. The development of new anti-T. cruzi agents is therefore imperative. The enzyme N-myristoyltransferase (NMT) has recently been biochemically characterized, shown to be essential in Leishmania major, Trypanosoma brucei, and T. cruzi¸ and proposed as promising chemotherapeutic target in these trypanosomatids. METHODOLOGY/PRINCIPAL FINDINGS Here, using high-content imaging we assayed eight known trypanosomatid NMT inhibitors, against mammal-dwelling intracellular amastigote and trypomastigote stages and demonstrated that three of them (compounds 1, 5, and 8) have potent anti-proliferative effect at submicromolar concentrations against T. cruzi, with very low toxicity against human epithelial cells. Moreover, metabolic labeling using myristic acid, azide showed a considerable decrease in the myristoylation of proteins in parasites treated with NMT inhibitors, providing evidence of the on-target activity of the inhibitors. CONCLUSIONS/SIGNIFICANCE Taken together, our data point out to the potential use of NMT inhibitors as anti-T. cruzi chemotherapy.
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Affiliation(s)
- Linda J. Herrera
- The Border Biomedical Research Center, Department of Biological Sciences, University of Texas at El Paso, El Paso, Texas, United States of America
| | - Stephen Brand
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, United Kingdom
| | - Andres Santos
- The Border Biomedical Research Center, Department of Biological Sciences, University of Texas at El Paso, El Paso, Texas, United States of America
| | - Lilian L. Nohara
- The Border Biomedical Research Center, Department of Biological Sciences, University of Texas at El Paso, El Paso, Texas, United States of America
| | - Justin Harrison
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, United Kingdom
| | - Neil R. Norcross
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, United Kingdom
| | - Stephen Thompson
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, United Kingdom
| | - Victoria Smith
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, United Kingdom
| | - Carolina Lema
- The Border Biomedical Research Center, Department of Biological Sciences, University of Texas at El Paso, El Paso, Texas, United States of America
| | - Armando Varela-Ramirez
- The Border Biomedical Research Center, Department of Biological Sciences, University of Texas at El Paso, El Paso, Texas, United States of America
| | - Ian H. Gilbert
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, United Kingdom
| | - Igor C. Almeida
- The Border Biomedical Research Center, Department of Biological Sciences, University of Texas at El Paso, El Paso, Texas, United States of America
| | - Rosa A. Maldonado
- The Border Biomedical Research Center, Department of Biological Sciences, University of Texas at El Paso, El Paso, Texas, United States of America
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17
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Singh N, Shah P, Dwivedi H, Mishra S, Tripathi R, Sahasrabuddhe AA, Siddiqi MI. Integrated machine learning, molecular docking and 3D-QSAR based approach for identification of potential inhibitors of trypanosomal N-myristoyltransferase. MOLECULAR BIOSYSTEMS 2016; 12:3711-3723. [DOI: 10.1039/c6mb00574h] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Integrated in silico approaches for the identification of antitrypanosomal inhibitors.
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Affiliation(s)
- Nidhi Singh
- Molecular and Structural Biology Division
- CSIR-Central Drug Research Institute
- Lucknow 226031
- India
| | - Priyanka Shah
- Molecular and Structural Biology Division
- CSIR-Central Drug Research Institute
- Lucknow 226031
- India
| | - Hemlata Dwivedi
- Division of Parasitology
- CSIR-Central Drug Research Institute
- Lucknow
- India
| | - Shikha Mishra
- Molecular and Structural Biology Division
- CSIR-Central Drug Research Institute
- Lucknow 226031
- India
| | - Renu Tripathi
- Division of Parasitology
- CSIR-Central Drug Research Institute
- Lucknow
- India
- Academy of Scientific and Innovative Research (AcSIR)
| | - Amogh A. Sahasrabuddhe
- Molecular and Structural Biology Division
- CSIR-Central Drug Research Institute
- Lucknow 226031
- India
- Academy of Scientific and Innovative Research (AcSIR)
| | - Mohammad Imran Siddiqi
- Molecular and Structural Biology Division
- CSIR-Central Drug Research Institute
- Lucknow 226031
- India
- Academy of Scientific and Innovative Research (AcSIR)
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18
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Spinks D, Smith V, Thompson S, Robinson DA, Luksch T, Smith A, Torrie LS, McElroy S, Stojanovski L, Norval S, Collie IT, Hallyburton I, Rao B, Brand S, Brenk R, Frearson JA, Read KD, Wyatt PG, Gilbert IH. Development of Small-Molecule Trypanosoma brucei N-Myristoyltransferase Inhibitors: Discovery and Optimisation of a Novel Binding Mode. ChemMedChem 2015; 10:1821-36. [PMID: 26395087 PMCID: PMC4648043 DOI: 10.1002/cmdc.201500301] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Indexed: 11/10/2022]
Abstract
The enzyme N-myristoyltransferase (NMT) from Trypanosoma brucei has been validated both chemically and biologically as a potential drug target for human African trypanosomiasis. We previously reported the development of some very potent compounds based around a pyrazole sulfonamide series, derived from a high-throughput screen. Herein we describe work around thiazolidinone and benzomorpholine scaffolds that were also identified in the screen. An X-ray crystal structure of the thiazolidinone hit in Leishmania major NMT showed the compound bound in the previously reported active site, utilising a novel binding mode. This provides potential for further optimisation. The benzomorpholinone was also found to bind in a similar region. Using an X-ray crystallography/structure-based design approach, the benzomorpholinone series was further optimised, increasing activity against T. brucei NMT by >1000-fold. A series of trypanocidal compounds were identified with suitable in vitro DMPK properties, including CNS exposure for further development. Further work is required to increase selectivity over the human NMT isoform and activity against T. brucei.
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Affiliation(s)
- Daniel Spinks
- Drug Discovery Unit, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, UK
| | - Victoria Smith
- Drug Discovery Unit, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, UK
| | - Stephen Thompson
- Drug Discovery Unit, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, UK
| | - David A Robinson
- Drug Discovery Unit, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, UK
| | - Torsten Luksch
- Drug Discovery Unit, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, UK
| | - Alasdair Smith
- Drug Discovery Unit, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, UK
| | - Leah S Torrie
- Drug Discovery Unit, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, UK
| | - Stuart McElroy
- Drug Discovery Unit, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, UK
| | - Laste Stojanovski
- Drug Discovery Unit, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, UK
| | - Suzanne Norval
- Drug Discovery Unit, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, UK
| | - Iain T Collie
- Drug Discovery Unit, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, UK
| | - Irene Hallyburton
- Drug Discovery Unit, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, UK
| | - Bhavya Rao
- Drug Discovery Unit, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, UK
| | - Stephen Brand
- Drug Discovery Unit, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, UK
| | - Ruth Brenk
- Drug Discovery Unit, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, UK
| | - Julie A Frearson
- Drug Discovery Unit, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, UK
| | - Kevin D Read
- Drug Discovery Unit, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, UK
| | - Paul G Wyatt
- Drug Discovery Unit, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, UK
| | - Ian H Gilbert
- Drug Discovery Unit, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, UK.
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19
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Robinson DA, Wyatt PG. Identification and structure solution of fragment hits against kinetoplastid N-myristoyltransferase. Acta Crystallogr F Struct Biol Commun 2015; 71:586-93. [PMID: 25945713 PMCID: PMC4427169 DOI: 10.1107/s2053230x15003040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 02/12/2015] [Indexed: 11/30/2022] Open
Abstract
Trypanosoma brucei N-myristoyltransferase (TbNMT) is an attractive therapeutic target for the treatment of human African trypanosomiasis. Pyrazole sulfonamide (DDD85646), a potent inhibitor of TbNMT, has been identified in previous studies; however, poor central nervous system exposure restricts its use to the haemolymphatic form (stage 1) of the disease. In order to identify new chemical matter, a fragment screen was carried out by ligand-observed NMR spectroscopy, identifying hits that occupy the DDD85646 binding site. Crystal structures of hits from this assay have been obtained in complex with the closely related NMT from Leishmania major, providing a structural starting point for the evolution of novel chemical matter.
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Affiliation(s)
- David A. Robinson
- Drug Discovery Unit, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, Scotland
| | - Paul G. Wyatt
- Drug Discovery Unit, College of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, Scotland
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20
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Hol WGJ. Three-dimensional structures in the design of therapeutics targeting parasitic protozoa: reflections on the past, present and future. Acta Crystallogr F Struct Biol Commun 2015; 71:485-99. [PMID: 25945701 PMCID: PMC4427157 DOI: 10.1107/s2053230x15004987] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 03/11/2015] [Indexed: 11/10/2022] Open
Abstract
Parasitic protozoa cause a range of diseases which threaten billions of human beings. They are responsible for tremendous mortality and morbidity in the least-developed areas of the world. Presented here is an overview of the evolution over the last three to four decades of structure-guided design of inhibitors, leads and drug candidates aiming at targets from parasitic protozoa. Target selection is a crucial and multi-faceted aspect of structure-guided drug design. The major impact of advances in molecular biology, genome sequencing and high-throughput screening is touched upon. The most advanced crystallographic techniques, including XFEL, have already been applied to structure determinations of drug targets from parasitic protozoa. Even cryo-electron microscopy is contributing to our understanding of the mode of binding of inhibitors to parasite ribosomes. A number of projects have been selected to illustrate how structural information has assisted in arriving at promising compounds that are currently being evaluated by pharmacological, pharmacodynamic and safety tests to assess their suitability as pharmaceutical agents. Structure-guided approaches are also applied to incorporate properties into compounds such that they are less likely to become the victim of resistance mechanisms. A great increase in the number of novel antiparasitic compounds will be needed in the future. These should then be combined into various multi-compound therapeutics to circumvent the diverse resistance mechanisms that render single-compound, or even multi-compound, drugs ineffective. The future should also see (i) an increase in the number of projects with a tight integration of structural biology, medicinal chemistry, parasitology and pharmaceutical sciences; (ii) the education of more `medicinal structural biologists' who are familiar with the properties that compounds need to have for a high probability of success in the later steps of the drug-development process; and (iii) the expansion of drug-development capabilities in middle- and low-income countries.
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Affiliation(s)
- Wim G. J. Hol
- Department of Biochemistry and Biomolecular Structure Center, University of Washington, Seattle, WA 98195, USA
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21
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Brand S, Norcross NR, Thompson S, Harrison JR, Smith VC, Robinson DA, Torrie LS, McElroy SP, Hallyburton I, Norval S, Scullion P, Stojanovski L, Simeons FRC, van Aalten D, Frearson JA, Brenk R, Fairlamb AH, Ferguson MAJ, Wyatt PG, Gilbert IH, Read KD. Lead optimization of a pyrazole sulfonamide series of Trypanosoma brucei N-myristoyltransferase inhibitors: identification and evaluation of CNS penetrant compounds as potential treatments for stage 2 human African trypanosomiasis. J Med Chem 2014; 57:9855-69. [PMID: 25412409 PMCID: PMC4269550 DOI: 10.1021/jm500809c] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
![]()
Trypanosoma bruceiN-myristoyltransferase
(TbNMT) is an attractive therapeutic
target for the treatment of human African trypanosomiasis (HAT). From
previous studies, we identified pyrazole sulfonamide, DDD85646 (1), a potent inhibitor of TbNMT. Although
this compound represents an excellent lead, poor central nervous system
(CNS) exposure restricts its use to the hemolymphatic form (stage
1) of the disease. With a clear clinical need for new drug treatments
for HAT that address both the hemolymphatic and CNS stages of the
disease, a chemistry campaign was initiated to address the shortfalls
of this series. This paper describes modifications to the pyrazole
sulfonamides which markedly improved blood–brain barrier permeability,
achieved by reducing polar surface area and capping the sulfonamide.
Moreover, replacing the core aromatic with a flexible linker significantly
improved selectivity. This led to the discovery of DDD100097 (40) which demonstrated partial efficacy in a stage 2 (CNS)
mouse model of HAT.
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Affiliation(s)
- Stephen Brand
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee , Sir James Black Centre, Dundee DD1 5EH, U.K
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A target repurposing approach identifies N-myristoyltransferase as a new candidate drug target in filarial nematodes. PLoS Negl Trop Dis 2014; 8:e3145. [PMID: 25188325 PMCID: PMC4154664 DOI: 10.1371/journal.pntd.0003145] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 07/25/2014] [Indexed: 11/19/2022] Open
Abstract
Myristoylation is a lipid modification involving the addition of a 14-carbon unsaturated fatty acid, myristic acid, to the N-terminal glycine of a subset of proteins, a modification that promotes their binding to cell membranes for varied biological functions. The process is catalyzed by myristoyl-CoA:protein N-myristoyltransferase (NMT), an enzyme which has been validated as a drug target in human cancers, and for infectious diseases caused by fungi, viruses and protozoan parasites. We purified Caenorhabditis elegans and Brugia malayi NMTs as active recombinant proteins and carried out kinetic analyses with their essential fatty acid donor, myristoyl-CoA and peptide substrates. Biochemical and structural analyses both revealed that the nematode enzymes are canonical NMTs, sharing a high degree of conservation with protozoan NMT enzymes. Inhibitory compounds that target NMT in protozoan species inhibited the nematode NMTs with IC50 values of 2.5–10 nM, and were active against B. malayi microfilariae and adult worms at 12.5 µM and 50 µM respectively, and C. elegans (25 µM) in culture. RNA interference and gene deletion in C. elegans further showed that NMT is essential for nematode viability. The effects observed are likely due to disruption of the function of several downstream target proteins. Potential substrates of NMT in B. malayi are predicted using bioinformatic analysis. Our genetic and chemical studies highlight the importance of myristoylation in the synthesis of functional proteins in nematodes and have shown for the first time that NMT is required for viability in parasitic nematodes. These results suggest that targeting NMT could be a valid approach for the development of chemotherapeutic agents against nematode diseases including filariasis. Lymphatic filariasis and onchocerciasis are neglected tropical diseases caused by filarial nematodes. The limitations of existing drugs to treat these infections highlight the need for new drugs. In the present study, we investigated myristoylation, a lipid modification of a subset of proteins that promotes their binding to cell membranes for varied biological functions. The process is catalyzed by N-myristoyltransferase (NMT), an enzyme which has been validated as a drug target in protozoan parasites. We performed kinetic analyses on Caenorhabditis elegans and Brugia malayi NMTs. NMT inhibitors were active against B. malayi microfilariae and adult worms, and C. elegans in culture. RNA interference and gene deletion in C. elegans further demonstrated that NMT is essential for nematode viability. Our genetic and chemical studies indicate the importance of myristoylation in the synthesis of functional proteins in nematodes and have shown for the first time that NMT is required for viability in parasitic nematodes. These results suggest that targeting NMT could be a valid approach for the development of new therapies against nematode infection including filarial diseases.
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23
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Drug target identification using a trypanosome overexpression library. Antimicrob Agents Chemother 2014; 58:6260-4. [PMID: 25049244 DOI: 10.1128/aac.03338-14] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Elucidation of molecular targets is very important for lead optimization during the drug development process. We describe a direct method to find targets of antitrypanosomal compounds against Trypanosoma brucei using a trypanosome overexpression library. As proof of concept, we treated the library with difluoromethylornithine and DDD85646 and identified their respective targets, ornithine decarboxylase and N-myristoyltransferase. The overexpression library could be a useful tool to study the modes of action of novel antitrypanosomal drug candidates.
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24
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Njoroge M, Njuguna NM, Mutai P, Ongarora DSB, Smith PW, Chibale K. Recent approaches to chemical discovery and development against malaria and the neglected tropical diseases human African trypanosomiasis and schistosomiasis. Chem Rev 2014; 114:11138-63. [PMID: 25014712 DOI: 10.1021/cr500098f] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
| | | | | | | | - Paul W Smith
- Novartis Institute for Tropical Diseases , Singapore 138670, Singapore
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25
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Brannigan JA, Roberts SM, Bell AS, Hutton JA, Hodgkinson MR, Tate EW, Leatherbarrow RJ, Smith DF, Wilkinson AJ. Diverse modes of binding in structures of Leishmania major N-myristoyltransferase with selective inhibitors. IUCRJ 2014; 1:250-60. [PMID: 25075346 PMCID: PMC4107925 DOI: 10.1107/s2052252514013001] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 06/04/2014] [Indexed: 05/08/2023]
Abstract
The leishmaniases are a spectrum of global diseases of poverty associated with immune dysfunction and are the cause of high morbidity. Despite the long history of these diseases, no effective vaccine is available and the currently used drugs are variously compromised by moderate efficacy, complex side effects and the emergence of resistance. It is therefore widely accepted that new therapies are needed. N-Myristoyltransferase (NMT) has been validated pre-clinically as a target for the treatment of fungal and parasitic infections. In a previously reported high-throughput screening program, a number of hit compounds with activity against NMT from Leishmania donovani have been identified. Here, high-resolution crystal structures of representative compounds from four hit series in ternary complexes with myristoyl-CoA and NMT from the closely related L. major are reported. The structures reveal that the inhibitors associate with the peptide-binding groove at a site adjacent to the bound myristoyl-CoA and the catalytic α-carboxylate of Leu421. Each inhibitor makes extensive apolar contacts as well as a small number of polar contacts with the protein. Remarkably, the compounds exploit different features of the peptide-binding groove and collectively occupy a substantial volume of this pocket, suggesting that there is potential for the design of chimaeric inhibitors with significantly enhanced binding. Despite the high conservation of the active sites of the parasite and human NMTs, the inhibitors act selectively over the host enzyme. The role of conformational flexibility in the side chain of Tyr217 in conferring selectivity is discussed.
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Affiliation(s)
- James A. Brannigan
- Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, England
| | - Shirley M. Roberts
- Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, England
| | - Andrew S. Bell
- Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, England
| | - Jennie A. Hutton
- Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, England
| | - Michael R. Hodgkinson
- Centre for Immunology and Infection, Department of Biology, University of York, York YO10 5DD, England
| | - Edward W. Tate
- Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, England
| | - Robin J. Leatherbarrow
- Department of Chemistry, Imperial College London, South Kensington Campus, London SW7 2AZ, England
| | - Deborah F. Smith
- Centre for Immunology and Infection, Department of Biology, University of York, York YO10 5DD, England
| | - Anthony J. Wilkinson
- Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, England
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26
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Goldston AM, Sharma AI, Paul KS, Engman DM. Acylation in trypanosomatids: an essential process and potential drug target. Trends Parasitol 2014; 30:350-60. [PMID: 24954795 DOI: 10.1016/j.pt.2014.05.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 05/06/2014] [Accepted: 05/06/2014] [Indexed: 12/11/2022]
Abstract
Fatty acylation--the addition of fatty acid moieties such as myristate and palmitate to proteins--is essential for the survival, growth, and infectivity of the trypanosomatids: Trypanosoma brucei, Trypanosoma cruzi, and Leishmania. Myristoylation and palmitoylation are critical for parasite growth, targeting and localization, and the intrinsic function of some proteins. The trypanosomatids possess a single N-myristoyltransferase (NMT) and multiple palmitoyl acyltransferases, and these enzymes and their protein targets are only now being characterized. Global inhibition of either process leads to cell death in trypanosomatids, and genetic ablation of NMT compromises virulence. Moreover, NMT inhibitors effectively cure T. brucei infection in rodents. Thus, protein acylation represents an attractive target for the development of new trypanocidal drugs.
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Affiliation(s)
- Amanda M Goldston
- Departments of Pathology and Microbiology-Immunology, Northwestern University, Chicago, Illinois, USA
| | - Aabha I Sharma
- Departments of Pathology and Microbiology-Immunology, Northwestern University, Chicago, Illinois, USA
| | - Kimberly S Paul
- Department of Genetics and Biochemistry, Clemson University, Clemson, South Carolina, USA
| | - David M Engman
- Departments of Pathology and Microbiology-Immunology, Northwestern University, Chicago, Illinois, USA.
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27
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Roberts A, Torrie L, Wyllie S, Fairlamb A. Biochemical and genetic characterization of Trypanosoma cruzi N-myristoyltransferase. Biochem J 2014; 459:323-32. [PMID: 24444291 PMCID: PMC3969225 DOI: 10.1042/bj20131033] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 01/20/2014] [Accepted: 01/21/2014] [Indexed: 12/20/2022]
Abstract
Co- and post-translational N-myristoylation is known to play a role in the correct subcellular localization of specific proteins in eukaryotes. The enzyme that catalyses this reaction, NMT (N-myristoyltransferase), has been pharmacologically validated as a drug target in the African trypanosome, Trypanosoma brucei. In the present study, we evaluate NMT as a potential drug target in Trypanosoma cruzi, the causative agent of Chagas' disease, using chemical and genetic approaches. Replacement of both allelic copies of TcNMT (T. cruzi NMT) was only possible in the presence of a constitutively expressed ectopic copy of the gene, indicating that this gene is essential for survival of T. cruzi epimastigotes. The pyrazole sulphonamide NMT inhibitor DDD85646 is 13-23-fold less potent against recombinant TcNMT than TbNMT (T. brucei NMT), with Ki values of 12.7 and 22.8 nM respectively, by scintillation proximity or coupled assay methods. DDD85646 also inhibits growth of T. cruzi epimastigotes (EC50=6.9 μM), but is ~1000-fold less potent than that reported for T. brucei. On-target activity is demonstrated by shifts in cell potency in lines that over- and under-express NMT and by inhibition of intracellular N-myristoylation of several proteins in a dose-dependent manner. Collectively, our findings suggest that N-myristoylation is an essential and druggable target in T. cruzi.
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Key Words
- chagas’ disease
- click chemistry
- drug target
- n-myristoylation
- trypanosoma cruzi
- validation
- cap5.5, cytoskeleton-associated protein 5.5
- dig, digoxigenin
- dko, double knockout
- dmem, dulbecco’s modified eagle’s medium
- hyg, hygromycin phosphotransferase
- nmt, n-myristoyltransferase
- nmtoe, nmt overexpressor
- pac, puromycin n-acetyltransferase
- rth/fbs, rpmi 1640 medium supplemented with trypticase, haemin, hepes and 10% heat-inactivated fbs
- sko, single knockout
- tbnmt, trypanosoma brucei nmt
- tcep, tris-(2-carboxyethyl)phosphine
- tcnmt, trypanosoma cruzi nmt
- tctryr, trypanosoma cruzi trypanothione reductase
- wt, wild-type
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Affiliation(s)
- Adam J. Roberts
- *Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee DD1 5EH, U.K
| | - Leah S. Torrie
- *Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee DD1 5EH, U.K
| | - Susan Wyllie
- *Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee DD1 5EH, U.K
| | - Alan H. Fairlamb
- *Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Dundee DD1 5EH, U.K
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28
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Tate EW, Bell AS, Rackham MD, Wright MH. N-Myristoyltransferase as a potential drug target in malaria and leishmaniasis. Parasitology 2014; 141:37-49. [PMID: 23611109 DOI: 10.1017/s0031182013000450] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Infections caused by protozoan parasites are among the most widespread and intractable transmissible diseases affecting the developing world, with malaria and leishmaniasis being the most costly in terms of morbidity and mortality. Although new drugs are urgently required against both diseases in the face of ever-rising resistance to frontline therapies, very few candidates passing through development pipelines possess a known and novel mode of action. Set in the context of drugs currently in use and under development, we present the evidence for N-myristoyltransferase (NMT), an enzyme that N-terminally lipidates a wide range of specific target proteins through post-translational modification, as a potential drug target in malaria and the leishmaniases. We discuss the limitations of current knowledge regarding the downstream targets of this enzyme in protozoa, and our recent progress towards potent cell-active NMT inhibitors against the most clinically-relevant species of parasite. Finally, we outline the next steps required in terms of both tools to understand N-myristoylation in protozoan parasites, and the generation of potential development candidates based on the output of our recently-reported high-throughput screens.
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Affiliation(s)
- Edward W Tate
- Department of Chemistry, Institute of Chemical Biology, Imperial College London, London SW7 2AZ, UK
| | - Andrew S Bell
- Department of Chemistry, Institute of Chemical Biology, Imperial College London, London SW7 2AZ, UK
| | - Mark D Rackham
- Department of Chemistry, Institute of Chemical Biology, Imperial College London, London SW7 2AZ, UK
| | - Megan H Wright
- Department of Chemistry, Institute of Chemical Biology, Imperial College London, London SW7 2AZ, UK
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29
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Gilbert IH. Drug discovery for neglected diseases: molecular target-based and phenotypic approaches. J Med Chem 2013; 56:7719-26. [PMID: 24015767 PMCID: PMC3954685 DOI: 10.1021/jm400362b] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
![]()
Drug
discovery for neglected tropical diseases is carried out using
both target-based and phenotypic approaches. In this paper, target-based
approaches are discussed, with a particular focus on human African
trypanosomiasis. Target-based drug discovery can be successful, but
careful selection of targets is required. There are still very few
fully validated drug targets in neglected diseases, and there is a
high attrition rate in target-based drug discovery for these diseases.
Phenotypic screening is a powerful method in both neglected and non-neglected
diseases and has been very successfully used. Identification of molecular
targets from phenotypic approaches can be a way to identify potential
new drug targets.
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Affiliation(s)
- Ian H Gilbert
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee , Dundee DD1 5EH, U.K
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30
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Target-based drug discovery for human African trypanosomiasis: selection of molecular target and chemical matter. Parasitology 2013; 141:28-36. [PMID: 23931634 PMCID: PMC3884840 DOI: 10.1017/s0031182013001017] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Target-based approaches for human African trypanosomiasis (HAT) and related parasites can be a valuable route for drug discovery for these diseases. However, care needs to be taken in selection of both the actual drug target and the chemical matter that is developed. In this article, potential criteria to aid target selection are described. Then the physiochemical properties of typical oral drugs are discussed and compared to those of known anti-parasitics.
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31
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Renna L, Stefano G, Majeran W, Micalella C, Meinnel T, Giglione C, Brandizzi F. Golgi traffic and integrity depend on N-myristoyl transferase-1 in Arabidopsis. THE PLANT CELL 2013; 25:1756-73. [PMID: 23673980 PMCID: PMC3694704 DOI: 10.1105/tpc.113.111393] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
N-myristoylation is a crucial irreversible eukaryotic lipid modification allowing a key subset of proteins to be targeted at the periphery of specific membrane compartments. Eukaryotes have conserved N-myristoylation enzymes, involving one or two N-myristoyltransferases (NMT1 and NMT2), among which NMT1 is the major enzyme. In the postembryonic developmental stages, defects in NMT1 lead to aberrant cell polarity, flower differentiation, fruit maturation, and innate immunity; however, no specific NMT1 target responsible for such deficiencies has hitherto been identified. Using a confocal microscopy forward genetics screen for the identification of Arabidopsis thaliana secretory mutants, we isolated STINGY, a recessive mutant with defective Golgi traffic and integrity. We mapped STINGY to a substitution at position 160 of Arabidopsis NMT1 (NMT1A160T). In vitro kinetic studies with purified NMT1A160T enzyme revealed a significant reduction in its activity due to a remarkable decrease in affinity for both myristoyl-CoA and peptide substrates. We show here that this recessive mutation is responsible for the alteration of Golgi traffic and integrity by predominantly affecting the Golgi membrane/cytosol partitioning of ADP-ribosylation factor proteins. Our results provide important functional insight into N-myristoylation in plants by ascribing postembryonic functions of Arabidopsis NMT1 that involve regulation of the functional and morphological integrity of the plant endomembranes.
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Affiliation(s)
- Luciana Renna
- Michigan State University–Department of Energy Plant Research Lab, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - Giovanni Stefano
- Michigan State University–Department of Energy Plant Research Lab, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
| | - Wojciech Majeran
- Centre National de la Recherche Scientifique, Campus de Recherche de Gif, Institut des Sciences du Végétal, F-91198 Gif-sur-Yvette cedex, France
| | - Chiara Micalella
- Centre National de la Recherche Scientifique, Campus de Recherche de Gif, Institut des Sciences du Végétal, F-91198 Gif-sur-Yvette cedex, France
| | - Thierry Meinnel
- Centre National de la Recherche Scientifique, Campus de Recherche de Gif, Institut des Sciences du Végétal, F-91198 Gif-sur-Yvette cedex, France
| | - Carmela Giglione
- Centre National de la Recherche Scientifique, Campus de Recherche de Gif, Institut des Sciences du Végétal, F-91198 Gif-sur-Yvette cedex, France
| | - Federica Brandizzi
- Michigan State University–Department of Energy Plant Research Lab, Michigan State University, East Lansing, Michigan 48824
- Department of Plant Biology, Michigan State University, East Lansing, Michigan 48824
- Address correspondence to
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32
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Price HP, Hodgkinson MR, Wright MH, Tate EW, Smith BA, Carrington M, Stark M, Smith DF. A role for the vesicle-associated tubulin binding protein ARL6 (BBS3) in flagellum extension in Trypanosoma brucei. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1823:1178-91. [PMID: 22609302 PMCID: PMC3793860 DOI: 10.1016/j.bbamcr.2012.05.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Revised: 04/23/2012] [Accepted: 05/05/2012] [Indexed: 11/17/2022]
Abstract
The small GTPase Arl6 is implicated in the ciliopathic human genetic disorder Bardet-Biedl syndrome, acting at primary cilia in recruitment of the octomeric BBSome complex, which is required for specific trafficking events to and from the cilium in eukaryotes. Here we describe functional characterisation of Arl6 in the flagellated model eukaryote Trypanosoma brucei, which requires motility for viability. Unlike human Arl6 which has a ciliary localisation, TbARL6 is associated with electron-dense vesicles throughout the cell body following co-translational modification by N-myristoylation. Similar to the related protein ARL-3A in T. brucei, modulation of expression of ARL6 by RNA interference does not prevent motility but causes a significant reduction in flagellum length. Tubulin is identified as an ARL6 interacting partner, suggesting that ARL6 may act as an anchor between vesicles and cytoplasmic microtubules. We provide evidence that the interaction between ARL6 and the BBSome is conserved in unicellular eukaryotes. Overexpression of BBS1 leads to translocation of endogenous ARL6 to the site of exogenous BBS1 at the flagellar pocket. Furthermore, a combination of BBS1 overexpression and ARL6 RNAi has a synergistic inhibitory effect on cell growth. Our findings indicate that ARL6 in trypanosomes contributes to flagellum biogenesis, most likely through an interaction with the BBSome.
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Affiliation(s)
- Helen P Price
- Centre for Immunology and Infection, Department of Biology, University of York, Heslington, York YO10 5YW, UK.
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Selective inhibitors of protozoan protein N-myristoyltransferases as starting points for tropical disease medicinal chemistry programs. PLoS Negl Trop Dis 2012; 6:e1625. [PMID: 22545171 PMCID: PMC3335879 DOI: 10.1371/journal.pntd.0001625] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Accepted: 03/07/2012] [Indexed: 01/11/2023] Open
Abstract
Inhibition of N-myristoyltransferase has been validated pre-clinically as a target for the treatment of fungal and trypanosome infections, using species-specific inhibitors. In order to identify inhibitors of protozoan NMTs, we chose to screen a diverse subset of the Pfizer corporate collection against Plasmodium falciparum and Leishmania donovani NMTs. Primary screening hits against either enzyme were tested for selectivity over both human NMT isoforms (Hs1 and Hs2) and for broad-spectrum anti-protozoan activity against the NMT from Trypanosoma brucei. Analysis of the screening results has shown that structure-activity relationships (SAR) for Leishmania NMT are divergent from all other NMTs tested, a finding not predicted by sequence similarity calculations, resulting in the identification of four novel series of Leishmania-selective NMT inhibitors. We found a strong overlap between the SARs for Plasmodium NMT and both human NMTs, suggesting that achieving an appropriate selectivity profile will be more challenging. However, we did discover two novel series with selectivity for Plasmodium NMT over the other NMT orthologues in this study, and an additional two structurally distinct series with selectivity over Leishmania NMT. We believe that release of results from this study into the public domain will accelerate the discovery of NMT inhibitors to treat malaria and leishmaniasis. Our screening initiative is another example of how a tripartite partnership involving pharmaceutical industries, academic institutions and governmental/non-governmental organisations such as Medical Research Council and Wellcome Trust can stimulate research for neglected diseases. Inhibition of N-myristoyltransferase has been validated pre-clinically as a target for the treatment of fungal and trypanosome infections, using species-specific inhibitors. In order to identify inhibitors of protozoan NMTs, we chose to screen a diverse subset of the Pfizer corporate collection against Plasmodium falciparum and Leishmania donovani NMTs. Primary screening hits against either enzyme were tested for selectivity over both human NMT isoforms (HsNMT1 and HsNMT2) and for broad-spectrum anti-protozoan activity against the NMT from Trypanosoma brucei. We have identified eight series of protozoan NMT inhibitors, six having good selectivity for either Plasmodium or Leishmania NMTs over the other orthologues in this study. We believe that all of these series could form the basis of medicinal chemistry programs to deliver drug candidates against either malaria or leishmaniasis. Our screening initiative is another example of how a tripartite partnership involving pharmaceutical industries, academic institutions and governmental/non-governmental organisations such as the UK Medical Research Council and Wellcome Trust can stimulate research for neglected diseases.
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Acylation-dependent and-independent membrane targeting and distinct functions of small myristoylated proteins (SMPs) in Leishmania major. Int J Parasitol 2012; 42:239-47. [DOI: 10.1016/j.ijpara.2011.12.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 12/21/2011] [Accepted: 12/22/2011] [Indexed: 11/20/2022]
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35
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Abstract
Parasitic diseases cause important losses in public and veterinary health worldwide. Novel drugs, more reliable diagnostic techniques and vaccine candidates are urgently needed. Due to the complexity of parasites and the intricate relationship with their hosts, development of successful tools to fight parasites has been very limited to date. The growing information on individual parasite genomes is now allowing the use of a broader range of potential strategies to gain deeper insights into the host-parasite relationship and has increased the possibilities to develop molecular-based tools in the field of parasitology. Nevertheless, functional studies of respective genes are still scarce. The RNA interference phenomenon resulting in the regulation of protein expression through the specific degradation of defined mRNAs, and more specifically the possibility of artificially induce it, has shown to be a powerful tool for the investigation of proteins function in many organisms. Recent advances in the design and delivery of targeting molecules allow efficient and highly specific gene silencing in different types of parasites, pointing out this technology as a powerful tool for the identification of novel vaccine candidates or drug targets at the high-throughput level in the near future, and could enable researchers to functionally annotate parasite genomes. The aim of this review is to provide a comprehensive overview on the current advances and pitfalls in gene silencing mechanisms, techniques, applications and prospects in animal parasites.
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Brand S, Cleghorn LAT, McElroy SP, Robinson DA, Smith VC, Hallyburton I, Harrison JR, Norcross NR, Spinks D, Bayliss T, Norval S, Stojanovski L, Torrie LS, Frearson JA, Brenk R, Fairlamb AH, Ferguson MAJ, Read KD, Wyatt PG, Gilbert IH. Discovery of a novel class of orally active trypanocidal N-myristoyltransferase inhibitors. J Med Chem 2011; 55:140-52. [PMID: 22148754 PMCID: PMC3256935 DOI: 10.1021/jm201091t] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
N-Myristoyltransferase (NMT) represents a promising drug target for human African trypanosomiasis (HAT), which is caused by the parasitic protozoa Trypanosoma brucei. We report the optimization of a high throughput screening hit (1) to give a lead molecule DDD85646 (63), which has potent activity against the enzyme (IC(50) = 2 nM) and T. brucei (EC(50) = 2 nM) in culture. The compound has good oral pharmacokinetics and cures rodent models of peripheral HAT infection. This compound provides an excellent tool for validation of T. brucei NMT as a drug target for HAT as well as a valuable lead for further optimization.
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Affiliation(s)
- Stephen Brand
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, College of Life Sciences, University of Dundee, Sir James Black Centre, Dundee, DD1 5EH, U.K
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37
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Creek DJ, Anderson J, McConville MJ, Barrett MP. Metabolomic analysis of trypanosomatid protozoa. Mol Biochem Parasitol 2011; 181:73-84. [PMID: 22027026 DOI: 10.1016/j.molbiopara.2011.10.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Revised: 10/04/2011] [Accepted: 10/06/2011] [Indexed: 01/05/2023]
Abstract
Metabolomics aims to measure all low molecular weight chemicals within a given system in a manner analogous to transcriptomics, proteomics and genomics. In this review we highlight metabolomics approaches that are currently being applied to the kinetoplastid parasites, Trypanosoma brucei and Leishmania spp. The use of untargeted metabolomics approaches, made possible through advances in mass spectrometry and informatics, and stable isotope labelling has increased our understanding of the metabolism in these organisms beyond the views established using classical biochemical approaches. Set within the context of metabolic networks, predicted using genome-wide reconstructions of metabolism, new hypotheses on how to target aspects of metabolism to design new drugs against these protozoa are emerging.
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Affiliation(s)
- Darren J Creek
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8TA, United Kingdom
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Brun R, Don R, Jacobs RT, Wang MZ, Barrett MP. Development of novel drugs for human African trypanosomiasis. Future Microbiol 2011; 6:677-91. [DOI: 10.2217/fmb.11.44] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Human African trypanosomiasis (HAT) or ‘sleeping sickness’ is a neglected tropical disease caused by the parasite Trypanosoma brucei. Novel models for funding pharmaceutical development against HAT are beginning to yield results. The Drugs for Neglected Diseases initiative (DNDi) rediscovered a nitroimidazole, fexinidazole, which is currently in Phase I clinical trials. Novel benzoxaboroles, discovered by Anacor, Scynexis and DNDi, have good pharmacokinetic properties in plasma and in the brain and are curative in a murine model of stage two HAT with brain infection. The Consortium for Parasitic Drug Development (CPDD) has identified a series of dicationic compounds that can cure a monkey model of stage two HAT. With other screening programs yielding hits, the pipeline for new HAT drugs might finally begin to fill.
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Affiliation(s)
- Reto Brun
- Department Medical Parasitology & Infection Biology, Swiss Tropical & Public Health Institute, and, University of Basel, CH-4002 Basel, Switzerland
| | - Robert Don
- Drugs for Neglected Diseases initiative, Geneva, Switzerland
| | - Robert T Jacobs
- Department of Chemistry, SCYNEXIS, Inc., PO Box 12878, Research Triangle Park, NC, 27709-2878, USA
| | - Michael Zhuo Wang
- Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Michael P Barrett
- Wellcome Trust Centre for Molecular Parasitology, University of Glasgow, Glasgow, Scotland
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Zucca M, Savoia D. Current developments in the therapy of protozoan infections. THE OPEN MEDICINAL CHEMISTRY JOURNAL 2011; 5:4-10. [PMID: 21629507 PMCID: PMC3103884 DOI: 10.2174/1874104501105010004] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Revised: 05/25/2010] [Accepted: 06/20/2010] [Indexed: 12/03/2022]
Abstract
Protozoan parasites cause serious human and zoonotic infections, including life-threatening diseases such as malaria, African and American trypanosomiasis, and leishmaniasis. These diseases are no more common in the developed world, but together they still threaten about 40% of the world population (WHO estimates). Mortality and morbidity are high in developing countries, and the lack of vaccines makes chemotherapy the only suitable option. However, available antiparasitic drugs are hampered by more or less marked toxic side effects and by the emergence of drug resistance. As the main prevalence of parasitic diseases occurs in the poorest areas of the world, the interest of the pharmaceutical companies in the development of new drugs has been traditionally scarce. The establishment of public-private partnerships focused on tropical diseases is changing this situation, allowing the exploitation of the technological advances that took place during the past decade related to genomics, proteomics, and in silico drug discovery approaches. These techniques allowed the identification of new molecular targets that in some cases are shared by different parasites. In this review we outline the recent developments in the fields of protease and topoisomerase inhibitors, antimicrobial and cell-penetrating peptides, and RNA interference. We also report on the rapidly developing field of new vectors (micro and nano particles, mesoporous materials) that in some cases can cross host or parasite natural barriers and, by selectively delivering new or already in use drugs to the target site, minimize dosage and side effects.
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Affiliation(s)
- Mario Zucca
- Department of Clinical and Biological Sciences, University of Torino, Italy
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Frearson JA, Brand S, McElroy SP, Cleghorn LAT, Smid O, Stojanovski L, Price HP, Guther MLS, Torrie LS, Robinson DA, Hallyburton I, Mpamhanga CP, Brannigan JA, Wilkinson AJ, Hodgkinson M, Hui R, Qiu W, Raimi OG, van Aalten DMF, Brenk R, Gilbert IH, Read KD, Fairlamb AH, Ferguson MAJ, Smith DF, Wyatt PG. N-myristoyltransferase inhibitors as new leads to treat sleeping sickness. Nature 2010; 464:728-32. [PMID: 20360736 PMCID: PMC2917743 DOI: 10.1038/nature08893] [Citation(s) in RCA: 221] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Accepted: 02/10/2010] [Indexed: 01/28/2023]
Abstract
African sleeping sickness or human African trypanosomiasis, caused by Trypanosoma brucei spp., is responsible for approximately 30,000 deaths each year. Available treatments for this disease are poor, with unacceptable efficacy and safety profiles, particularly in the late stage of the disease when the parasite has infected the central nervous system. Here we report the validation of a molecular target and the discovery of associated lead compounds with the potential to address this lack of suitable treatments. Inhibition of this target-T. brucei N-myristoyltransferase-leads to rapid killing of trypanosomes both in vitro and in vivo and cures trypanosomiasis in mice. These high-affinity inhibitors bind into the peptide substrate pocket of the enzyme and inhibit protein N-myristoylation in trypanosomes. The compounds identified have promising pharmaceutical properties and represent an opportunity to develop oral drugs to treat this devastating disease. Our studies validate T. brucei N-myristoyltransferase as a promising therapeutic target for human African trypanosomiasis.
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Affiliation(s)
- Julie A Frearson
- Drug Discovery Unit, Division of Biological Chemistry and Drug Discovery, University of Dundee, Dundee DD1 5EH, UK
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Lipid metabolism in Trypanosoma brucei. Mol Biochem Parasitol 2010; 172:66-79. [PMID: 20382188 DOI: 10.1016/j.molbiopara.2010.04.001] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Revised: 03/31/2010] [Accepted: 04/01/2010] [Indexed: 11/28/2022]
Abstract
Trypanosoma brucei membranes consist of all major eukaryotic glycerophospholipid and sphingolipid classes. These are de novo synthesized from precursors obtained either from the host or from catabolised endocytosed lipids. In recent years, substantial progress has been made in the molecular and biochemical characterisation of several of these lipid biosynthetic pathways, using gene knockout or RNA interference strategies or by enzymatic characterization of individual reactions. Together with the completed genome, these studies have highlighted several possible differences between mammalian and trypanosome lipid biosynthesis that could be exploited for the development of drugs against the diseases caused by these parasites.
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Brannigan JA, Smith BA, Yu Z, Brzozowski AM, Hodgkinson MR, Maroof A, Price HP, Meier F, Leatherbarrow RJ, Tate EW, Smith DF, Wilkinson AJ. N-myristoyltransferase from Leishmania donovani: structural and functional characterisation of a potential drug target for visceral leishmaniasis. J Mol Biol 2010; 396:985-99. [PMID: 20036251 PMCID: PMC2829124 DOI: 10.1016/j.jmb.2009.12.032] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2009] [Revised: 12/15/2009] [Accepted: 12/16/2009] [Indexed: 12/30/2022]
Abstract
N-Myristoyltransferase (NMT) catalyses the attachment of the 14-carbon saturated fatty acid, myristate, to the amino-terminal glycine residue of a subset of eukaryotic proteins that function in multiple cellular processes, including vesicular protein trafficking and signal transduction. In these pathways, N-myristoylation facilitates association of substrate proteins with membranes or the hydrophobic domains of other partner peptides. NMT function is essential for viability in all cell types tested to date, demonstrating that this enzyme has potential as a target for drug development. Here, we provide genetic evidence that NMT is likely to be essential for viability in insect stages of the pathogenic protozoan parasite, Leishmania donovani, causative agent of the tropical infectious disease, visceral leishmaniasis. The open reading frame of L. donovani NMT has been amplified and used to overproduce active recombinant enzyme in Escherichia coli, as demonstrated by gel mobility shift assays of ligand binding and peptide-myristoylation activity in scintillation proximity assays. The purified protein has been crystallized in complex with the non-hydrolysable substrate analogue S-(2-oxo)pentadecyl-CoA, and its structure was solved by molecular replacement at 1.4 A resolution. The structure has as its defining feature a 14-stranded twisted beta-sheet on which helices are packed so as to form an extended and curved substrate-binding groove running across two protein lobes. The fatty acyl-CoA is largely buried in the N-terminal lobe, its binding leading to the loosening of a flap, which in unliganded NMT structures, occludes the protein substrate binding site in the carboxy-terminal lobe. These studies validate L. donovani NMT as a potential target for development of new therapeutic agents against visceral leishmaniasis.
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Key Words
- arf, adp-ribosylation factor
- dig, digoxigenin
- hasp, hydrophilic acylated surface protein
- hyg, hygromycin
- neo, neomycin
- nhm, non-hydrolysable myristoyl-coa analogue
- nmt, n-myristoyltransferase
- orf, open reading frame
- pac, puromycin
- spa, scintillation proximity assay
- vl, visceral leishmaniasis
- canmt, hsnmt, ldnmt and scnmt, n-myristoyltransferase from candida albicans, homo sapiens, leishmania donovani and saccharomyces cerevisiae, respectively
- n-myristoyltransferase
- leishmania
- visceral leishmaniasis
- crystal structure
- drug target
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Affiliation(s)
- James A. Brannigan
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5YW, UK
| | - Barbara A. Smith
- Centre for Immunology and Infection, Department of Biology/Hull York Medical School, University of York, York YO10 5YW, UK
| | - Zhiyong Yu
- Department of Chemistry, Imperial College, London SW7 2AZ, UK
| | - Andrzej M. Brzozowski
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5YW, UK
| | - Michael R. Hodgkinson
- Centre for Immunology and Infection, Department of Biology/Hull York Medical School, University of York, York YO10 5YW, UK
| | - Asher Maroof
- Centre for Immunology and Infection, Department of Biology/Hull York Medical School, University of York, York YO10 5YW, UK
| | - Helen P. Price
- Centre for Immunology and Infection, Department of Biology/Hull York Medical School, University of York, York YO10 5YW, UK
| | - Franziska Meier
- Department of Chemistry, Imperial College, London SW7 2AZ, UK
| | | | - Edward W. Tate
- Department of Chemistry, Imperial College, London SW7 2AZ, UK
| | - Deborah F. Smith
- Centre for Immunology and Infection, Department of Biology/Hull York Medical School, University of York, York YO10 5YW, UK
| | - Anthony J. Wilkinson
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5YW, UK
- Corresponding author.
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