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Cleghorn LAT, Woodland A, Collie IT, Torrie LS, Norcross N, Luksch T, Mpamhanga C, Walker RG, Mottram JC, Brenk R, Frearson JA, Gilbert IH, Wyatt PG. Identification of inhibitors of the Leishmania cdc2-related protein kinase CRK3. ChemMedChem 2011; 6:2214-24. [PMID: 21913331 PMCID: PMC3272345 DOI: 10.1002/cmdc.201100344] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Revised: 08/16/2011] [Indexed: 12/03/2022]
Abstract
New drugs are urgently needed for the treatment of tropical parasitic diseases such as leishmaniasis and human African trypanosomiasis (HAT). This work involved a high-throughput screen of a focussed kinase set of ∼3400 compounds to identify potent and parasite-selective inhibitors of an enzymatic Leishmania CRK3–cyclin 6 complex. The aim of this study is to provide chemical validation that Leishmania CRK3–CYC6 is a drug target. Eight hit series were identified, of which four were followed up. The optimisation of these series using classical SAR studies afforded low-nanomolar CRK3 inhibitors with significant selectivity over the closely related human cyclin dependent kinase CDK2.
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Affiliation(s)
- Laura A T Cleghorn
- Drug Discovery Unit, College of Life Sciences, James Black Centre, University of Dundee, Dundee, DD1 5EH, UK
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Jorda R, Sacerdoti-Sierra N, Voller J, Havlíček L, Kráčalíková K, Nowicki MW, Nasereddin A, Kryštof V, Strnad M, Walkinshaw MD, Jaffe CL. Anti-leishmanial activity of disubstituted purines and related pyrazolo[4,3-d]pyrimidines. Bioorg Med Chem Lett 2011; 21:4233-7. [DOI: 10.1016/j.bmcl.2011.05.076] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2011] [Revised: 05/19/2011] [Accepted: 05/20/2011] [Indexed: 12/25/2022]
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Allahverdiyev AM, Koc RC, Ates SC, Bagirova M, Elcicek S, Oztel ON. Leishmania tropica: the effect of darkness and light on biological activities in vitro. Exp Parasitol 2011; 128:318-23. [PMID: 21510933 DOI: 10.1016/j.exppara.2011.04.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Revised: 04/01/2011] [Accepted: 04/05/2011] [Indexed: 11/27/2022]
Abstract
Leishmania parasites can be exposed to effects of light in their vectors and hosts, at various periods. However, there is no information about the effects of light on Leishmania parasites. The aim of this study is to investigate the effects of light on various cell parameters of Leishmania tropica, in vitro. All experiments were conducted on L. tropica promastigotes and amastigote-macrophage cultures, using flow cytometric analysis, MTT and phenol-sulfuric acid assay, DAPI and Giemsa. The results showed that the morphology of parasites has changed; the cell cycle has been affected and this caused parasites to remain at G0/G1 phase. Furthermore the proliferation, infectivity, glucose consumption and mitochondrial dehydrogenase activities of parasites were decreased. Thus, for the first time, in this study, the effects of light on biological activities of Leishmania parasites were shown. These new information about parasites' biology, would be very important to investigate the effects of light on the parasites in infected vectors and hosts.
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Affiliation(s)
- Adil M Allahverdiyev
- Yildiz Technical University, Department of Bioengineering, 34220 Istanbul, Turkey.
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Walker RG, Thomson G, Malone K, Nowicki MW, Brown E, Blake DG, Turner NJ, Walkinshaw MD, Grant KM, Mottram JC. High throughput screens yield small molecule inhibitors of Leishmania CRK3:CYC6 cyclin-dependent kinase. PLoS Negl Trop Dis 2011; 5:e1033. [PMID: 21483720 PMCID: PMC3071374 DOI: 10.1371/journal.pntd.0001033] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Accepted: 03/10/2011] [Indexed: 11/19/2022] Open
Abstract
Background Leishmania species are parasitic protozoa that have a tightly controlled cell cycle, regulated by cyclin-dependent kinases (CDKs). Cdc2-related kinase 3 (CRK3), an essential CDK in Leishmania and functional orthologue of human CDK1, can form an active protein kinase complex with Leishmania cyclins CYCA and CYC6. Here we describe the identification and synthesis of specific small molecule inhibitors of bacterially expressed Leishmania CRK3:CYC6 using a high throughput screening assay and iterative chemistry. We also describe the biological activity of the molecules against Leishmania parasites. Methodology/Principal Findings In order to obtain an active Leishmania CRK3:CYC6 protein kinase complex, we developed a co-expression and co-purification system for Leishmania CRK3 and CYC6 proteins. This active enzyme was used in a high throughput screening (HTS) platform, utilising an IMAP fluorescence polarisation assay. We carried out two chemical library screens and identified specific inhibitors of CRK3:CYC6 that were inactive against the human cyclin-dependent kinase CDK2:CycA. Subsequently, the best inhibitors were tested against 11 other mammalian protein kinases. Twelve of the most potent hits had an azapurine core with structure activity relationship (SAR) analysis identifying the functional groups on the 2 and 9 positions as essential for CRK3:CYC6 inhibition and specificity against CDK2:CycA. Iterative chemistry allowed synthesis of a number of azapurine derivatives with one, compound 17, demonstrating anti-parasitic activity against both promastigote and amastigote forms of L. major. Following the second HTS, 11 compounds with a thiazole core (active towards CRK3:CYC6 and inactive against CDK2:CycA) were tested. Ten of these hits demonstrated anti-parasitic activity against promastigote L. major. Conclusions/Significance The pharmacophores identified from the high throughput screens, and the derivatives synthesised, selectively target the parasite enzyme and represent compounds for future hit-to-lead synthesis programs to develop therapeutics against Leishmania species. Challenges remain in identifying specific CDK inhibitors with both target selectivity and potency against the parasite. CRK3, a cdc2-related serine/threonine protein kinase of the CDK family, is essential for transition through the G2-M phase checkpoint of the Leishmania cell cycle. An expression and purification system has been developed to produce active L. major CRK3 in complex with a cyclin partner, CYC6. CRK3:CYC6 was used to develop an assay suitable for high throughput screening (HTS) using IMAP fluorescence polarization technology. Two compound chemical libraries were screened against CRK3:CYC6 and counter screened against a human cyclin-dependent kinase complex CDK2:CycA. Two main chemical families of inhibitors were identified that specifically inhibited the leishmanial cyclin-dependent kinase, the azapurines and the thiazoles. Structure activity relationship (SAR) analysis of the hits identified the chemical groups attached to the azapurine scaffold that are essential for the inhibition of CRK3:CYC6 protein kinase activity. The CRK3:CYC6 hits were subsequently tested against a panel of 11 mammalian kinases including human CDK1:CYCB, human CDK2:CYCA and human CDK4:CYCD1 to determine their selectivity. Compounds selective to CRK3:CYC6 were tested against Leishmania. Progress towards synthesising potent and selective derivatives of the HTS hits are discussed, with the view to evaluating their potential for the development of novel therapeutics against leishmaniasis.
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Affiliation(s)
- Roderick G. Walker
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | | | - Kirk Malone
- Manchester Interdisciplinary Biocentre, University of Manchester, Manchester, United Kingdom
| | - Matthew W. Nowicki
- Institute of Structural and Molecular Biology, The University of Edinburgh, Edinburgh, United Kingdom
| | - Elaine Brown
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | | | - Nicholas J. Turner
- Manchester Interdisciplinary Biocentre, University of Manchester, Manchester, United Kingdom
| | - Malcolm D. Walkinshaw
- Institute of Structural and Molecular Biology, The University of Edinburgh, Edinburgh, United Kingdom
| | - Karen M. Grant
- School of Health & Medicine, Division of Medicine, Lancaster University, Lancaster, United Kingdom
| | - Jeremy C. Mottram
- Wellcome Trust Centre for Molecular Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- * E-mail:
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Seifert K. Structures, targets and recent approaches in anti-leishmanial drug discovery and development. THE OPEN MEDICINAL CHEMISTRY JOURNAL 2011; 5:31-9. [PMID: 21629509 PMCID: PMC3103891 DOI: 10.2174/1874104501105010031] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/18/2010] [Revised: 05/12/2010] [Accepted: 06/20/2010] [Indexed: 11/22/2022]
Abstract
Recent years have seen a significant improvement in available treatment options for leishmaniasis. Two new drugs, miltefosine and paromomycin, have been registered for the treatment of visceral leishmaniasis (VL) in India since 2002. Combination therapy is now explored in clinical trials as a new treatment approach for VL to reduce the length of treatment and potentially prevent selection of resistant parasites. However there is still a need for new drugs due to safety, resistance, stability and cost issues with existing therapies. The search for topical treatments for cutaneous leishmaniasis (CL) is ongoing. This review gives a brief overview of recent developments and approaches in anti-leishmanial drug discovery and development.
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Affiliation(s)
- Karin Seifert
- London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
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Mercer L, Bowling T, Perales J, Freeman J, Nguyen T, Bacchi C, Yarlett N, Don R, Jacobs R, Nare B. 2,4-Diaminopyrimidines as potent inhibitors of Trypanosoma brucei and identification of molecular targets by a chemical proteomics approach. PLoS Negl Trop Dis 2011; 5:e956. [PMID: 21347454 PMCID: PMC3035674 DOI: 10.1371/journal.pntd.0000956] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2010] [Accepted: 01/07/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND There is an urgent need to develop new, safe and effective treatments for human African trypanosomiasis (HAT) because current drugs have extremely poor safety profiles and are difficult to administer. Here we report the discovery of 2,4-diaminopyrimidines, exemplified by 4-[4-amino-5-(2-methoxy-benzoyl)-pyrimidin-2-ylamino]-piperidine-1-carboxylic acid phenylamide (SCYX-5070), as potent inhibitors of Trypanosoma brucei and the related trypanosomatid protozoans Leishmania spp. METHODOLOGY/PRINCIPAL FINDINGS In this work we show that loss of T. brucei viability following SCYX-5070 exposure was dependent on compound concentration and incubation time. Pulse incubation of T. brucei with SCYX-5070 demonstrates that a short period of exposure (10-12 hrs) is required to produce irreversible effects on survival or commit the parasites to death. SCYX-5070 cured an acute trypanosomiasis infection in mice without exhibiting signs of compound related acute or chronic toxicity. To identify the molecular target(s) responsible for the mechanism of action of 2,4-diaminopyrimidines against trypanosomatid protozoa, a representative analogue was immobilized on a solid matrix (sepharose) and used to isolate target proteins from parasite extracts. Mitogen-activated protein kinases (MAPKs) and cdc2-related kinases (CRKs) were identified as the major proteins specifically bound to the immobilized compound, suggesting their participation in the pharmacological effects of 2,4-diaminopyrimidines against trypanosomatid protozoan parasites. CONCLUSIONS/SIGNIFICANCE Results show that 2,4-diaminopyrimidines have a good in vitro and in vivo pharmacological profile against trypanosomatid protozoans and that MAPKs and CRKs are potential molecular targets of these compounds. The 2,4-diminipyrimidines may serve as suitable leads for the development of novel treatments for HAT.
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Affiliation(s)
- Luke Mercer
- SCYNEXIS Inc., Research Triangle Park, North Carolina, United States of America
| | - Tana Bowling
- SCYNEXIS Inc., Research Triangle Park, North Carolina, United States of America
| | - Joe Perales
- SCYNEXIS Inc., Research Triangle Park, North Carolina, United States of America
| | - Jennifer Freeman
- SCYNEXIS Inc., Research Triangle Park, North Carolina, United States of America
| | - Tien Nguyen
- SCYNEXIS Inc., Research Triangle Park, North Carolina, United States of America
| | - Cyrus Bacchi
- Haskins Laboratories, Pace University, New York, New York, United States of America
| | - Nigel Yarlett
- Haskins Laboratories, Pace University, New York, New York, United States of America
| | - Robert Don
- Drugs for Neglected Diseases initiative (DNDi), Geneva, Switzerland
| | - Robert Jacobs
- SCYNEXIS Inc., Research Triangle Park, North Carolina, United States of America
| | - Bakela Nare
- SCYNEXIS Inc., Research Triangle Park, North Carolina, United States of America
- * E-mail:
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57
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Ramana J, Gupta D. Machine learning methods for prediction of CDK-inhibitors. PLoS One 2010; 5:e13357. [PMID: 20967128 PMCID: PMC2954193 DOI: 10.1371/journal.pone.0013357] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2010] [Accepted: 09/13/2010] [Indexed: 01/04/2023] Open
Abstract
Progression through the cell cycle involves the coordinated activities of a suite of cyclin/cyclin-dependent kinase (CDK) complexes. The activities of the complexes are regulated by CDK inhibitors (CDKIs). Apart from its role as cell cycle regulators, CDKIs are involved in apoptosis, transcriptional regulation, cell fate determination, cell migration and cytoskeletal dynamics. As the complexes perform crucial and diverse functions, these are important drug targets for tumour and stem cell therapeutic interventions. However, CDKIs are represented by proteins with considerable sequence heterogeneity and may fail to be identified by simple similarity search methods. In this work we have evaluated and developed machine learning methods for identification of CDKIs. We used different compositional features and evolutionary information in the form of PSSMs, from CDKIs and non-CDKIs for generating SVM and ANN classifiers. In the first stage, both the ANN and SVM models were evaluated using Leave-One-Out Cross-Validation and in the second stage these were tested on independent data sets. The PSSM-based SVM model emerged as the best classifier in both the stages and is publicly available through a user-friendly web interface at http://bioinfo.icgeb.res.in/cdkipred.
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Affiliation(s)
- Jayashree Ramana
- Structural and Computational Biology Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
| | - Dinesh Gupta
- Structural and Computational Biology Group, International Centre for Genetic Engineering and Biotechnology (ICGEB), New Delhi, India
- * E-mail:
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58
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Chawla B, Madhubala R. Drug targets in Leishmania. J Parasit Dis 2010; 34:1-13. [PMID: 21526026 DOI: 10.1007/s12639-010-0006-3] [Citation(s) in RCA: 131] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Accepted: 06/22/2010] [Indexed: 02/03/2023] Open
Abstract
Leishmaniasis is a major public health problem and till date there are no effective vaccines available. The control strategy relies solely on chemotherapy of the infected people. However, the present repertoire of drugs is limited and increasing resistance towards them has posed a major concern. The first step in drug discovery is to identify a suitable drug target. The genome sequences of Leishmania major and Leishmania infantum has revealed immense amount of information and has given the opportunity to identify novel drug targets that are unique to these parasites. Utilization of this information in order to come up with a candidate drug molecule requires combining all the technology and using a multi-disciplinary approach, right from characterizing the target protein to high throughput screening of compounds. Leishmania belonging to the order kinetoplastidae emerges from the ancient eukaryotic lineages. They are quite diverse from their mammalian hosts and there are several cellular processes that we are getting to know of, which exist distinctly in these parasites. In this review, we discuss some of the metabolic pathways that are essential and could be used as potential drug targets in Leishmania.
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Affiliation(s)
- Bhavna Chawla
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067 India
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59
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Alex D, Lam IK, Lin Z, Lee SMY. Indirubin shows anti-angiogenic activity in an in vivo zebrafish model and an in vitro HUVEC model. JOURNAL OF ETHNOPHARMACOLOGY 2010; 131:242-247. [PMID: 20488232 DOI: 10.1016/j.jep.2010.05.016] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Revised: 05/04/2010] [Accepted: 05/08/2010] [Indexed: 05/29/2023]
Abstract
AIM OF THE STUDY Indirubin is an active ingredient of the traditional Chinese medicine, Dang Gui Long Hui Wan, commonly used for the treatment of chronic myelocytic leukemia (CML) and other inflammatory conditions. These anti-leukemic and anti-inflammatory activities may be mediated by anti-angiogenic action. To investigate the anti-angiogenic activity of indirubin, we tested its inhibitory effect on blood vessel formation in zebrafish embryos and on endothelial cell proliferation in culture. MATERIALS AND METHODS The anti-angiogenic activity of indirubin was tested using transgenic zebrafish embryos with fluorescent vasculature and human umbilical vein endothelial cells (HUVECs). Apoptosis was analyzed with a terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) assay. RESULTS Indirubin dose-dependently inhibited intersegmental vessel formation in zebrafish embryos. It also inhibited HUVEC proliferation by the induction of cellular apoptosis and cell-cycle arrest at the G0/G1 phase. CONCLUSIONS The anti-angiogenic activity of indirubin may partly contribute to its anti-leukemic and anti-psoriatic properties and may be valuable for the treatment of diseases with excessive angiogenesis. The zebrafish model of angiogenesis was further validated in this study.
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Affiliation(s)
- Deepa Alex
- Institute of Chinese Medical Sciences, University of Macau, Taipa, Macao, China
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60
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Collaborative actions in anti-trypanosomatid chemotherapy with partners from disease endemic areas. Trends Parasitol 2010; 26:395-403. [DOI: 10.1016/j.pt.2010.04.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Revised: 04/28/2010] [Accepted: 04/29/2010] [Indexed: 11/22/2022]
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Gomes FC, Ali NOM, Brown E, Walker RG, Grant KM, Mottram JC. Recombinant Leishmania mexicana CRK3:CYCA has protein kinase activity in the absence of phosphorylation on the T-loop residue Thr178. Mol Biochem Parasitol 2010; 171:89-96. [PMID: 20338198 DOI: 10.1016/j.molbiopara.2010.03.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2009] [Revised: 03/01/2010] [Accepted: 03/02/2010] [Indexed: 10/19/2022]
Abstract
The activity of cyclin-dependent kinases (CDKs), which are key regulators of the eukaryotic cell cycle, is regulated through post-translational mechanisms, including binding of a cyclin and phosphorylation. Previously studies have shown that Leishmania mexicana CRK3 is an essential CDK that is a functional homologue of human CDK1. In this study, recombinant histidine tagged L. mexicana CRK3 and the cyclin CYCA were combined in vitro to produce an active histone H1 kinase that was inhibited by the CDK inhibitors, flavopiridol and indirubin-3'-monoxime. Protein kinase activity was observed in the absence of phosphorylation of the T-loop residue Thr178, but increased 5-fold upon phosphorylation by the CDK activating kinase Civ1 of Saccharomyces cerevisiae. Seven recombinant L. major CRKs (1, 2, 3, 4, 6, 7 and 8) were also expressed and purified, none of which were active as monomers. Moreover, only CRK3 was phosphorylated by Civ1. HA-tagged CYCA expressed in L. major procyclic promastigotes was co-precipitated with CRK3 and exhibited histone H1 kinase activity. These data indicate that in Leishmania CYCA interacts with CRK3 to form an active protein kinase, confirm the conservation of the regulatory mechanisms that control CDK activity in other eukaryotes, but identifies biochemical differences to human CDK1.
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Affiliation(s)
- Felipe C Gomes
- Wellcome Trust Centre for Molecular Parasitology and Division of Infection & Immunity, Faculty of Biomedical and Life Sciences, University of Glasgow, 120 University Place, Glasgow G12 8TA, UK
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Awale M, Kumar V, Saravanan P, Mohan CG. Homology modeling and atomic level binding study of Leishmania MAPK with inhibitors. J Mol Model 2009; 16:475-88. [PMID: 19649663 DOI: 10.1007/s00894-009-0565-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2009] [Accepted: 07/08/2009] [Indexed: 12/11/2022]
Abstract
The current therapy for leishmaniasis is not sufficient and it has two severe drawbacks, host-toxicity and drug resistance. The substantial knowledge of parasite biology is not yet translating into novel drugs for leishmaniasis. Based on this observation, a 3D structural model of Leishmania mitogen-activated protein kinase (MAPK) homologue has been developed, for the first time, by homology modeling and molecular dynamics simulation techniques. The model provided clear insight in its structure features, i.e. ATP binding pocket, phosphorylation lip, and common docking site. Sequence-structure homology recognition identified Leishmania CRK3 (LCRK3) as a distant member of the MAPK superfamily. Multiple sequence alignment and 3D structure model provided the putative ATP binding pocket of Leishmania with respect to human ERK2 and LCRK3. This analysis was helpful in identifying the binding sites and molecular function of the Leishmania specific MAPK homologue. Molecular docking study was performed on this 3D structural model, using different classes of competitive ATP inhibitors of LCRK3, to check whether they exhibit affinity and could be identified as Leishmania MAPK specific inhibitors. It is well known that MAP kinases are extracellular signal regulated kinases ERK1 and ERK2, which are components of the Ras-MAPK signal transduction pathway which is complexed with HDAC4 protein, and their inhibition is of significant therapeutic interest in cancer biology. In order to understand the mechanism of action, docking of indirubin class of molecules to the active site of histone deacetylase 4 (HDAC4) protein is performed, and the binding affinity of the protein-ligand interaction was computed. The new structural insights obtained from this study are all consistent with the available experimental data, suggesting that the homology model of the Leishmania MAPK and its ligand interaction modes are reasonable. Further the comparative molecular electrostatic potential and cavity depth analysis of Leishmania MAPK and human ERK2 suggested several important differences in its ATP binding pocket. Such differences could be exploited in the future for designing Leishmania specific MAPK inhibitors.
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Affiliation(s)
- Mahendra Awale
- National Institute of Pharmaceutical Education and Research, Nagar, Punjab, India
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63
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Link A, Heidler P, Kaiser M, Brun R. Parallel synthesis of a series of non-functional ATP/NAD analogs with activity against trypanosomatid parasites. Mol Divers 2009; 14:215-24. [PMID: 19484371 DOI: 10.1007/s11030-009-9160-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2009] [Accepted: 05/09/2009] [Indexed: 11/29/2022]
Abstract
Non-functional analogs of the cofactors ATP and NAD are putative inhibitors of ATP- or NAD-dependant enzymes. Since pathogenic protozoa rely heavily on the salvage of purine nucleosides from the bloodstream of their host, such compounds are of interest as antiplasmodial and antitrypanosomal agents with a multitude of molecular targets. By replacing the negatively charged phosphate residues with a constrained unsaturated amide spacer and the nicotinamide moiety of NAD with various lipophilic substituents, 15 new ATP/NAD analogs were obtained in screening quantities. In these compounds, a 5'-desoxyadenosine moiety was conserved as key molecular recognition motif. The inhibition of P. falciparum and T. brucei ssp. in a whole parasite in vitro assay is reported.
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Affiliation(s)
- Andreas Link
- Institute of Pharmacy, Ernst-Moritz-Arndt-University, Friedrich-Ludwig-Jahn-Strasse 17, 17487, Greifswald, Germany.
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64
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Xingi E, Smirlis D, Myrianthopoulos V, Magiatis P, Grant KM, Meijer L, Mikros E, Skaltsounis AL, Soteriadou K. 6-Br-5methylindirubin-3'oxime (5-Me-6-BIO) targeting the leishmanial glycogen synthase kinase-3 (GSK-3) short form affects cell-cycle progression and induces apoptosis-like death: exploitation of GSK-3 for treating leishmaniasis. Int J Parasitol 2009; 39:1289-303. [PMID: 19445946 DOI: 10.1016/j.ijpara.2009.04.005] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Revised: 03/31/2009] [Accepted: 04/03/2009] [Indexed: 01/17/2023]
Abstract
Indirubins known to target mammalian cyclin-dependent kinases (CDKs) and glycogen synthase kinase (GSK-3) were tested for their antileishmanial activity. 6-Br-indirubin-3'-oxime (6-BIO), 6-Br-indirubin-3'acetoxime and 6-Br-5methylindirubin-3'oxime (5-Me-6-BIO) were the most potent inhibitors of Leishmania donovani promastigote and amastigote growth (half maximal inhibitory concentration (IC(50)) values < or =1.2 microM). Since the 6-Br substitution on the indirubin backbone greatly enhances the selectivity for mammalian GSK-3 over CDKs, we identified the leishmanial GSK-3 homologues, a short (LdGSK-3s) and a long one, focusing on LdGSK-3s which is closer to human GSK-3beta, for further studies. Kinase assays showed that 5-Me-6-BIO inhibited LdGSK-3s more potently than CRK3 (the CDK1 homologue in Leishmania), whilst 6-BIO was more selective for CRK3. Promastigotes treated with 5-Me-6-BIO accumulated in the S and G2/M cell-cycle phases and underwent apoptosis-like death. Interestingly, these phenotypes were completely reversed in parasites over-expressing LdGSK-3s. This finding strongly supports that LdGSK-3s is: (i) the intracellular target of 5-Me-6-BIO, and (ii) involved in cell-cycle control and in pathways leading to apoptosis-like death. 6-BIO treatment induced a G2/M arrest, consistent with inhibition of CRK3 and apoptosis-like death. These effects were partially reversed in parasites over-expressing LdGSK-3s suggesting that in vivo 6-BIO may also target LdGSK-3s. Molecular docking of 5-Me-6-BIO in CRK3 and 6-BIO in human GSK-3beta and LdGSK-3s active sites predict the existence of functional/structural differences that are sufficient to explain the observed difference in their affinity. In conclusion, LdGSK-3s is validated as a potential drug target in Leishmania and could be exploited for the development of selective indirubin-based leishmanicidals.
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Affiliation(s)
- Evangelia Xingi
- Laboratory of Molecular Parasitology, Department of Microbiology, Hellenic Pasteur Institute, 127 Vas. Sofias Ave., 11521 Athens, Greece
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Park EJ, Choi SJ, Kim YC, Lee SH, Park SW, Lee SK. Novel small molecule activators of β-catenin-mediated signaling pathway: structure–activity relationships of indirubins. Bioorg Med Chem Lett 2009; 19:2282-4. [DOI: 10.1016/j.bmcl.2009.02.083] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2008] [Revised: 02/18/2009] [Accepted: 02/21/2009] [Indexed: 10/21/2022]
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66
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Le Pape P. Development of new antileishmanial drugs – current knowledge and future prospects. J Enzyme Inhib Med Chem 2008; 23:708-18. [DOI: 10.1080/14756360802208137] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Affiliation(s)
- Patrice Le Pape
- Département de Parasitologie et de Mycologie Médicale, Université de Nantes, Nantes Atlantique Universités, IICiMed UPRES EA 1155, UFR de Sciences Pharmaceutiques, 1 rue Gaston VeilNantes cedex 01F-44035, France
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67
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Shimony O, Jaffe CL. Rapid fluorescent assay for screening drugs on Leishmania amastigotes. J Microbiol Methods 2008; 75:196-200. [DOI: 10.1016/j.mimet.2008.05.026] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2008] [Accepted: 05/29/2008] [Indexed: 10/22/2022]
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68
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Inhibition of Toxoplasma gondii by indirubin and tryptanthrin analogs. Antimicrob Agents Chemother 2008; 52:4466-9. [PMID: 18824607 DOI: 10.1128/aac.00903-08] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
New drugs are needed for treatment of Toxoplasma gondii infections. We tested derivatives of principles found in Isatis indigotica for in vitro efficacy against T. gondii infection. Indirubin-3'-oxime analogs showed modest micromolar activity, while tryptanthrin derivatives displayed 50% inhibitory doses in the low nanomolar range. Tryptanthrins have potential as anti-Toxoplasma infection therapeutics.
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69
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Glycogen synthase kinase 3 is a potential drug target for African trypanosomiasis therapy. Antimicrob Agents Chemother 2008; 52:3710-7. [PMID: 18644955 DOI: 10.1128/aac.00364-08] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Development of a safe, effective, and inexpensive therapy for African trypanosomiasis is an urgent priority. In this study, we evaluated the validity of Trypanosoma brucei glycogen synthase kinase 3 (GSK-3) as a potential drug target. Interference with the RNA of either of two GSK-3 homologues in bloodstream-form T. brucei parasites led to growth arrest and altered parasite morphology, demonstrating their requirement for cell survival. Since the growth arrest after RNA interference appeared to be more profound for T. brucei GSK-3 "short" (Tb10.161.3140) than for T. brucei GSK-3 "long" (Tb927.7.2420), we focused on T. brucei GSK-3 short for further studies. T. brucei GSK-3 short with an N-terminal maltose-binding protein fusion was cloned, expressed, and purified in a functional form. The potency of a GSK-3-focused inhibitor library against the recombinant enzyme of T. brucei GSK-3 short, as well as bloodstream-form parasites, was evaluated with the aim of determining if compounds that inhibit enzyme activity could also block the parasites' growth and proliferation. Among the compounds active against the cell, there was an excellent correlation between activity inhibiting the T. brucei GSK-3 short enzyme and the inhibition of T. brucei growth. Thus, there is reasonable genetic and chemical validation of GSK-3 short as a drug target for T. brucei. Finally, selective inhibition may be required for therapy targeting the GSK-3 enzyme, and a molecular model of the T. brucei GSK-3 short enzyme suggests that compounds that selectively inhibit T. brucei GSK-3 short over the human GSK-3 enzymes can be found.
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70
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Morgan RE, Westwood NJ. Screening and synthesis: high throughput technologies applied to parasitology. Parasitology 2008; 128 Suppl 1:S71-9. [PMID: 16454900 DOI: 10.1017/s0031182004007073] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
High throughput technologies continue to develop in response to the challenges set by the genome projects. This article discusses how the techniques of both high throughput screening (HTS) and synthesis can influence research in parasitology. Examples of the use of targeted and phenotype-based HTS using unbiased compound collections are provided. The important issue of identifying the protein target(s) of bioactive compounds is discussed from the synthetic chemist's perspective. This article concludes by reviewing recent examples of successful target identification studies in parasitology.
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Affiliation(s)
- R E Morgan
- School of Chemistry, Centre for Biomolecular Sciences, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST, UK
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71
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Reichwald C, Shimony O, Dunkel U, Sacerdoti-Sierra N, Jaffe CL, Kunick C. 2-(3-aryl-3-oxopropen-1-yl)-9-tert-butyl-paullones: a new antileishmanial chemotype. J Med Chem 2008; 51:659-65. [PMID: 18186603 DOI: 10.1021/jm7012166] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A screening program directed to find new agents against Leishmania donovani, the parasite causing visceral leishmaniasis, revealed that paullones attenuate the proliferation of axenic amastigotes. Because these structures were not active in a test system involving infected macrophages, a structure optimization campaign was carried out. Concomitant introduction of an unsaturated side chain into the 2-position and a tert-butyl substituent into the 9-position of the parent scaffold led to compounds inhibiting also parasites dwelling in macrophages. By inclusion of the so elaborated scaffold into a chalcone substructure, the toxicity against uninfected host cells was significantly reduced. For the synthesis of this new compound class, a novel modification of the Heck-type palladium-catalyzed C,C-cross coupling strategy was used, employing a ketone Mannich base as precursor for the alkene reactant. The so-prepared compounds exhibited improved antileishmanial activity both on axenic amastigotes (GI50 < 1 microM) as well as on parasites in infected macrophages.
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Affiliation(s)
- Christina Reichwald
- Technische Universität Braunschweig, Institut für Pharmazeutische Chemie, Beethovenstrasse 55, Braunschweig, Germany
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72
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Cuervo P, de Jesus JB, Junqueira M, Mendonça-Lima L, González LJ, Betancourt L, Grimaldi G, Domont GB, Fernandes O, Cupolillo E. Proteome analysis of Leishmania (Viannia) braziliensis by two-dimensional gel electrophoresis and mass spectrometry. Mol Biochem Parasitol 2007; 154:6-21. [PMID: 17499861 DOI: 10.1016/j.molbiopara.2007.03.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2006] [Revised: 03/12/2007] [Accepted: 03/21/2007] [Indexed: 10/23/2022]
Abstract
Leishmania (Viannia) braziliensis, a protozoan parasite widespread in the New World, is responsible for the infection of different mammal orders, including humans. This species is considered to be a major etiological agent of American cutaneous leishmaniasis. A proteomic study was carried out to identify proteins expressed by L. (V.) braziliensis. One hundred and one spots representing 75 protein entries were identified by MALDI-TOF-TOF. Isoelectric point values estimated by gel electrophoresis matched closely with predicted values, although some discrepancies existed suggesting that post-translational protein modifications may be common in L. braziliensis. Moreover, 20 hypothetical proteins were experimentally identified. Identified proteins were classified into 15 groups according to biological process. Among the proteins identified, approximately 40% have not been previously reported in a proteomic map of Leishmania. In addition, a number of potential virulence factors and drug targets were identified in this protein map, including some proteins associated with the metastatic phenotype. This study describes the first compilation of a proteomic reference map for L. braziliensis (pI 4-7, M(r) 10-130 kDa) and provides a very useful tool for comparative studies of strains isolated from patients presenting different clinical manifestations of leishmaniasis as well as a potential tool to identify markers for clinical diagnosis, therapeutics, and prognosis.
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Affiliation(s)
- Patricia Cuervo
- Departamento de Imunologia, Instituto Oswaldo Cruz, FIOCRUZ, Av. Brasil 4365, Manguinhos, 21045-900 Rio de Janeiro, RJ, Brazil
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73
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Naula C, Parsons M, Mottram JC. Protein kinases as drug targets in trypanosomes and Leishmania. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2005; 1754:151-9. [PMID: 16198642 PMCID: PMC1452262 DOI: 10.1016/j.bbapap.2005.08.018] [Citation(s) in RCA: 158] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2005] [Revised: 08/08/2005] [Accepted: 08/10/2005] [Indexed: 11/26/2022]
Abstract
Protein kinases represent promising drug targets for a number of human and animal diseases. The recent completion of the sequenced genomes of three human-infective trypanosomatid protozoa, Leishmania major, Trypanosoma brucei and Trypanosoma cruzi, has allowed the kinome for each parasite to be defined as 179, 156 and 171 eukaryotic protein kinases respectively, that is about one third of the human complement. The analysis revealed that the trypanosomatids lack members of the receptor-linked or cytosolic tyrosine kinase families, but have an abundance of STE and CMGC family protein kinases likely to be involved in regulating cell cycle control, differentiation and response to stress during their complex life-cycles. In this review, we examine the prospects for exploiting differences between parasite and mammalian protein kinases to develop novel anti-parasitic chemotherapeutic agents.
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Affiliation(s)
- Christina Naula
- Wellcome Centre for Molecular Parasitology, The Anderson College, 56 Dumbarton Road, University of Glasgow, Glasgow G11 6NU, UK
| | - Marilyn Parsons
- Seattle Biomedical Research Institute, 307 Westlake Ave. N., Seattle, WA, 98109 USA
- Department of Pathobiology, University of Washington, Seattle, WA, 98195 USA
| | - Jeremy C. Mottram
- Wellcome Centre for Molecular Parasitology, The Anderson College, 56 Dumbarton Road, University of Glasgow, Glasgow G11 6NU, UK
- *Corresponding author:
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