1
|
Burge RJ, Jameson KH, Geoghegan V, Dowle AA, Mottram JC, Wilkinson AJ. Formation of functional E3 ligase complexes with UBC2 and UEV1 of Leishmania mexicana. Mol Biochem Parasitol 2024; 258:111619. [PMID: 38556171 DOI: 10.1016/j.molbiopara.2024.111619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 03/14/2024] [Accepted: 03/26/2024] [Indexed: 04/02/2024]
Abstract
In eukaryotic cells, molecular fate and cellular responses are shaped by multicomponent enzyme systems which reversibly attach ubiquitin and ubiquitin-like modifiers to target proteins. The extent of the ubiquitin proteasome system in Leishmania mexicana and its importance for parasite survival has recently been established through deletion mutagenesis and life-cycle phenotyping studies. The ubiquitin conjugating E2 enzyme UBC2, and the E2 enzyme variant UEV1, with which it forms a stable complex in vitro, were shown to be essential for the differentiation of promastigote parasites to the infectious amastigote form. To investigate further, we used immunoprecipitation of Myc-UBC2 or Myc-UEV1 to identify interacting proteins in L. mexicana promastigotes. The interactome of UBC2 comprises multiple ubiquitin-proteasome components including UEV1 and four RING E3 ligases, as well as potential substrates predicted to have roles in carbohydrate metabolism and intracellular trafficking. The smaller UEV1 interactome comprises six proteins, including UBC2 and shared components of the UBC2 interactome consistent with the presence of intracellular UBC2-UEV1 complexes. Recombinant RING1, RING2 and RING4 E3 ligases were shown to support ubiquitin transfer reactions involving the E1, UBA1a, and UBC2 to available substrate proteins or to unanchored ubiquitin chains. These studies define additional components of a UBC2-dependent ubiquitination pathway shown previously to be essential for promastigote to amastigote differentiation.
Collapse
Affiliation(s)
- Rebecca J Burge
- York Biomedical Research Institute, Department of Biology, University of York, York YO10 5DD, UK
| | - Katie H Jameson
- York Structural Biology Laboratory and York Biomedical Research Institute, Department of Chemistry, University of York, York YO10 5DD, UK
| | - Vincent Geoghegan
- York Biomedical Research Institute, Department of Biology, University of York, York YO10 5DD, UK
| | - Adam A Dowle
- Bioscience Technology Facility, Department of Biology, University of York, York YO10 5DD, UK
| | - Jeremy C Mottram
- York Biomedical Research Institute, Department of Biology, University of York, York YO10 5DD, UK.
| | - Anthony J Wilkinson
- York Structural Biology Laboratory and York Biomedical Research Institute, Department of Chemistry, University of York, York YO10 5DD, UK.
| |
Collapse
|
2
|
Betancourt-Conde I, Avitia-Domínguez C, Hernández-Campos A, Castillo R, Yépez-Mulia L, Oria-Hernández J, Méndez ST, Sierra-Campos E, Valdez-Solana M, Martínez-Caballero S, Hermoso JA, Romo-Mancillas A, Téllez-Valencia A. Benzimidazole Derivatives as New and Selective Inhibitors of Arginase from Leishmania mexicana with Biological Activity against Promastigotes and Amastigotes. Int J Mol Sci 2021; 22:ijms222413613. [PMID: 34948408 PMCID: PMC8705706 DOI: 10.3390/ijms222413613] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 12/14/2021] [Accepted: 12/16/2021] [Indexed: 11/16/2022] Open
Abstract
Leishmaniasis is a disease caused by parasites of the Leishmania genus that affects 98 countries worldwide, 2 million of new cases occur each year and more than 350 million people are at risk. The use of the actual treatments is limited due to toxicity concerns and the apparition of resistance strains. Therefore, there is an urgent necessity to find new drugs for the treatment of this disease. In this context, enzymes from the polyamine biosynthesis pathway, such as arginase, have been considered a good target. In the present work, a chemical library of benzimidazole derivatives was studied performing computational, enzyme kinetics, biological activity, and cytotoxic effect characterization, as well as in silico ADME-Tox predictions, to find new inhibitors for arginase from Leishmania mexicana (LmARG). The results show that the two most potent inhibitors (compounds 1 and 2) have an I50 values of 52 μM and 82 μM, respectively. Moreover, assays with human arginase 1 (HsARG) show that both compounds are selective for LmARG. According to molecular dynamics simulation studies these inhibitors interact with important residues for enzyme catalysis. Biological activity assays demonstrate that both compounds have activity against promastigote and amastigote, and low cytotoxic effect in murine macrophages. Finally, in silico prediction of their ADME-Tox properties suggest that these inhibitors support the characteristics to be considered drug candidates. Altogether, the results reported in our study suggest that the benzimidazole derivatives are an excellent starting point for design new drugs against leishmanisis.
Collapse
Affiliation(s)
- Irene Betancourt-Conde
- Facultad de Medicina y Nutrición, Universidad Juárez del Estado de Durango, Av. Universidad y Fanny Anitúa S/N, Durango 34000, Mexico;
| | - Claudia Avitia-Domínguez
- Facultad de Medicina y Nutrición, Universidad Juárez del Estado de Durango, Av. Universidad y Fanny Anitúa S/N, Durango 34000, Mexico;
- Correspondence: (C.A.-D.); (A.T.-V.); Tel.: +52-618-812-1687 (A.T.-V.)
| | - Alicia Hernández-Campos
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico; (A.H.-C.); (R.C.)
| | - Rafael Castillo
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico; (A.H.-C.); (R.C.)
| | - Lilián Yépez-Mulia
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Unidad Médica de Alta Especialidad-Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City 06720, Mexico;
| | - Jesús Oria-Hernández
- Laboratorio de Bioquímica-Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico; (J.O.-H.); (S.T.M.)
| | - Sara T. Méndez
- Laboratorio de Bioquímica-Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City 04530, Mexico; (J.O.-H.); (S.T.M.)
| | - Erick Sierra-Campos
- Facultad de Ciencias Químicas, Universidad Juárez del Estado de Durango, Av. Artículo 123 S/N Fracc. Filadelfia, Gómez Palacio 35010, Mexico; (E.S.-C.); (M.V.-S.)
| | - Mónica Valdez-Solana
- Facultad de Ciencias Químicas, Universidad Juárez del Estado de Durango, Av. Artículo 123 S/N Fracc. Filadelfia, Gómez Palacio 35010, Mexico; (E.S.-C.); (M.V.-S.)
| | - Siseth Martínez-Caballero
- Departamento de Cristalografía y Biología Estructural, Instituto Química-Física Rocasolano, Consejo Superior de Investigaciones Científicas, 28006 Madrid, Spain; (S.M.-C.); (J.A.H.)
| | - Juan A. Hermoso
- Departamento de Cristalografía y Biología Estructural, Instituto Química-Física Rocasolano, Consejo Superior de Investigaciones Científicas, 28006 Madrid, Spain; (S.M.-C.); (J.A.H.)
| | - Antonio Romo-Mancillas
- Laboratorio de Diseño Asistido por Computadora y Síntesis de Fármacos, Facultad de Química, Universidad Autónoma de Querétaro, Querétaro 76010, Mexico;
| | - Alfredo Téllez-Valencia
- Facultad de Medicina y Nutrición, Universidad Juárez del Estado de Durango, Av. Universidad y Fanny Anitúa S/N, Durango 34000, Mexico;
- Correspondence: (C.A.-D.); (A.T.-V.); Tel.: +52-618-812-1687 (A.T.-V.)
| |
Collapse
|
3
|
Baker N, Catta-Preta CMC, Neish R, Sadlova J, Powell B, Alves-Ferreira EVC, Geoghegan V, Carnielli JBT, Newling K, Hughes C, Vojtkova B, Anand J, Mihut A, Walrad PB, Wilson LG, Pitchford JW, Volf P, Mottram JC. Systematic functional analysis of Leishmania protein kinases identifies regulators of differentiation or survival. Nat Commun 2021; 12:1244. [PMID: 33623024 PMCID: PMC7902614 DOI: 10.1038/s41467-021-21360-8] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 01/13/2021] [Indexed: 01/31/2023] Open
Abstract
Differentiation between distinct stages is fundamental for the life cycle of intracellular protozoan parasites and for transmission between hosts, requiring stringent spatial and temporal regulation. Here, we apply kinome-wide gene deletion and gene tagging in Leishmania mexicana promastigotes to define protein kinases with life cycle transition roles. Whilst 162 are dispensable, 44 protein kinase genes are refractory to deletion in promastigotes and are likely core genes required for parasite replication. Phenotyping of pooled gene deletion mutants using bar-seq and projection pursuit clustering reveal functional phenotypic groups of protein kinases involved in differentiation from metacyclic promastigote to amastigote, growth and survival in macrophages and mice, colonisation of the sand fly and motility. This unbiased interrogation of protein kinase function in Leishmania allows targeted investigation of organelle-associated signalling pathways required for successful intracellular parasitism.
Collapse
Affiliation(s)
- N Baker
- York Biomedical Research Institute, University of York, York, UK
- Department of Biology, University of York, York, UK
| | - C M C Catta-Preta
- York Biomedical Research Institute, University of York, York, UK
- Department of Biology, University of York, York, UK
| | - R Neish
- York Biomedical Research Institute, University of York, York, UK
- Department of Biology, University of York, York, UK
| | - J Sadlova
- Department of Parasitology, Faculty of Science, Charles University, Prague, Czech Republic
| | - B Powell
- Department of Mathematics, University of York, York, UK
| | - E V C Alves-Ferreira
- York Biomedical Research Institute, University of York, York, UK
- Department of Biology, University of York, York, UK
| | - V Geoghegan
- York Biomedical Research Institute, University of York, York, UK
- Department of Biology, University of York, York, UK
| | - J B T Carnielli
- York Biomedical Research Institute, University of York, York, UK
- Department of Biology, University of York, York, UK
| | - K Newling
- Department of Biology, University of York, York, UK
| | - C Hughes
- York Biomedical Research Institute, University of York, York, UK
- Department of Biology, University of York, York, UK
| | - B Vojtkova
- Department of Parasitology, Faculty of Science, Charles University, Prague, Czech Republic
| | - J Anand
- York Biomedical Research Institute, University of York, York, UK
- Department of Biology, University of York, York, UK
| | - A Mihut
- Department of Biology, University of York, York, UK
| | - P B Walrad
- York Biomedical Research Institute, University of York, York, UK
- Department of Biology, University of York, York, UK
| | - L G Wilson
- York Biomedical Research Institute, University of York, York, UK
- Department of Physics, University of York, York, UK
| | - J W Pitchford
- Department of Biology, University of York, York, UK
- Department of Mathematics, University of York, York, UK
| | - P Volf
- Department of Parasitology, Faculty of Science, Charles University, Prague, Czech Republic
| | - J C Mottram
- York Biomedical Research Institute, University of York, York, UK.
- Department of Biology, University of York, York, UK.
| |
Collapse
|
4
|
Ribeiro JFR, Cianni L, Li C, Warwick TG, de Vita D, Rosini F, Dos Reis Rocho F, Martins FCP, Kenny PW, Lameira J, Leitão A, Emsley J, Montanari CA. Crystal structure of Leishmania mexicana cysteine protease B in complex with a high-affinity azadipeptide nitrile inhibitor. Bioorg Med Chem 2020; 28:115743. [PMID: 33038787 DOI: 10.1016/j.bmc.2020.115743] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 08/20/2020] [Accepted: 08/22/2020] [Indexed: 11/19/2022]
Abstract
Leishmania mexicana is an obligate intracellular protozoan parasite that causes the cutaneous form of leishmaniasis affecting South America and Mexico. The cysteine protease LmCPB is essential for the virulence of the parasite and therefore, it is an appealing target for antiparasitic therapy. A library of nitrile-based cysteine protease inhibitors was screened against LmCPB to develop a treatment of cutaneous leishmaniasis. Several compounds are sufficiently high-affinity LmCPB inhibitors to serve both as starting points for drug discovery projects and as probes for target validation. A 1.4 Å X ray crystal structure, the first to be reported for LmCPB, was determined for the complex of this enzyme covalently bound to an azadipeptide nitrile ligand. Mapping the structure-activity relationships for LmCPB inhibition revealed superadditive effects for two pairs of structural transformations. Therefore, this work advances our understanding of azadipeptidyl and dipeptidyl nitrile structure-activity relationships for LmCPB structure-based inhibitor design. We also tested the same series of inhibitors on related cysteine proteases cathepsin L and Trypanosoma cruzi cruzain. The modulation of these mammalian and protozoan proteases represents a new framework for targeting papain-like cysteine proteases.
Collapse
Affiliation(s)
- Jean F R Ribeiro
- Medicinal and Biological Chemistry Group, Institute of Chemistry of São Carlos, University of São Paulo, São Carlos, Brazil
| | - Lorenzo Cianni
- Medicinal and Biological Chemistry Group, Institute of Chemistry of São Carlos, University of São Paulo, São Carlos, Brazil
| | - Chan Li
- School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - Thomas G Warwick
- School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK
| | - Daniela de Vita
- Medicinal and Biological Chemistry Group, Institute of Chemistry of São Carlos, University of São Paulo, São Carlos, Brazil
| | - Fabiana Rosini
- Medicinal and Biological Chemistry Group, Institute of Chemistry of São Carlos, University of São Paulo, São Carlos, Brazil
| | - Fernanda Dos Reis Rocho
- Medicinal and Biological Chemistry Group, Institute of Chemistry of São Carlos, University of São Paulo, São Carlos, Brazil
| | - Felipe C P Martins
- Medicinal and Biological Chemistry Group, Institute of Chemistry of São Carlos, University of São Paulo, São Carlos, Brazil
| | - Peter W Kenny
- Medicinal and Biological Chemistry Group, Institute of Chemistry of São Carlos, University of São Paulo, São Carlos, Brazil
| | - Jeronimo Lameira
- Medicinal and Biological Chemistry Group, Institute of Chemistry of São Carlos, University of São Paulo, São Carlos, Brazil; Laboratory of Design and Development of Pharmaceuticals, Federal University of Pará, Belém, Brazil
| | - Andrei Leitão
- Medicinal and Biological Chemistry Group, Institute of Chemistry of São Carlos, University of São Paulo, São Carlos, Brazil
| | - Jonas Emsley
- School of Pharmacy, Centre for Biomolecular Sciences, University of Nottingham, Nottingham, UK.
| | - Carlos A Montanari
- Medicinal and Biological Chemistry Group, Institute of Chemistry of São Carlos, University of São Paulo, São Carlos, Brazil.
| |
Collapse
|
5
|
Damianou A, Burge RJ, Catta-Preta CMC, Geoghegan V, Nievas YR, Newling K, Brown E, Burchmore R, Rodenko B, Mottram JC. Essential roles for deubiquitination in Leishmania life cycle progression. PLoS Pathog 2020; 16:e1008455. [PMID: 32544189 PMCID: PMC7319358 DOI: 10.1371/journal.ppat.1008455] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 06/26/2020] [Accepted: 05/07/2020] [Indexed: 12/22/2022] Open
Abstract
The parasitic protozoan Leishmania requires proteasomal, autophagic and lysosomal proteolytic pathways to enact the extensive cellular remodelling that occurs during its life cycle. The proteasome is essential for parasite proliferation, yet little is known about the requirement for ubiquitination/deubiquitination processes in growth and differentiation. Activity-based protein profiling of L. mexicana C12, C19 and C65 deubiquitinating cysteine peptidases (DUBs) revealed DUB activity remains relatively constant during differentiation of procyclic promastigote to amastigote. However, when life cycle phenotyping (bar-seq) was performed on a pool including 15 barcoded DUB null mutants created in promastigotes using CRISPR-Cas9, significant loss of fitness was observed during differentiation and intracellular infection. DUBs 4, 7, and 13 are required for successful transformation from metacyclic promastigote to amastigote and DUBs 3, 5, 6, 8, 10, 11 and 14 are required for normal amastigote proliferation in mice. DUBs 1, 2, 12 and 16 are essential for promastigote viability and the essential role of DUB2 in establishing infection was demonstrated using DiCre inducible gene deletion in vitro and in vivo. DUB2 is found in the nucleus and interacts with nuclear proteins associated with transcription/chromatin dynamics, mRNA splicing and mRNA capping. DUB2 has broad linkage specificity, cleaving all the di-ubiquitin chains except for Lys27 and Met1. Our study demonstrates the crucial role that DUBs play in differentiation and intracellular survival of Leishmania and that amastigotes are exquisitely sensitive to disruption of ubiquitination homeostasis.
Collapse
Affiliation(s)
- Andreas Damianou
- York Biomedical Research Institute and Department of Biology, University of York, United Kingdom
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Rebecca J. Burge
- York Biomedical Research Institute and Department of Biology, University of York, United Kingdom
| | | | - Vincent Geoghegan
- York Biomedical Research Institute and Department of Biology, University of York, United Kingdom
| | - Y. Romina Nievas
- York Biomedical Research Institute and Department of Biology, University of York, United Kingdom
| | - Katherine Newling
- York Biomedical Research Institute and Department of Biology, University of York, United Kingdom
| | - Elaine Brown
- York Biomedical Research Institute and Department of Biology, University of York, United Kingdom
| | - Richard Burchmore
- Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Boris Rodenko
- UbiQ Bio BV, Amsterdam Science Park, The Netherlands
| | - Jeremy C. Mottram
- York Biomedical Research Institute and Department of Biology, University of York, United Kingdom
| |
Collapse
|
6
|
Matadamas-Martínez F, Hernández-Campos A, Téllez-Valencia A, Vázquez-Raygoza A, Comparán-Alarcón S, Yépez-Mulia L, Castillo R. Leishmania mexicana Trypanothione Reductase Inhibitors: Computational and Biological Studies. Molecules 2019; 24:molecules24183216. [PMID: 31487860 PMCID: PMC6767256 DOI: 10.3390/molecules24183216] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 08/24/2019] [Accepted: 08/31/2019] [Indexed: 12/27/2022]
Abstract
Leishmanicidal drugs have many side effects, and drug resistance to all of them has been documented. Therefore, the development of new drugs and the identification of novel therapeutic targets are urgently needed. Leishmania mexicana trypanothione reductase (LmTR), a NADPH-dependent flavoprotein oxidoreductase important to thiol metabolism, is essential for parasite viability. Its absence in the mammalian host makes this enzyme an attractive target for the development of new anti-Leishmania drugs. Herein, a tridimensional model of LmTR was constructed and the molecular docking of 20 molecules from a ZINC database was performed. Five compounds (ZINC04684558, ZINC09642432, ZINC12151998, ZINC14970552, and ZINC11841871) were selected (docking scores -10.27 kcal/mol to -5.29 kcal/mol and structurally different) and evaluated against recombinant LmTR (rLmTR) and L. mexicana promastigote. Additionally, molecular dynamics simulation of LmTR-selected compound complexes was achieved. The five selected compounds inhibited rLmTR activity in the range of 32.9% to 40.1%. The binding of selected compounds to LmTR involving different hydrogen bonds with distinct residues of the molecule monomers A and B is described. Compound ZINC12151998 (docking score -10.27 kcal/mol) inhibited 32.9% the enzyme activity (100 µM) and showed the highest leishmanicidal activity (IC50 = 58 µM) of all the selected compounds. It was more active than glucantime, and although its half-maximal cytotoxicity concentration (CC50 = 53 µM) was higher than that of the other four compounds, it was less cytotoxic than amphotericin B. Therefore, compound ZINC12151998 provides a promising starting point for a hit-to-lead process in our search for new anti-Leishmania drugs that are more potent and less cytotoxic.
Collapse
Affiliation(s)
- Félix Matadamas-Martínez
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Unidad Médica de Alta Especialidad-Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City 06720, Mexico
| | - Alicia Hernández-Campos
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
| | - Alfredo Téllez-Valencia
- Facultad de Medicina y Nutrición, Universidad Juárez del Estado de Durango Av. Universidad y Fanny Anitúa S/N, Durango 34000, Mexico
| | - Alejandra Vázquez-Raygoza
- Facultad de Medicina y Nutrición, Universidad Juárez del Estado de Durango Av. Universidad y Fanny Anitúa S/N, Durango 34000, Mexico
| | - Sandra Comparán-Alarcón
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Unidad Médica de Alta Especialidad-Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City 06720, Mexico
| | - Lilián Yépez-Mulia
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Unidad Médica de Alta Especialidad-Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City 06720, Mexico.
| | - Rafael Castillo
- Departamento de Farmacia, Facultad de Química, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico.
| |
Collapse
|
7
|
Kelpšas V, Lafumat B, Blakeley MP, Coquelle N, Oksanen E, von Wachenfeldt C. Perdeuteration, large crystal growth and neutron data collection of Leishmania mexicana triose-phosphate isomerase E65Q variant. Acta Crystallogr F Struct Biol Commun 2019; 75:260-269. [PMID: 30950827 PMCID: PMC6450519 DOI: 10.1107/s2053230x19001882] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 01/31/2019] [Indexed: 01/07/2023] Open
Abstract
Triose-phosphate isomerase (TIM) catalyses the interconversion of dihydroxyacetone phosphate and glyceraldehyde 3-phosphate. Two catalytic mechanisms have been proposed based on two reaction-intermediate analogues, 2-phosphoglycolate (2PG) and phosphoglycolohydroxamate (PGH), that have been used as mimics of the cis-enediol(ate) intermediate in several studies of TIM. The protonation states that are critical for the mechanistic interpretation of these structures are generally not visible in the X-ray structures. To resolve these questions, it is necessary to determine the hydrogen positions using neutron crystallography. Neutron crystallography requires large crystals and benefits from replacing all hydrogens with deuterium. Leishmania mexicana triose-phosphate isomerase was therefore perdeuterated and large crystals with 2PG and PGH were produced. Neutron diffraction data collected from two crystals with different volumes highlighted the importance of crystal volume, as smaller crystals required longer exposures and resulted in overall worse statistics.
Collapse
Affiliation(s)
- Vinardas Kelpšas
- Department of Biology, Lund University, Sölvegatan 35, 223 62 Lund, Sweden
| | - Bénédicte Lafumat
- Department of Biology, Lund University, Sölvegatan 35, 223 62 Lund, Sweden
- European Spallation Source ESS ERIC, Odarslövsvägen 113, 224 84 Lund, Sweden
| | | | - Nicolas Coquelle
- Insitut Laue–Langevin, 71 Avenue des Martyrs, 38042 Grenoble, France
| | - Esko Oksanen
- European Spallation Source ESS ERIC, Odarslövsvägen 113, 224 84 Lund, Sweden
- Department of Biochemistry and Structural Biology, Lund University, Sölvegatan 39A, 221 00 Lund, Sweden
| | | |
Collapse
|
8
|
Hernández-Chinea C, Maimone L, Campos Y, Mosca W, Romero PJ. Apparent isocitrate lyase activity in Leishmania amazonensis. Acta Parasitol 2017; 62:701-707. [PMID: 29035856 DOI: 10.1515/ap-2017-0084] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 06/23/2017] [Indexed: 11/15/2022]
Abstract
Early reports have demonstrated the occurrence of glyoxylate cycle enzymes in several Leishmania species. However, these results have been underestimated because genes for the two key enzymes of the cycle, isocitrate lyase (ICL) and malate synthase (MS), are not annotated in Leishmania genomes. We have re-examined this issue in promastigotes of Leishmania amazonensis. Enzyme activities were assayed spectrophotometrically in cellular extracts and characterized partially. A 40 kDa band displaying ICL activity was visualized on zymograms of the extracts. By immunoblotting with mouse antibodies against ICL from Bacillus stearothermophilus, a band of approximately 40 kDa was identified, coincident with the relative molecular mass of the activity band revealed on zymograms. Indirect immunofluorescence of intact promastigotes showed that the recognized antigen is distributed as a punctuated pattern, mainly distributed beneath the subpellicular microtubules, over a diffused cytoplasmic stain. These results clearly demonstrate the existence of an apparent ICL activity in L. amazonensis promastigotes, which is associated to a 40 kDa polypeptide and distributed both diffused and as punctuate aggregates in the cytoplasm. The relevance of this activity is discussed.
Collapse
|
9
|
Aoki JI, Muxel SM, Zampieri RA, Laranjeira-Silva MF, Müller KE, Nerland AH, Floeter-Winter LM. RNA-seq transcriptional profiling of Leishmania amazonensis reveals an arginase-dependent gene expression regulation. PLoS Negl Trop Dis 2017; 11:e0006026. [PMID: 29077741 PMCID: PMC5678721 DOI: 10.1371/journal.pntd.0006026] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 11/08/2017] [Accepted: 10/10/2017] [Indexed: 01/01/2023] Open
Abstract
Background Leishmania is a protozoan parasite that alternates its life cycle between the sand-fly vector and the mammalian host. This alternation involves environmental changes and leads the parasite to dynamic modifications in morphology, metabolism, cellular signaling and regulation of gene expression to allow for a rapid adaptation to new conditions. The L-arginine pathway in L. amazonensis is important during the parasite life cycle and interferes in the establishment and maintenance of the infection in mammalian macrophages. Host arginase is an immune-regulatory enzyme that can reduce the production of nitric oxide by activated macrophages, directing the availability of L-arginine to the polyamine pathway, resulting in parasite replication. In this work, we performed transcriptional profiling to identify differentially expressed genes in L. amazonensis wild-type (La-WT) versus L. amazonensis arginase knockout (La-arg-) promastigotes and axenic amastigotes. Methodology/Principal findings A total of 8253 transcripts were identified in La-WT and La-arg- promastigotes and axenic amastigotes, about 60% of them codifying hypothetical proteins and 443 novel transcripts, which did not match any previously annotated genes. Our RNA-seq data revealed that 85% of genes were constitutively expressed. The comparison of transcriptome and metabolome data showed lower levels of arginase and higher levels of glutamate-5-kinase in La-WT axenic amastigotes compared to promastigotes. The absence of arginase activity in promastigotes increased the levels of pyrroline 5-carboxylate reductase, but decreased the levels of arginosuccinate synthase, pyrroline 5-carboxylate dehydrogenase, acetylornithine deacetylase and spermidine synthase transcripts levels. These observations can explain previous metabolomic data pointing to the increase of L-arginine, citrulline and L-glutamate and reduction of aspartate, proline, ornithine and putrescine. Altogether, these results indicate that arginase activity is important in Leishmania gene expression modulation during differentiation and adaptation to environmental changes. Here, we confirmed this hypothesis with the identification of differential gene expression of the enzymes involved in biosynthesis of amino acids, arginine and proline metabolism and arginine biosynthesis. Conclusions/Significance All data provided information about the transcriptomic profiling and the expression levels of La-WT and La-arg- promastigotes and axenic amastigotes. These findings revealed the importance of arginase in parasite survival and differentiation, and indicated the existence of a coordinated response in the absence of arginase activity related to arginine and polyamine pathways. Leishmania are auxotrophic for many essential nutrients, including amino acids. In this way, the parasite needs to uptake the amino acids from the environment. The uptake of amino acids is mediated by amino acid transporters that are unique for Leishmania. As part of polyamine pathway, the arginase converts L-arginine to ornithine and furthermore to putrescine, products which are essential for parasite growth. On the other hand, the absence of arginase activity could alter the metabolism of the parasite to surpass the external signals during the life cycle and the fate of infection. The transcriptional profiling of La-WT and La-arg- promastigotes and axenic amastigotes revealed 8253 transcripts, 60% encoding hypothetical proteins and 443 novel transcripts. In addition, our data revealed that 85% of the genes were constitutively expressed. Among the 15% (1268 genes) of the differentially expressed genes, we identified genes up- and down-regulated comparing the transcript abundance from different life cycle stages of the parasite and in the presence or absence of arginase. We also combined the transcriptional with metabolic profile that revealed a proportional correlation between enzyme and metabolites in the polyamine pathway. The differentiation of promastigotes to amastigotes alters the expression of enzymes from polyamines biosynthesis, which modulates ornithine, L-glutamate, proline and putrescine levels. In addition, the absence of arginase activity increased the levels of L-arginine, citrulline and L-glutamate and decreased the levels of aspartate, proline, ornithine and putrescine in promastigotes by differential modulation of genes involved in its metabolism. Altogether these data provided additional insights into how Leishmania is able to modulate its biological functions in the presence or absence of arginase activity to survive during environmental changes.
Collapse
Affiliation(s)
- Juliana Ide Aoki
- Department of Physiology, Institute of Bioscience, University of Sao Paulo, Sao Paulo, Brazil
- * E-mail: (JIA); (LMFW)
| | - Sandra Marcia Muxel
- Department of Physiology, Institute of Bioscience, University of Sao Paulo, Sao Paulo, Brazil
| | | | | | - Karl Erik Müller
- Department of Clinical Science, University of Bergen, Bergen, Norway
| | | | - Lucile Maria Floeter-Winter
- Department of Physiology, Institute of Bioscience, University of Sao Paulo, Sao Paulo, Brazil
- * E-mail: (JIA); (LMFW)
| |
Collapse
|
10
|
Mwenechanya R, Kovářová J, Dickens NJ, Mudaliar M, Herzyk P, Vincent IM, Weidt SK, Burgess KE, Burchmore RJS, Pountain AW, Smith TK, Creek DJ, Kim DH, Lepesheva GI, Barrett MP. Sterol 14α-demethylase mutation leads to amphotericin B resistance in Leishmania mexicana. PLoS Negl Trop Dis 2017. [PMID: 28622334 PMCID: PMC5498063 DOI: 10.1371/journal.pntd.0005649] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Amphotericin B has emerged as the therapy of choice for use against the leishmaniases. Administration of the drug in its liposomal formulation as a single injection is being promoted in a campaign to bring the leishmaniases under control. Understanding the risks and mechanisms of resistance is therefore of great importance. Here we select amphotericin B-resistant Leishmania mexicana parasites with relative ease. Metabolomic analysis demonstrated that ergosterol, the sterol known to bind the drug, is prevalent in wild-type cells, but diminished in the resistant line, where alternative sterols become prevalent. This indicates that the resistance phenotype is related to loss of drug binding. Comparing sequences of the parasites' genomes revealed a plethora of single nucleotide polymorphisms that distinguish wild-type and resistant cells, but only one of these was found to be homozygous and associated with a gene encoding an enzyme in the sterol biosynthetic pathway, sterol 14α-demethylase (CYP51). The mutation, N176I, is found outside of the enzyme's active site, consistent with the fact that the resistant line continues to produce the enzyme's product. Expression of wild-type sterol 14α-demethylase in the resistant cells caused reversion to drug sensitivity and a restoration of ergosterol synthesis, showing that the mutation is indeed responsible for resistance. The amphotericin B resistant parasites become hypersensitive to pentamidine and also agents that induce oxidative stress. This work reveals the power of combining polyomics approaches, to discover the mechanism underlying drug resistance as well as offering novel insights into the selection of resistance to amphotericin B itself.
Collapse
Affiliation(s)
- Roy Mwenechanya
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
- Wellcome Centre for Molecular Parasitology, University of Glasgow, 120 University Place, Glasgow, United Kingdom
| | - Julie Kovářová
- Wellcome Centre for Molecular Parasitology, University of Glasgow, 120 University Place, Glasgow, United Kingdom
| | - Nicholas J. Dickens
- Wellcome Centre for Molecular Parasitology, University of Glasgow, 120 University Place, Glasgow, United Kingdom
| | - Manikhandan Mudaliar
- Glasgow Polyomics, Wolfson Wohl Cancer Research Centre, University of Glasgow, Garscube Estate, Bearsden, Glasgow, United Kingdom
| | - Pawel Herzyk
- Glasgow Polyomics, Wolfson Wohl Cancer Research Centre, University of Glasgow, Garscube Estate, Bearsden, Glasgow, United Kingdom
| | - Isabel M. Vincent
- Wellcome Centre for Molecular Parasitology, University of Glasgow, 120 University Place, Glasgow, United Kingdom
| | - Stefan K. Weidt
- Glasgow Polyomics, Wolfson Wohl Cancer Research Centre, University of Glasgow, Garscube Estate, Bearsden, Glasgow, United Kingdom
| | - Karl E. Burgess
- Glasgow Polyomics, Wolfson Wohl Cancer Research Centre, University of Glasgow, Garscube Estate, Bearsden, Glasgow, United Kingdom
| | - Richard J. S. Burchmore
- Wellcome Centre for Molecular Parasitology, University of Glasgow, 120 University Place, Glasgow, United Kingdom
- Glasgow Polyomics, Wolfson Wohl Cancer Research Centre, University of Glasgow, Garscube Estate, Bearsden, Glasgow, United Kingdom
| | - Andrew W. Pountain
- Wellcome Centre for Molecular Parasitology, University of Glasgow, 120 University Place, Glasgow, United Kingdom
| | - Terry K. Smith
- Biomedical Sciences Research Complex, University of St Andrews, North Haugh, St. Andrews, Fife, United Kingdom
| | - Darren J. Creek
- Drug Delivery, Disposition & Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, Australia
| | - Dong-Hyun Kim
- Centre for Analytical Bioscience, School of Pharmacy, University of Nottingham, University Park, Nottingham, United Kingdom
| | - Galina I. Lepesheva
- Vanderbilt University School of Medicine, Nashville, TN, United States of America
| | - Michael P. Barrett
- Wellcome Centre for Molecular Parasitology, University of Glasgow, 120 University Place, Glasgow, United Kingdom
- Glasgow Polyomics, Wolfson Wohl Cancer Research Centre, University of Glasgow, Garscube Estate, Bearsden, Glasgow, United Kingdom
- * E-mail:
| |
Collapse
|
11
|
Hai Y, Christianson DW. Crystal structures of Leishmania mexicana arginase complexed with α,α-disubstituted boronic amino-acid inhibitors. Acta Crystallogr F Struct Biol Commun 2016; 72:300-6. [PMID: 27050264 PMCID: PMC4822987 DOI: 10.1107/s2053230x16003630] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 03/01/2016] [Indexed: 02/06/2023] Open
Abstract
Leishmania arginase is a potential drug target for the treatment of leishmaniasis because this binuclear manganese metalloenzyme initiates de novo polyamine biosynthesis by catalyzing the hydrolysis of L-arginine to generate L-ornithine and urea. The product L-ornithine subsequently undergoes decarboxylation to yield putrescine, which in turn is utilized for spermidine biosynthesis. Polyamines such as spermidine are essential for the growth and survival of the parasite, so inhibition of enzymes in the polyamine-biosynthetic pathway comprises an effective strategy for treating parasitic infections. To this end, two X-ray crystal structures of L. mexicana arginase complexed with α,α-disubstituted boronic amino-acid inhibitors based on the molecular scaffold of 2-(S)-amino-6-boronohexanoic acid are now reported. Structural comparisons with human and parasitic arginase complexes reveal interesting differences in the binding modes of the additional α-substituents, i.e. the D side chains, of these inhibitors. Subtle differences in the three-dimensional contours of the outer active-site rims among arginases from different species lead to different conformations of the D side chains and thus different inhibitor-affinity trends. The structures suggest that it is possible to maintain affinity while fine-tuning intermolecular interactions of the D side chain of α,α-disubstituted boronic amino-acid inhibitors in the search for isozyme-specific and species-specific arginase inhibitors.
Collapse
Affiliation(s)
- Yang Hai
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - David W. Christianson
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
- Radcliffe Institute for Advanced Study and Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138, USA
| |
Collapse
|
12
|
Shio MT, Christian JG, Jung JY, Chang KP, Olivier M. PKC/ROS-Mediated NLRP3 Inflammasome Activation Is Attenuated by Leishmania Zinc-Metalloprotease during Infection. PLoS Negl Trop Dis 2015; 9:e0003868. [PMID: 26114647 PMCID: PMC4482689 DOI: 10.1371/journal.pntd.0003868] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 06/01/2015] [Indexed: 01/06/2023] Open
Abstract
Parasites of the Leishmania genus infect and survive within macrophages by inhibiting several microbicidal molecules, such as nitric oxide and pro-inflammatory cytokines. In this context, various species of Leishmania have been reported to inhibit or reduce the production of IL-1β both in vitro and in vivo. However, the mechanism whereby Leishmania parasites are able to affect IL-1β production and secretion by macrophages is still not fully understood. Dependent on the stimulus at hand, the maturation of IL-1β is facilitated by different inflammasome complexes. The NLRP3 inflammasome has been shown to be of pivotal importance in the detection of danger molecules such as inorganic crystals like asbestos, silica and malarial hemozoin, (HZ) as well as infectious agents. In the present work, we investigated whether Leishmania parasites modulate NLRP3 inflammasome activation. Using PMA-differentiated THP-1 cells, we demonstrate that Leishmania infection effectively inhibits macrophage IL-1β production upon stimulation. In this context, the expression and activity of the metalloprotease GP63 - a critical virulence factor expressed by all infectious Leishmania species - is a prerequisite for a Leishmania-mediated reduction of IL-1β secretion. Accordingly, L. mexicana, purified GP63 and GP63-containing exosomes, caused the inhibition of macrophage IL-1β production. Leishmania-dependent suppression of IL-1β secretion is accompanied by an inhibition of reactive oxygen species (ROS) production that has previously been shown to be associated with NLRP3 inflammasome activation. The observed loss of ROS production was due to an impaired PKC-mediated protein phosphorylation. Furthermore, ROS-independent inflammasome activation was inhibited, possibly due to an observed GP63-dependent cleavage of inflammasome and inflammasome-related proteins. Collectively for the first time, we herein provide evidence that the protozoan parasite Leishmania, through its surface metalloprotease GP63, can significantly inhibit NLRP3 inflammasome function and IL-1β production. Leishmania parasites are the causative agent of leishmaniasis, a wide spread disease in tropical and subtropical areas. The microorganisms have been shown to be well-adapted to their hosts and are able to enter their target cells where they replicate themselves. To ensure these processes, Leishmania disrupts a multitude of cellular signals and protective mechanisms, which overall attenuates immune responses against the parasites. A key factor for inflammatory processes, also during infections, is IL-1β. As previous studies suggested a dysregulation of IL-1β levels after infection with Leishmania parasites, we herein investigated the underlying mechanisms. Our work reveals that Leishmania suppressing IL-1β production through its virulence factor GP63. Furthermore, our data suggests that the parasites can dampen the maturation of IL-1β after different stimuli. In this regard we established a role for the suppression of the kinase PKC and the generation of reactive oxygen species, as well as the cleavage of cellular proteins that are important for IL-1β-generation. Thus, we here present a novel aspect for how Leishmania parasites can counteract host protective mechanisms.
Collapse
Affiliation(s)
- Marina Tiemi Shio
- Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada
- Department of Microbiology, Immunology and Parasitology, Universidade Federal de São Paulo, São Paulo, Brazil
| | - Jan Gregor Christian
- Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada
- McGill International Tuberculosis (TB) Centre and the Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Jee Yong Jung
- Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada
| | - Kwang-Poo Chang
- Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, Illinois, United States of America
| | - Martin Olivier
- Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada
- McGill International Tuberculosis (TB) Centre and the Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
- * E-mail:
| |
Collapse
|
13
|
Pitaluga AN, Moreira MEC, Traub-Csekö YM. A putative role for inosine 5' monophosphate dehydrogenase (IMPDH) in Leishmania amazonensis programmed cell death. Exp Parasitol 2014; 149:32-8. [PMID: 25499513 DOI: 10.1016/j.exppara.2014.12.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 11/25/2014] [Accepted: 12/04/2014] [Indexed: 11/18/2022]
Abstract
Leishmania amazonensis undergoes apoptosis-like programmed cell death (PCD) under heat shock conditions. We identified a potential role for inosine 5' monophosphate dehydrogenase (IMPDH) in L. amazonensis PCD. Trypanosomatids do not have a "de novo" purine synthesis pathway, relying on the salvage pathway for survival. IMPDH, a key enzyme in the purine nucleotide pathway, is related to cell growth and apoptosis. Since guanine nucleotide depletion triggers cell cycle arrest and apoptosis in several organisms we analyzed the correlation between IMPDH and apoptosis-like death in L. amazonensis. The L. amazonensis IMPDH inhibition effect on PCD was evaluated through gene expression analysis, mitochondrial depolarization and detection of Annexin-V labeled parasites. We demonstrated a down-regulation of impdh expression under heat shock treatment, which mimics the natural mammalian host infection. Also, IMPDH inhibitors ribavirin and mycophenolic acid (MPA) prevented cell growth and generated an apoptosis-like phenotype in sub-populations of L. amazonensis promastigotes. Our results are in accordance with previous results showing that a subpopulation of parasites undergoes apoptosis-like cell death in the nutrient poor environment of the vector gut. Here, we suggest the involvement of purine metabolism in previously observed apoptosis-like cell death during Leishmania infection.
Collapse
Affiliation(s)
- A N Pitaluga
- Laboratório de Biologia Molecular de Parasitas e Vetores, Instituto Oswaldo Cruz/FIOCRUZ, Rio de Janeiro, Brazil.
| | - M E C Moreira
- Divisão de Medicina Experimental, Instituto Nacional de Câncer, Rio de Janeiro, Brazil
| | - Y M Traub-Csekö
- Laboratório de Biologia Molecular de Parasitas e Vetores, Instituto Oswaldo Cruz/FIOCRUZ, Rio de Janeiro, Brazil
| |
Collapse
|
14
|
Lozano NBH, Oliveira RF, Weber KC, Honorio KM, Guido RVC, Andricopulo AD, de Sousa AG, da Silva ABF. Pattern recognition techniques applied to the study of leishmanial glyceraldehyde-3-phosphate dehydrogenase inhibition. Int J Mol Sci 2014; 15:3186-203. [PMID: 24566143 PMCID: PMC3958905 DOI: 10.3390/ijms15023186] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 01/21/2014] [Accepted: 01/24/2014] [Indexed: 11/16/2022] Open
Abstract
Chemometric pattern recognition techniques were employed in order to obtain Structure-Activity Relationship (SAR) models relating the structures of a series of adenosine compounds to the affinity for glyceraldehyde 3-phosphate dehydrogenase of Leishmania mexicana (LmGAPDH). A training set of 49 compounds was used to build the models and the best ones were obtained with one geometrical and four electronic descriptors. Classification models were externally validated by predictions for a test set of 14 compounds not used in the model building process. Results of good quality were obtained, as verified by the correct classifications achieved. Moreover, the results are in good agreement with previous SAR studies on these molecules, to such an extent that we can suggest that these findings may help in further investigations on ligands of LmGAPDH capable of improving treatment of leishmaniasis.
Collapse
Affiliation(s)
- Norka B H Lozano
- Instituto de Química de São Carlos, USP, São Carlos (SP), 13566-590, Brazil.
| | - Rafael F Oliveira
- Universidade Federal da Paraíba, João Pessoa (PB), 58051-900, Brazil.
| | - Karen C Weber
- Universidade Federal da Paraíba, João Pessoa (PB), 58051-900, Brazil.
| | - Kathia M Honorio
- Escola de Artes Ciências e Humanidades, USP, São Paulo (SP), 03828-000, Brazil.
| | - Rafael V C Guido
- Instituto de Física de São Carlos, USP, São Carlos (SP), 13566-590, Brazil.
| | | | | | | |
Collapse
|
15
|
de Macedo-Silva ST, Urbina JA, de Souza W, Rodrigues JCF. In vitro activity of the antifungal azoles itraconazole and posaconazole against Leishmania amazonensis. PLoS One 2013; 8:e83247. [PMID: 24376670 PMCID: PMC3871555 DOI: 10.1371/journal.pone.0083247] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Accepted: 10/31/2013] [Indexed: 01/13/2023] Open
Abstract
Leishmaniasis, caused by protozoan parasites of the Leishmania genus, is one of the most prevalent neglected tropical diseases. It is endemic in 98 countries, causing considerable morbidity and mortality. Pentavalent antimonials are the first line of treatment for leishmaniasis except in India. In resistant cases, miltefosine, amphotericin B and pentamidine are used. These treatments are unsatisfactory due to toxicity, limited efficacy, high cost and difficult administration. Thus, there is an urgent need to develop drugs that are efficacious, safe, and more accessible to patients. Trypanosomatids, including Leishmania spp. and Trypanosoma cruzi, have an essential requirement for ergosterol and other 24-alkyl sterols, which are absent in mammalian cells. Inhibition of ergosterol biosynthesis is increasingly recognized as a promising target for the development of new chemotherapeutic agents. The aim of this work was to investigate the antiproliferative, physiological and ultrastructural effects against Leishmania amazonensis of itraconazole (ITZ) and posaconazole (POSA), two azole antifungal agents that inhibit sterol C14α-demethylase (CYP51). Antiproliferative studies demonstrated potent activity of POSA and ITZ: for promastigotes, the IC50 values were 2.74 µM and 0.44 µM for POSA and ITZ, respectively, and for intracellular amastigotes, the corresponding values were 1.63 µM and 0.08 µM, for both stages after 72 h of treatment. Physiological studies revealed that both inhibitors induced a collapse of the mitochondrial membrane potential (ΔΨm), which was consistent with ultrastructural alterations in the mitochondrion. Intense mitochondrial swelling, disorganization and rupture of mitochondrial membranes were observed by transmission electron microscopy. In addition, accumulation of lipid bodies, appearance of autophagosome-like structures and alterations in the kinetoplast were also observed. In conclusion, our results indicate that ITZ and POSA are potent inhibitors of L. amazonensis and suggest that these drugs could represent novel therapies for the treatment of leishmaniasis, either alone or in combination with other agents.
Collapse
Affiliation(s)
- Sara Teixeira de Macedo-Silva
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Instituto Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem, Rio de Janeiro, Brazil
| | - Julio A. Urbina
- Instituto Venezolano de Investigaciones Científicas, Centro de Bioquímica y Biofísica, Caracas, Venezuela
| | - Wanderley de Souza
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Instituto Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem, Rio de Janeiro, Brazil
- Instituto Nacional de Metrologia, Qualidade e Tecnologia, Inmetro, Rio de Janeiro, Brazil
| | - Juliany Cola Fernandes Rodrigues
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
- Instituto Nacional de Ciência e Tecnologia de Biologia Estrutural e Bioimagem, Rio de Janeiro, Brazil
- Instituto Nacional de Metrologia, Qualidade e Tecnologia, Inmetro, Rio de Janeiro, Brazil
- Núcleo Multidisciplinar de Pesquisa em Biologia (NUMPEX-BIO), Polo Avançado de Xerém, Universidade Federal do Rio de Janeiro, Duque de Caxias, Brazil
- * E-mail:
| |
Collapse
|
16
|
Schröder J, Noack S, Marhöfer RJ, Mottram JC, Coombs GH, Selzer PM. Identification of semicarbazones, thiosemicarbazones and triazine nitriles as inhibitors of Leishmania mexicana cysteine protease CPB. PLoS One 2013; 8:e77460. [PMID: 24146999 PMCID: PMC3797739 DOI: 10.1371/journal.pone.0077460] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Accepted: 09/09/2013] [Indexed: 11/19/2022] Open
Abstract
Cysteine proteases of the papain superfamily are present in nearly all eukaryotes. They play pivotal roles in the biology of parasites and inhibition of cysteine proteases is emerging as an important strategy to combat parasitic diseases such as sleeping sickness, Chagas' disease and leishmaniasis. Homology modeling of the mature Leishmania mexicana cysteine protease CPB2.8 suggested that it differs significantly from bovine cathepsin B and thus could be a good drug target. High throughput screening of a compound library against this enzyme and bovine cathepsin B in a counter assay identified four novel inhibitors, containing the warhead-types semicarbazone, thiosemicarbazone and triazine nitrile, that can be used as leads for antiparasite drug design. Covalent docking experiments confirmed the SARs of these lead compounds in an effort to understand the structural elements required for specific inhibition of CPB2.8. This study has provided starting points for the design of selective and highly potent inhibitors of L. mexicana cysteine protease CPB that may also have useful efficacy against other important cysteine proteases.
Collapse
Affiliation(s)
- Jörg Schröder
- Molecular Discovery Sciences, MSD Animal Health Innovation GmbH, Schwabenheim, Germany
| | - Sandra Noack
- Molecular Discovery Sciences, MSD Animal Health Innovation GmbH, Schwabenheim, Germany
| | - Richard J. Marhöfer
- Molecular Discovery Sciences, MSD Animal Health Innovation GmbH, Schwabenheim, Germany
| | - 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
| | - Graham H. Coombs
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom
- * E-mail: (PMS); (GHC)
| | - Paul M. Selzer
- Molecular Discovery Sciences, MSD Animal Health Innovation GmbH, Schwabenheim, Germany
- 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
- Interfakultäres Institut für Biochemie, University of Tübingen, Tübingen, Germany
- * E-mail: (PMS); (GHC)
| |
Collapse
|
17
|
Lozano NBH, Oliveira RF, Weber KC, Honorio KM, Guido RV, Andricopulo AD, Da Silva ABF. Identification of electronic and structural descriptors of adenosine analogues related to inhibition of leishmanial glyceraldehyde-3-phosphate dehydrogenase. Molecules 2013; 18:5032-50. [PMID: 23629757 PMCID: PMC6269754 DOI: 10.3390/molecules18055032] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Revised: 04/27/2013] [Accepted: 04/28/2013] [Indexed: 11/24/2022] Open
Abstract
Quantitative structure-activity relationship (QSAR) studies were performed in order to identify molecular features responsible for the antileishmanial activity of 61 adenosine analogues acting as inhibitors of the enzyme glyceraldehyde 3-phosphate dehydrogenase of Leishmania mexicana (LmGAPDH). Density functional theory (DFT) was employed to calculate quantum-chemical descriptors, while several structural descriptors were generated with Dragon 5.4. Variable selection was undertaken with the ordered predictor selection (OPS) algorithm, which provided a set with the most relevant descriptors to perform PLS, PCR and MLR regressions. Reliable and predictive models were obtained, as attested by their high correlation coefficients, as well as the agreement between predicted and experimental values for an external test set. Additional validation procedures were carried out, demonstrating that robust models were developed, providing helpful tools for the optimization of the antileishmanial activity of adenosine compounds.
Collapse
Affiliation(s)
- Norka B. H. Lozano
- Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos, SP 13566-590, Brazil; E-Mail:
| | - Rafael F. Oliveira
- Departamento de Química, Universidade Federal da Paraiba, João Pessoa, PB 13083-970, Brazil; E-Mails: (R.F.O.); (K.W.C.)
| | - Karen C. Weber
- Departamento de Química, Universidade Federal da Paraiba, João Pessoa, PB 13083-970, Brazil; E-Mails: (R.F.O.); (K.W.C.)
| | - Kathia M. Honorio
- Centro de Ciência Naturais e Humanas, Universidade Federal do ABC, Santo Andre, SP 09210-170, Brazil; E-Mail:
- Escola de Artes, Ciências e Humanidades, Universidade de São Paulo, São Paulo, SP 03828-000, Brazil; E-Mail:
| | - Rafael V. Guido
- Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP 13560-590, Brazil; E-Mails: (R.V.G.); (A.D.A.)
| | - Adriano D. Andricopulo
- Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP 13560-590, Brazil; E-Mails: (R.V.G.); (A.D.A.)
| | - Albérico B. F. Da Silva
- Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos, SP 13566-590, Brazil; E-Mail:
| |
Collapse
|
18
|
Mutlu O. Molecular modeling, structural analysis and identification of ligand binding sites of trypanothione reductase from Leishmania mexicana. J Vector Borne Dis 2013; 50:38-44. [PMID: 23703438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023] Open
Abstract
BACKGROUND & OBJECTIVES Trypanothione reductase (TR) is a member of FAD-dependent NADPH oxidoreductase protein family and it is a key enzyme which connects the NADPH and the thiol-based redox system. Inhibition studies indicate that TR is an essential enzyme for parasite survival. Therefore, it is an attractive target enzyme for novel drug candidates. There is no structural model for TR of Leishmania mexicana (LmTR) in the protein databases. In this work, 3D structure of TR from L. mexicana was identified by template-based in silico homology modeling method, resultant model was validated, structurally analyzed and possible ligand binding pockets were identified. METHODS For computational molecular modeling study, firstly, template was identified by BLAST search against PDB database. Multiple alignments were achieved by ClustalW2. Molecular modeling of LmTR was done and possible drug targeting sites were identified. Refinement of the model was done by performing local energy minimization for backbone, hydrogen and side chains. Model was validated by web-based servers. RESULTS A reliable 3D model for TR from L. mexicana was modeled by using L. infantum trypanothione reductase (LiTR) as a template. RMSD results according to C-alpha, visible atoms and backbone were 0.809 Å, 0.732 Å and 0.728 Å respectively. Ramachandran plot indicates that model shows an acceptable stereochemistry. CONCLUSION Modeled structure of LmTR shows high similarity with LiTR based on overall structural features like domains and folding patterns. Predicted structure will provide a source for the further docking studies of various peptide-based inhibitors.
Collapse
Affiliation(s)
- Ozal Mutlu
- Marmara University, Faculty of Arts and Sciences, Department of Biology, Istanbul, Turkey.
| |
Collapse
|
19
|
Morgan HP, Walsh MJ, Blackburn EA, Wear MA, Boxer MB, Shen M, Mcnae IW, Nowicki MW, Michels PAM, Auld DS, Fothergill-Gilmore LA, Walkinshaw MD. A new family of covalent inhibitors block nucleotide binding to the active site of pyruvate kinase. Biochem J 2012; 448:67-72. [PMID: 22906073 PMCID: PMC3498827 DOI: 10.1042/bj20121014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
PYK (pyruvate kinase) plays a central role in the metabolism of many organisms and cell types, but the elucidation of the details of its function in a systems biology context has been hampered by the lack of specific high-affinity small-molecule inhibitors. High-throughput screening has been used to identify a family of saccharin derivatives which inhibit LmPYK (Leishmania mexicana PYK) activity in a time- (and dose-) dependent manner, a characteristic of irreversible inhibition. The crystal structure of DBS {4-[(1,1-dioxo-1,2-benzothiazol-3-yl)sulfanyl]benzoic acid} complexed with LmPYK shows that the saccharin moiety reacts with an active-site lysine residue (Lys335), forming a covalent bond and sterically hindering the binding of ADP/ATP. Mutation of the lysine residue to an arginine residue eliminated the effect of the inhibitor molecule, providing confirmation of the proposed inhibitor mechanism. This lysine residue is conserved in the active sites of the four human PYK isoenzymes, which were also found to be irreversibly inhibited by DBS. X-ray structures of PYK isoforms show structural differences at the DBS-binding pocket, and this covalent inhibitor of PYK provides a chemical scaffold for the design of new families of potentially isoform-specific irreversible inhibitors.
Collapse
Affiliation(s)
- Hugh P. Morgan
- Centre for Translational and Chemical Biology, School of Biological Sciences, University of Edinburgh, Michael Swann Building, The King’s Buildings, Mayfield Road, Edinburgh EH9 3JR, UK
| | - Martin J. Walsh
- NIH Chemical Genomics Center, NIH Center for Translational Therapeutics, National Human, Genome Research Institute, National Institutes of Health, 9800 Medical Center Drive, Rockville, MD 20850, U.S.A
| | - Elizabeth A. Blackburn
- Centre for Translational and Chemical Biology, School of Biological Sciences, University of Edinburgh, Michael Swann Building, The King’s Buildings, Mayfield Road, Edinburgh EH9 3JR, UK
| | - Martin A. Wear
- Centre for Translational and Chemical Biology, School of Biological Sciences, University of Edinburgh, Michael Swann Building, The King’s Buildings, Mayfield Road, Edinburgh EH9 3JR, UK
| | - Matthew B. Boxer
- NIH Chemical Genomics Center, NIH Center for Translational Therapeutics, National Human, Genome Research Institute, National Institutes of Health, 9800 Medical Center Drive, Rockville, MD 20850, U.S.A
| | - Min Shen
- NIH Chemical Genomics Center, NIH Center for Translational Therapeutics, National Human, Genome Research Institute, National Institutes of Health, 9800 Medical Center Drive, Rockville, MD 20850, U.S.A
| | - Iain W. Mcnae
- Centre for Translational and Chemical Biology, School of Biological Sciences, University of Edinburgh, Michael Swann Building, The King’s Buildings, Mayfield Road, Edinburgh EH9 3JR, UK
| | - Matthew W. Nowicki
- Centre for Translational and Chemical Biology, School of Biological Sciences, University of Edinburgh, Michael Swann Building, The King’s Buildings, Mayfield Road, Edinburgh EH9 3JR, UK
| | - Paul A. M. Michels
- Research Unit for Tropical Diseases, de Duve Institute and Laboratory of Biochemistry, Université catholique de Louvain, Avenue Hippocrate 74, B-1200 Brussels, Belgium
| | - Douglas S. Auld
- NIH Chemical Genomics Center, NIH Center for Translational Therapeutics, National Human, Genome Research Institute, National Institutes of Health, 9800 Medical Center Drive, Rockville, MD 20850, U.S.A
| | - Linda A. Fothergill-Gilmore
- Centre for Translational and Chemical Biology, School of Biological Sciences, University of Edinburgh, Michael Swann Building, The King’s Buildings, Mayfield Road, Edinburgh EH9 3JR, UK
| | - Malcolm D. Walkinshaw
- Centre for Translational and Chemical Biology, School of Biological Sciences, University of Edinburgh, Michael Swann Building, The King’s Buildings, Mayfield Road, Edinburgh EH9 3JR, UK
| |
Collapse
|
20
|
Ali NOM, Ibrahim ME, Grant KM, Mottram JC. Leishmania mexicana: expression; characterization and activity assessment of E. coli-expressed recombinant CRK3. Eur Rev Med Pharmacol Sci 2012; 16:1338-1345. [PMID: 23104649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
OBJECTIVES AND METHODS Previous studies have shown that CRK3 protein kinase of Leishmania mexicana is a potential drug target. Therefore, the aim of this study was to provide an active protein kinase for chemical inhibitors testing. A system was developed to express and affinity-purify recombinant L. mexicana CRK3 protein from Escherichia coli. RESULTS Biochemical analysis has confirmed the expression of the pure kinase. The bacterial-expressed kinase was found to be inactive as a monomer. The mutated CRK3-E178 protein kinase was also found to be inactive. CONCLUSION This study suggests that cyclin binding and phosphorylation status are both important for reconstituting protein kinase activity. Work presented by this paper has confirmed the usefulness of the prokaryotic system for production of pure homogenous recombinant protein kinase of Leishmania parasite, though this system is unable to produce active CRK3 protein kinase
Collapse
Affiliation(s)
- N O M Ali
- Department of Parasitology, Faculty of Veterinary Medicine, University of Khartoum, Sudan.
| | | | | | | |
Collapse
|
21
|
Morgan HP, McNae IW, Nowicki MW, Zhong W, Michels PAM, Auld DS, Fothergill-Gilmore LA, Walkinshaw MD. The trypanocidal drug suramin and other trypan blue mimetics are inhibitors of pyruvate kinases and bind to the adenosine site. J Biol Chem 2011; 286:31232-40. [PMID: 21733839 PMCID: PMC3173065 DOI: 10.1074/jbc.m110.212613] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2010] [Revised: 06/06/2011] [Indexed: 11/06/2022] Open
Abstract
Ehrlich's pioneering chemotherapeutic experiments published in 1904 (Ehrlich, P., and Shiga, K. (1904) Berlin Klin. Wochenschrift 20, 329-362) described the efficacy of a series of dye molecules including trypan blue and trypan red to eliminate trypanosome infections in mice. The molecular structures of the dyes provided a starting point for the synthesis of suramin, which was developed and used as a trypanocidal drug in 1916 and is still in clinical use. Despite the biological importance of these dye-like molecules, the mode of action on trypanosomes has remained elusive. Here we present crystal structures of suramin and three related dyes in complex with pyruvate kinases from Leishmania mexicana or from Trypanosoma cruzi. The phenyl sulfonate groups of all four molecules (suramin, Ponceau S, acid blue 80, and benzothiazole-2,5-disulfonic acid) bind in the position of ADP/ATP at the active sites of the pyruvate kinases (PYKs). The binding positions in the two different trypanosomatid PYKs are nearly identical. We show that suramin competitively inhibits PYKs from humans (muscle, tumor, and liver isoenzymes, K(i) = 1.1-17 μM), T. cruzi (K(i) = 108 μM), and L. mexicana (K(i) = 116 μM), all of which have similar active sites. Synergistic effects were observed when examining suramin inhibition in the presence of an allosteric effector molecule, whereby IC(50) values decreased up to 2-fold for both trypanosomatid and human PYKs. These kinetic and structural analyses provide insight into the promiscuous inhibition observed for suramin and into the mode of action of the dye-like molecules used in Ehrlich's original experiments.
Collapse
Affiliation(s)
- Hugh P. Morgan
- From the Structural Biochemistry Group, Institute of Structural and Molecular Biology, University of Edinburgh, King's Buildings, Mayfield Road, Edinburgh EH9 3JR, Scotland, United Kingdom
| | - Iain W. McNae
- From the Structural Biochemistry Group, Institute of Structural and Molecular Biology, University of Edinburgh, King's Buildings, Mayfield Road, Edinburgh EH9 3JR, Scotland, United Kingdom
| | - Matthew W. Nowicki
- From the Structural Biochemistry Group, Institute of Structural and Molecular Biology, University of Edinburgh, King's Buildings, Mayfield Road, Edinburgh EH9 3JR, Scotland, United Kingdom
| | - Wenhe Zhong
- From the Structural Biochemistry Group, Institute of Structural and Molecular Biology, University of Edinburgh, King's Buildings, Mayfield Road, Edinburgh EH9 3JR, Scotland, United Kingdom
| | - Paul A. M. Michels
- the Research Unit for Tropical Diseases, de Duve Institute and Laboratory of Biochemistry, Université catholique de Louvain, Avenue Hippocrate 74, B-1200 Brussels, Belgium, and
| | - Douglas S. Auld
- the National Institutes of Health Chemical Genomics Center, National Human Genome Research Institute, National Institutes of Health, Rockville, Maryland 20850
| | - Linda A. Fothergill-Gilmore
- From the Structural Biochemistry Group, Institute of Structural and Molecular Biology, University of Edinburgh, King's Buildings, Mayfield Road, Edinburgh EH9 3JR, Scotland, United Kingdom
| | - Malcolm D. Walkinshaw
- From the Structural Biochemistry Group, Institute of Structural and Molecular Biology, University of Edinburgh, King's Buildings, Mayfield Road, Edinburgh EH9 3JR, Scotland, United Kingdom
| |
Collapse
|
22
|
Riley E, Roberts SC, Ullman B. Inhibition profile of Leishmania mexicana arginase reveals differences with human arginase I. Int J Parasitol 2011; 41:545-52. [PMID: 21232540 DOI: 10.1016/j.ijpara.2010.12.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2010] [Accepted: 12/09/2010] [Indexed: 12/25/2022]
Abstract
Arginase (ARG), the enzyme that catalyzes the conversion of arginine to ornithine and urea, is the first and committed step in polyamine biosynthesis in Leishmania. The creation of a conditionally lethal Δarg null mutant in Leishmania mexicana has established that ARG is an essential enzyme for the promastigote form of the parasite and that the enzyme provides an important defense mechanism for parasite survival in the eukaryotic host. Furthermore, human ARGI (HsARGI) has also been implicated as a key factor in parasite proliferation. Thus, inhibitors of ARG offer a rational paradigm for drug design. To initiate a search for inhibitors of the L. mexicana ARG (LmARG), recombinant LmARG and HsARGI enzymes were purified from Escherichia coli. Both LmARG and HsARGI were specific for l-arginine and exhibited no activity with either d-arginine or agmatine as possible substrates. LmARG exhibited a K(m) of 25±4mM for l-arginine, a pH optimum ∼9.0, and was dependent upon the presence of a divalent cation, preferentially manganese. A K(m) of 13.5 ± 2mM for l-arginine was calculated for the HsARGI. A collection of 37 compounds was evaluated against both enzymes. Twelve of these compounds were identified as being either strong inhibitors of both LmARG and HsARGI or differential inhibitors between the two enzymes. Of the 12 compounds, six were selected for further analysis and the type and extent of inhibition determined.
Collapse
Affiliation(s)
- Eric Riley
- Department of Biochemistry and Molecular Biology, Oregon Health and Science University, 3181 S.W. Sam Jackson Park Rd., Portland, OR 97239-3098, USA
| | | | | |
Collapse
|
23
|
Castro-Pinto DB, Echevarria A, Genestra MS, Cysne-Finkelstein L, Leon LL. Trypanothione Reductase Activity is Prominent in Metacyclic Promastigotes and Axenic Amastigotes of Leishmania amazonesis. Evaluation of its Potential as a Therapeutic Target. J Enzyme Inhib Med Chem 2008; 19:57-63. [PMID: 15202494 DOI: 10.1080/14756360310001624966] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
The activity of trypanothione reductase in Leishmania amazonensis was evaluated and it was demonstrated that TR is expressed in the soluble fractions of infective promastigotes and amastigotes, while non-infective promastigotes expressed the enzyme at basal levels. This data allows an association of enzyme activity and the infective capacity of the parasite. We have also previously demonstrated that amidine compounds (N, N'-diphenyl-4-methoxy-benzamidine and pentamidine) were active against this parasite. Here, experiments concerning the effect of these compounds on TR activity, showed that both compounds significantly inhibited the enzyme. However, against glutathione reductase, only pentamidine showed a significant inhibitory action, suggesting an association with the toxic effects of this drug used in the clinic for the treatment of leishmaniasis.
Collapse
Affiliation(s)
- Denise B Castro-Pinto
- Department of Immunology, Oswaldo Cruz Institute, FIOCRUZ, Av. Brasil, 4365-Manguinhos CEP 21042-900, Rio de Janeiro, RJ, Brazil
| | | | | | | | | |
Collapse
|
24
|
Tulloch LB, Morgan HP, Hannaert V, Michels PAM, Fothergill-Gilmore LA, Walkinshaw MD. Sulphate removal induces a major conformational change in Leishmania mexicana pyruvate kinase in the crystalline state. J Mol Biol 2008; 383:615-26. [PMID: 18775437 DOI: 10.1016/j.jmb.2008.08.037] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2008] [Accepted: 08/14/2008] [Indexed: 11/17/2022]
Abstract
We report X-ray structures of pyruvate kinase from Leishmania mexicana (LmPYK) that are trapped in different conformations. These, together with the previously reported structure of LmPYK in its inactive (T-state) conformation, allow comparisons of three different conformers of the same species of pyruvate kinase (PYK). Four new site point mutants showing the effects of side-chain alteration at subunit interfaces are also enzymatically characterised. The LmPYK tetramer crystals grown with ammonium sulphate as precipitant adopt an active-like conformation, with sulphate ions at the active and effector sites. The sulphates occupy positions similar to those of the phosphates of ligands bound to active (R-state) and constitutively active (nonallosteric) PYKs from several species, and provide insight into the structural roles of the phosphates of the substrates and effectors. Crystal soaking in sulphate-free buffers was found to induce major conformational changes in the tetramer. In particular, the unwinding of the Aalpha6' helix and the inward hinge movement of the B domain are coupled with a significant widening (4 A) of the tetramer caused by lateral movement of the C domains. The two new LmPYK structures and the activity studies of site point mutations described in this article are consistent with a developing picture of allosteric activity in which localised changes in protein flexibility govern the distribution of conformer families adopted by the tetramer in its active and inactive states.
Collapse
Affiliation(s)
- Lindsay B Tulloch
- Institute of Structural and Molecular Biology, The University of Edinburgh, Michael Swann Building, The King's Buildings, Edinburgh, UK
| | | | | | | | | | | |
Collapse
|
25
|
Xin L, Li K, Soong L. Down-regulation of dendritic cell signaling pathways by Leishmania amazonensis amastigotes. Mol Immunol 2008; 45:3371-82. [PMID: 18538399 DOI: 10.1016/j.molimm.2008.04.018] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Revised: 04/03/2008] [Accepted: 04/12/2008] [Indexed: 11/18/2022]
Abstract
We have previously reported a link between a deficient Th1 response to Leishmania amazonensis (La) parasites and profound impairments in the cytokine/chemokine network at early stages of the infection. To define the molecular basis of these deficiencies, we focused on early and intracellular events in La-infected dendritic cells (DCs) in this study. La amastigote-infected DCs were less mature and less potent antigen-presenting cells (APC) than their promastigote-infected counterparts, as judged by the lower expression of CD40 and CD83, suppressed cytokine expression (IL-12p40 and IL-10), reduced effectiveness for priming CD4+ T cells from naïve or infected mice. Infection with La promastigotes, but not amastigotes, triggered transient expression of IL-12p40 by DC. Both forms of parasites markedly suppressed IL-12p40, IL-12p70, and IL-6 production and increased IL-10 production when DCs were treated with LPS, IFN-gamma/LPS or IFN-alpha/LPS as positive stimuli. Of note, pre-infection of DCs with live amastigotes resulted in multiple alterations in innate signaling pathways, including degradation of STAT2, decreased phosphorylation of STAT1, 2, 3 and ERK1/2, and markedly reduced expression of interferon regulatory factor-1 (IRF-1) and IRF-8, some of which were partially reversed by pretreatment of parasites with proteasome or protease inhibitors. The impaired IL-12 production in infected DCs was not attributed to increased IL-10 production. Together, our data suggest that La parasites, especially in their intracellular forms, have evolved unique strategies to actively down-regulate early innate signaling events, resulting in impaired DC function and Th1 activation.
Collapse
Affiliation(s)
- Lijun Xin
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555-1070, USA
| | | | | |
Collapse
|
26
|
Vendrame CMV, Carvalho MDT, Rios FJO, Manuli ER, Petitto-Assis F, Goto H. Effect of insulin-like growth factor-I on Leishmania amazonensis promastigote arginase activation and reciprocal inhibition of NOS2 pathway in macrophage in vitro. Scand J Immunol 2007; 66:287-96. [PMID: 17635806 DOI: 10.1111/j.1365-3083.2007.01950.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
We showed previously that insulin-like growth factor (IGF)-I induces an exacerbation of the lesion development in experimental cutaneous leishmaniasis favouring parasite growth within host macrophages. Here we studied the effect of IGF-I in vitro in BALB/c mouse peritoneal macrophages infected with stationary phase Leishmania amazonensis promastigotes. IGF-I was used to pre-incubate either macrophage or parasite before infection of the macrophages or adding it at the start of the Leishmania-macrophage culture and maintaining it throughout the experimental period. Independent of stimulation protocol, IGF-I induced significantly increased parasite growth within macrophages. Arginase activation considered as a key factor in Leishmania growth was studied, and its expression and activity were increased in Leishmania-infected macrophages but significantly more in infected cells upon IGF-I stimulus, an effect specifically inhibited by NOHA. Arginase known to be present on Leishmania was also studied, and its expression and activity were seen in the absence of any stimulus but significantly increased after 5 min of incubation with IGF-I. In addition, Leishmania was pre-incubated with NOHA for 5 min, washed, then macrophages infected observing a significantly reduced parasite burden in both IGF-I-stimulated and non-stimulated macrophages. Reciprocal decrease in the nitric oxide (NO) level and inhibition of nitric oxide synthase (NOS2) expression were also observed in IGF-I-stimulated infected macrophages. Our data strongly suggest that IGF-I induces preferential expression and activation of Leishmania promastigote arginase, contributes to the alternative activation of macrophages in the context of innate immunity and interferes with NOS pathway in infected macrophages probably as a reciprocal effect.
Collapse
Affiliation(s)
- C M V Vendrame
- Laboratório de Soroepidemiologia e Imunobiologia, Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, Brazil
| | | | | | | | | | | |
Collapse
|
27
|
Silva-Lopez RE, Morgado-Díaz JA, Chávez MA, Giovanni-De-Simone S. Effects of serine protease inhibitors on viability and morphology of Leishmania (Leishmania) amazonensis promastigotes. Parasitol Res 2007; 101:1627-35. [PMID: 17726617 DOI: 10.1007/s00436-007-0706-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2007] [Accepted: 07/27/2007] [Indexed: 10/22/2022]
Abstract
To investigate the importance of serine proteases in Leishmania amazonensis promastigotes, we analyzed the effects of classical serine protease inhibitors and a Kunitz-type inhibitor, obtained from sea anemone Stichodactyla helianthus (ShPI-I), on the viability and morphology of parasites in culture. Classical inhibitors were selected on the basis of their ability to inhibit L. amazonensis serine proteases, previously described. The N-tosyl-L: -phenylalanine chloromethyl ketone (TPCK) and benzamidine (Bza) inhibitors, which are potential Leishmania proteases inhibitors, in all experimental conditions reduced the parasite viability, with regard to time dependence. On the other hand, N-tosyl-lysine chloromethyl ketone (TLCK) did not significantly affect the parasite viability, as it was poor Leishmania enzymes inhibitor. Ultrastructural analysis demonstrated that both Bza and TPCK induced changes in the flagellar pocket region with membrane alteration, including bleb formation. However, TPCK effects were more pronounced than those of Bza in Leishmania flagellar pocket in plasma membrane, and intracellular vesicular bodies was visualized. ShPI-I proved to be a powerful inhibitor of L. amazonensis serine proteases and the parasite viability. The ultrastructural alterations caused by ShPI-I were more dramatic than those induced by the classical inhibitors. Vesiculation of the flagellar pocket membrane, the appearance of a cytoplasmic vesicle that resembles an autophagic vacuole, and alterations of promastigotes shape resulted.
Collapse
Affiliation(s)
- R E Silva-Lopez
- Laboratório de Bioquímica de Proteínas e Peptídeos, Departamento de Bioquímica e Biologia Molecular, Instituto Oswaldo Cruz, FIOCRUZ, Av. Brasil 4365, 21045-900 Rio de Janeiro, RJ, Brazil.
| | | | | | | |
Collapse
|
28
|
de Almeida-Amaral EE, Caruso-Neves C, Pires VMP, Meyer-Fernandes JR. Leishmania amazonensis: characterization of an ouabain-insensitive Na+-ATPase activity. Exp Parasitol 2007; 118:165-71. [PMID: 17825292 DOI: 10.1016/j.exppara.2007.07.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2006] [Revised: 06/27/2007] [Accepted: 07/16/2007] [Indexed: 12/29/2022]
Abstract
We characterized ouabain-insensitive Na+-ATPase activity present in the plasma membrane of Leishmania amazonensis and investigated its possible role in the growth of the parasite. An increase in Na+ concentration in the presence of 1mM ouabain, increased the ATPase activity with a V(max) of 154.1+/-13.5nmol Pi x h(-1) x mg(-1) and a K0.5 of 28.9+/-7.7mM. Furosemide and sodium orthovanadate inhibited the Na+-stimulated ATPase activity with an IC(50) of 270microM and 0.10microM, respectively. Furosemide inhibited the growth of L. amazonensis after 48h incubation, with maximal effect after 96h. The IC50 for furosemide was 840. On the other hand, ouabain (1mM) did not change the growth of the parasite. Taken together, these results show that L. amazonensis expresses a P-type, ouabain-insensitive Na+-ATPase that could be involved with the growth of the parasite.
Collapse
Affiliation(s)
- Elmo Eduardo de Almeida-Amaral
- Laboratório de Bioquímica Celular, Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, CCS, Bloco H sala H2-013, Cidade Universitária, Ilha do Fundão, 21941-590, Rio de Janeiro, RJ, Brazil
| | | | | | | |
Collapse
|
29
|
Vanegas G, Quiñones W, Carrasco-López C, Concepción JL, Albericio F, Avilán L. Enolase as a plasminogen binding protein in Leishmania mexicana. Parasitol Res 2007; 101:1511-6. [PMID: 17653767 DOI: 10.1007/s00436-007-0668-7] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2007] [Revised: 07/07/2007] [Accepted: 07/09/2007] [Indexed: 10/23/2022]
Abstract
Enolase is a glycolytic and gluconeogenic enzyme also found on the surface of several eukaryotic and prokaryotic cells where it acts as plasminogen binding protein. Leishmania mexicana, one of the causative agents of Leishmaniasis, binds plasminogen and, in this parasite, enolase has been previously found associated with the external face of the plasma membrane. In this work, we show that the purified recombinant enolase has plasminogen binding activity indicating that, at the surface of the parasite, the protein may function as one of the plasminogen receptors. An internal motif (249)AYDAERKMY(257), similar to the nine amino-acid internal plasminogen-binding motif in Streptococcus pneumoniae enolase, is responsible for plasminogen interaction with the parasite enolase. Anti-enolase antibodies inhibited up to 60% of plasminogen binding on live parasites indicating that enolase act as a plasminogen receptor on the parasite. The fact that enolase acts as a possible plasminogen receptor in vivo makes this protein a promising target for therapy.
Collapse
Affiliation(s)
- Gilmer Vanegas
- Laboratorio de Fisiología, Centro de Ingeniería Genética, Facultad de Ciencias, Universidad de Los Andes, La Hechicera, Mérida 5101, Venezuela
| | | | | | | | | | | |
Collapse
|
30
|
Quiñones W, Peña P, Domingo-Sananes M, Cáceres A, Michels PAM, Avilan L, Concepción JL. Leishmania mexicana: Molecular cloning and characterization of enolase. Exp Parasitol 2007; 116:241-51. [PMID: 17382932 DOI: 10.1016/j.exppara.2007.01.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2006] [Revised: 12/23/2006] [Accepted: 01/11/2007] [Indexed: 10/23/2022]
Abstract
The gene of Leishmania mexicana enolase was cloned and overexpressed in Escherichia coli as an active enzyme; the protein was biochemically analyzed. This enolase shares with enolases from other trypanosomatids the presence of three atypical residues, each with a reactive side group, near the active site, already described for the enzyme from Trypanosoma brucei. The natural enzyme was purified, using a three-step procedure, from a cytosolic fraction of L. mexicana promastigotes. The kinetic properties of the purified recombinant enzyme were similar to those of the natural enzyme. Both the recombinant and natural enzyme were inhibited by inorganic pyrophosphate. Subcellular localization analysis after differential centrifugation showed that the enzyme activity is only associated with the cytosolic fraction. However, an apparently inactive form of enolase was detected by Western blots in the microsomal fraction. Digitonin treatment of parasites and immunofluorescence studies with permeabilized and non-permeabilized parasites showed that enolase is also associated with membranes and it was found at the external face of the plasma membrane.
Collapse
Affiliation(s)
- Wilfredo Quiñones
- Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, Apartado Postal 38, Ipostel-La hechicera, Mérida, Venezuela
| | | | | | | | | | | | | |
Collapse
|
31
|
Rodríguez-Almazán C, Torner FJ, Costas M, Pérez-Montfort R, de Gómez-Puyou MT, Puyou AG. The stability and formation of native proteins from unfolded monomers is increased through interactions with unrelated proteins. PLoS One 2007; 2:e497. [PMID: 17551578 PMCID: PMC1876261 DOI: 10.1371/journal.pone.0000497] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2007] [Accepted: 05/11/2007] [Indexed: 11/19/2022] Open
Abstract
The intracellular concentration of protein may be as high as 400 mg per ml; thus it seems inevitable that within the cell, numerous protein-protein contacts are constantly occurring. A basic biochemical principle states that the equilibrium of an association reaction can be shifted by ligand binding. This indicates that if within the cell many protein-protein interactions are indeed taking place, some fundamental characteristics of proteins would necessarily differ from those observed in traditional biochemical systems. Accordingly, we measured the effect of eight different proteins on the formation of homodimeric triosephosphate isomerase from Trypanosoma brucei (TbTIM) from guanidinium chloride unfolded monomers. The eight proteins at concentrations of micrograms per ml induced an important increase on active dimer formation. Studies on the mechanism of this phenomenon showed that the proteins stabilize the dimeric structure of TbTIM, and that this is the driving force that promotes the formation of active dimers. Similar data were obtained with TIM from three other species. The heat changes that occur when TbTIM is mixed with lysozyme were determined by isothermal titration calorimetry; the results provided direct evidence of the weak interaction between apparently unrelated proteins. The data, therefore, are strongly suggestive that the numerous protein-protein interactions that occur in the intracellular space are an additional control factor in the formation and stability of proteins.
Collapse
Affiliation(s)
- Claudia Rodríguez-Almazán
- Departamento de Bioquímica, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Francisco J. Torner
- Laboratorio de Biofisicoquímica, Departamento de Fisicoquímica, Facultad de Química, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Miguel Costas
- Laboratorio de Biofisicoquímica, Departamento de Fisicoquímica, Facultad de Química, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Ruy Pérez-Montfort
- Departamento de Bioquímica, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Marieta Tuena de Gómez-Puyou
- Departamento de Bioquímica, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Armando Gómez Puyou
- Departamento de Bioquímica, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
- * To whom correspondence should be addressed. E-mail:
| |
Collapse
|
32
|
Valdivieso E, Dagger F, Rascón A. Leishmania mexicana: Identification and characterization of an aspartyl proteinase activity. Exp Parasitol 2007; 116:77-82. [PMID: 17126324 DOI: 10.1016/j.exppara.2006.10.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2006] [Revised: 10/09/2006] [Accepted: 10/12/2006] [Indexed: 11/25/2022]
Abstract
An aspartyl proteinase activity was detected in the soluble fraction (SF) of Leishmania mexicana promastigotes by the use of the synthetic substrate benzoyl-Arg-Gly-Phe-Phe-Leu-4-methoxy-beta-naphthylamide selective for Cathepsin D like aspartyl-proteinases. This peptide was hydrolyzed with an apparent K(m) of 2.3+/-0.3 microM. The classic inhibitor of aspartyl-proteinases, diazo-acetyl-norleucinemethylester (DAN) inhibited the proteolytic activity with an IC(50) of 400 microM. The soluble fraction degraded (in absence of thiol groups) human fibrinogen with a specific activity of 533 U/mg protein. When tested for the ability to inhibit the "in vitro" proliferation of L. mexicana promastigotes, DAN showed concentration dependent anti-proliferative effects with a LD(50) of 466 microM at 48 h, with a significant fall in this value to 22 microM after 72 h. This is the first characterization of an aspartyl-proteinase activity in Leishmania, calling for further studies directed towards the physiologic role of these enzymes in the parasite. The anti-proliferative effect of its inhibition makes this enzyme a putative new target for the development of leishmanicidal drugs.
Collapse
Affiliation(s)
- Elizabeth Valdivieso
- Laboratorio de Biología Celular de Parásitos, Instituto de Biología Experimental, Facultad de Ciencias, Universidad Central de Venezuela, Apartado Postal 47069, Caracas 1041-A, Venezuela.
| | | | | |
Collapse
|
33
|
Ueda-Nakamura T, Attias M, de Souza W. Comparative analysis of megasomes in members of the Leishmania mexicana complex. Res Microbiol 2007; 158:456-62. [PMID: 17524623 DOI: 10.1016/j.resmic.2007.03.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2005] [Revised: 01/17/2007] [Accepted: 03/21/2007] [Indexed: 11/28/2022]
Abstract
Megasomes are large lysosome-like structures, previously described in amastigote forms of Leishmania belonging to the mexicana complex, whose major constituents are the cysteine proteinases. Routine observation of thin sections of amastigotes obtained from species of the mexicana complex revealed variations in size and number of megasomes according to the species, and also between amastigotes obtained from axenic cultures and from infected animals. Three-dimensional reconstruction of amastigotes, stereology and immunocytochemical localization of cysteine proteinase revealed significant differences between the three Leishmania species examined, L. amazonensis, L. mexicana and L. pifanoi. The relative volume of megasomes in lesion-derived amastigotes was higher than in axenic amastigotes of L. amazonensis and L. mexicana. The relative volume of megasomes from lesion-derived amastigotes of L. mexicana was 2-3 times higher than in L. amazonensis. Axenic amastigotes of L. pifanoi showed a small relative volume of megasomes and low cysteine proteinase activity, and were not able to produce lesions in the animals, whereas axenic amastigotes of L. mexicana and L. amazonensis did. There were significant differences in the structural organization, distribution within the cell, size and number of megasomes, and in the characteristics of cysteine proteinases found in the amastigotes of the three Leishmania species. These results suggest that these organelles and their constituents may be involved in the infectivity and virulence of Leishmania species.
Collapse
Affiliation(s)
- Tania Ueda-Nakamura
- Laboratório de Microbiologia, Departamento de Análises Clínicas, Universidade Estadual de Maringá, Av. Colombo, 5790, Bloco I90, 87020-900, Maringá, PR, Brazil.
| | | | | |
Collapse
|
34
|
Almeida-Amaral EED, Caruso-Neves C, Lara LS, Pinheiro CM, Meyer-Fernandes JR. Leishmania amazonensis: PKC-like protein kinase modulates the (Na++K+)ATPase activity. Exp Parasitol 2007; 116:419-26. [PMID: 17475255 DOI: 10.1016/j.exppara.2007.02.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2007] [Revised: 02/15/2007] [Accepted: 02/17/2007] [Indexed: 02/08/2023]
Abstract
The present study aimed to identify the presence of protein kinase C-like (PKC-like) in Leishmania amazonensis and to elucidate its possible role in the modulation of the (Na(+)+K(+))ATPase activity. Immunoblotting experiments using antibody against a consensus sequence (Ac 543-549) of rabbit protein kinase C (PKC) revealed the presence of a protein kinase of 80 kDa in L. amazonensis. Measurements of protein kinase activity showed the presence of both (Ca(2+)-dependent) and (Ca(2+)-independent) protein kinase activity in plasma membrane and cytosol. Phorbol ester (PMA) activation of the Ca(2+)-dependent protein kinase stimulated the (Na(+)+K(+))ATPase activity, while activation of the Ca(2+)-independent protein kinase was inhibitory. Both effects of protein kinase on the (Na(+)+K(+))ATPase of the plasma membrane were lower than that observed in intact cells. PMA induced the translocation of protein kinase from cytosol to plasma membrane, indicating that the maximal effect of protein kinase on the (Na(+)+K(+))ATPase activity depends on the synergistic action of protein kinases from both plasma membrane and cytosol. This is the first demonstration of a protein kinase activated by PMA in L. amazonensis and the first evidence for a possible role in the regulation of the (Na(+)+K(+))ATPase activity in this trypanosomatid. Modulation of the (Na(+)+K(+))ATPase by protein kinase in a trypanosomatid opens up new possibilities to understand the regulation of ion homeostasis in this parasite.
Collapse
Affiliation(s)
- Elmo Eduardo de Almeida-Amaral
- Laboratório de Bioquímica Celular, Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro-UFRJ, CCS, Bloco H, Cidade Universitária, Ilha do Fundão, 21941-590 Rio de Janeiro, RJ, Brazil
| | | | | | | | | |
Collapse
|
35
|
de Almeida-Amaral EE, Belmont-Firpo R, Vannier-Santos MA, Meyer-Fernandes JR. Leishmania amazonensis: Characterization of an ecto-phosphatase activity. Exp Parasitol 2006; 114:334-40. [PMID: 16814776 DOI: 10.1016/j.exppara.2006.04.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2005] [Revised: 04/26/2006] [Accepted: 04/29/2006] [Indexed: 11/21/2022]
Abstract
We have characterized a phosphatase activity present on the external surface of Leishmania amazonensis, using intact living parasites. This enzyme hydrolyzes the substrate p-nitrophenylphosphate (p-NPP) at the rate of 25.70+/-1.17 nmol Pi x h(-1) x 10(-7)cells. The dependence on p-NPP concentration shows a normal Michaelis-Menten kinetics for this ecto-phosphatase activity present a V(max) of 31.93+/-3.04 nmol Pi x h(-1) x 10(-7)cells and apparent K(m) of 1.78+/-0.32 mM. Inorganic phosphate inhibited the ecto-phoshatase activity in a dose-dependent manner with the K(i) value of 2.60 mM. Experiments using classical inhibitor of acid phosphatase, such as ammonium molybdate, as well as inhibitors of phosphotyrosine phosphatase, such as sodium orthovanadate and [potassiumbisperoxo(1,10-phenanthroline)oxovanadate(V)] (bpV-PHEN), inhibited the ecto-phosphatase activity, with the K(i) values of 0.33 microM, 0.36 microM and 0.25 microM, respectively. Zinc chloride, another classical phosphotyrosine phosphatase inhibitor, also inhibited the ecto-phosphatase activity in a dose-dependent manner with K(i) 2.62 mM. Zinc inhibition was reversed by incubation with reduced glutathione (GSH) and cysteine, but not serine, showing that cysteine residues are important for enzymatic activity. Promastigote growth in a medium supplemented with 1mM sodium orthovanadate was completely inhibited as compared to the control medium. Taken together, these results suggest that L. amazonensis express a phosphohydrolase ectoenzyme with phosphotyrosine phosphatase activity.
Collapse
Affiliation(s)
- Elmo Eduardo de Almeida-Amaral
- Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro-UFRJ, CCS, Bloco H sala H2-013, Cidade Universitária, Ilha do Fundão, 21941-590 Rio de Janeiro, RJ, Brazil
| | | | | | | |
Collapse
|
36
|
van der Peet P, Gannon CT, Walker I, Dinev Z, Angelin M, Tam S, Ralton JE, McConville MJ, Williams SJ. Use of click chemistry to define the substrate specificity of Leishmania beta-1,2-mannosyltransferases. Chembiochem 2006; 7:1384-91. [PMID: 16841351 DOI: 10.1002/cbic.200600159] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Leishmania spp. are human pathogens that utilize a novel beta-1,2-mannan as their major carbohydrate reserve material. We describe a new approach that combines traditional substrate-modification methods and "click chemistry" to assemble a library of modified substrates that were used to qualitatively define the substrate tolerance of the Leishmania beta-1,2-mannosyltransferases responsible for beta-1,2-mannan biosynthesis. The library was assembled by using the highly selective copper(I)-catalysed cycloaddition reaction of azides and alkynes to couple an assortment of azide- and alkyne-functionalized small molecules with complementary alkyne- and azide-functionalized mannose derivatives. All mannose derivatives with alpha-orientated substituents on the anomeric carbon were found to act as substrates when incubated with a Leishmania mexicana particulate fraction containing GDP-mannose. In contrast, 6-substituted mannose derivatives were not substrates. Representative products formed from the library compounds were analysed by mass spectrometry, methylation linkage analysis and beta-mannosidase digestions and showed extension with up to four beta-1,2-linked mannosyl residues. This work provides insights into the substrate specificity of this new class of glycosyltransferases that can be applied to the development of highly specific tools and inhibitors for their study.
Collapse
Affiliation(s)
- Phillip van der Peet
- School of Chemistry, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria 3010, Australia
| | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Pabón MA, Cáceres AJ, Gualdrón M, Quiñones W, Avilán L, Concepción JL. Purification and characterization of hexokinase from Leishmania mexicana. Parasitol Res 2006; 100:803-10. [PMID: 17061112 DOI: 10.1007/s00436-006-0351-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2006] [Accepted: 09/26/2006] [Indexed: 11/29/2022]
Abstract
Hexokinase from Leishmania mexicana was purified to homogeneity from a glycosome-enriched fraction obtained after a differential centrifugation of promastigote form. The kinetic properties of the pure enzyme were determined and the Km values for glucose (Km = 66 microM) and ATP (Km = 303 muM) were comparable to those from hexokinase of Trypanosoma cruzi. L. mexicana hexokinase was able to use fructose (Km = 142 microM), which reflects the condition found in the insect host. In contrast with hexokinases from other trypanosomatids, the enzyme exhibited a moderate sensitivity to inhibition by glucose 6-phosphate. This inhibition was competitive with respect to both ATP and glucose, indicating that an allosteric site for glucose 6-phosphate does not exist in this enzyme. The enzyme was also inhibited by inorganic pyrophosphate, the inhibition being higher than that observed for T. cruzi enzyme. As expected, the enzyme was localized, by immunofluorescence analysis, in glycosomes and is present in both promastigotes and true amastigotes obtained from hamster lesion. Hexokinase specific activity increased with the aging of promastigote culture, and this increment was related to glucose consumption. However, the level of the hexokinase protein remains constant as determined by Western blotting. Several hypotheses are discussed to explain this result.
Collapse
Affiliation(s)
- Miguel A Pabón
- Laboratorio de Enzimología de Parásitos, Centro de Ingeniería Genética, Facultad de Ciencias, Universidad de Los Andes, La Hechicera, Mérida, 5101, Venezuela
| | | | | | | | | | | |
Collapse
|
38
|
Kedzierski L, Malby RL, Smith BJ, Perugini MA, Hodder AN, Ilg T, Colman PM, Handman E. Structure of Leishmania mexicana Phosphomannomutase Highlights Similarities with Human Isoforms. J Mol Biol 2006; 363:215-27. [PMID: 16963079 DOI: 10.1016/j.jmb.2006.08.023] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2006] [Revised: 08/04/2006] [Accepted: 08/10/2006] [Indexed: 11/18/2022]
Abstract
Phosphomannomutase (PMM) catalyses the conversion of mannose-6-phosphate to mannose-1-phosphate, an essential step in mannose activation and the biosynthesis of glycoconjugates in all eukaryotes. Deletion of PMM from Leishmania mexicana results in loss of virulence, suggesting that PMM is a promising drug target for the development of anti-leishmanial inhibitors. We report the crystallization and structure determination to 2.1 A of L. mexicana PMM alone and in complex with glucose-1,6-bisphosphate to 2.9 A. PMM is a member of the haloacid dehalogenase (HAD) family, but has a novel dimeric structure and a distinct cap domain of unique topology. Although the structure is novel within the HAD family, the leishmanial enzyme shows a high degree of similarity with its human isoforms. We have generated L. major PMM knockouts, which are avirulent. We expressed the human pmm2 gene in the Leishmania PMM knockout, but despite the similarity between Leishmania and human PMM, expression of the human gene did not restore virulence. Similarities in the structure of the parasite enzyme and its human isoforms suggest that the development of parasite-selective inhibitors will not be an easy task.
Collapse
Affiliation(s)
- Lukasz Kedzierski
- Infection and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
| | | | | | | | | | | | | | | |
Collapse
|
39
|
Leroux A, Fleming-Canepa X, Aranda A, Maugeri D, Cazzulo JJ, Sánchez MA, Nowicki C. Functional characterization and subcellular localization of the three malate dehydrogenase isozymes in Leishmania spp. Mol Biochem Parasitol 2006; 149:74-85. [PMID: 16750864 DOI: 10.1016/j.molbiopara.2006.04.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2005] [Revised: 04/25/2006] [Accepted: 04/27/2006] [Indexed: 11/19/2022]
Abstract
As part of a study on the malate dehydrogenase isozymes (MDHs) from Trypanosomatids, three different fractions with MDH activity were obtained from crude extracts of Leishmania mexicana promastigotes combining two different chromatographic steps. Gel filtration chromatography in native conditions showed that most of the MDH activity present in the crude extracts eluted in a single peak, which corresponded to a lower apparent molecular mass ( congruent with 57kDa) than the value expected for typical MDHs. To further characterize the leishmanial isozymes, three putative MDH genes, presumably corresponding to the mitochondrial, glycosomal and cytosolic isoforms were amplified by PCR, cloned into bacterial expression vectors, and the recombinant enzymes purified. Digitonin extraction of intact L. mexicana promastigotes and immunofluorescence microscopy of L. major promastigotes confirmed the subcellular compartmentation of each of the three isozymes. Western blot analysis showed that the three MDHs are developmentally regulated. At the protein level, these isozymes are remarkably more abundant in amastigotes than in promastigotes of L. mexicana. Altogether our results demonstrate the presence of three MDH isoforms with slightly distinct biochemical properties and different subcellular localization in Leishmania spp. Presumably the functional and biochemical features of these isozymes reflect the metabolic adaptation to the different nutrient sources these parasites have to face along their life cycle. These results also emphasize the differences among Trypanosomatids in this area of metabolism, since in the case of Trypanosoma brucei the cMDH is the only isoform expressed in bloodstream trypomastigotes, whereas in Trypanosoma cruzi cMDH is absent.
Collapse
Affiliation(s)
- Alejandro Leroux
- Instituto de Química y Fisicoquímica Biológica IQUIFIB-CONICET, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, CP1113 Buenos Aires, Argentina
| | | | | | | | | | | | | |
Collapse
|
40
|
Olivares-Illana V, Pérez-Montfort R, López-Calahorra F, Costas M, Rodríguez-Romero A, Tuena de Gómez-Puyou M, Gómez Puyou A. Structural differences in triosephosphate isomerase from different species and discovery of a multitrypanosomatid inhibitor. Biochemistry 2006; 45:2556-60. [PMID: 16489748 DOI: 10.1021/bi0522293] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We examined the interfaces of homodimeric triosephosphate isomerase (TIM) from eight different species. The crystal structures of the enzymes showed that a portion of the interface is markedly similar in TIMs from Trypanosoma cruzi (TcTIM), Trypanosoma brucei, and Leishmania mexicana and significantly different from that of TIMs from human, yeast, chicken, Plasmodium falciparum, and Entamoeba histolytica. Since this interfacial region is central in the stability of TcTIM, we hypothesized that it would be possible to find agents that selectively affect the stability of TIMs from the three trypanosomatids. We found that 6,6'-bisbenzothiazole-2,2' diamine in the low micromolar range causes a desirable irreversible inactivation of the enzymes from the three trypanosomatids and has no effect on the other five TIMs. Thus, the data indicate that it is possible to find compounds that induce selective inactivation of the enzymes from three different trypanosomatids.
Collapse
Affiliation(s)
- Vanesa Olivares-Illana
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México, D. F., México
| | | | | | | | | | | | | |
Collapse
|
41
|
Brobey RKB, Soong L. Leishmania species: evidence for transglutaminase activity and its role in parasite proliferation. Exp Parasitol 2006; 114:94-102. [PMID: 16620812 DOI: 10.1016/j.exppara.2006.02.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2006] [Revised: 02/18/2006] [Accepted: 02/20/2006] [Indexed: 11/15/2022]
Abstract
Albeit transglutaminase (TGase) activity has been reported to play crucial physiological roles in several organisms including parasites; however, there was no previous report(s) whether Leishmania parasites exhibit this activity. We demonstrate herein that TGase is functionally active in Leishmania parasites by using labeled polyamine that becomes conjugated into protein substrates. The parasite enzyme was about 2- to 4-fold more abundant in Old World species than in New World ones. In L. amazonensis, comparable TGase activity was found in both promastigotes and amastigotes. TGase activity in either parasite stage was optimal at the basic pH, but the enzyme in amastigote lysates was more stable at higher temperatures (37-55 degrees C) than that in promastigote lysates. Leishmania TGase differs from mouse macrophage (M Phi) TGase in two ways: (1) the parasite enzyme is Ca(2+)-independent, whereas the mammalian TGase depends on the cation for activity, and (2) major protein substrates for L. amazonensis TGase were found within the 50-75 kDa region, while those for the M Phi TGase were located within 37-50 kDa. The potential contribution of TGase-catalyzed reactions in promastigote proliferation was supported by findings that standard inhibitors of TGase [e.g., monodansylcadaverine (MDC), cystamine (CS), and iodoacetamide (IodoA)], but not didansylcadaverine (DDC), a close analogue of MDC, had a profound dose-dependent inhibition on parasite growth. Myo-inositol-1-phosphate synthase and leishmanolysin (gp63) were identified as possible endogenous substrates for L. amazonensis TGase, implying a role for TGase in parasite growth, development, and survival.
Collapse
Affiliation(s)
- Reynolds K B Brobey
- Department of Microbiology and Immunology, Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX 77555-1070, USA
| | | |
Collapse
|
42
|
Pinheiro CM, Martins-Duarte ES, Ferraro RB, Fonseca de Souza AL, Gomes MT, Lopes AHCS, Vannier-Santos MA, Santos ALS, Meyer-Fernandes JR. Leishmania amazonensis: Biological and biochemical characterization of ecto-nucleoside triphosphate diphosphohydrolase activities. Exp Parasitol 2006; 114:16-25. [PMID: 16603157 DOI: 10.1016/j.exppara.2006.02.007] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2005] [Revised: 02/02/2006] [Accepted: 02/06/2006] [Indexed: 10/24/2022]
Abstract
The presence of Leishmania amazonensis ecto-nucleoside triphosphate triphosphohydrolase activities was demonstrated using antibodies against different NTPDase members by Western blotting, flow cytometry, and immunoelectron microscopy analysis. Living promastigote cells sequentially hydrolyzed the ATP molecule generating ADP, AMP, and adenosine, indicating that this surface enzyme may play a role in the salvage of purines from the extracellular medium. The L. amazonensis ecto-NTPDase activities were insensitive to Triton X-100, but they were enhanced by divalent cations, such as Mg(2+). In addition, the ecto-NTPDase activities decreased with time for 96 h when promastigotes were grown in vitro. On the other hand, these activities increased considerably when measured in living amastigote forms. Furthermore, the treatment with adenosine, a mediator of several relevant biological phenomena, induced a decrease in the reactivity with anti-CD39 antibody, raised against mammalian E-NTPDase, probably because of down regulation in the L. amazonensis ecto-NTPDase expression. Also, adenosine and anti-NTPDase antibodies induced a significant diminishing in the interaction between promastigotes of L. amazonensis and mouse peritoneal macrophages.
Collapse
Affiliation(s)
- Carla M Pinheiro
- Instituto de Bioquímica Médica (IBqM), Universidade Federal do Rio de Janeiro (UFRJ), Centro de Ciências da Saúde (CCS), Bloco H, Cidade Universitária, Ilha do Fundão, 21541-590 Rio de Janeiro, Brazil
| | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Panizzutti R, de Souza Leite M, Pinheiro CM, Meyer-Fernandes JR. The occurrence of free d-alanine and an alanine racemase activity inLeishmania amazonensis. FEMS Microbiol Lett 2006; 256:16-21. [PMID: 16487314 DOI: 10.1111/j.1574-6968.2006.00064.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Free D-amino acids are implicated in several biological functions. This study examined the presence of D-alanine in Leishmania amazonensis. Measuring chiral amino acid content by high-performance liquid chromatography we detected a significant amount of free D-alanine in promastigotes of these parasites. D-alanine accounts for 8.9% of total free alanine and is found primarily in the soluble fraction. Specific racemization of L-alanine to D-alanine was detected in cell lysates and this enzyme activity was inhibited by D-cycloserine, an alanine racemase inhibitor. Furthermore, we were able to decrease this pool of D-amino acid by treating our cultures with D-cycloserine. We demonstrate for the first time the existence of a significant amount of free D-alanine in L. amazonensis and an alanine racemase activity present in cell lysates. The restriction of D-alanine to bacteria, some fungi and now in L. amazonensis opens a new perspective on treatment of diseases caused by these microorganisms.
Collapse
Affiliation(s)
- Rogério Panizzutti
- Departamento de Anatomia, ICB, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | | | | |
Collapse
|
44
|
Abstract
A striking difference of the life stages of the protozoan parasite Leishmania is a long flagellum in the insect stage promastigotes and a rudimentary organelle in the mammalian amastigotes. LmxMKK, a mitogen-activated protein (MAP) kinase kinase from Leishmania mexicana, is required for growth of a full-length flagellum. We identified LmxMPK3, a MAP kinase homologue, with a similar expression pattern as LmxMKK being not detectable in amastigotes, up-regulated during the differentiation to promastigotes, constantly expressed in promastigotes, and shut down during the differentiation to amastigotes. LmxMPK3 null mutants resemble the LmxMKK knockouts with flagella reduced to one-fifth of the wild-type length, stumpy cell bodies, and vesicles and membrane fragments in the flagellar pocket. A constitutively activated recombinant LmxMKK activates LmxMPK3 in vitro. Moreover, LmxMKK is likely to be directly involved in the phosphorylation of LmxMPK3 in vivo. Finally, LmxMPK3 is able to phosphorylate LmxMKK, indicating a possible feedback regulation. This is the first time that two interacting components of a signaling cascade have been described in the genus Leishmania. Moreover, we set the stage for the analysis of reversible phosphorylation in flagellar morphogenesis.
Collapse
Affiliation(s)
- Maja Erdmann
- Bernhard Nocht Institute for Tropical Medicine, Parasitology Section, D-20359 Hamburg, Germany
| | | | | | | | | |
Collapse
|
45
|
Giardini MA, Lira CBB, Conte FF, Camillo LR, de Siqueira Neto JL, Ramos CHI, Cano MIN. The putative telomerase reverse transcriptase component of Leishmania amazonensis: gene cloning and characterization. Parasitol Res 2006; 98:447-54. [PMID: 16416120 DOI: 10.1007/s00436-005-0036-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2005] [Accepted: 09/26/2005] [Indexed: 01/18/2023]
Abstract
The Leishmania amazonensis telomerase gene was cloned by a polymerase chain reaction-based strategy using primers designed from a Leishmania major sequence that shared similarities with conserved telomerase motifs. The genes from three other species were cloned for comparative purposes. A ClustalW multiple-sequence alignment demonstrated that the Leishmania telomerases show greater homology with each other than with the proteins of other kinetoplastids and eukaryotes. Characterization experiments indicated that the putative Leishmania telomerase gene was probably in single copy and located in the largest chromosomes. A single messenger ribonucleic acid transcript was found in promastigotes. Phylogenetic analysis suggested that Leishmania telomerase might represent a liaison between the oldest and the newest branches of telomerases.
Collapse
Affiliation(s)
- Miriam A Giardini
- Departamento de Patologia Clínica, Núcleo de Medicina e Cirurgia Experimental, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), CP 6109, Campinas, SP, CEP 13083-970, Brazil
| | | | | | | | | | | | | |
Collapse
|
46
|
Adhiambo C, Forney JD, Asai DJ, LeBowitz JH. The two cytoplasmic dynein-2 isoforms in Leishmania mexicana perform separate functions. Mol Biochem Parasitol 2006; 143:216-25. [PMID: 16054709 DOI: 10.1016/j.molbiopara.2005.04.017] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2004] [Revised: 04/07/2005] [Accepted: 04/20/2005] [Indexed: 11/23/2022]
Abstract
Eukaryotic organisms with cilia or flagella typically express two non-axonemal or "cytoplasmic" dyneins, dynein-1 and dynein-2. Interestingly, we find that Leishmania mexicana is unusual and contains two distinct cytoplasmic dynein-2 heavy chain genes (designated LmxDHC2.1 and LmxDHC2.2) along with a single dynein-1 heavy chain (LmxDHC1). Disruption of LmxDHC2.2 resulted in immotile parasites that had a rounded cell body. Although they assume amastigote morphology, immunoblot analysis of these cells demonstrates protein expression consistent with the promastigote stage. Ultrastructural analysis revealed non-emergent flagella that lacked the paraflagellar rod and an axoneme with deficiencies in several components. We confirmed the absence of paraflagellar rod proteins PFR1 and PFR2. These results show that LmxDHC2.2 is required for flagellar assembly and also participates in the maintenance of promastigote cell shape. In contrast to the results with LmxDHC2.2, we were unable to generate homologous disruptions of LmxDHC2.1. This result suggests that, unlike LmxDHC2.2, LmxDHC2.1 is an essential gene in Leishmania. Together, these findings demonstrate that the two dynein-2 heavy chain isoforms in Leishmania perform distinct functions. The observation that the genomes of Leishmania major, Leishmania infantum and Trypanosoma brucei also contain two dynein-2 isoforms suggests that this unusual aspect of cytoplasmic dynein is a conserved feature of the kinetoplastids.
Collapse
Affiliation(s)
- Christine Adhiambo
- Purdue University, Department of Biochemistry, 175 S. University Street, West Lafayette, IN 47907-2063, USA
| | | | | | | |
Collapse
|
47
|
Judice WAS, Mottram JC, Coombs GH, Juliano MA, Juliano L. Specific negative charges in cysteine protease isoforms of Leishmaniamexicana are highly influential on the substrate binding and hydrolysis. Mol Biochem Parasitol 2005; 144:36-43. [PMID: 16125801 DOI: 10.1016/j.molbiopara.2005.07.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2005] [Revised: 07/15/2005] [Accepted: 07/20/2005] [Indexed: 10/25/2022]
Abstract
We focused on the importance of the electrostatic environment on the catalytic properties of the Leishmania mexicana CPB recombinant isoenzymes (rCPB2.8, rCPB3 and its mutant rH84Y), by investigating the influence of pH and NaCl on their hydrolytic activities. rCPB2.8 contains the residues Asn60, Asp61 and Asp64; rCPB3 presents the three variant residues Asp60, Asn61 and Ser64 and the mutant of the latter isoform, rH84Y, has a mutation on the outer loop residue (His84 to Tyr). Synthetic fluorescence resonance energy transfer (FRET) peptides, which contain different positive charge distribution in their sequences were used as substrates. The results show that hydrolytic efficiency is dependent of the positive charge distribution in the substrates and that NaCl activated rCPB2.8 and rCPB3 in acidic pH but inhibited them at pH higher than 5. The rate constants of substrate diffusion (k1), substrate dissociation (k-1), acylation (k2) and deacylation (k3) and the corresponding activation energies and entropies were derived. Significant differences in the kinetic rate constants (k) and entropies were found between the CPB isoforms, and the diffusion process seems to be the limiting step. The activation energy of denaturation (Ea-Den) and entropy of denaturation (DeltaSDen) of rCPB3 were higher than those for rCPB2.8, suggesting higher salvation and protein structure for rCPB3. Thus the findings suggest that the two CPB isoenzymes with a few negative charge modifications provide the parasite with an array of hydrolytic activity and enzymatic adaptation to pH, salinity and temperature that may be needed for its interaction with the mammalian host.
Collapse
Affiliation(s)
- Wagner A S Judice
- Department of Biophysics, Escola Paulista de Medicina, Universidade Federal de São Paulo, Rua Tres de Maio 100, 04044-20 São Paulo, Brazil
| | | | | | | | | |
Collapse
|
48
|
Saravia NG, Escorcia B, Osorio Y, Valderrama L, Brooks D, Arteaga L, Coombs G, Mottram J, Travi BL. Pathogenicity and protective immunogenicity of cysteine proteinase-deficient mutants of Leishmania mexicana in non-murine models. Vaccine 2005; 24:4247-59. [PMID: 16216395 DOI: 10.1016/j.vaccine.2005.05.045] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2004] [Revised: 02/06/2005] [Accepted: 05/08/2005] [Indexed: 11/22/2022]
Abstract
This study demonstrates that deletion of cysteine proteinase (CP) genes diminishes pathogenicity of Leishmania mexicana in non-murine experimental host models while preserving immunogenicity. Both cpb and cpa/cpb-deficient lines induced delayed disease onset, smaller lesions and lower parasite burden in hamsters. cpa/cpb-deficient L. mexicana grew more slowly as promastigotes and presented lower infectivity and growth in human mononuclear phagocytic host cells. Protection against homologous challenge comparable to that induced by infection with the virulent wild-type (WT) L. mexicana strain was achieved in the highly susceptible hamster model by immunization with 1000 cpb-deficient promastigotes. CP-deficient L. mexicana elicited significantly lower levels of Th2-associated cytokines IL-10 and TGF-beta than the WT in the primary lesion of hamsters. These findings support the feasibility of using genetically attenuated live Leishmania to achieve protective immunity.
Collapse
Affiliation(s)
- Nancy Gore Saravia
- Centro Internacional de Entrenamiento e Investigaciones Médicas (CIDEIM), Apartado Aéreo 5390, Cali, Colombia.
| | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Abstract
Members of the mitogen-activated protein (MAP) kinase cascade are important for the establishment of a Leishmania mexicana infection and are involved in flagellar length control, although the underlying molecular mechanisms remain to be elucidated. This study reports the cloning and characterization of LmxPK4, a MAP kinase kinase homologue of L. mexicana displaying putative plant-like regulatory phosphorylation sites. The recombinant protein has autophosphorylating activity and phosphorylates myelin basic protein. An LmxPK4 gene deletion mutant showed a proliferation defect after infection of macrophages and no or delayed lesion development in mice. Irrespective of the onset of lesion development parasites showed an early and homogeneous lesion development in re-infection experiments. This is indicative for a compensation of the null mutant phenotype. Additionally, this phenotype could be reverted by reintroduction of the wild-type gene into the deletion background. Mutants expressing loss-of-function or N-terminally truncated versions of LmxPK4 retained the null mutant phenotype. LmxPK4 is stage-specifically expressed in promastigotes and during differentiation to amastigotes, but is not detectable in amastigotes isolated from the mammalian host. Moreover, its in vitro kinase activity increases with temperature rise up to 40 degrees C. Our results suggest that LmxPK4 is involved in the differentiation process and affects virulence of Leishmania mexicana.
Collapse
Affiliation(s)
- Daniela Kuhn
- Bernhard Nocht Institute for Tropical Medicine, Parasitology Section, Bernhard-Nocht-Strasse 74, D-20359 Hamburg, Germany
| | | |
Collapse
|
50
|
Weise F, Thilo L, Engstler M, Wiese M, Benzel I, Kühn C, Bühring HJ, Overath P. Binding affinity and capacity of putative adaptor-mediated sorting of a Type I membrane protein in Leishmania mexicana. Mol Biochem Parasitol 2005; 142:203-11. [PMID: 15890416 DOI: 10.1016/j.molbiopara.2005.04.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2005] [Revised: 03/28/2005] [Accepted: 04/11/2005] [Indexed: 10/25/2022]
Abstract
The membrane-bound acid phosphatase (MBAP), a Type I membrane protein predominantly associated with endosomal/lysosomal structures of Leishmania mexicana promastigotes, contains motifs in its cytosolic COOH-terminal tail (-MEVWRRYMKFKNKQSEAIIV-COOH) akin to tyrosine- and di-leucine-based sorting signals in multicellular organisms. Here, we first show that the COOH-terminal residues IIV of MBAP, but not the Y-residue, are required for endosomal targeting, suggesting specific binding to an adaptor complex at the cell surface. We then determine whether specific binding can be saturated by analysing the efficiency of endosomal targeting for increasing numbers of MBAP molecules per cell. The ratio of the steady-state abundance of wild-type MBAP on the cell surface to MBAP on endosomes increases until the distribution is no longer different from that observed for a mutant MBAP which lacks the IIV-motif or for a glycosylphosphatidylinositol-anchored form, both of which are distributed according to bulk membrane flow. A quantitative analysis of these in vivo results indicates specific binding to a putative adaptor complex with an affinity of about 10-4M to 50,000 sorting sites on the cell surface.
Collapse
Affiliation(s)
- Frank Weise
- Max-Planck-Institut für Biologie, Abteilung Membranbiochemie, D-72076 Tübingen, Germany
| | | | | | | | | | | | | | | |
Collapse
|