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Dong H, Yang J, He K, Zheng WB, Lai DH, Liu J, Ding HY, Wu RB, Brown KM, Hide G, Lun ZR, Zhu XQ, Long S. The Toxoplasma monocarboxylate transporters are involved in the metabolism within the apicoplast and are linked to parasite survival. eLife 2024; 12:RP88866. [PMID: 38502570 PMCID: PMC10950331 DOI: 10.7554/elife.88866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024] Open
Abstract
The apicoplast is a four-membrane plastid found in the apicomplexans, which harbors biosynthesis and organelle housekeeping activities in the matrix. However, the mechanism driving the flux of metabolites, in and out, remains unknown. Here, we used TurboID and genome engineering to identify apicoplast transporters in Toxoplasma gondii. Among the many novel transporters, we show that one pair of apicomplexan monocarboxylate transporters (AMTs) appears to have evolved from a putative host cell that engulfed a red alga. Protein depletion showed that AMT1 and AMT2 are critical for parasite growth. Metabolite analyses supported the notion that AMT1 and AMT2 are associated with biosynthesis of isoprenoids and fatty acids. However, stronger phenotypic defects were observed for AMT2, including in the inability to establish T. gondii parasite virulence in mice. This study clarifies, significantly, the mystery of apicoplast transporter composition and reveals the importance of the pair of AMTs in maintaining the apicoplast activity in apicomplexans.
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Affiliation(s)
- Hui Dong
- National Key Laboratory of Veterinary Public Health Safety, and College of Veterinary Medicine, China Agricultural University, Beijing, China
- National Animal Protozoa Laboratory and School of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Jiong Yang
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Kai He
- National Key Laboratory of Veterinary Public Health Safety, and College of Veterinary Medicine, China Agricultural University, Beijing, China
- National Animal Protozoa Laboratory and School of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Wen-Bin Zheng
- College of Veterinary Medicine, Shanxi Agricultural University, Taigu, China
| | - De-Hua Lai
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Jing Liu
- National Key Laboratory of Veterinary Public Health Safety, and College of Veterinary Medicine, China Agricultural University, Beijing, China
- National Animal Protozoa Laboratory and School of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Hui-Yong Ding
- National Key Laboratory of Veterinary Public Health Safety, and College of Veterinary Medicine, China Agricultural University, Beijing, China
- National Animal Protozoa Laboratory and School of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Rui-Bin Wu
- National Key Laboratory of Veterinary Public Health Safety, and College of Veterinary Medicine, China Agricultural University, Beijing, China
- National Animal Protozoa Laboratory and School of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Kevin M Brown
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, United States
| | - Geoff Hide
- Biomedical Research and Innovation Centre and Environmental Research and Innovation Centre, School of Science, Engineering and Environment, University of Salford, Salford, United Kingdom
| | - Zhao-Rong Lun
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol and Guangdong Provincial Key Laboratory of Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China
| | - Xing-Quan Zhu
- College of Veterinary Medicine, Shanxi Agricultural University, Taigu, China
| | - Shaojun Long
- National Key Laboratory of Veterinary Public Health Safety, and College of Veterinary Medicine, China Agricultural University, Beijing, China
- National Animal Protozoa Laboratory and School of Veterinary Medicine, China Agricultural University, Beijing, China
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Abstract
Purpose of Review Review building of programs to eliminate Toxoplasma infections. Recent Findings
Morbidity and mortality from toxoplasmosis led to programs in USA, Panama, and Colombia to facilitate understanding, treatment, prevention, and regional resources, incorporating student work. Summary Studies foundational for building recent, regional approaches/programs are reviewed. Introduction provides an overview/review of programs in Panamá, the United States, and other countries. High prevalence/risk of exposure led to laws mandating testing in gestation, reporting, and development of broad-based teaching materials about Toxoplasma. These were tested for efficacy as learning tools for high-school students, pregnant women, medical students, physicians, scientists, public health officials and general public. Digitized, free, smart phone application effectively taught pregnant women about toxoplasmosis prevention. Perinatal infection care programs, identifying true regional risk factors, and point-of-care gestational screening facilitate prevention and care. When implemented fully across all demographics, such programs present opportunities to save lives, sight, and cognition with considerable spillover benefits for individuals and societies. Supplementary Information The online version contains supplementary material available at 10.1007/s40124-022-00269-w.
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Building Programs to Eradicate Toxoplasmosis Part IV: Understanding and Development of Public Health Strategies and Advances “Take a Village”. CURRENT PEDIATRICS REPORTS 2022; 10:125-154. [PMID: 35991908 PMCID: PMC9379243 DOI: 10.1007/s40124-022-00268-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/29/2022] [Indexed: 11/12/2022]
Abstract
Purpose of Review Review international efforts to build a global public health initiative focused on toxoplasmosis with spillover benefits to save lives, sight, cognition and motor function benefiting maternal and child health. Recent Findings Multiple countries’ efforts to eliminate toxoplasmosis demonstrate progress and context for this review and new work. Summary Problems with potential solutions proposed include accessibility of accurate, inexpensive diagnostic testing, pre-natal screening and facilitating tools, missed and delayed neonatal diagnosis, restricted access, high costs, delays in obtaining medicines emergently, delayed insurance pre-approvals and high medicare copays taking considerable physician time and effort, harmful shortcuts being taken in methods to prepare medicines in settings where access is restricted, reluctance to perform ventriculoperitoneal shunts promptly when needed without recognition of potential benefit, access to resources for care, especially for marginalized populations, and limited use of recent advances in management of neurologic and retinal disease which can lead to good outcomes. Supplementary Information The online version contains supplementary material available at 10.1007/s40124-022-00268-x.
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Sukhoverkov KV, Breese KJ, Debowski AW, Murcha MW, Stubbs KA, Mylne JS. Inhibition of chloroplast translation as a new target for herbicides. RSC Chem Biol 2022; 3:37-43. [PMID: 35128407 PMCID: PMC8729176 DOI: 10.1039/d1cb00192b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 11/10/2021] [Indexed: 12/21/2022] Open
Abstract
The rise in herbicide resistance over recent decades threatens global agriculture and food security and so discovery of new modes of action is increasingly important. Here we reveal linezolid, an oxazolidinone antibiotic that inhibits microbial translation, is also herbicidal. To validate the herbicidal mode of action of linezolid we confirmed its micromolar inhibition is specific to chloroplast translation and did not affect photosynthesis directly. To assess the herbicide potential of linezolid, testing against a range of weed and crop species found it effective pre- and post-emergence. Using structure-activity analysis we identified the critical elements for herbicidal activity, but importantly also show, using antimicrobial susceptibility assays, that separation of antibacterial and herbicidal activities was possible. Overall these results validate chloroplast translation as a viable herbicidal target.
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Affiliation(s)
- Kirill V Sukhoverkov
- The University of Western Australia, School of Molecular Sciences 35 Stirling Highway Crawley Perth 6009 Australia
- The ARC Centre of Excellence in Plant Energy Biology 35 Stirling Highway Crawley Perth 6009 Australia
| | - Karen J Breese
- The University of Western Australia, School of Molecular Sciences 35 Stirling Highway Crawley Perth 6009 Australia
| | - Aleksandra W Debowski
- The University of Western Australia, School of Molecular Sciences 35 Stirling Highway Crawley Perth 6009 Australia
- School of Biomedical Sciences 35 Stirling Highway Crawley Perth 6009 Australia
| | - Monika W Murcha
- The University of Western Australia, School of Molecular Sciences 35 Stirling Highway Crawley Perth 6009 Australia
- The ARC Centre of Excellence in Plant Energy Biology 35 Stirling Highway Crawley Perth 6009 Australia
| | - Keith A Stubbs
- The University of Western Australia, School of Molecular Sciences 35 Stirling Highway Crawley Perth 6009 Australia
| | - Joshua S Mylne
- The University of Western Australia, School of Molecular Sciences 35 Stirling Highway Crawley Perth 6009 Australia
- The ARC Centre of Excellence in Plant Energy Biology 35 Stirling Highway Crawley Perth 6009 Australia
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University Bentley WA 6102 Australia
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5
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Hajj RE, Tawk L, Itani S, Hamie M, Ezzeddine J, El Sabban M, El Hajj H. Toxoplasmosis: Current and Emerging Parasite Druggable Targets. Microorganisms 2021; 9:microorganisms9122531. [PMID: 34946133 PMCID: PMC8707595 DOI: 10.3390/microorganisms9122531] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 11/10/2021] [Accepted: 11/10/2021] [Indexed: 12/19/2022] Open
Abstract
Toxoplasmosis is a prevalent disease affecting a wide range of hosts including approximately one-third of the human population. It is caused by the sporozoan parasite Toxoplasma gondii (T. gondii), which instigates a range of symptoms, manifesting as acute and chronic forms and varying from ocular to deleterious congenital or neuro-toxoplasmosis. Toxoplasmosis may cause serious health problems in fetuses, newborns, and immunocompromised patients. Recently, associations between toxoplasmosis and various neuropathies and different types of cancer were documented. In the veterinary sector, toxoplasmosis results in recurring abortions, leading to significant economic losses. Treatment of toxoplasmosis remains intricate and encompasses general antiparasitic and antibacterial drugs. The efficacy of these drugs is hindered by intolerance, side effects, and emergence of parasite resistance. Furthermore, all currently used drugs in the clinic target acute toxoplasmosis, with no or little effect on the chronic form. In this review, we will provide a comprehensive overview on the currently used and emergent drugs and their respective parasitic targets to combat toxoplasmosis. We will also abridge the repurposing of certain drugs, their targets, and highlight future druggable targets to enhance the therapeutic efficacy against toxoplasmosis, hence lessening its burden and potentially alleviating the complications of its associated diseases.
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Affiliation(s)
- Rana El Hajj
- Department of Biological Sciences, Beirut Arab University, P.O. Box 11-5020, Riad El Solh, Beirut 1107 2809, Lebanon;
| | - Lina Tawk
- Department of Medical Laboratory Sciences, Faculty of Health Sciences, University of Balamand, Beirut 1100 2807, Lebanon; (L.T.); (J.E.)
| | - Shaymaa Itani
- Department of Experimental Pathology, Microbiology and Immunology, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236, Riad El-Solh, Beirut 1107 2020, Lebanon; (S.I.); (M.H.)
| | - Maguy Hamie
- Department of Experimental Pathology, Microbiology and Immunology, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236, Riad El-Solh, Beirut 1107 2020, Lebanon; (S.I.); (M.H.)
| | - Jana Ezzeddine
- Department of Medical Laboratory Sciences, Faculty of Health Sciences, University of Balamand, Beirut 1100 2807, Lebanon; (L.T.); (J.E.)
| | - Marwan El Sabban
- Department of Anatomy, Cell Biology and Physiological Sciences, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236, Riad El-Solh, Beirut 1107 2020, Lebanon;
| | - Hiba El Hajj
- Department of Experimental Pathology, Microbiology and Immunology, Faculty of Medicine, American University of Beirut, P.O. Box 11-0236, Riad El-Solh, Beirut 1107 2020, Lebanon; (S.I.); (M.H.)
- Correspondence: ; Tel.: +961–1-350000 (ext. 4897)
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Kimmel J, Kehrer J, Frischknecht F, Spielmann T. Proximity-dependent biotinylation approaches to study apicomplexan biology. Mol Microbiol 2021; 117:553-568. [PMID: 34587292 DOI: 10.1111/mmi.14815] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 09/20/2021] [Indexed: 11/28/2022]
Abstract
In the last 10 years, proximity-dependent biotinylation (PDB) techniques greatly expanded the ability to study protein environments in the living cell that range from specific protein complexes to entire compartments. This is achieved by using enzymes such as BirA* and APEX that are fused to proteins of interest and biotinylate proteins in their proximity. PDB techniques are now also increasingly used in apicomplexan parasites. In this review, we first give an overview of the main PDB approaches and how they compare with other techniques that address similar questions. PDB is particularly valuable to detect weak or transient protein associations under physiological conditions and to study cellular structures that are difficult to purify or have a poorly understood protein composition. We also highlight new developments such as novel smaller or faster-acting enzyme variants and conditional PDB approaches, providing improvements in both temporal and spatial resolution which may offer broader application possibilities useful in apicomplexan research. In the second part, we review work using PDB techniques in apicomplexan parasites and how this expanded our knowledge about these medically important parasites.
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Affiliation(s)
- Jessica Kimmel
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Jessica Kehrer
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Heidelberg, Germany.,German Center for Infectious Disease Research, DZIF, Heidelberg, Germany
| | - Friedrich Frischknecht
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Heidelberg, Germany.,German Center for Infectious Disease Research, DZIF, Heidelberg, Germany
| | - Tobias Spielmann
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
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7
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Lathe R, St Clair D. From conifers to cognition: Microbes, brain and behavior. GENES BRAIN AND BEHAVIOR 2020; 19:e12680. [PMID: 32515128 DOI: 10.1111/gbb.12680] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 05/12/2020] [Accepted: 05/29/2020] [Indexed: 12/25/2022]
Abstract
A diversity of bacteria, protozoans and viruses ("endozoites") were recently uncovered within healthy tissues including the human brain. By contrast, it was already recognized a century ago that healthy plants tissues contain abundant endogenous microbes ("endophytes"). Taking endophytes as an informative precedent, we overview the nature, prevalence, and role of endozoites in mammalian tissues, centrally focusing on the brain, concluding that endozoites are ubiquitous in diverse tissues. These passengers often remain subclinical, but they are not silent. We address their routes of entry, mechanisms of persistence, tissue specificity, and potential to cause long-term behavioral changes and/or immunosuppression in mammals, where rabies virus is the exemplar. We extend the discussion to Herpesviridae, Coronaviridae, and Toxoplasma, as well as to diverse bacteria and yeasts, and debate the advantages and disadvantages that endozoite infection might afford to the host and to the ecosystem. We provide a clinical perspective in which endozoites are implicated in neurodegenerative disease, anxiety/depression, and schizophrenia. We conclude that endozoites are instrumental in the delicate balance between health and disease, including age-related brain disease, and that endozoites have played an important role in the evolution of brain function and human behavior.
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Affiliation(s)
- Richard Lathe
- Division of Infection Medicine, University of Edinburgh Medical School, Edinburgh, UK
| | - David St Clair
- Institute of Medical Sciences, School of Medicine, University of Aberdeen, Aberdeen, UK
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8
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Wang L, Zhang L, Feng RR, Dong X, Lu HZ, Zhang JJ. Unravelling the binding affinity between model transport protein and a prospective tuberculosis therapeutic agent: a spectroscopic and theoretical simulation exploration. J Biomol Struct Dyn 2019; 37:4507-4521. [DOI: 10.1080/07391102.2018.1552624] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Leng Wang
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, China
| | - Li Zhang
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, China
| | - Rui Rui Feng
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, China
| | - Xue Dong
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, China
| | - Hui Zhe Lu
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, China
| | - Jian Jun Zhang
- Department of Applied Chemistry, College of Science, China Agricultural University, Beijing, China
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9
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Patent highlights February–March 2017. Pharm Pat Anal 2017; 6:151-159. [DOI: 10.4155/ppa-2017-0016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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10
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Haq S, Bachvaroff TR, Place AR. Characterization of Acetyl-CoA Carboxylases in the Basal Dinoflagellate Amphidinium carterae. Mar Drugs 2017; 15:md15060149. [PMID: 28587129 PMCID: PMC5484099 DOI: 10.3390/md15060149] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 05/20/2017] [Accepted: 05/23/2017] [Indexed: 11/28/2022] Open
Abstract
Dinoflagellates make up a diverse array of fatty acids and polyketides. A necessary precursor for their synthesis is malonyl-CoA formed by carboxylating acetyl CoA using the enzyme acetyl-CoA carboxylase (ACC). To date, information on dinoflagellate ACC is limited. Through transcriptome analysis in Amphidinium carterae, we found three full-length homomeric type ACC sequences; no heteromeric type ACC sequences were found. We assigned the putative cellular location for these ACCs based on transit peptide predictions. Using streptavidin Western blotting along with mass spectrometry proteomics, we validated the presence of ACC proteins. Additional bands showing other biotinylated proteins were also observed. Transcript abundance for these ACCs follow the global pattern of expression for dinoflagellate mRNA messages over a diel cycle. This is one of the few descriptions at the transcriptomic and protein level of ACCs in dinoflagellates. This work provides insight into the enzymes which make the CoA precursors needed for fatty acid and toxin synthesis in dinoflagellates.
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Affiliation(s)
- Saddef Haq
- Graduate Program in Life Sciences, University of Maryland, Baltimore, MD 21201, USA.
| | - Tsvetan R Bachvaroff
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, Baltimore, MD 21201, USA.
| | - Allen R Place
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, Baltimore, MD 21201, USA.
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11
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Review of Experimental Compounds Demonstrating Anti-Toxoplasma Activity. Antimicrob Agents Chemother 2016; 60:7017-7034. [PMID: 27600037 DOI: 10.1128/aac.01176-16] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Toxoplasma gondii is a ubiquitous apicomplexan parasite capable of infecting humans and other animals. Current treatment options for T. gondii infection are limited and most have drawbacks, including high toxicity and low tolerability. Additionally, no FDA-approved treatments are available for pregnant women, a high-risk population due to transplacental infection. Therefore, the development of novel treatment options is needed. To aid this effort, this review highlights experimental compounds that, at a minimum, demonstrate inhibition of in vitro growth of T. gondii When available, host cell toxicity and in vivo data are also discussed. The purpose of this review is to facilitate additional development of anti-Toxoplasma compounds and potentially to extend our knowledge of the parasite.
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12
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Global iTRAQ-based proteomic profiling of Toxoplasma gondii oocysts during sporulation. J Proteomics 2016; 148:12-9. [DOI: 10.1016/j.jprot.2016.07.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Revised: 06/15/2016] [Accepted: 07/11/2016] [Indexed: 12/19/2022]
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13
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Martins-Duarte ÉS, Carias M, Vommaro R, Surolia N, de Souza W. Apicoplast fatty acid synthesis is essential for pellicle formation at the end of cytokinesis in Toxoplasma gondii. J Cell Sci 2016; 129:3320-31. [PMID: 27457282 DOI: 10.1242/jcs.185223] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Accepted: 07/19/2016] [Indexed: 01/19/2023] Open
Abstract
The apicomplexan protozoan Toxoplasma gondii, the causative agent of toxoplasmosis, harbors an apicoplast, a plastid-like organelle with essential metabolic functions. Although the FASII fatty acid biosynthesis pathway located in the apicoplast is essential for parasite survival, the cellular effects of FASII disruption in T. gondii had not been examined in detail. Here, we combined light and electron microscopy techniques - including focused ion beam scanning electron microscopy (FIB-SEM) - to characterize the effect of FASII disruption in T. gondii, by treatment with the FASII inhibitor triclosan or by inducible knockdown of the FASII component acyl carrier protein. Morphological analyses showed that FASII disruption prevented cytokinesis completion in T. gondii tachyzoites, leading to the formation of large masses of 'tethered' daughter cells. FIB-SEM showed that tethered daughters had a mature basal complex, but a defect in new membrane addition between daughters resulted in incomplete pellicle formation. Addition of exogenous fatty acids to medium suppressed the formation of tethered daughter cells and supports the notion that FASII is essential to generate lipid substrates required for the final step of parasite division.
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Affiliation(s)
- Érica S Martins-Duarte
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil, 21.941-902 Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens, Rio de Janeiro, Brazil, 21.941-902
| | - Maira Carias
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil, 21.941-902 Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens, Rio de Janeiro, Brazil, 21.941-902
| | - Rossiane Vommaro
- Laboratório de Ultraestrutura Celular Hertha Meyer, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil, 21.941-902 Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens, Rio de Janeiro, Brazil, 21.941-902
| | - Namita Surolia
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore, India, 560064
| | - 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, 21.941-902 Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagens, Rio de Janeiro, Brazil, 21.941-902
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14
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Activity of several kinds of drugs against Neospora caninum. Parasitol Int 2015; 64:597-602. [PMID: 26264260 DOI: 10.1016/j.parint.2015.08.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 08/05/2015] [Accepted: 08/07/2015] [Indexed: 11/22/2022]
Abstract
Neosporosis caused by Neospora caninum is a serious disease in cattle and dogs worldwide. It is the major cause of abortion and neonatal mortality in cattle. In this study, we evaluated the anti-N. caninum activity of Chinese medicine extracts (curcumin, artemether), herbicides (atrazine, glyphosate), anticoccidiosis drugs (toltrazuril and ponazuril), cyclophosphamide, diminazene aceturate and praziquantel in vitro using parasite growth, replication and host cell invasion assays in human foreskin fibroblast cultures. Curcumin, artemether, atrazine, toltrazuril and ponazuril exhibited inhibitory activity with 50% growth inhibitory concentration (IC50) of 1.1±0.4, 1.0±0.05, 11.2±2.7, 30.3±2.0 and 33.3±4.1μg/ml, respectively, in the growth inhibition assay. They were also active against protozoa replication, but only curcumin was effective against host cell invasion. Glyphosate, cyclophosphamide, diminazene aceturate and praziquantel were ineffective. In an in vivo infection model, curcumin showed no activity against N. caninum infection. We showed that curcumin, artemether, atrazine, toltrazuril, and ponazuril exhibited anti-N. caninum activity in vitro, providing important information for further studies on anti-N. caninum drugs.
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15
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Phylogenetic Analysis of Nucleus-Encoded Acetyl-CoA Carboxylases Targeted at the Cytosol and Plastid of Algae. PLoS One 2015; 10:e0131099. [PMID: 26131555 PMCID: PMC4489017 DOI: 10.1371/journal.pone.0131099] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 05/28/2015] [Indexed: 11/19/2022] Open
Abstract
The understanding of algal phylogeny is being impeded by an unknown number of events of horizontal gene transfer (HGT), and primary and secondary/tertiary endosymbiosis. Through these events, previously heterotrophic eukaryotes developed photosynthesis and acquired new biochemical pathways. Acetyl-CoA carboxylase (ACCase) is a key enzyme in the fatty acid synthesis and elongation pathways in algae, where ACCase exists in two locations (cytosol and plastid) and in two forms (homomeric and heteromeric). All algae contain nucleus-encoded homomeric ACCase in the cytosol, independent of the origin of the plastid. Nucleus-encoded homomeric ACCase is also found in plastids of algae that arose from a secondary/tertiary endosymbiotic event. In contrast, plastids of algae that arose from a primary endosymbiotic event contain heteromeric ACCase, which consists of three nucleus-encoded and one plastid-encoded subunits. These properties of ACCase provide the potential to inform on the phylogenetic relationships of hosts and their plastids, allowing different hypothesis of endosymbiotic events to be tested. Alveolata (Dinoflagellata and Apicomplexa) and Chromista (Stramenopiles, Haptophyta and Cryptophyta) have traditionally been grouped together as Chromalveolata, forming the red lineage. However, recent genetic evidence groups the Stramenopiles, Alveolata and green plastid containing Rhizaria as SAR, excluding Haptophyta and Cryptophyta. Sequences coding for plastid and cytosol targeted homomeric ACCases were isolated from Isochrysis aff. galbana (TISO), Chromera velia and Nannochloropsis oculata, representing three taxonomic groups for which sequences were lacking. Phylogenetic analyses show that cytosolic ACCase strongly supports the SAR grouping. Conversely, plastidial ACCase groups the SAR with the Haptophyta, Cryptophyta and Prasinophyceae (Chlorophyta). These two ACCase based, phylogenetic relationships suggest that the plastidial homomeric ACCase was acquired by the Haptophyta, Cryptophyta and SAR, before the photosynthetic Rhizaria acquired their green plastid. Additionally, plastidial ACCase was derived by HGT from an ancestor or relative of the Prasinophyceae and not by duplication of cytosolic ACCase.
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16
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New method for the orthogonal labeling and purification of Toxoplasma gondii proteins while inside the host cell. mBio 2015; 6:e01628. [PMID: 25759504 PMCID: PMC4453564 DOI: 10.1128/mbio.01628-14] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Toxoplasma gondii is an obligate intracellular protozoan parasite that is capable of causing severe disease in immunocompromised humans. How T. gondii is able to modulate the host cell to support itself is still poorly understood. Knowledge pertaining to the host-parasite interaction could be bolstered by developing a system to specifically label parasite proteins while the parasite grows inside the host cell. For this purpose, we have created a strain of T. gondii that expresses a mutant Escherichia coli methionyl-tRNA synthetase (MetRSNLL) that allows methionine tRNA to be loaded with the azide-containing methionine analog azidonorleucine (Anl). Anl-containing proteins are susceptible to a copper-catalyzed “click” reaction to attach affinity tags for purification or fluorescent tags for visualization. The MetRSNLL-Anl system labels nascent T. gondii proteins in an orthogonal fashion, labeling proteins only in MetRSNLL-expressing parasites. This system should be useful for nonradioactive pulse-chase studies and purification of nascently translated proteins. Although this approach allows labeling of a diverse array of parasite proteins, secreted parasite proteins appear to be only minimally labeled in MetRSNLL-expressing T. gondii. The minimal labeling of secreted proteins is likely a consequence of the selective charging of the initiator tRNA (and not the elongator methionine tRNA) by the heterologously expressed bacterial MetRS. Studying how T. gondii modifies the host cell to permit its survival is complicated by the complex protein environment of the host cell. The approach presented in this article provides the first method for specific labeling of T. gondii proteins while the parasite grows inside the host cell. We show that this approach is useful for pulse-chase labeling of parasite proteins during in vitro growth. It should also be applicable during in vivo infections and in other apicomplexan parasites, including Plasmodium spp.
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Fatty acid metabolism in the Plasmodium apicoplast: Drugs, doubts and knockouts. Mol Biochem Parasitol 2015; 199:34-50. [DOI: 10.1016/j.molbiopara.2015.03.004] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2015] [Revised: 03/16/2015] [Accepted: 03/17/2015] [Indexed: 12/25/2022]
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18
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Denny PW, Steel PG. Yeast as a potential vehicle for neglected tropical disease drug discovery. ACTA ACUST UNITED AC 2014; 20:56-63. [PMID: 25121554 DOI: 10.1177/1087057114546552] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
High-throughput screening (HTS) efforts for neglected tropical disease (NTD) drug discovery have recently received increased attention because several initiatives have begun to attempt to reduce the deficit in new and clinically acceptable therapies for this spectrum of infectious diseases. HTS primarily uses two basic approaches, cell-based and in vitro target-directed screening. Both of these approaches have problems; for example, cell-based screening does not reveal the target or targets that are hit, whereas in vitro methodologies lack a cellular context. Furthermore, both can be technically challenging, expensive, and difficult to miniaturize for ultra-HTS [(u)HTS]. The application of yeast-based systems may overcome some of these problems and offer a cost-effective platform for target-directed screening within a eukaryotic cell context. Here, we review the advantages and limitations of the technologies that may be used in yeast cell-based, target-directed screening protocols, and we discuss how these are beginning to be used in NTD drug discovery.
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Affiliation(s)
- P W Denny
- Biophysical Sciences Institute, Department of Chemistry and School of Biological Sciences, University Science Laboratories, Durham, UK School of Medicine, Pharmacy and Health, Durham University, Durham, UK
| | - P G Steel
- Biophysical Sciences Institute, Department of Chemistry and School of Biological Sciences, University Science Laboratories, Durham, UK
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Structure, activity, and inhibition of the Carboxyltransferase β-subunit of acetyl coenzyme A carboxylase (AccD6) from Mycobacterium tuberculosis. Antimicrob Agents Chemother 2014; 58:6122-32. [PMID: 25092705 DOI: 10.1128/aac.02574-13] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Mycobacterium tuberculosis, the carboxylation of acetyl coenzyme A (acetyl-CoA) to produce malonyl-CoA, a building block in long-chain fatty acid biosynthesis, is catalyzed by two enzymes working sequentially: a biotin carboxylase (AccA) and a carboxyltransferase (AccD). While the exact roles of the three different biotin carboxylases (AccA1 to -3) and the six carboxyltransferases (AccD1 to -6) in M. tuberculosis are still not clear, AccD6 in complex with AccA3 can synthesize malonyl-CoA from acetyl-CoA. A series of 10 herbicides that target plant acetyl-CoA carboxylases (ACC) were tested for inhibition of AccD6 and for whole-cell activity against M. tuberculosis. From the tested herbicides, haloxyfop, an arylophenoxypropionate, showed in vitro inhibition of M. tuberculosis AccD6, with a 50% inhibitory concentration (IC50) of 21.4 ± 1 μM. Here, we report the crystal structures of M. tuberculosis AccD6 in the apo form (3.0 Å) and in complex with haloxyfop-R (2.3 Å). The structure of M. tuberculosis AccD6 in complex with haloxyfop-R shows two molecules of the inhibitor bound on each AccD6 subunit. These results indicate the potential for developing novel therapeutics for tuberculosis based on herbicides with low human toxicity.
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Chen N, LaCrue AN, Teuscher F, Waters NC, Gatton ML, Kyle DE, Cheng Q. Fatty acid synthesis and pyruvate metabolism pathways remain active in dihydroartemisinin-induced dormant ring stages of Plasmodium falciparum. Antimicrob Agents Chemother 2014; 58:4773-81. [PMID: 24913167 PMCID: PMC4135995 DOI: 10.1128/aac.02647-14] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 06/01/2014] [Indexed: 11/20/2022] Open
Abstract
Artemisinin (ART)-based combination therapy (ACT) is used as the first-line treatment of uncomplicated falciparum malaria worldwide. However, despite high potency and rapid action, there is a high rate of recrudescence associated with ART monotherapy or ACT long before the recent emergence of ART resistance. ART-induced ring-stage dormancy and recovery have been implicated as possible causes of recrudescence; however, little is known about the characteristics of dormant parasites, including whether dormant parasites are metabolically active. We investigated the transcription of 12 genes encoding key enzymes in various metabolic pathways in P. falciparum during dihydroartemisinin (DHA)-induced dormancy and recovery. Transcription analysis showed an immediate downregulation for 10 genes following exposure to DHA but continued transcription of 2 genes encoding apicoplast and mitochondrial proteins. Transcription of several additional genes encoding apicoplast and mitochondrial proteins, particularly of genes encoding enzymes in pyruvate metabolism and fatty acid synthesis pathways, was also maintained. Additions of inhibitors for biotin acetyl-coenzyme A (CoA) carboxylase and enoyl-acyl carrier reductase of the fatty acid synthesis pathways delayed the recovery of dormant parasites by 6 and 4 days, respectively, following DHA treatment. Our results demonstrate that most metabolic pathways are downregulated in DHA-induced dormant parasites. In contrast, fatty acid and pyruvate metabolic pathways remain active. These findings highlight new targets to interrupt recovery of parasites from ART-induced dormancy and to reduce the rate of recrudescence following ART treatment.
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Affiliation(s)
- Nanhua Chen
- Drug Resistance and Diagnostics, Australian Army Malaria Institute, Brisbane, Australia
| | - Alexis N LaCrue
- Department of Global Health, University of South Florida, Tampa, Florida, USA
| | - Franka Teuscher
- Drug Resistance and Diagnostics, Australian Army Malaria Institute, Brisbane, Australia Malaria Drug Resistance and Chemotherapy, Queensland Institute of Medical Research, Brisbane, Australia
| | - Norman C Waters
- Experimental Therapeutics, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Michelle L Gatton
- Malaria Drug Resistance and Chemotherapy, Queensland Institute of Medical Research, Brisbane, Australia School of Public Health & Social Work, Queensland University of Technology, Brisbane, Australia
| | - Dennis E Kyle
- Department of Global Health, University of South Florida, Tampa, Florida, USA
| | - Qin Cheng
- Drug Resistance and Diagnostics, Australian Army Malaria Institute, Brisbane, Australia Malaria Drug Resistance and Chemotherapy, Queensland Institute of Medical Research, Brisbane, Australia
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A survey of innovation through duplication in the reduced genomes of twelve parasites. PLoS One 2014; 9:e99213. [PMID: 24919110 PMCID: PMC4053351 DOI: 10.1371/journal.pone.0099213] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Accepted: 05/12/2014] [Indexed: 11/24/2022] Open
Abstract
We characterize the prevalence, distribution, divergence, and putative functions of detectable two-copy paralogs and segmental duplications in the Apicomplexa, a phylum of parasitic protists. Apicomplexans are mostly obligate intracellular parasites responsible for human and animal diseases (e.g. malaria and toxoplasmosis). Gene loss is a major force in the phylum. Genomes are small and protein-encoding gene repertoires are reduced. Despite this genomic streamlining, duplications and gene family amplifications are present. The potential for innovation introduced by duplications is of particular interest. We compared genomes of twelve apicomplexans across four lineages and used orthology and genome cartography to map distributions of duplications against genome architectures. Segmental duplications appear limited to five species. Where present, they correspond to regions enriched for multi-copy and species-specific genes, pointing toward roles in adaptation and innovation. We found a phylum-wide association of duplications with dynamic chromosome regions and syntenic breakpoints. Trends in the distribution of duplicated genes indicate that recent, species-specific duplicates are often tandem while most others have been dispersed by genome rearrangements. These trends show a relationship between genome architecture and gene duplication. Functional analysis reveals: proteases, which are vital to a parasitic lifecycle, to be prominent in putative recent duplications; a pair of paralogous genes in Toxoplasma gondii previously shown to produce the rate-limiting step in dopamine synthesis in mammalian cells, a possible link to the modification of host behavior; and phylum-wide differences in expression and subcellular localization, indicative of modes of divergence. We have uncovered trends in multiple modes of duplicate divergence including sequence, intron content, expression, subcellular localization, and functions of putative recent duplicates that highlight the role of duplications in the continuum of forces that have shaped these genomes.
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Goodman CD, Mollard V, Louie T, Holloway GA, Watson KG, McFadden GI. Apicoplast acetyl Co-A carboxylase of the human malaria parasite is not targeted by cyclohexanedione herbicides. Int J Parasitol 2014; 44:285-9. [DOI: 10.1016/j.ijpara.2014.01.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 12/22/2013] [Accepted: 01/07/2014] [Indexed: 10/25/2022]
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23
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Martins Alho MA, Marrero-Ponce Y, Barigye SJ, Meneses-Marcel A, Machado Tugores Y, Montero-Torres A, Gómez-Barrio A, Nogal JJ, García-Sánchez RN, Vega MC, Rolón M, Martínez-Fernández AR, Escario JA, Pérez-Giménez F, Garcia-Domenech R, Rivera N, Mondragón R, Mondragón M, Ibarra-Velarde F, Lopez-Arencibia A, Martín-Navarro C, Lorenzo-Morales J, Cabrera-Serra MG, Piñero J, Tytgat J, Chicharro R, Arán VJ. Antiprotozoan lead discovery by aligning dry and wet screening: Prediction, synthesis, and biological assay of novel quinoxalinones. Bioorg Med Chem 2014; 22:1568-85. [DOI: 10.1016/j.bmc.2014.01.036] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 01/13/2014] [Accepted: 01/21/2014] [Indexed: 12/20/2022]
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24
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Afanador GA, Muench SP, McPhillie M, Fomovska A, Schön A, Zhou Y, Cheng G, Stec J, Freundlich JS, Shieh HM, Anderson JW, Jacobus DP, Fidock DA, Kozikowski AP, Fishwick CW, Rice DW, Freire E, McLeod R, Prigge ST. Discrimination of potent inhibitors of Toxoplasma gondii enoyl-acyl carrier protein reductase by a thermal shift assay. Biochemistry 2013; 52:9155-66. [PMID: 24295325 DOI: 10.1021/bi400945y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Many microbial pathogens rely on a type II fatty acid synthesis (FASII) pathway that is distinct from the type I pathway found in humans. Enoyl-acyl carrier protein reductase (ENR) is an essential FASII pathway enzyme and the target of a number of antimicrobial drug discovery efforts. The biocide triclosan is established as a potent inhibitor of ENR and has been the starting point for medicinal chemistry studies. We evaluated a series of triclosan analogues for their ability to inhibit the growth of Toxoplasma gondii, a pervasive human pathogen, and its ENR enzyme (TgENR). Several compounds that inhibited TgENR at low nanomolar concentrations were identified but could not be further differentiated because of the limited dynamic range of the TgENR activity assay. Thus, we adapted a thermal shift assay (TSA) to directly measure the dissociation constant (Kd) of the most potent inhibitors identified in this study as well as inhibitors from previous studies. Furthermore, the TSA allowed us to determine the mode of action of these compounds in the presence of the reduced nicotinamide adenine dinucleotide (NADH) or nicotinamide adenine dinucleotide (NAD⁺) cofactor. We found that all of the inhibitors bind to a TgENR-NAD⁺ complex but that they differed in their dependence on NAD⁺ concentration. Ultimately, we were able to identify compounds that bind to the TgENR-NAD⁺ complex in the low femtomolar range. This shows how TSA data combined with enzyme inhibition, parasite growth inhibition data, and ADMET predictions allow for better discrimination between potent ENR inhibitors for the future development of medicine.
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Affiliation(s)
- Gustavo A Afanador
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health , Baltimore, Maryland 21205, United States
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25
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Metabolic reconstruction identifies strain‐specific regulation of virulence in
Toxoplasma gondii. Mol Syst Biol 2013; 9:708. [PMID: 24247825 PMCID: PMC4039375 DOI: 10.1038/msb.2013.62] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 10/10/2013] [Indexed: 12/27/2022] Open
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26
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Stec J, Fomovska A, Afanador GA, Muench SP, Zhou Y, Lai BS, El Bissati K, Hickman MR, Lee PJ, Leed SE, Auschwitz JM, Sommervile C, Woods S, Roberts CW, Rice D, Prigge ST, McLeod R, Kozikowski AP. Modification of triclosan scaffold in search of improved inhibitors for enoyl-acyl carrier protein (ACP) reductase in Toxoplasma gondii. ChemMedChem 2013; 8:1138-60. [PMID: 23776166 DOI: 10.1002/cmdc.201300050] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 04/26/2013] [Indexed: 11/08/2022]
Abstract
Through our focused effort to discover new and effective agents against toxoplasmosis, a structure-based drug design approach was used to develop a series of potent inhibitors of the enoyl-acyl carrier protein (ACP) reductase (ENR) enzyme in Toxoplasma gondii (TgENR). Modifications to positions 5 and 4' of the well-known ENR inhibitor triclosan afforded a series of 29 new analogues. Among the resulting compounds, many showed high potency and improved physicochemical properties in comparison with the lead. The most potent compounds 16 a and 16 c have IC50 values of 250 nM against Toxoplasma gondii tachyzoites without apparent toxicity to the host cells. Their IC50 values against recombinant TgENR were found to be 43 and 26 nM, respectively. Additionally, 11 other analogues in this series had IC50 values ranging from 17 to 130 nM in the enzyme-based assay. With respect to their excellent in vitro activity as well as improved drug-like properties, the lead compounds 16 a and 16 c are deemed to be excellent starting points for the development of new medicines to effectively treat Toxoplasma gondii infections.
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Affiliation(s)
- Jozef Stec
- Drug Discovery Program, Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, 833 South Wood Street, Chicago, IL 60612, USA
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27
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Cheng G, Muench SP, Zhou Y, Afanador GA, Mui EJ, Fomovska A, Lai BS, Prigge ST, Woods S, Roberts CW, Hickman MR, Lee PJ, Leed SE, Auschwitz JM, Rice DW, McLeod R. Design, synthesis, and biological activity of diaryl ether inhibitors of Toxoplasma gondii enoyl reductase. Bioorg Med Chem Lett 2013; 23:2035-43. [PMID: 23453069 PMCID: PMC3625046 DOI: 10.1016/j.bmcl.2013.02.019] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2012] [Revised: 01/24/2013] [Accepted: 02/01/2013] [Indexed: 01/09/2023]
Abstract
Triclosan is a potent inhibitor of Toxoplasma gondii enoyl reductase (TgENR), which is an essential enzyme for parasite survival. In view of triclosan's poor druggability, which limits its therapeutic use, a new set of B-ring modified analogs were designed to optimize its physico-chemical properties. These derivatives were synthesized and evaluated by in vitro assay and TgENR enzyme assay. Some analogs display improved solubility, permeability and a comparable MIC50 value to that of triclosan. Modeling of these inhibitors revealed the same overall binding mode with the enzyme as triclosan, but the B-ring modifications have additional interactions with the strongly conserved Asn130.
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Affiliation(s)
- Gang Cheng
- Drug Discovery Program, Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, 833 South Wood Street, Chicago, Illinois, 60612, United States
| | | | - Ying Zhou
- Department of Ophthalmology and Visual Sciences, Pediatrics (Infectious Diseases), Committees on Genetics, Immunology, and Molecular Medicine, Institute of Genomics and Systems Biology, and The College, The University of Chicago, Chicago, Illinois 60637, United States
| | - Gustavo A. Afanador
- Johns Hopkins School of Public Health Rm. E5132, 615 N. Wolfe St. Baltimore MD 21205, United States
| | - Ernest J. Mui
- Department of Ophthalmology and Visual Sciences, Pediatrics (Infectious Diseases), Committees on Genetics, Immunology, and Molecular Medicine, Institute of Genomics and Systems Biology, and The College, The University of Chicago, Chicago, Illinois 60637, United States
| | - Alina Fomovska
- Department of Ophthalmology and Visual Sciences, Pediatrics (Infectious Diseases), Committees on Genetics, Immunology, and Molecular Medicine, Institute of Genomics and Systems Biology, and The College, The University of Chicago, Chicago, Illinois 60637, United States
| | - Bo Shiun Lai
- Department of Ophthalmology and Visual Sciences, Pediatrics (Infectious Diseases), Committees on Genetics, Immunology, and Molecular Medicine, Institute of Genomics and Systems Biology, and The College, The University of Chicago, Chicago, Illinois 60637, United States
| | - Sean T. Prigge
- Johns Hopkins School of Public Health Rm. E5132, 615 N. Wolfe St. Baltimore MD 21205, United States
| | - Stuart Woods
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, U.K
| | - Craig W. Roberts
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow, G4 0RE, U.K
| | - Mark R. Hickman
- Department of Discovery, Division of Experimental Therapeutics Walter Reed Army Institute of Research, Rm 2N61 503 Robert Grant Avenue, Silver Spring, MD 20910
| | - Patty J. Lee
- Department of Discovery, Division of Experimental Therapeutics Walter Reed Army Institute of Research, Rm 2N61 503 Robert Grant Avenue, Silver Spring, MD 20910
| | - Susan E. Leed
- Department of Discovery, Division of Experimental Therapeutics Walter Reed Army Institute of Research, Rm 2N61 503 Robert Grant Avenue, Silver Spring, MD 20910
| | - Jennifer M. Auschwitz
- Department of Discovery, Division of Experimental Therapeutics Walter Reed Army Institute of Research, Rm 2N61 503 Robert Grant Avenue, Silver Spring, MD 20910
| | - David W. Rice
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, U.K
| | - Rima McLeod
- Department of Ophthalmology and Visual Sciences, Pediatrics (Infectious Diseases), Committees on Genetics, Immunology, and Molecular Medicine, Institute of Genomics and Systems Biology, and The College, The University of Chicago, Chicago, Illinois 60637, United States
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Jang S, Marjanovic J, Gornicki P. Resistance to herbicides caused by single amino acid mutations in acetyl-CoA carboxylase in resistant populations of grassy weeds. THE NEW PHYTOLOGIST 2013; 197:1110-1116. [PMID: 23301879 DOI: 10.1111/nph.12117] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Accepted: 11/25/2012] [Indexed: 06/01/2023]
Abstract
Eleven spontaneous mutations of acetyl-CoA carboxylase have been identified in many herbicide-resistant populations of 42 species of grassy weeds, hampering application of aryloxyphenoxypropionate, cyclohexadione and phenylpyrazoline herbicides in agriculture. IC(50) shifts (resistance indices) caused by herbicide-resistant mutations were determined using a recombinant yeast system that allows comparison of the effects of single amino acid mutations in the same biochemical background, avoiding the complexity inherent in the in planta experiments. The effect of six mutations on the sensitivity of acetyl-CoA carboxylase to nine herbicides representing the three chemical classes was studied. A combination of partially overlapping binding sites of the three classes of herbicides and the structure of their variable parts explains cross-resistance among and between the three classes of inhibitors, as well as differences in their specificity. Some degree of resistance was detected for 51 of 54 herbicide/mutation combinations. Introduction of new herbicides targeting acetyl-CoA carboxylase will depend on their ability to overcome the high degree of cross-resistance already existing in weed populations.
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Affiliation(s)
- SoRi Jang
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL, 60637, USA
| | - Jasmina Marjanovic
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL, 60637, USA
| | - Piotr Gornicki
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, IL, 60637, USA
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Abstract
INTRODUCTION Toxoplasma gondii, the agent that causes toxoplasmosis, is an opportunistic parasite that infects many mammalian species. It is an obligate intracellular parasite that causes severe congenital neurological and ocular disease mostly in immunocompromised humans. The current regimen of therapy includes only a few medications that often lead to hypersensitivity and toxicity. In addition, there are no vaccines available to prevent the transmission of this agent. Therefore, safer and more effective medicines to treat toxoplasmosis are urgently needed. AREAS COVERED The author presents in silico and in vitro strategies that are currently used to screen for novel targets and unique chemotypes against T. gondii. Furthermore, this review highlights the screening technologies and characterization of some novel targets and new chemical entities that could be developed into highly efficacious treatments for toxoplasmosis. EXPERT OPINION A number of diverse methods are being used to design inhibitors against T. gondii. These include ligand-based methods, in which drugs that have been shown to be efficacious against other Apicomplexa parasites can be repurposed to identify lead molecules against T. gondii. In addition, structure-based methods use currently available repertoire of structural information in various databases to rationally design small-molecule inhibitors of T. gondii. Whereas the screening methods have their advantages and limitations, a combination of methods is ideally suited to design small-molecule inhibitors of complex parasites such as T. gondii.
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Affiliation(s)
- Sandhya Kortagere
- Drexel University College of Medicine, Institute for Molecular Medicine, Department of Microbiology and Immunology, 2900, Queen Lane, PA 19129, USA.
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Li Z, Li Q, Cheng F, Zhang W, Wang W, Li J. Enantioselectivity in degradation and transformation of quizalofop-ethyl in soils. Chirality 2012; 24:552-7. [DOI: 10.1002/chir.22053] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Accepted: 03/19/2012] [Indexed: 11/10/2022]
Affiliation(s)
- Zhaoyang Li
- College of Science; Hebei University of Science and Technology; Shijiazhuang Hebei Province China
| | - Qiaoling Li
- College of Bioscience and Bioengineering; Hebei University of Science and Technology; Shijiazhuang Hebei Province China
| | - Fengning Cheng
- College of Science; Hebei University of Science and Technology; Shijiazhuang Hebei Province China
| | - Wenshu Zhang
- College of Science; Hebei University of Science and Technology; Shijiazhuang Hebei Province China
| | - Weixiao Wang
- College of Science; Hebei University of Science and Technology; Shijiazhuang Hebei Province China
| | - Jingyin Li
- College of Science; Hebei University of Science and Technology; Shijiazhuang Hebei Province China
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Pedroni MJ, Luu TNK, Lau AOT. Babesia bovis: a bipartite signal directs the glutamyl-tRNA synthetase to the apicoplast. Exp Parasitol 2012; 131:261-6. [PMID: 22561041 PMCID: PMC3377962 DOI: 10.1016/j.exppara.2012.04.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 04/14/2012] [Accepted: 04/18/2012] [Indexed: 12/03/2022]
Abstract
Babesia bovis contains a prokaryotic derived organelle known as the apicoplast. Many participants of the metabolic pathways within the apicoplast are encoded in the nuclear genome and post-translationally imported with the help of a bipartite signal. Recently, an all encompassing algorithm was derived to predict apicoplast targeted proteins for many non-Plasmodium apicomplexans in which it reported the presence of 260 apicoplast targeted proteins in Babesia. One of these proteins is glutamyl tRNA synthetase (GltX). This study investigates if the putative bipartite signal of GltX alone is sufficient to direct proteins into the apicoplast. Using a transient transfection system consisting of a green fluorescent protein as the reporter, we tested the signal and transit portions of the bipartite signal in apicoplastic transport. We first identified the transcript of gltX to be expressed during the asexual blood stages and subsequently confirmed that the complete bipartite signal is responsible for directing the reporter protein into a compartment distinct from the nucleus and the mitochondrion. As GltX bipartite signal successfully guided the reporter protein into the apicoplast, our finding implies that it also directs native GltX into the same organelle.
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Affiliation(s)
- Monica J Pedroni
- Program of Genomics, Department of Veterinary Microbiology & Pathology, Paul G. Allen School for Global Animal Health, College of Veterinary Medicine, Washington State University, Pullman, WA 99164-7040, USA
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Abstract
Lipids from microalgae have become an important commodity in the last 20 years, biodiesel and supplementing human diets with ω-3 fatty acids are just two of the many applications. Acetyl-CoA carboxylase (ACCase) is a key enzyme in the lipid synthesis pathway. In general, ACCases consist of four functional domains: the biotin carboxylase (BC), the biotin carboxyl binding protein (BCCP), and α-and β-carboxyltransferases (α-and β-CT). In algae, like in plants, lipid synthesis is another function of the chloroplast. Despite being well researched in plants and animals, there is a distinct lack of information about this enzyme in the taxonomically diverse algae. In plastid-containing organisms, ACCases are present in the cytosol and the plastid (chloroplasts) and two different forms exist, the heteromeric (prokaryotic) and homomeric (eukaryotic) form. Despite recognition of the existence of the two ACCase forms, generalized published statements still list the heteromeric form as the one present in algal plastids. In this study, the authors show this is not the case for all algae. The presence of heteromeric or homomeric ACCase is dependent on the origin of plastid. The authors used ACCase amino acid sequence comparisons to show that green (Chlorophyta) and red (Rhodophyta) algae, with the exception of the green algal class Prasinophyceae, contain heteromeric ACCase in their plastids, which are of primary symbiotic origin and surrounded by two envelope membranes. In contrast, algal plastids surrounded by three to four membranes were derived through secondary endosymbiosis (Heterokontophyta and Haptophyta), as well as apicoplast containing Apicomplexa, contain homomeric ACCase in their plastids. Distinctive differences in the substrate binding regions of heteromeric and homomeric α-CT and β-CT were discovered, which can be used to distinguish between the two ACCase types. Furthermore, the acetyl-CoA binding region of homomeric α-CT can be used to distinguish between cytosolic and plastidial ACCase. The information provided here will be of fundamental importance in ACCase expression and activity research to unravel impacts of environmental and physicochemical parameters on lipid content and productivity.
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Affiliation(s)
- Roger Huerlimann
- School of Marine and Tropical Biology, James Cook University, Townsville, Queensland, Australia
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Barbosa-Cabrera E, Salas-Casas A, Rojas-Hernández S, Jarillo-Luna A, Abarca-Rojano E, Rodríguez MA, Campos-Rodríguez R. Purification and cellular localization of the Entamoeba histolytica transcarboxylase. Parasitol Res 2012; 111:1401-5. [PMID: 22453500 DOI: 10.1007/s00436-012-2898-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Accepted: 03/14/2012] [Indexed: 11/26/2022]
Abstract
Genome analysis of Entamoeba histolytica predicts the presence of acetyl-CoA carboxylase. Using Western blot, histochemistry, and confocal microscopy, we demonstrated the presence of a biotin-containing protein in the cytoplasm of E. histolytica, with a molecular weight of 136 kDa and biotin-carboxylase activity. This protein probably corresponds to a transcarboxylase that catalyzes the rate-limiting reaction leading to fatty acid elongation.
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Affiliation(s)
- E Barbosa-Cabrera
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Plan de San Luís y Díaz Mirón, CP 11340, Mexico, D.F., Mexico
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Vigueira PA, Paul KS. Trypanosoma brucei: inhibition of acetyl-CoA carboxylase by haloxyfop. Exp Parasitol 2011; 130:159-65. [PMID: 22119241 DOI: 10.1016/j.exppara.2011.10.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2011] [Revised: 10/08/2011] [Accepted: 10/31/2011] [Indexed: 10/15/2022]
Abstract
Trypanosoma brucei, a eukaryotic pathogen that causes African sleeping sickness in humans and nagana in cattle, depends on the enzyme acetyl-CoA carboxylase (ACC) for full virulence in mice. ACC produces malonyl-CoA, the two carbon donor for fatty acid synthesis. We assessed the effect of haloxyfop, an aryloxyphenoxypropionate herbicide inhibitor of plastid ACCs in many plants as well as Toxoplasma gondii, on T. brucei ACC activity and growth in culture. Haloxyfop inhibited TbACC in cell lysate (EC(50) 67 μM), despite the presence of an amino acid motif typically associated with resistance. Haloxyfop also reduced growth of bloodstream and procyclic form parasites (EC(50) of 0.8 and 1.2 mM). However, the effect on growth was likely due to off-target effects because haloxyfop treatment had no effect on fatty acid elongation or incorporation into complex lipids in vivo.
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Affiliation(s)
- Patrick A Vigueira
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA.
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Botté CY, Dubar F, McFadden GI, Maréchal E, Biot C. Plasmodium falciparum apicoplast drugs: targets or off-targets? Chem Rev 2011; 112:1269-83. [PMID: 22026508 DOI: 10.1021/cr200258w] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Cyrille Y Botté
- Laboratoire de Physiologie Cellulaire Végétale, UMR 5168, CNRS, CEA, INRA, Université Joseph Fourier, Grenoble, France
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Ekland EH, Schneider J, Fidock DA. Identifying apicoplast-targeting antimalarials using high-throughput compatible approaches. FASEB J 2011; 25:3583-93. [PMID: 21746861 DOI: 10.1096/fj.11-187401] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Malarial parasites have evolved resistance to all previously used therapies, and recent evidence suggests emerging resistance to the first-line artemisinins. To identify antimalarials with novel mechanisms of action, we have developed a high-throughput screen targeting the apicoplast organelle of Plasmodium falciparum. Antibiotics known to interfere with this organelle, such as azithromycin, exhibit an unusual phenotype whereby the progeny of drug-treated parasites die. Our screen exploits this phenomenon by assaying for "delayed death" compounds that exhibit a higher potency after two cycles of intraerythrocytic development compared to one. We report a primary assay employing parasites with an integrated copy of a firefly luciferase reporter gene and a secondary flow cytometry-based assay using a nucleic acid stain paired with a mitochondrial vital dye. Screening of the U.S. National Institutes of Health Clinical Collection identified known and novel antimalarials including kitasamycin. This inexpensive macrolide, used for agricultural applications, exhibited an in vitro IC(50) in the 50 nM range, comparable to the 30 nM activity of our control drug, azithromycin. Imaging and pharmacologic studies confirmed kitasamycin action against the apicoplast, and in vivo activity was observed in a murine malaria model. These assays provide the foundation for high-throughput campaigns to identify novel chemotypes for combination therapies to treat multidrug-resistant malaria.
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Affiliation(s)
- Eric H Ekland
- Department of Microbiology and Immunology, Columbia University College of Physicians and Surgeons, 701 W. 168th St., New York, NY 10032, USA.
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Swanton CJ, Mashhadi HR, Solomon KR, Afifi MM, Duke SO. Similarities between the discovery and regulation of pharmaceuticals and pesticides: in support of a better understanding of the risks and benefits of each. PEST MANAGEMENT SCIENCE 2011; 67:790-797. [PMID: 21520394 DOI: 10.1002/ps.2179] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Revised: 02/03/2011] [Accepted: 02/25/2011] [Indexed: 05/30/2023]
Abstract
An argument is presented by which the role of pharmaceuticals and pesticides can both be viewed in terms of contributing to human health. Comparisons are made in terms of discovery and development, regulatory policies and environmental and human impacts. Both technologies target particular biological functions, and in many cases they target similar molecular sites of action. Pharmaceuticals and pesticides undergo a similar registration process; however, both can enter the environment where they can have adverse effects on non-target organisms and, if misused, will have detrimental effects on human health or the environment. It is suggested that the risks associated with the two technologies are similar. The rejection of pesticides by the general public is based primarily on personal value systems and the uncertainty of risk management. It is concluded that plant and animal health are vital to maintaining human health, and that pesticides used in food production are, as with pharmaceuticals, a vital tool used to maintain human health.
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Affiliation(s)
- Clarence J Swanton
- Department of Plant Agriculture, University of Guelph, Guelph, Ontario, Canada.
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Vigueira PA, Paul KS. Requirement for acetyl-CoA carboxylase in Trypanosoma brucei is dependent upon the growth environment. Mol Microbiol 2011; 80:117-32. [PMID: 21306439 DOI: 10.1111/j.1365-2958.2011.07563.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Trypanosoma brucei, the causative agent of human African trypanosomiasis, possesses two fatty acid synthesis pathways: a major de novo synthesis pathway in the ER and a mitochondrial pathway. The 2-carbon donor for both pathways is malonyl-CoA, which is synthesized from acetyl-CoA by Acetyl-CoA carboxylase (ACC). Here, we show that T. brucei ACC shares the same enzyme architecture and moderate ∼ 30% identity with yeast and human ACCs. ACC is cytoplasmic and appears to be distributed throughout the cell in numerous puncta distinct from glycosomes and other organelles. ACC is active in both bloodstream and procyclic forms. Reduction of ACC activity by RNA interference (RNAi) resulted in a stage-specific phenotype. In procyclic forms, ACC RNAi resulted in 50-75% reduction in fatty acid elongation and a 64% reduction in growth in low-lipid media. In bloodstream forms, ACC RNAi resulted in a minor 15% decrease in fatty acid elongation and no growth defect in culture, even in low-lipid media. However, ACC RNAi did attenuate virulence in a mouse model of infection. Thus the requirement for ACC in T. brucei is dependent upon the growth environment in two different life cycle stages.
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Affiliation(s)
- Patrick A Vigueira
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA
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Zhang X, Wang S, Wang Y, Xia T, Chen J, Cai X. Differential enantioselectivity of quizalofop ethyl and its acidic metabolite: direct enantiomeric separation and assessment of multiple toxicological endpoints. JOURNAL OF HAZARDOUS MATERIALS 2011; 186:876-882. [PMID: 21159424 DOI: 10.1016/j.jhazmat.2010.11.081] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 10/24/2010] [Accepted: 11/21/2010] [Indexed: 05/30/2023]
Abstract
Transformation products usually differ in environmental and toxicological properties compared to the parent contaminants, thus causing potential and unknown environmental risks. To elucidate differential chiral recognition of the aryloxypropanoate herbicide quizalofop ethyl (QE) and its primary product (quizalofop acid, QA), their enantiomeric separation and toxicological impacts to two freshwater algae were investigated. Addition of trace water (0.02-0.08%, v/v) to the mobile phase selectively affected retention of analyte and induced simultaneous enantio-separation for the two compounds with intrinsical water-specific resolution mechanisms, although they both possessed a chiral center in the 2-position of propionates. In algal suspensions, QE was rapidly degraded to produce the acid metabolite (QA), and the product further declined, whereas a reduction of QA as starting compound did not occur. Uptake and/or transformation of QE and QA were found a lack of enantioselectivity and isomer inversion, while cellular membrane permeability, membrane potential and algal growth showed enantioselectivity to different extents. These results suggested the presence of receptor chirality that was involved in the toxicological processes but invalid for uptake and transformation. Therefore, quizalofop acid, identified as environmentally relevant contaminant associated with application of the herbicide, participated in the toxicological processes of the parent compound, and exhibited distinct toxicological and chromatographic retention properties.
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Affiliation(s)
- Xiaoxiang Zhang
- Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education), School of Environmental Science and Technology, Dalian University of Technology, Dalian, China
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Tipparaju SK, Muench SP, Mui EJ, Ruzheinikov SN, Lu JZ, Hutson SL, Kirisits MJ, Prigge ST, Roberts CW, Henriquez FL, Kozikowski AP, Rice DW, McLeod RL. Identification and development of novel inhibitors of Toxoplasma gondii enoyl reductase. J Med Chem 2010; 53:6287-300. [PMID: 20698542 DOI: 10.1021/jm9017724] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Toxoplasmosis causes significant morbidity and mortality, and yet available medicines are limited by toxicities and hypersensitivity. Because improved medicines are needed urgently, rational approaches were used to identify novel lead compounds effective against Toxoplasma gondii enoyl reductase (TgENR), a type II fatty acid synthase enzyme essential in parasites but not present in animals. Fifty-three compounds, including three classes that inhibit ENRs, were tested. Six compounds have antiparasite MIC(90)s < or = 6 microM without toxicity to host cells, three compounds have IC(90)s < 45 nM against recombinant TgENR, and two protect mice. To further understand the mode of inhibition, the cocrystal structure of one of the most promising candidate compounds in complex with TgENR has been determined to 2.7 A. The crystal structure reveals that the aliphatic side chain of compound 19 occupies, as predicted, space made available by replacement of a bulky hydrophobic residue in homologous bacterial ENRs by Ala in TgENR. This provides a paradigm, conceptual foundation, reagents, and lead compounds for future rational development and discovery of improved inhibitors of T. gondii.
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Affiliation(s)
- Suresh K Tipparaju
- Drug Discovery Program, Department of Medicinal Chemistry and Pharmacognosy, University of Illinois at Chicago, Chicago, Illinois, USA
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Recombinant yeast screen for new inhibitors of human acetyl-CoA carboxylase 2 identifies potential drugs to treat obesity. Proc Natl Acad Sci U S A 2010; 107:9093-8. [PMID: 20439761 DOI: 10.1073/pnas.1003721107] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Acetyl-CoA carboxylase (ACC) is a key enzyme of fatty acid metabolism with multiple isozymes often expressed in different eukaryotic cellular compartments. ACC-made malonyl-CoA serves as a precursor for fatty acids; it also regulates fatty acid oxidation and feeding behavior in animals. ACC provides an important target for new drugs to treat human diseases. We have developed an inexpensive nonradioactive high-throughput screening system to identify new ACC inhibitors. The screen uses yeast gene-replacement strains depending for growth on cloned human ACC1 and ACC2. In "proof of concept" experiments, growth of such strains was inhibited by compounds known to target human ACCs. The screen is sensitive and robust. Medium-size chemical libraries yielded new specific inhibitors of human ACC2. The target of the best of these inhibitors was confirmed with in vitro enzymatic assays. This compound is a new drug chemotype inhibiting human ACC2 with 2.8 muM IC(50) and having no effect on human ACC1 at 100 muM.
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Seeber F, Soldati-Favre D. Metabolic Pathways in the Apicoplast of Apicomplexa. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2010; 281:161-228. [DOI: 10.1016/s1937-6448(10)81005-6] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Garrison EM, Arrizabalaga G. Disruption of a mitochondrial MutS DNA repair enzyme homologue confers drug resistance in the parasite Toxoplasma gondii. Mol Microbiol 2009; 72:425-41. [PMID: 19291232 DOI: 10.1111/j.1365-2958.2009.06655.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
MutS homologues (MSHs) are critical components of the eukaryotic mismatch repair machinery. In addition to repairing mismatched DNA, mismatch repair enzymes are known in higher eukaryotes to directly signal cell cycle arrest and apoptosis in response to DNA-damaging agents. Accordingly, mammalian cells lacking certain MSHs are resistant to chemotherapeutic drugs. Interestingly, we have discovered that the disruption of TgMSH-1, an MSH in the pathogenic parasite, Toxoplasma gondii, confers drug resistance. Through a genetic selection for T. gondii mutants resistant to the antiparasitic drug monensin, we have isolated a strain that is resistant not only to monensin but also to salinomycin and the alkylating agent, methylnitrosourea. We have shown that this phenotype is due to the disruption of TgMSH-1 as the multidrug-resistance phenotype is complemented by a wild-type copy of TgMSH-1 and is recapitulated by a directed disruption of this gene in a wild-type strain. We have also shown that, unlike previously described MSHs involved in signalling, TgMSH-1 localizes to the parasite mitochondrion. These results provide the first example of a mitochondrial MSH that is involved in drug sensitivity and implicate the induction of mitochondrial stress as a mode of action of the widely used drug, monensin.
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Affiliation(s)
- Erin M Garrison
- Department of Microbiology, Molecular Biology and Biochemistry, University of Idaho, Moscow, ID 83844, USA
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McLeod R, Kieffer F, Sautter M, Hosten T, Pelloux H. Why prevent, diagnose and treat congenital toxoplasmosis? Mem Inst Oswaldo Cruz 2009; 104:320-44. [PMID: 19430661 PMCID: PMC2735102 DOI: 10.1590/s0074-02762009000200029] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2008] [Accepted: 10/20/2008] [Indexed: 11/21/2022] Open
Abstract
Evidence that prevention, diagnosis and treatment of toxoplasmosis is beneficial developed as follows: anti-parasitic agents abrogate Toxoplasma gondii tachyzoite growth, preventing destruction of infected, cultured, mammalian cells and cure active infections in experimental animals, including primates. They treat active infections in persons who are immune-compromised, limit destruction of retina by replicating parasites and thereby treat ocular toxoplasmosis and treat active infection in the fetus and infant. Outcomes of untreated congenital toxoplasmosis include adverse ocular and neurologic sequelae described in different countries and decades. Better outcomes are associated with treatment of infected infants throughout their first year of life. Shorter intervals between diagnosis and treatment in utero improve outcomes. A French approach for diagnosis and treatment of congenital toxoplasmosis in the fetus and infant can prevent toxoplasmosis and limit adverse sequelae. In addition, new data demonstrate that this French approach results in favorable outcomes with some early gestation infections. A standardized approach to diagnosis and treatment during gestation has not yet been applied generally in the USA. Nonetheless, a small, similar experience confirms that this French approach is feasible, safe, and results in favorable outcomes in the National Collaborative Chicago-based Congenital Toxoplasmosis Study cohort. Prompt diagnosis, prevention and treatment reduce adverse sequelae of congenital toxoplasmosis.
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Affiliation(s)
- Rima McLeod
- Department of Ophthalmology and Visual Sciences, Committees on Immunology, Genetics, Molecular Medicine, The College, University of Chicago, Chicago, IL 60637, USA.
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Abstract
Theileria parasites cause severe bovine disease and death in a large part of the world. These apicomplexan parasites possess a relic plastid (apicoplast), whose metabolic pathways include several promising drug targets. Putative inhibitors of these targets were screened, and we identified antiproliferative compounds that merit further characterization.
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Cai X, Liu W, Sheng G. Enantioselective degradation and ecotoxicity of the chiral herbicide diclofop in three freshwater alga cultures. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2008; 56:2139-2146. [PMID: 18318497 DOI: 10.1021/jf0728855] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Aryloxyphenoxypropanoates are a class of chiral herbicides. They have a pair of enantiomers, only the R(+) form of which is herbicidally active. Diclofop, the model compound of these herbicides, is commercialized as the racemate of the ester form, diclofop-methyl, consisting of a 1:1 mixture of the enantiomers. This study evaluated the enantioselectivity in aquatic toxicity and biodegradation of diclofop and diclofop-methyl. The herbicidally inactive S(-) enantiomers of both diclofop-methyl and diclofop were similar to or higher than the corresponding R(+) forms in toxicity to algae, depending on specific species. Although no enantiomeric conversion occurred for diclofop-methyl and diclofop, the difference in the enantioselective degradation of these herbicides observed in algae cultures suggested that their application forms were an important factor determining their enantioselective environmental behavior. The cell permeability and heat treatment of algae revealed that the enantioselective degradation of diclofop in algae cultures was governed primarily by the facilitated uptake by algae, whereas the enantioselective toxicity was primarily governed by the passive uptake. These results suggested that the acute toxicity test such as the 96 h EC 50 was insufficient to assess the ecological risk of chiral pesticides because of the differential degradation as well as possibly differential action sites of enantiomers. From this study, it was concluded that the enantioselective degradation and toxicity of chiral herbicides may result in their ecotoxicological effects being difficult to predict and that specific attention should thus be paid to currently used racemic pesticides as less active or inactive enantiomers may pose higher ecological risks.
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Affiliation(s)
- Xiyun Cai
- Research Center of Environmental Science, College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032, China
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Mui EJ, Schiehser GA, Milhous WK, Hsu H, Roberts CW, Kirisits M, Muench S, Rice D, Dubey JP, Fowble JW, Rathod PK, Queener SF, Liu SR, Jacobus DP, McLeod R. Novel triazine JPC-2067-B inhibits Toxoplasma gondii in vitro and in vivo. PLoS Negl Trop Dis 2008; 2:e190. [PMID: 18320016 PMCID: PMC2254147 DOI: 10.1371/journal.pntd.0000190] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2007] [Accepted: 01/16/2008] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND AND METHODOLOGY Toxoplasma gondii causes substantial morbidity, mortality, and costs for healthcare in the developed and developing world. Current medicines are not well tolerated and cause hypersensitivity reactions. The dihydrotriazine JPC-2067-B (4, 6-diamino-1, 2-dihydro-2, 2-dimethyl-1-(3'(2-chloro-, 4-trifluoromethoxyphenoxy)propyloxy)-1, 3, 5-triazine), which inhibits dihydrofolate reductase (DHFR), is highly effective against Plasmodium falciparum, Plasmodium vivax, and apicomplexans related to T. gondii. JPC-2067-B is the primary metabolite of the orally active biguanide JPC-2056 1-(3'-(2-chloro-4-trifluoromethoxyphenyloxy)propyl oxy)- 5-isopropylbiguanide, which is being advanced to clinical trials for malaria. Efficacy of the prodrug JPC-2056 and the active metabolite JPC-2067-B against T. gondii and T. gondii DHFR as well as toxicity toward mammalian cells were tested. PRINCIPAL FINDINGS AND CONCLUSIONS Herein, we found that JPC-2067-B is highly effective against T. gondii. We demonstrate that JPC-2067-B inhibits T. gondii growth in culture (IC50 20 nM), inhibits the purified enzyme (IC50 6.5 nM), is more efficacious than pyrimethamine, and is cidal in vitro. JPC-2067-B administered parenterally and the orally administered pro-drug (JPC-2056) are also effective against T. gondii tachyzoites in vivo. A molecular model of T. gondii DHFR-TS complexed with JPC-2067-B was developed. We found that the three main parasite clonal types and isolates from South and Central America, the United States, Canada, China, and Sri Lanka have the same amino acid sequences preserving key binding sites for the triazine. SIGNIFICANCE JPC-2056/JPC-2067-B have potential to be more effective and possibly less toxic treatments for toxoplasmosis than currently available medicines.
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Affiliation(s)
- Ernest J. Mui
- Department of Ophthalmology and Visual Science, University of Chicago, Chicago, Illinois, United States of America
| | - Guy A. Schiehser
- Jacobus Pharmaceutical Company, Inc., Princeton, New Jersey, United States of America
| | - Wilbur K. Milhous
- Walter Reed Army Institute for Research, Silver Spring, Maryland, United States of America
| | - Honghue Hsu
- Jacobus Pharmaceutical Company, Inc., Princeton, New Jersey, United States of America
| | - Craig W. Roberts
- Department of Immunology, Strathclyde Institute for Biomedical Sciences, University of Strathclyde, Scotland, United Kingdom
| | - Michael Kirisits
- Department of Ophthalmology and Visual Science, University of Chicago, Chicago, Illinois, United States of America
| | - Stephen Muench
- Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, England, United Kingdom
| | - David Rice
- Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, England, United Kingdom
| | - J. P. Dubey
- United States Department of Agriculture, Agricultural Research Services, Animal and Natural Resources Institute, Animal Parasitic Diseases Laboratory, Beltsville, Maryland, United States of America
| | - Joseph W. Fowble
- Department of Chemistry, University of Washington, Seattle, Washington, United States of America
| | - Pradipsinh K. Rathod
- Department of Chemistry, University of Washington, Seattle, Washington, United States of America
| | - Sherry F. Queener
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Susan R. Liu
- Department of Ophthalmology and Visual Science, University of Chicago, Chicago, Illinois, United States of America
| | - David P. Jacobus
- Jacobus Pharmaceutical Company, Inc., Princeton, New Jersey, United States of America
| | - Rima McLeod
- Department of Ophthalmology and Visual Science, University of Chicago, Chicago, Illinois, United States of America
- Department of Pediatrics, Committee on Molecular Medicines, Genetics, and Immunology and The College, University of Chicago, Chicago, Illinois, United States of America
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Botté C, Saïdani N, Mondragon R, Mondragón M, Isaac G, Mui E, McLeod R, Dubremetz JF, Vial H, Welti R, Cesbron-Delauw MF, Mercier C, Maréchal E. Subcellular localization and dynamics of a digalactolipid-like epitope in Toxoplasma gondii. J Lipid Res 2008; 49:746-62. [PMID: 18182683 DOI: 10.1194/jlr.m700476-jlr200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Toxoplasma gondii is a unicellular parasite characterized by unique extracellular and intracellular membrane compartments. The lipid composition of subcellular membranes has not been determined, limiting our understanding of lipid homeostasis, control, and trafficking, a series of processes involved in pathogenesis. In addition to a mitochondrion, Toxoplasma contains a plastid called the apicoplast. The occurrence of a plastid raised the question of the presence of chloroplast galactolipids. Using three independent rabbit and rat antibodies against digalactosyldiacylglycerol (DGDG) from plant chloroplasts, we detected a class of Toxoplasma lipids harboring a digalactolipid-like epitope (DGLE). Immunolabeling characterization supports the notion that the DGLE polar head is similar to that of DGDG. Mass spectrometry analyses indicated that dihexosyl lipids having various hydrophobic moieties (ceramide, diacylglycerol, and acylalkylglycerol) might react with anti-DGDG, but we cannot exclude the possibility that more complex dihexosyl-terminated lipids might also be immunolabeled. DGLE localization was analyzed by immunofluorescence and immunoelectron microscopy and confirmed by subcellular fractionation. No immunolabeling of the apicoplast could be observed. DGLE was scattered in pellicle membrane domains in extracellular tachyzoites and was relocalized to the anterior tip of the cell upon invasion in an actin-dependent manner, providing insights on a possible role in pathogenetic processes. DGLE was detected in other Apicomplexa (i.e., Neospora, Plasmodium, Babesia, and Cryptosporidium).
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Affiliation(s)
- Cyrille Botté
- Unité Mixte de Recherche 5168, Centre National de la Recherche Scientifique-Commissariat à l'Energie, Institut de Recherches en Technologies et Sciences pour le Vivant, 38058 Grenoble, France
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Welti R, Mui E, Sparks A, Wernimont S, Isaac G, Kirisits M, Roth M, Roberts CW, Botté C, Maréchal E, McLeod R. Lipidomic analysis of Toxoplasma gondii reveals unusual polar lipids. Biochemistry 2007; 46:13882-90. [PMID: 17988103 PMCID: PMC2576749 DOI: 10.1021/bi7011993] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Analysis of the polar lipids of Toxoplasma gondii by electrospray ionization tandem mass spectrometry provides a detailed picture of the lipid molecular species of this parasitic protozoan. Most notably, T. gondii contains a relatively high level, estimated to about 2% of the total polar lipid, of ceramide phosphoethanolamine. The ceramide phosphoethanolamine has a fatty amide profile with only 16- and 18-carbon species. Compared with the host fibroblasts in which it was grown, T. gondii also has higher levels of phosphatidylcholine but lower levels of sphingomyelin and phosphatidylserine. Analysis at the molecular species level indicated that T. gondii has greater amounts of shorter-chain fatty acid in its polar lipid molecular species than the host fibroblasts. Shorter-chain fatty acids with a combined total of 30 or fewer acyl carbons make up 21% of Toxoplasma's, but only 3% of the host's, diacyl phosphatidylcholine. Furthermore, diacyl phosphatidylcholine with two saturated acyl chains with 12, 14, or 16 carbons make up over 11% of parasite phosphatidylcholine but less than 3% of the host phosphatidylcholine molecular species. The distinctive T. gondii tachyzoite lipid profile may be particularly suited to the function of parasitic membranes and the interaction of the parasite with the host cell and the host's immune system. Combined with T. gondii genomic data, these lipidomic data will assist in elucidation of metabolic pathways for lipid biosynthesis in this important human pathogen.
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Affiliation(s)
- Ruth Welti
- Kansas Lipidomics Research Center, Division of Biology, Kansas State University, Manhattan, Kansas 66506, USA
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Bajsa J, Singh K, Nanayakkara D, Duke SO, Rimando AM, Evidente A, Tekwani BL. A survey of synthetic and natural phytotoxic compounds and phytoalexins as potential antimalarial compounds. Biol Pharm Bull 2007; 30:1740-4. [PMID: 17827731 DOI: 10.1248/bpb.30.1740] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The apicomplexan parasites pathogens such as Plasmodium spp. possess an apicoplast, a plastid organelle similar to those of plants. The apicoplast has some essential plant-like metabolic pathways and processes, making these parasites susceptible to inhibitors of these functions. The main objective of this paper is to determine if phytotoxins with plastid target sites are more likely to be good antiplasmodial compounds than are those with other modes of action. The antiplasmodial activities of some compounds with established phytotoxic action were determined in vitro on a chloroquine (CQ) sensitive (D6, Sierra Leone) strain of Plasmodium falciparum. In this study, we provide in vitro activities of almost 50 such compounds, as well as a few phytoalexins against P. falciparum. Endothall, anisomycin, and cerulenin had sufficient antiplasmodial action to be considered as new lead antimalarial structures. Some derivatives of fusicoccin possessed markedly improved antiplasmodial action than the parent compound. Our results suggest that phytotoxins with plastid targets may not necessarily be better antiplasmodials than those that act at other molecular sites. The herbicides, phytotoxins and the phytoalexins reported here with significant antiplasmodial activity may be useful probes for identification of new antimalarial drug targets and may also be used as new lead structures for new antiplasmodial drug discovery.
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Affiliation(s)
- Joanna Bajsa
- National Center for Natural Products Research, School of Pharmacy, University of Mississippi, MS 38677, U.S.A.
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