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Flores-Huerta N, Pacheco-Yépez J, Sánchez-Monroy V, Rosales-Hernández MC, Silva-Olivares A, Serrano-Luna J, Shibayama M. The MPO system participates actively in the formation of an oxidative environment produced by neutrophils and activates the antioxidant mechanism of Naegleria fowleri. J Leukoc Biol 2020; 108:895-908. [PMID: 32531828 DOI: 10.1002/jlb.4ma0520-565rr] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 05/13/2020] [Accepted: 05/24/2020] [Indexed: 12/23/2022] Open
Abstract
Naegleria fowleri produces a fatal disease called primary amebic meningoencephalitis (PAM), which is characterized by an extensive inflammatory reaction in the CNS. It is known that the immune response is orchestrated mainly by neutrophils, which activate several defense mechanisms in the host, including phagocytosis, the release of different enzymes such as myeloperoxidase (MPO), and the production of neutrophil extracellular traps. However, the mechanisms by which amoebas evade the neutrophil response are still unknown. In this study, we analyzed the ability of N. fowleri to respond to the stress exerted by MPO. Interestingly, after the interaction of trophozoites with neutrophils, the amoeba viability was not altered; however, ultrastructural changes were observed. To analyze the influence of MPO against N. fowleri and its participation in free radical production, we evaluated its enzymatic activity, expression, and localization with and without the specific 4-aminobenzoic acid hydrazide inhibitor. The production of oxidizing molecules is the principal mechanism used by neutrophils to eliminate pathogens. In this context, we demonstrated an increase in the production of NO, superoxide anion, and reactive oxygen species; in addition, the overexpression of several antioxidant enzymes present in the trophozoites was quantified. The findings strongly suggest that N. fowleri possesses antioxidant machinery that is activated in response to an oxidative environment, allowing it to evade the neutrophil-mediated immune response, which may contribute to the establishment of PAM.
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Affiliation(s)
- Nadia Flores-Huerta
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies of the National Polytechnic Institute, Mexico City, Mexico
| | - Judith Pacheco-Yépez
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina, Instituto Politécnico Nacional, Ciudad de México, México
| | - Virginia Sánchez-Monroy
- Laboratorio de Biomedicina Molecular, Escuela Nacional de Medicina y Homeopatía, Instituto Politécnico Nacional, Ciudad de México, México
| | - Martha Cecilia Rosales-Hernández
- Laboratorio de Biofísica y Biocatálisis, Sección de Estudios de Posgrado e Investigación Escuela Superior de Medicina, Instituto Politécnico Nacional, Ciudad de México, México
| | - Angélica Silva-Olivares
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies of the National Polytechnic Institute, Mexico City, Mexico
| | - Jesús Serrano-Luna
- Department of Cell Biology, Center for Research and Advanced Studies of the National Polytechnic Institute, Mexico City, Mexico
| | - Mineko Shibayama
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies of the National Polytechnic Institute, Mexico City, Mexico
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Martínez-Castillo M, Pacheco-Yepez J, Flores-Huerta N, Guzmán-Téllez P, Jarillo-Luna RA, Cárdenas-Jaramillo LM, Campos-Rodríguez R, Shibayama M. Flavonoids as a Natural Treatment Against Entamoeba histolytica. Front Cell Infect Microbiol 2018; 8:209. [PMID: 29988403 PMCID: PMC6024094 DOI: 10.3389/fcimb.2018.00209] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 06/05/2018] [Indexed: 02/05/2023] Open
Abstract
Over the past 20 years, gastrointestinal infections in developing countries have been a serious health problem and are the second leading cause of morbidity among all age groups. Among pathogenic protozoans that cause diarrheal disease, the parasite Entamoeba histolytica produces amebic colitis as well as the most frequent extra-intestinal lesion, an amebic liver abscess (ALA). Usually, intestinal amebiasis and ALA are treated with synthetic chemical compounds (iodoquinol, paromomycin, diloxanide furoate, and nitroimidazoles). Metronidazole is the most common treatment for amebiasis. Although the efficacy of nitroimidazoles in killing amebas is known, the potential resistance of E. histolytica to this treatment is a concern. In addition, controversial studies have reported that metronidazole could induce mutagenic effects and cerebral toxicity. Therefore, natural and safe alternative drugs against this parasite are needed. Flavonoids are natural polyphenolic compounds. Flavonoids depend on malonyl-CoA and phenylalanine to be synthesized. Several flavonoids have anti-oxidant and anti-microbial properties. Since the 1990s, several works have focused on the identification and purification of different flavonoids with amebicidal effects, such as, -(-)epicatechin, kaempferol, and quercetin. In this review, we investigated the effects of flavonoids that have potential amebicidal activity and that can be used as complementary and/or specific therapeutic strategies against E. histolytica trophozoites. Interestingly, it was found that these natural compounds can induce morphological changes in the amebas, such as chromatin condensation and cytoskeletal protein re-organization, as well as the upregulation and downregulation of fructose-1,6-bisphosphate aldolase, glyceraldehyde-phosphate dehydrogenase, and pyruvate:ferredoxin oxidoreductase (enzymes of the glycolytic pathway). Although the specific molecular targets, bioavailability, route of administration, and doses of some of these natural compounds need to be determined, flavonoids represent a very promising and innocuous strategy that should be considered for use against E. histolytica in the era of microbial drug resistance.
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Affiliation(s)
- Moisés Martínez-Castillo
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México, Mexico
| | - Judith Pacheco-Yepez
- Sección de Estudios de Posgrado e Investigación, Instituto Politécnico Nacional, Escuela Superior de Medicina, Ciudad de México, Mexico
| | - Nadia Flores-Huerta
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México, Mexico
| | - Paula Guzmán-Téllez
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México, Mexico
| | - Rosa A Jarillo-Luna
- Sección de Estudios de Posgrado e Investigación, Instituto Politécnico Nacional, Escuela Superior de Medicina, Ciudad de México, Mexico
| | - Luz M Cárdenas-Jaramillo
- Coordinación de Morfología, Departamento de Formación Básica Disciplinaria, Instituto Politécnico Nacional, Escuela Superior de Medicina, Ciudad de México, Mexico
| | - Rafael Campos-Rodríguez
- Sección de Estudios de Posgrado e Investigación, Instituto Politécnico Nacional, Escuela Superior de Medicina, Ciudad de México, Mexico
| | - Mineko Shibayama
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México, Mexico
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Jeelani G, Nozaki T. Entamoeba thiol-based redox metabolism: A potential target for drug development. Mol Biochem Parasitol 2016; 206:39-45. [PMID: 26775086 DOI: 10.1016/j.molbiopara.2016.01.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 01/08/2016] [Accepted: 01/09/2016] [Indexed: 02/06/2023]
Abstract
Amebiasis is an intestinal infection widespread throughout the world caused by the human pathogen Entamoeba histolytica. Metronidazole has been a drug of choice against amebiasis for decades despite its low efficacy against asymptomatic cyst carriers and emergence of resistance in other protozoa with similar anaerobic metabolism. Therefore, identification and characterization of specific targets is urgently needed to design new therapeutics for improved treatment against amebiasis. Toward this goal, thiol-dependent redox metabolism is of particular interest. The thiol-dependent redox metabolism in E. histolytica consists of proteins including peroxiredoxin, rubrerythrin, Fe-superoxide dismutase, flavodiiron proteins, NADPH: flavin oxidoreductase, and amino acids including l-cysteine, S-methyl-l-cysteine, and thioprolines (thiazolidine-4-carboxylic acids). E. histolytica completely lacks glutathione and its metabolism, and l-cysteine is the major intracellular low molecular mass thiol. Moreover, this parasite possesses a functional thioredoxin system consisting of thioredoxin and thioredoxin reductase, which is a ubiquitous oxidoreductase system with antioxidant and redox regulatory roles. In this review, we summarize and highlight the thiol-based redox metabolism and its control mechanisms in E. histolytica, in particular, the features of the system unique to E. histolytica, and its potential use for drug development against amebiasis.
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Affiliation(s)
- Ghulam Jeelani
- Department of Parasitology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan
| | - Tomoyoshi Nozaki
- Department of Parasitology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku, Tokyo 162-8640, Japan; Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan.
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Trypanothione: A unique bis-glutathionyl derivative in trypanosomatids. Biochim Biophys Acta Gen Subj 2013; 1830:3199-216. [DOI: 10.1016/j.bbagen.2013.01.013] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 01/11/2013] [Accepted: 01/16/2013] [Indexed: 11/21/2022]
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Gretes MC, Poole LB, Karplus PA. Peroxiredoxins in parasites. Antioxid Redox Signal 2012; 17:608-33. [PMID: 22098136 PMCID: PMC3373223 DOI: 10.1089/ars.2011.4404] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 11/18/2011] [Indexed: 12/11/2022]
Abstract
SIGNIFICANCE Parasite survival and virulence relies on effective defenses against reactive oxygen and nitrogen species produced by the host immune system. Peroxiredoxins (Prxs) are ubiquitous enzymes now thought to be central to such defenses and, as such, have potential value as drug targets and vaccine antigens. RECENT ADVANCES Plasmodial and kinetoplastid Prx systems are the most extensively studied, yet remain inadequately understood. For many other parasites our knowledge is even less well developed. Through parasite genome sequencing efforts, however, the key players are being discovered and characterized. Here we describe what is known about the biochemistry, regulation, and cell biology of Prxs in parasitic protozoa, helminths, and fungi. At least one Prx is found in each parasite with a sequenced genome, and a notable theme is the common patterns of expression, localization, and functionality among sequence-similar Prxs in related species. CRITICAL ISSUES The nomenclature of Prxs from parasites is in a state of disarray, causing confusion and making comparative inferences difficult. Here we introduce a systematic Prx naming convention that is consistent between organisms and informative about structural and evolutionary relationships. FUTURE DIRECTIONS The new nomenclature should stimulate the crossfertilization of ideas among parasitologists and with the broader redox research community. The diverse parasite developmental stages and host environments present complex systems in which to explore the variety of roles played by Prxs, with a view toward parlaying what is learned into novel therapies and vaccines that are urgently needed.
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Affiliation(s)
- Michael C. Gretes
- Department of Biochemistry & Biophysics, Oregon State University, Corvallis, Oregon
| | - Leslie B. Poole
- Department of Biochemistry, Wake Forest University School of Medicine, Winston-Salem, North Carolina
| | - P. Andrew Karplus
- Department of Biochemistry & Biophysics, Oregon State University, Corvallis, Oregon
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Arias DG, Carranza PG, Lujan HD, Iglesias AA, Guerrero SA. Immunolocalization and enzymatic functional characterization of the thioredoxin system in Entamoeba histolytica. Free Radic Biol Med 2008; 45:32-9. [PMID: 18394433 DOI: 10.1016/j.freeradbiomed.2008.03.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2007] [Revised: 02/18/2008] [Accepted: 03/02/2008] [Indexed: 10/22/2022]
Abstract
The components of the redox metabolism in Entamoeba histolytica have been recently revisited by Arias et al. (Free Radic. Biol. Med. 42:1496-1505; 2007), after the identification and characterization of a thioredoxin-linked system. The present work deals with studies performed for a better understanding of the localization and identification of different components of the redox machinery present in the parasite. The gene encoding for amoebic thioredoxin 8 was cloned and the recombinant protein typified as having properties similar to those of thioredoxin 41. The ability of these thioredoxins and the specific reductase to assemble a system utilizing NADPH to metabolize hydroperoxides in association with a peroxiredoxin has been kinetically characterized. The peroxiredoxin behaved as a typical 2 cysteine enzyme, exhibiting a ping-pong mechanism with hyperbolic saturation kinetics for thioredoxin 8 (K(m)=3.8 microM), thioredoxin 41 (K(m)=3.1 microM), and tert-butyl hydroperoxide (K(m) about 35 microM). Moreover, the tandem system involving thioredoxin reductase and either thioredoxin proved to be operative for reducing low molecular weight disulfides, including putative physiological substrates as cystine and oxidized trypanothione. Thioredoxin reductase and thioredoxin 41 (by association also the functional redox system) have been immunolocalized underlying the plasma membrane in Entamoeba histolytica cells. These findings suggest an important role for the metabolic pathway involving thioredoxin as a redox interchanger, which could be critical for the maintenance and virulence of the parasite when exposed to highly toxic reactive oxygen species.
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Affiliation(s)
- Diego G Arias
- Laboratorio de Bioquímica Microbiana, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Ciudad Universitaria-Paraje El Pozo, 3000 Santa Fe, Argentina
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Krauth-Siegel RL, Comini MA. Redox control in trypanosomatids, parasitic protozoa with trypanothione-based thiol metabolism. Biochim Biophys Acta Gen Subj 2008; 1780:1236-48. [PMID: 18395526 DOI: 10.1016/j.bbagen.2008.03.006] [Citation(s) in RCA: 291] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2008] [Revised: 02/26/2008] [Accepted: 03/11/2008] [Indexed: 01/09/2023]
Abstract
Trypanosomes and leishmania, the causative agents of several tropical diseases, possess a unique redox metabolism which is based on trypanothione. The bis(glutathionyl)spermidine is the central thiol that delivers electrons for the synthesis of DNA precursors, the detoxification of hydroperoxides and other trypanothione-dependent pathways. Many of the reactions are mediated by tryparedoxin, a distant member of the thioredoxin protein family. Trypanothione is kept reduced by the parasite-specific flavoenzyme trypanothione reductase. Since glutathione reductases and thioredoxin reductases are missing, the reaction catalyzed by trypanothione reductase represents the only connection between the NADPH- and the thiol-based redox metabolisms. Thus, cellular thiol redox homeostasis is maintained by the biosynthesis and reduction of trypanothione. Nearly all proteins of the parasite-specific trypanothione metabolism have proved to be essential.
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8
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Arias DG, Gutierrez CE, Iglesias AA, Guerrero SA. Thioredoxin-linked metabolism in Entamoeba histolytica. Free Radic Biol Med 2007; 42:1496-505. [PMID: 17448896 DOI: 10.1016/j.freeradbiomed.2007.02.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2006] [Revised: 01/15/2007] [Accepted: 02/08/2007] [Indexed: 01/08/2023]
Abstract
Entamoeba histolytica, an intestinal protozoan that is the causative agent of amoebiasis, is exposed to elevated amounts of highly toxic reactive oxygen species during tissue invasion. In this work, we report the molecular cloning, from E. histolytica genomic DNA, of the genes ehtrxr and ehtrx41, respectively coding for thioredoxin reductase (EhTRXR) and thioredoxin (EhTRX41). The genes were expressed in Escherichia coli cells, and the corresponding recombinant proteins were purified and characterized. EhTRXR catalyzed the NADPH (Km=4.5 microM)-dependent reduction of 5,5'-dithiobis-(2-nitrobenzoic) acid (Km=1.7 mM), EhTRX41 (Km=3.6 microM), and E. coli TRX (Km=4.6 microM). EhTRXR and EhTRX41 could be assayed as a functional redox pair that, together with peroxiredoxin, mediate the NADPH-dependent reduction of hydrogen peroxide and tert-butyl hydroperoxide. It is proposed that this detoxifying system could be operative in vivo. Results add value to the genome project information and advise reconsideration of key metabolic pathways operating in E. histolytica.
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Affiliation(s)
- Diego G Arias
- Laboratorio de Bioquímica Microbiana, Facultad de Bioquímica y Ciencias Biológicas, Universidad Nacional del Litoral, Ciudad Universitaria-Paraje El Pozo, 3000 Santa Fe, Argentina
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9
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Ondarza RN, Hurtado G, Tamayo E, Iturbe A, Hernández E. Naegleria fowleri: A free-living highly pathogenic amoeba contains trypanothione/trypanothione reductase and glutathione/glutathione reductase systems. Exp Parasitol 2006; 114:141-6. [DOI: 10.1016/j.exppara.2006.03.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2005] [Revised: 02/28/2006] [Accepted: 03/03/2006] [Indexed: 10/24/2022]
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10
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Ondarza RN, Iturbe A, Hernández E. The effects by neuroleptics, antimycotics and antibiotics on disulfide reducing enzymes from the human pathogens Acanthamoeba polyphaga and Naegleria fowleri. Exp Parasitol 2006; 115:41-7. [PMID: 16806188 DOI: 10.1016/j.exppara.2006.05.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2006] [Revised: 05/18/2006] [Accepted: 05/19/2006] [Indexed: 12/01/2022]
Abstract
This paper discusses the effects of two neuroleptic agents, chlorpromazine and trifluoperazine; three antimycotics, amphotericin B, ketoconazole and miconazole and four antibiotics, pentamidine, rifampicin, mepacrine and metronidazole on the NADPH-dependent disulfide reducing enzymes cystine reductase (CysR), glutathione reductase (GR) trypanothione reductase (TR) and a putative disulfide reductase for compound X in Acanthamoeba polyphaga from the human pathogens A. polyphaga and Naegleria fowleri. Against A. polyphaga, all nine drugs studied had the capacity to inhibit the putative disulfide reductase from the trophozoites at a concentration of 32microg/ml during a 24h incubation and they were: the neuroleptics trifluoperazine (100%) and chlorpromazine (96%), the antimycotics miconazole (89%) ketoconazole (81%) and amphotericin B, (53%) and the antibiotics pentamidine (89%), rifampicin (64%), mepacrine (57%) and metronidazole (14%). Only six of the nine drugs simultaneously inhibited CysR, GR and the putative disulfide reductase. In N. fowleri, the most potent inhibitors of trypanothione reductase were amphotericin B and miconazole which inhibited 100% at a concentration of 32microg/ml during the 24h incubation followed by the neuroleptics trifluoperazine (92%) and chlorpromazine (80%) and the antibiotic mepacrine (70%). All these also inhibited CysR and GR from the trophozoites other than mepacrine which inhibited only CysR and TR. Ketoconazole, rifampicin (which did not affect CysR), pentamidine and metronidazole had opposite effects since they did not inhibit but increased the amount of the three thiols.
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Affiliation(s)
- Raúl N Ondarza
- Center of Research on Infectious Diseases, National Institute of Public Health, Cuernavaca, Mor. 62508, Mexico.
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Abstract
Hydroperoxide metabolism in diverse pathogens is reviewed under consideration of involved enzymes as potential drug targets. The common denominator of the peroxidase systems of Trypanosoma, Leishmania, Plasmodium, and Mycobacterium species is the use of NAD(P)H to reduce hydroperoxides including peroxynitrite via a flavin-containing disulfide reductase, a thioredoxin (Trx)-related protein and a peroxidase that operates with thiol catalysis. In Plasmodium falciparum, thioredoxin- and glutathione dependent systems appear to be linked via glutaredoxin and plasmoredoxin to terminal thioredoxin peroxidases belonging to both, the peroxiredoxin (Prx) and glutathione peroxidase (GPx) family. In Mycobacterium tuberculosis, a catalase-type peroxidase is complemented by the typical 2-C-Prx AhpC that, in contrast to most bacteria, is reduced by TrxC, and an atypical 2-C-Prx reduced by TrxB or C. A most complex variation of the scheme is found in trypanosomatids, where the unique redox metabolite trypanothione reduces the thioredoxin-related tryparedoxin, which fuels Prx- and GPx-type peroxidases as well as ribonucleotide reductase. In Trypanosoma brucei and Leishmania donovani the system has been shown to be essential for viability and virulence by inversed genetics. It is concluded that optimum efficacy can be expected from inhibitors of the most upstream components of the redox cascades. For trypanosomatids attractive validated drug targets are trypanothione reductase and trypanothione synthetase; for mycobacteria thioredoxin reductase appears most appealing, while in Plasmodium simultaneous inhibition of both the thioredoxin and the glutathione pathway appears advisable to avoid mutual substitution in co-substrate supply to the peroxidases. Financial and organisational needs to translate the scientific progress into applicable drugs are discussed under consideration of the socio-economic impact of the addressed diseases.
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Affiliation(s)
- Timo Jaeger
- MOLISA GmbH, Molecular Links Sachsen-Anhalt, Universitätsplatz 2, D-39106 Magdeburg, Germany.
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Nozaki T, Ali V, Tokoro M. Sulfur-Containing Amino Acid Metabolism in Parasitic Protozoa. ADVANCES IN PARASITOLOGY 2005; 60:1-99. [PMID: 16230102 DOI: 10.1016/s0065-308x(05)60001-2] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Sulfur-containing amino acids play indispensable roles in a wide variety of biological activities including protein synthesis, methylation, and biosynthesis of polyamines and glutathione. Biosynthesis and catabolism of these amino acids need to be carefully regulated to achieve the requirement of the above-mentioned activities and also to eliminate toxicity attributable to the amino acids. Genome-wide analyses of enzymes involved in the metabolic pathways of sulfur-containing amino acids, including transsulfuration, sulfur assimilatory de novo cysteine biosynthesis, methionine cycle, and degradation, using genome databases available from a variety of parasitic protozoa, reveal remarkable diversity between protozoan parasites and their mammalian hosts. Thus, the sulfur-containing amino acid metabolic pathways are a rational target for the development of novel chemotherapeutic and prophylactic agents against diseases caused by protozoan parasites. These pathways also demonstrate notable heterogeneity among parasites, suggesting that the metabolism of sulfur-containing amino acids reflects the diversity of parasitism among parasite species, and probably influences their biology and pathophysiology such as virulence competence and stress defense.
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Affiliation(s)
- Tomoyoshi Nozaki
- Department of Parasitology, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma, 371-8511, Japan
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