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Suganuma K, Mochabo KM, Chemuliti JK, Kiyoshi K, Noboru I, Kawazu SI. Ascofuranone antibiotic is a promising trypanocidal drug for nagana. Onderstepoort J Vet Res 2024; 91:e1-e6. [PMID: 38426744 PMCID: PMC11005941 DOI: 10.4102/ojvr.v91i1.2115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 11/22/2023] [Accepted: 11/28/2023] [Indexed: 03/02/2024] Open
Abstract
Trypanosomosis is a disease complex which affects both humans and animals in sub-Saharan Africa, transmitted by the tsetse fly and distributed within the tsetse belt of Africa. But some trypanosome species, for example, Trypanosoma brucei evansi, T. vivax, T. theileri and T. b. equiperdum are endemic outside the tsetse belt of Africa transmitted by biting flies, for example, Tabanus and Stomoxys, or venereal transmission, respectively. Trypanocidal drugs remain the principal method of animal trypanosomosis control in most African countries. However, there is a growing concern that their effectiveness may be severely curtailed by widespread drug resistance. A minimum number of six male cattle calves were recruited for the study. They were randomly grouped into two (T. vivax and T. congolense groups) of three calves each. One calf per group served as a control while two calves were treatment group. They were inoculated with 105 cells/mL parasites in phosphate buffered solution (PBS) in 2 mL. When parasitaemia reached 1 × 107.8 cells/mL trypanosomes per mL in calves, treatment was instituted with 20 mL (25 mg/kg in 100 kg calf) ascofuranone (AF) for treatment calves, while the control ones were administered a placebo (20 mL PBS) intramuscularly. This study revealed that T. vivax was successfully cleared by AF but the T. congolense group was not cleared effectively.Contribution: There is an urgent need to develop new drugs which this study sought to address. It is suggested that the AF compound can be developed further to be a sanative drug for T. vivax in non-tsetse infested areas like South Americas.
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Affiliation(s)
- Keisuke Suganuma
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro.
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Gao H, Zhou L, Zhang P, Wang Y, Qian X, Liu Y, Wu G. Filamentous Fungi-Derived Orsellinic Acid-Sesquiterpene Meroterpenoids: Fungal Sources, Chemical Structures, Bioactivities, and Biosynthesis. PLANTA MEDICA 2023; 89:1110-1124. [PMID: 37225133 DOI: 10.1055/a-2099-4932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Fungi-derived polyketide-terpenoid hybrids are important meroterpenoid natural products that possess diverse structure scaffolds with a broad spectrum of bioactivities. Herein, we focus on an ever-increasing group of meroterpenoids, orsellinic acid-sesquiterpene hybrids comprised of biosynthetic start unit orsellinic acid coupling to a farnesyl group or/and its modified cyclic products. The review entails the search of China National Knowledge Infrastructure (CNKI), Web of Science, Science Direct, Google Scholar, and PubMed databases up to June 2022. The key terms include "orsellinic acid", "sesquiterpene", "ascochlorin", "ascofuranone", and "Ascochyta viciae", which are combined with the structures of "ascochlorin" and "ascofuranone" drawn by the Reaxys and Scifinder databases. In our search, these orsellinic acid-sesquiterpene hybrids are mainly produced by filamentous fungi. Ascochlorin was the first compound reported in 1968 and isolated from filamentous fungus Ascochyta viciae (synonym: Acremonium egyptiacum; Acremonium sclerotigenum); to date, 71 molecules are discovered from various filamentous fungi inhabiting in a variety of ecological niches. As typical representatives of the hybrid molecules, the biosynthetic pathway of ascofuranone and ascochlorin are discussed. The group of meroterpenoid hybrids exhibits a broad arrange of bioactivities, as highlighted by targeting hDHODH (human dihydroorotate dehydrogenase) inhibition, antitrypanosomal, and antimicrobial activities. This review summarizes the findings related to the structures, fungal sources, bioactivities, and their biosynthesis from 1968 to June 2022.
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Affiliation(s)
- Hua Gao
- College of Chemical Engineering, Nanjing Forestry University, Nanjing, People's Republic of China
| | - Luning Zhou
- Key Laboratory of Marine Drugs, Chinese Ministry of Education; School of Medicine and Pharmacy, Ocean University of China, Qingdao, Shandong, People's Republic of China
| | - Peng Zhang
- Department of Medicinal Chemistry, University of Utah, Salt Lake City, Utah, United States
| | - Ying Wang
- College of Chemical Engineering, Nanjing Forestry University, Nanjing, People's Republic of China
| | - Xuan Qian
- College of Chemical Engineering, Nanjing Forestry University, Nanjing, People's Republic of China
| | - Yujia Liu
- College of Chemical Engineering, Nanjing Forestry University, Nanjing, People's Republic of China
| | - Guangwei Wu
- College of Chemical Engineering, Nanjing Forestry University, Nanjing, People's Republic of China
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Jeelani G, Balogun EO, Husain A, Nozaki T. Glycerol biosynthetic pathway plays an essential role in proliferation and antioxidative defense in the human enteric protozoan parasite Entamoeba histolytica. Sci Rep 2023; 13:14596. [PMID: 37669981 PMCID: PMC10480196 DOI: 10.1038/s41598-023-40670-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 08/16/2023] [Indexed: 09/07/2023] Open
Abstract
Amebiasis is caused by the protozoan parasite Entamoeba histolytica. Treatment options other than metronidazole and its derivatives are few, and their low efficacy against asymptomatic cyst carriers, and experimental evidence of resistance in vitro justify the discovery/repurposing campaign for new drugs against amebiasis. Global metabolic responses to oxidative stress and cysteine deprivation by E. histolytica revealed glycerol metabolism may represent a rational target for drug development. In this study using 14C-labelled glucose, only 11% of the total glucose taken up by E. histolytica trophozoites is incorporated to lipids. To better understand the role of glycerol metabolism in this parasite, we focused on characterizing two important enzymes, glycerol kinase (GK) and glycerol 3-phosphate dehydrogenase (G3PDH). Recombinant GK was biochemically characterized in detail, while G3PDH was not due to failure of protein expression and purification. GK revealed novel characteristics and unprecedented kinetic properties in reverse reaction. Gene silencing revealed that GK is essential for optimum growth, whereas G3PDH is not. Gene silencing of G3PDH caused upregulated GK expression, while that of GK resulted in upregulation of antioxidant enzymes as shown by RNA-seq analysis. Although the precise molecular link between GK and the upregulation of antioxidant enzymes was not demonstrated, the observed increase in antioxidant enzyme expression upon GK gene silencing suggests a potential connection between GK and the cellular response to oxidative stress. Together, these results provide the first direct evidence of the biological importance and coordinated regulation of the glycerol metabolic pathways for proliferation and antioxidative defense in E. histolytica, justifying the exploitation of these enzymes as future drug targets.
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Affiliation(s)
- Ghulam Jeelani
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Emmanuel Oluwadare Balogun
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
- Department of Biochemistry, Ahmadu Bello University, Zaria, Nigeria
| | - Afzal Husain
- Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, India
| | - Tomoyoshi Nozaki
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
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4
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Recent advances on the piezoelectric, electrochemical, and optical biosensors for the detection of protozoan pathogens. Trends Analyt Chem 2022. [DOI: 10.1016/j.trac.2022.116803] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Araki Y, Shinohara Y, Hara S, Sato A, Sakaue R, Gomi K, Kita K, Ito K. Heterologous production of ascofuranone and ilicicolin A in Aspergillus sojae. J GEN APPL MICROBIOL 2022; 68:10-16. [PMID: 35418536 DOI: 10.2323/jgam.2021.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Ascofuranone and its precursor, ilicicolin A, are secondary metabolites with various pharmacological activities that are produced by Acremonium egyptiacum. In particular, ascofuranone strongly inhibits trypanosome alternative oxidase and represents a potential drug candidate against African trypanosomiasis. However, difficulties associated with industrial production of ascofuranone by A. egyptiacum, specifically the co-production of ascochlorin, which inhibits mammalian respiratory chain complex III at low concentrations, has precluded its widespread application. Therefore, in this study, ascofuranone biosynthetic genes (ascA-E and H-J) were heterologously expressed in Aspergillus sojae, which produced very low-levels of endogenous secondary metabolites under conventional culture conditions. As a result, although we obtained transformants producing both ilicicolin A and ascofuranone, they were produced only when an adequate concentration of chloride ions was added to the medium. In addition, we succeeded in increasing the production of ilicicolin A, by enhancing the expression of the rate-determining enzyme AscD, using a multi-copy integration system. The heterologous expression approach described here afforded the production of both ascofuranone and ilicicolin A, allowing for their development as therapeutics.
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Affiliation(s)
- Yasuko Araki
- Research and Development Division, Kikkoman Corporation
| | | | - Seiichi Hara
- Research and Development Division, Kikkoman Corporation
| | - Atsushi Sato
- Research and Development Division, Kikkoman Corporation
| | | | - Keiko Gomi
- Research and Development Division, Kikkoman Corporation
| | - Kiyoshi Kita
- School of Tropical Medicine and Global Health, Nagasaki University.,Department of Host-Defense Biochemistry, Institute of Tropical Medicine
| | - Kotaro Ito
- Research and Development Division, Kikkoman Corporation
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Chan-Bacab MJ, Reyes-Estebanez MM, Camacho-Chab JC, Ortega-Morales BO. Microorganisms as a Potential Source of Molecules to Control Trypanosomatid Diseases. Molecules 2021; 26:molecules26051388. [PMID: 33806654 PMCID: PMC7962016 DOI: 10.3390/molecules26051388] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/25/2021] [Accepted: 03/01/2021] [Indexed: 11/17/2022] Open
Abstract
Trypanosomatids are the causative agents of leishmaniasis and trypanosomiasis, which affect about 20 million people in the world’s poorest countries, leading to 95,000 deaths per year. They are often associated with malnutrition, weak immune systems, low quality housing, and population migration. They are generally recognized as neglected tropical diseases. New drugs against these parasitic protozoa are urgently needed to counteract drug resistance, toxicity, and the high cost of commercially available drugs. Microbial bioprospecting for new molecules may play a crucial role in developing a new generation of antiparasitic drugs. This article reviews the current state of the available literature on chemically defined metabolites of microbial origin that have demonstrated antitrypanosomatid activity. In this review, bacterial and fungal metabolites are presented; they originate from a range of microorganisms, including cyanobacteria, heterotrophic bacteria, and filamentous fungi. We hope to provide a useful overview for future research to identify hits that may become the lead compounds needed to accelerate the discovery of new drugs against trypanosomatids.
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Rosell-Hidalgo A, Young L, Moore AL, Ghafourian T. QSAR and molecular docking for the search of AOX inhibitors: a rational drug discovery approach. J Comput Aided Mol Des 2020; 35:245-260. [PMID: 33289903 PMCID: PMC7904559 DOI: 10.1007/s10822-020-00360-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 11/12/2020] [Indexed: 11/24/2022]
Abstract
The alternative oxidase (AOX) is a monotopic diiron carboxylate protein that catalyses the oxidation of ubiquinol and the reduction of oxygen to water. Although a number of AOX inhibitors have been discovered, little is still known about the ligand–protein interaction and essential chemical characteristics of compounds required for a potent inhibition. Furthermore, owing to the rapidly growing resistance to existing inhibitors, new compounds with improved potency and pharmacokinetic properties are urgently required. In this study we used two computational approaches, ligand–protein docking and Quantitative Structure–Activity Relationships (QSAR) to investigate binding of AOX inhibitors to the enzyme and the molecular characteristics required for inhibition. Docking studies followed by protein–ligand interaction fingerprint (PLIF) analysis using the AOX enzyme and the mutated analogues revealed the importance of the residues Leu 122, Arg 118 and Thr 219 within the hydrophobic cavity. QSAR analysis, using stepwise regression analysis with experimentally obtained IC50 values as the response variable, resulted in a multiple regression model with a good prediction accuracy. The model highlighted the importance of the presence of hydrogen bonding acceptor groups on specific positions of the aromatic ring of ascofuranone derivatives, acidity of the compounds, and a large linker group on the compounds on the inhibitory effect of AOX.
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Affiliation(s)
- Alicia Rosell-Hidalgo
- Department of Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK
| | - Luke Young
- Department of Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK
| | - Anthony L Moore
- Department of Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK
| | - Taravat Ghafourian
- Department of Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK. .,School of Life Sciences, Faculty of Creative Arts, Technologies and Science, University of Bedfordshire, Luton, Bedfordshire, LU1 3JU, UK.
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Abstract
Covering: up to July 2020Fungal meroterpenoid cyclases are a recently discovered emerging family of membrane-integrated, non-canonical terpene cyclases. They catalyze the conversion of hybrid isoprenic precursors towards complex scaffolds and are therefore of great importance in the structure diversification in meroterpenoid biosynthesis. The products of these pathways exhibit intriguing molecular scaffolds and highly potent bioactivities, making them privileged structures from Nature and attractive candidates for drug development or industrial applications. This review will provide a comprehensive and comparative view on fungal meroterpenoid cyclases, their intriguing chemistries and importance for the scaffold formation step towards polycyclic meroterpenoid natural products.
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Affiliation(s)
- Lena Barra
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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Abstract
The evaluation of mitochondrial functionality is critical to interpret most biological data at the (eukaryotic) cellular level. For example, metabolism, cell cycle, epigenetic regulation, cell death mechanisms, autophagy, differentiation, and response redox imbalance are dependent on the mitochondrial state. In case of parasitic organisms, such as trypanosomatids, it is very often important to have information on mitochondrial functionality in order to assess the mechanisms of actions of drugs being proposed for therapy. In this chapter we present a set of methods that together allow to evaluate with some precision the mitochondrial functionality in Trypanosoma cruzi and Trypanosoma brucei. We discuss how to determine O2 consumption, mitochondrial inner membrane potential, ATP production, and the endogenous production of reactive oxygen species.
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Affiliation(s)
- Mayke Bezerra Alencar
- Laboratory of Biochemistry of Tryps - LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Richard Bruno Marcel Moreira Girard
- Laboratory of Biochemistry of Tryps - LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Ariel Mariano Silber
- Laboratory of Biochemistry of Tryps - LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil.
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Araki Y, Awakawa T, Matsuzaki M, Cho R, Matsuda Y, Hoshino S, Shinohara Y, Yamamoto M, Kido Y, Inaoka DK, Nagamune K, Ito K, Abe I, Kita K. Complete biosynthetic pathways of ascofuranone and ascochlorin in Acremonium egyptiacum. Proc Natl Acad Sci U S A 2019; 116:8269-8274. [PMID: 30952781 PMCID: PMC6486709 DOI: 10.1073/pnas.1819254116] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Ascofuranone (AF) and ascochlorin (AC) are meroterpenoids produced by various filamentous fungi, including Acremonium egyptiacum (synonym: Acremonium sclerotigenum), and exhibit diverse physiological activities. In particular, AF is a promising drug candidate against African trypanosomiasis and a potential anticancer lead compound. These compounds are supposedly biosynthesized through farnesylation of orsellinic acid, but the details have not been established. In this study, we present all of the reactions and responsible genes for AF and AC biosyntheses in A. egyptiacum, identified by heterologous expression, in vitro reconstruction, and gene deletion experiments with the aid of a genome-wide differential expression analysis. Both pathways share the common precursor, ilicicolin A epoxide, which is processed by the membrane-bound terpene cyclase (TPC) AscF in AC biosynthesis. AF biosynthesis branches from the precursor by hydroxylation at C-16 by the P450 monooxygenase AscH, followed by cyclization by a membrane-bound TPC AscI. All genes required for AC biosynthesis (ascABCDEFG) and a transcriptional factor (ascR) form a functional gene cluster, whereas those involved in the late steps of AF biosynthesis (ascHIJ) are present in another distantly located cluster. AF is therefore a rare example of fungal secondary metabolites requiring multilocus biosynthetic clusters, which are likely to be controlled by the single regulator, AscR. Finally, we achieved the selective production of AF in A. egyptiacum by genetically blocking the AC biosynthetic pathway; further manipulation of the strain will lead to the cost-effective mass production required for the clinical use of AF.
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Affiliation(s)
- Yasuko Araki
- Research and Development Division, Kikkoman Corporation, Noda City, Chiba 278-0037, Japan
| | - Takayoshi Awakawa
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo 113-8657, Japan
| | - Motomichi Matsuzaki
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan;
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki City, Nagasaki 852-8523, Japan
- Department of Parasitology, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Rihe Cho
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Yudai Matsuda
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Shotaro Hoshino
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Yasutomo Shinohara
- Research and Development Division, Kikkoman Corporation, Noda City, Chiba 278-0037, Japan
| | - Masaichi Yamamoto
- Institute of Mitochondrial Science Company, Ltd., Tokyo 176-0025, Japan
| | - Yasutoshi Kido
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
- Institute of Mitochondrial Science Company, Ltd., Tokyo 176-0025, Japan
- Department of Parasitology, Graduate School of Medicine, Osaka City University, Osaka 545-8585, Japan
- Research Center for Infectious Disease Sciences, Graduate School of Medicine, Osaka City University, Osaka 545-8585, Japan
| | - Daniel Ken Inaoka
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki City, Nagasaki 852-8523, Japan
- Department of Host-Defense Biochemistry, Institute of Tropical Medicine, Nagasaki University, Nagasaki 852-8523, Japan
| | - Kisaburo Nagamune
- Department of Parasitology, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
| | - Kotaro Ito
- Research and Development Division, Kikkoman Corporation, Noda City, Chiba 278-0037, Japan
| | - Ikuro Abe
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan;
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo 113-8657, Japan
| | - Kiyoshi Kita
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki City, Nagasaki 852-8523, Japan
- Department of Host-Defense Biochemistry, Institute of Tropical Medicine, Nagasaki University, Nagasaki 852-8523, Japan
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Cerone M, Uliassi E, Prati F, Ebiloma GU, Lemgruber L, Bergamini C, Watson DG, de A. M. Ferreira T, Roth Cardoso GSH, Soares Romeiro LA, de Koning HP, Bolognesi ML. Discovery of Sustainable Drugs for Neglected Tropical Diseases: Cashew Nut Shell Liquid (CNSL)-Based Hybrids Target Mitochondrial Function and ATP Production in Trypanosoma brucei. ChemMedChem 2019; 14:621-635. [PMID: 30664325 PMCID: PMC6686156 DOI: 10.1002/cmdc.201800790] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Indexed: 02/02/2023]
Abstract
In the search for effective and sustainable drugs for human African trypanosomiasis (HAT), we developed hybrid compounds by merging the structural features of quinone 4 (2-phenoxynaphthalene-1,4-dione) with those of phenolic constituents from cashew nut shell liquid (CNSL). CNSL is a waste product from cashew nut processing factories, with great potential as a source of drug precursors. The synthesized compounds were tested against Trypanosoma brucei brucei, including three multidrug-resistant strains, T. congolense, and a human cell line. The most potent activity was found against T. b. brucei, the causative agent of HAT. Shorter-chain derivatives 20 (2-(3-(8-hydroxyoctyl)phenoxy)-5-methoxynaphthalene-1,4-dione) and 22 (5-hydroxy-2-(3-(8-hydroxyoctyl)phenoxy)naphthalene-1,4-dione) were more active than 4, displaying rapid micromolar trypanocidal activity, and no human cytotoxicity. Preliminary studies probing their mode of action on trypanosomes showed ATP depletion, followed by mitochondrial membrane depolarization and mitochondrion ultrastructural damage. This was accompanied by reactive oxygen species production. We envisage that such compounds, obtained from a renewable and inexpensive material, might be promising bio-based sustainable hits for anti-trypanosomatid drug discovery.
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Affiliation(s)
- Michela Cerone
- Department of Pharmacy and BiotechnologyAlma Mater Studiorum – University of BolognaVia Belmeloro 640126BolognaItaly
- Institute of Infection, Immunity and InflammationUniversity of GlasgowGBRC, University PlaceG12 8ATGlasgowUK
| | - Elisa Uliassi
- Department of Pharmacy and BiotechnologyAlma Mater Studiorum – University of BolognaVia Belmeloro 640126BolognaItaly
| | - Federica Prati
- Department of Pharmacy and BiotechnologyAlma Mater Studiorum – University of BolognaVia Belmeloro 640126BolognaItaly
| | - Godwin U. Ebiloma
- Institute of Infection, Immunity and InflammationUniversity of GlasgowGBRC, University PlaceG12 8ATGlasgowUK
- Department of BiochemistryFaculty of Natural SciencesKogi State UniversityP.M.B. 1008AnyigbaKogi StateNigeria
| | - Leandro Lemgruber
- Institute of Infection, Immunity and InflammationUniversity of GlasgowGBRC, University PlaceG12 8ATGlasgowUK
- Wellcome Trust Centre for Molecular ParasitologyInstitute of Infection, Immunity and InflammationUniversity of GlasgowGBRC, University PlaceG12 8ATGlasgowUK
| | - Christian Bergamini
- Department of Pharmacy and BiotechnologyAlma Mater Studiorum – University of BolognaVia Belmeloro 640126BolognaItaly
| | - David G. Watson
- Strathclyde Institute of Pharmacy and Biomedical SciencesUniversity of Strathclyde16 Richmond StreetG1 1XQGlasgowUK
| | - Thais de A. M. Ferreira
- Department of Pharmacy, Health Sciences FacultyUniversity of BrasíliaCampus Universitário Darcy Ribeiro70910-900BrasíliaDFBrazil
| | | | - Luiz A. Soares Romeiro
- Department of Pharmacy, Health Sciences FacultyUniversity of BrasíliaCampus Universitário Darcy Ribeiro70910-900BrasíliaDFBrazil
| | - Harry P. de Koning
- Institute of Infection, Immunity and InflammationUniversity of GlasgowGBRC, University PlaceG12 8ATGlasgowUK
| | - Maria Laura Bolognesi
- Department of Pharmacy and BiotechnologyAlma Mater Studiorum – University of BolognaVia Belmeloro 640126BolognaItaly
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12
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Shiba T, Inaoka DK, Takahashi G, Tsuge C, Kido Y, Young L, Ueda S, Balogun EO, Nara T, Honma T, Tanaka A, Inoue M, Saimoto H, Harada S, Moore AL, Kita K. Insights into the ubiquinol/dioxygen binding and proton relay pathways of the alternative oxidase. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:375-382. [PMID: 30910528 DOI: 10.1016/j.bbabio.2019.03.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 03/20/2019] [Indexed: 12/21/2022]
Abstract
The alternative oxidase (AOX) is a monotopic diiron carboxylate protein which catalyzes the four-electron reduction of dioxygen to water by ubiquinol. Although we have recently determined the crystal structure of Trypanosoma brucei AOX (TAO) in the presence and absence of ascofuranone (AF) derivatives (which are potent mixed type inhibitors) the mechanism by which ubiquinol and dioxygen binds to TAO remain inconclusive. In this article, ferulenol was identified as the first competitive inhibitor of AOX which has been used to probe the binding of ubiquinol. Surface plasmon resonance reveals that AF is a quasi-irreversible inhibitor of TAO whilst ferulenol binding is completely reversible. The structure of the TAO-ferulenol complex, determined at 2.7 Å, provided insights into ubiquinol binding and has also identified a potential dioxygen molecule bound in a side-on conformation to the diiron center for the first time.
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Affiliation(s)
- Tomoo Shiba
- Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Sakyo-ku, Matsugasaki, Kyoto 606-8585, Japan.
| | - Daniel Ken Inaoka
- School of Tropical Medicine and Global Health, Nagasaki University, Sakamoto 1-12-4, Nagasaki 852-8523, Japan; Department of Host-Defense Biochemistry, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Sakamoto 1-12-4, Nagasaki 852-8523, Japan; Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Hongo 7-3-1, Tokyo 113-0033, Japan.
| | - Gen Takahashi
- Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Sakyo-ku, Matsugasaki, Kyoto 606-8585, Japan
| | - Chiaki Tsuge
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Hongo 7-3-1, Tokyo 113-0033, Japan
| | - Yasutoshi Kido
- School of Tropical Medicine and Global Health, Nagasaki University, Sakamoto 1-12-4, Nagasaki 852-8523, Japan; Department of Parasitology, Graduate School of Medicine, Osaka City University, Abeno-ku, Asahimachi 1-4-3, Osaka 545-8585, Japan
| | - Luke Young
- Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK
| | - Satoshi Ueda
- Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Sakyo-ku, Matsugasaki, Kyoto 606-8585, Japan
| | - Emmanuel Oluwadare Balogun
- Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Sakyo-ku, Matsugasaki, Kyoto 606-8585, Japan; Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Hongo 7-3-1, Tokyo 113-0033, Japan; Department of Biochemistry, Ahmadu Bello University, Zaria 2222, Nigeria
| | - Takeshi Nara
- Department of Molecular and Cellular Parasitology, Juntendo University School of Medicine, Bunkyo-ku, Hongo 2-1-1, Tokyo, 113-8421, Japan
| | - Teruki Honma
- Systems and Structural Biology Center, RIKEN, Tsurumi, Suehiro 1-7-22, Yokohama, Kanagawa 230-0045, Japan
| | - Akiko Tanaka
- Systems and Structural Biology Center, RIKEN, Tsurumi, Suehiro 1-7-22, Yokohama, Kanagawa 230-0045, Japan
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Hongo 7-3-1, Tokyo 113-0033, Japan
| | - Hiroyuki Saimoto
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Koyamacho-Minami 4, Tottori 680-8552, Japan
| | - Shigeharu Harada
- Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Sakyo-ku, Matsugasaki, Kyoto 606-8585, Japan
| | - Anthony L Moore
- Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Falmer, Brighton, BN1 9QG, UK
| | - Kiyoshi Kita
- School of Tropical Medicine and Global Health, Nagasaki University, Sakamoto 1-12-4, Nagasaki 852-8523, Japan; Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Hongo 7-3-1, Tokyo 113-0033, Japan; Department of Host-Defense Biochemistry, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Sakamoto 1-12-4, Nagasaki 852-8523, Japan
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13
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Ebiloma GU, Balogun EO, Cueto-Díaz EJ, de Koning HP, Dardonville C. Alternative oxidase inhibitors: Mitochondrion-targeting as a strategy for new drugs against pathogenic parasites and fungi. Med Res Rev 2019; 39:1553-1602. [PMID: 30693533 DOI: 10.1002/med.21560] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 11/07/2018] [Accepted: 12/08/2018] [Indexed: 12/11/2022]
Abstract
The alternative oxidase (AOX) is a ubiquitous terminal oxidase of plants and many fungi, catalyzing the four-electron reduction of oxygen to water alongside the cytochrome-based electron transfer chain. Unlike the classical electron transfer chain, however, the activity of AOX does not generate adenosine triphosphate but has functions such as thermogenesis and stress response. As it lacks a mammalian counterpart, it has been investigated intensely in pathogenic fungi. However, it is in African trypanosomes, which lack cytochrome-based respiration in their infective stages, that trypanosome alternative oxidase (TAO) plays the central and essential role in their energy metabolism. TAO was validated as a drug target decades ago and among the first inhibitors to be identified was salicylhydroxamic acid (SHAM), which produced the expected trypanocidal effects, especially when potentiated by coadministration with glycerol to inhibit anaerobic energy metabolism as well. However, the efficacy of this combination was too low to be of practical clinical use. The antibiotic ascofuranone (AF) proved a much stronger TAO inhibitor and was able to cure Trypanosoma vivax infections in mice without glycerol and at much lower doses, providing an important proof of concept milestone. Systematic efforts to improve the SHAM and AF scaffolds, aided with the elucidation of the TAO crystal structure, provided detailed structure-activity relationship information and reinvigorated the drug discovery effort. Recently, the coupling of mitochondrion-targeting lipophilic cations to TAO inhibitors has dramatically improved drug targeting and trypanocidal activity while retaining target protein potency. These developments appear to have finally signposted the way to preclinical development of TAO inhibitors.
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Affiliation(s)
- Godwin U Ebiloma
- Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Kyoto, Japan.,Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Emmanuel O Balogun
- Department of Biochemistry, Ahmadu Bello University, Zaria, Nigeria.,Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan
| | | | - Harry P de Koning
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
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14
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Meco-Navas A, Ebiloma GU, Martín-Domínguez A, Martínez-Benayas I, Cueto-Díaz EJ, Alhejely AS, Balogun EO, Saito M, Matsui M, Arai N, Shiba T, Harada S, de Koning HP, Dardonville C. SAR of 4-Alkoxybenzoic Acid Inhibitors of the Trypanosome Alternative Oxidase. ACS Med Chem Lett 2018; 9:923-928. [PMID: 30258542 DOI: 10.1021/acsmedchemlett.8b00282] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 07/31/2018] [Indexed: 11/30/2022] Open
Abstract
The SAR of 4-hydroxybenzaldehyde inhibitors of the trypanosome alternative oxidase (TAO), a critical enzyme for the respiration of bloodstream forms of trypanosomes, was investigated. Replacing the aldehyde group with a methyl ester resulted in a 10-fold increase in TAO inhibition and activity against T. brucei. Remarkably, two analogues containing the 2-hydroxy-6-methyl scaffold (9e and 16e) displayed single digit nanomolar TAO inhibition, which constitute the most potent 4-alkoxybenzoic acid derivatives described to date. 9e was 50-times more potent against TAO and 10-times more active against T. brucei compared to its benzaldehyde analogue 1. The farnesyl derivative 16e was as potent a TAO inhibitor as ascofuranone with IC50 = 3.1 nM. Similar to ascofuranone derivatives, the 2-hydroxy and 6-methyl groups seemed essential for low nanomolar TAO inhibition of acid derivatives, suggesting analogous binding interactions with the TAO active site.
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Affiliation(s)
- Alejandro Meco-Navas
- Instituto de Química Médica, IQM-CSIC, Juan de la Cierva 3, E-28006 Madrid, Spain
| | - Godwin U. Ebiloma
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Ana Martín-Domínguez
- Instituto de Química Médica, IQM-CSIC, Juan de la Cierva 3, E-28006 Madrid, Spain
| | | | | | - Amani Saud Alhejely
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | | | - Machi Saito
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Miho Matsui
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Natsumi Arai
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Tomoo Shiba
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Shigeharu Harada
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Harry P. de Koning
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
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15
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Ebiloma GU, Ayuga TD, Balogun EO, Gil LA, Donachie A, Kaiser M, Herraiz T, Inaoka DK, Shiba T, Harada S, Kita K, de Koning HP, Dardonville C. Inhibition of trypanosome alternative oxidase without its N-terminal mitochondrial targeting signal (ΔMTS-TAO) by cationic and non-cationic 4-hydroxybenzoate and 4-alkoxybenzaldehyde derivatives active against T. brucei and T. congolense. Eur J Med Chem 2018; 150:385-402. [PMID: 29544150 DOI: 10.1016/j.ejmech.2018.02.075] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 02/22/2018] [Accepted: 02/23/2018] [Indexed: 11/28/2022]
Abstract
African trypanosomiasis is a neglected parasitic disease that is still of great public health relevance, and a severe impediment to agriculture in endemic areas. The pathogens possess certain unique metabolic features that can be exploited for the development of new drugs. Notably, they rely on an essential, mitochondrially-localized enzyme, Trypanosome Alternative Oxidase (TAO) for their energy metabolism, which is absent in the mammalian hosts and therefore an attractive target for the design of safe drugs. In this study, we cloned, expressed and purified the physiologically relevant form of TAO, which lacks the N-terminal 25 amino acid mitochondrial targeting sequence (ΔMTS-TAO). A new class of 32 cationic and non-cationic 4-hydroxybenzoate and 4-alkoxybenzaldehyde inhibitors was designed and synthesized, enabling the first structure-activity relationship studies on ΔMTS-TAO. Remarkably, we obtained compounds with enzyme inhibition values (IC50) as low as 2 nM, which were efficacious against wild type and multidrug-resistant strains of T. brucei and T. congolense. The inhibitors 13, 15, 16, 19, and 30, designed with a mitochondrion-targeting lipophilic cation tail, displayed trypanocidal potencies comparable to the reference drugs pentamidine and diminazene, and showed no cross-resistance with the critical diamidine and melaminophenyl arsenical classes of trypanocides. The cationic inhibitors 15, 16, 19, 20, and 30 were also much more selective (900 - 344,000) over human cells than the non-targeted neutral derivatives (selectivity >8-fold). A preliminary in vivo study showed that modest doses of 15 and 16 reduced parasitaemia of mice infected with T. b. rhodesiense (STIB900). These compounds represent a promising new class of potent and selective hits against African trypanosomes.
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Affiliation(s)
- Godwin U Ebiloma
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom; Department of Biochemistry, Kogi State University, Anyigba, Nigeria
| | - Teresa Díaz Ayuga
- Instituto de Química Médica, IQM-CSIC, Juan de la Cierva 3, E-28006 Madrid, Spain
| | - Emmanuel O Balogun
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Japan; Department of Biochemistry, Ahmadu Bello University, Zaria 2222, Nigeria
| | - Lucía Abad Gil
- Instituto de Química Médica, IQM-CSIC, Juan de la Cierva 3, E-28006 Madrid, Spain
| | - Anne Donachie
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Marcel Kaiser
- Swiss Tropical and Public Health Institute, Socinstrasse, 57, CH-4002 Basel, Switzerland
| | - Tomás Herraiz
- Instituto de Ciencia y Tecnología de Alimentos y Nutrición, ICTAN-CSIC, Juan de la Cierva 3, E-28006 Madrid, Spain
| | - Daniel K Inaoka
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Japan; School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, 852-8523, Japan
| | - Tomoo Shiba
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Shigeharu Harada
- Department of Applied Biology, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Kiyoshi Kita
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Japan; School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, 852-8523, Japan
| | - Harry P de Koning
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom.
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16
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West RA, O'Doherty OG, Askwith T, Atack J, Beswick P, Laverick J, Paradowski M, Pennicott LE, Rao SPS, Williams G, Ward SE. African trypanosomiasis: Synthesis & SAR enabling novel drug discovery of ubiquinol mimics for trypanosome alternative oxidase. Eur J Med Chem 2017; 141:676-689. [PMID: 29107420 PMCID: PMC5697954 DOI: 10.1016/j.ejmech.2017.09.067] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 09/13/2017] [Accepted: 09/29/2017] [Indexed: 11/24/2022]
Abstract
African trypanosomiasis is a parasitic disease affecting 5000 humans and millions of livestock animals in sub-Saharan Africa every year. Current treatments are limited, difficult to administer and often toxic causing long term injury or death in many patients. Trypanosome alternative oxidase is a parasite specific enzyme whose inhibition by the natural product ascofuranone (AF) has been shown to be curative in murine models. Until now synthetic methods to AF analogues have been limited, this has restricted both understanding of the key structural features required for binding and also how this chemotype could be developed to an effective therapeutic agent. The development of 3 amenable novel synthetic routes to ascofuranone-like compounds is described. The SAR generated around the AF chemotype is reported with correlation to the inhibition of T. b. brucei growth and corresponding selectivity in cytotoxic assessment in mammalian HepG2 cell lines. These methods allow access to greater synthetic diversification and have enabled the synthesis of compounds that have and will continue to facilitate further optimisation of the AF chemotype into a drug-like lead. Synthesis of ascofuranone like inhibitors of trypanosome alternative oxidase. Structure activity relationships of trypanosome alternative oxidase inhibitors. Correlation of trypanosome alternative oxidase inhibition and T. b. brucei growth.
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Affiliation(s)
- Ryan A West
- Sussex Drug Discovery Centre, University of Sussex, Brighton, BN1 9QJ, UK
| | - Oran G O'Doherty
- Sussex Drug Discovery Centre, University of Sussex, Brighton, BN1 9QJ, UK
| | - Trevor Askwith
- Sussex Drug Discovery Centre, University of Sussex, Brighton, BN1 9QJ, UK
| | - John Atack
- Sussex Drug Discovery Centre, University of Sussex, Brighton, BN1 9QJ, UK; Medicines Discovery Institute, Cardiff University, Park Place, Cardiff, CF10 3AT, UK
| | - Paul Beswick
- Sussex Drug Discovery Centre, University of Sussex, Brighton, BN1 9QJ, UK
| | - Jamie Laverick
- Sussex Drug Discovery Centre, University of Sussex, Brighton, BN1 9QJ, UK
| | - Michael Paradowski
- Sussex Drug Discovery Centre, University of Sussex, Brighton, BN1 9QJ, UK
| | - Lewis E Pennicott
- Sussex Drug Discovery Centre, University of Sussex, Brighton, BN1 9QJ, UK
| | - Srinivasa P S Rao
- Novartis Institutes for Tropical Diseases, 5300 Chiron Way, California, 94608-2916, USA
| | - Gareth Williams
- Sussex Drug Discovery Centre, University of Sussex, Brighton, BN1 9QJ, UK
| | - Simon E Ward
- Sussex Drug Discovery Centre, University of Sussex, Brighton, BN1 9QJ, UK; Medicines Discovery Institute, Cardiff University, Park Place, Cardiff, CF10 3AT, UK.
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17
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Balogun EO, Inaoka DK, Shiba T, Tokuoka SM, Tokumasu F, Sakamoto K, Kido Y, Michels PAM, Watanabe YI, Harada S, Kita K. Glycerol kinase of African trypanosomes possesses an intrinsic phosphatase activity. Biochim Biophys Acta Gen Subj 2017; 1861:2830-2842. [PMID: 28778484 DOI: 10.1016/j.bbagen.2017.07.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 07/28/2017] [Accepted: 07/29/2017] [Indexed: 11/30/2022]
Abstract
BACKGROUND In general, glycerol kinases (GKs) are transferases that catalyze phospho group transfer from ATP to glycerol, and the mechanism was suggested to be random bi-bi. The reverse reaction i.e. phospho transfer from glycerol 3-phosphate (G3P) to ADP is only physiologically feasible by the African trypanosome GK. In contrast to other GKs the mechanism of Trypanosoma brucei gambiense glycerol kinase (TbgGK) was shown to be in an ordered fashion, and proceeding via autophosphorylation. From the unique reaction mechanism of TbgGK, we envisaged its potential to possess phosphatase activity in addition to being a kinase. METHODS Our hypothesis was tested by spectrophotometric and LC-MS/MS analyses using paranitrophenyl phosphate (pNPP) and TbgGK's natural substrate, G3P respectively. Furthermore, protein X-ray crystallography and site-directed mutagenesis were performed to examine pNPP binding, catalytic residues, and the possible reaction mechanism. RESULTS In addition to its widely known and expected phosphotransferase (class II) activity, TbgGK can efficiently facilitate the hydrolytic cleavage of phosphoric anhydride bonds (a class III property). This phosphatase activity followed the classical Michaelis-Menten pattern and was competitively inhibited by ADP and G3P, suggesting a common catalytic site for both activities (phosphatase and kinase). The structure of the TGK-pNPP complex, and structure-guided mutagenesis implicated T276 to be important for the catalysis. Remarkably, we captured a crystallographic molecular snapshot of the phosphorylated T276 reaction intermediate. CONCLUSION We conclude that TbgGK has both kinase and phosphatase activities. GENERAL SIGNIFICANCE This is the first report on a bifunctional kinase/phosphatase enzyme among members of the sugar kinase family.
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Affiliation(s)
- Emmanuel Oluwadare Balogun
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; Department of Biochemistry, Ahmadu Bello University, Zaria 2222, Nigeria.
| | - Daniel Ken Inaoka
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; School of Tropical Medicine and Global Health, Nagasaki University 1-12-4, Sakamoto, Nagasaki 852-8523, Japan
| | - Tomoo Shiba
- Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585, Japan
| | - Suzumi M Tokuoka
- Department of Lipidomics, Faculty of Medicine, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, Japan
| | - Fuyuki Tokumasu
- Department of Lipidomics, Faculty of Medicine, The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, Japan
| | - Kimitoshi Sakamoto
- Faculty of Agriculture and Life Science, Hirosaki University, Hirosaki 036-8561, Japan
| | - Yasutoshi Kido
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Paul A M Michels
- Centre for Immunity, Infection and Evolution and Centre for Translational and Chemical Biology, School of Biological Sciences, University of Edinburgh, King's Buildings, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK
| | - Yoh-Ichi Watanabe
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Shigeharu Harada
- Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585, Japan
| | - Kiyoshi Kita
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; School of Tropical Medicine and Global Health, Nagasaki University 1-12-4, Sakamoto, Nagasaki 852-8523, Japan.
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18
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Park JY, Chung TW, Jeong YJ, Kwak CH, Ha SH, Kwon KM, Abekura F, Cho SH, Lee YC, Ha KT, Magae J, Chang YC, Kim CH. Ascofuranone inhibits lipopolysaccharide-induced inflammatory response via NF-kappaB and AP-1, p-ERK, TNF-α, IL-6 and IL-1β in RAW 264.7 macrophages. PLoS One 2017; 12:e0171322. [PMID: 28207754 PMCID: PMC5313137 DOI: 10.1371/journal.pone.0171322] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 01/19/2017] [Indexed: 12/19/2022] Open
Abstract
The natural fungal compound ascofuranone (5-chloro-3-[(2E,6E)-7-[(2S)-5,5-dimethyl-4-oxo-tetrahydrofuran-2-yl]-3-methyl-octa-2,6-dienyl]-2,4-dihydroxy-6-methyl-benzaldehyde, MW 420.93) (AF) isolated from Ascochyta viciae has been known to promote cell cycle arrest and inhibit invasion of tumor cells. We have previously studied a structurally similar compound ascochlorin (ASC; MW 404.93) with regard to its anti-inflammatory activity in LPS- stimulated RAW 264.7 macrophages. In order to examine the relationship between the anti-inflammatory activities and the molecular differences between AF and ASC, the activity of AF is herein studied, because ASC has a unique trimethyl oxocyclohexyl structure, while AF has a unique dimethyl-oxo-tetrahydrofuran structure. AF dose-dependently inhibited the production of NO and iNOS and the COX-2 mRNA and protein levels in RAW 264.7 cells. In addition, AF suppressed mRNA expression levels of inflammatory cytokines such as TNF-α, IL-6, and IL-1β, as assessed by RT-PCR. AF (30-50 μg/ml) treatment clearly inhibited the nuclear translocation of NF-κB, AP-1 (p-c-Jun) from the cytosolic space. Phosphorylation of IκB, which functions to maintain the activity of NF-κB, was decreased by AF treatment. Moreover, AF suppressed the binding of NF-κB (p65). Inhibition of IkBa phosphorylation and degradation inhibits nuclear translocation of p65. Immunofluorescence confocal microscopy analysis also revealed that translocation of NF-κB and AP-1 (p-c-Jun) was decreased upon AF treatment. AF specifically decreased the expression level of p-ERK, but not the expression level of p-p38 or p-JNK. Given these results, we suggest that AF suppresses the inflammatory response by targeting p-ERK. This indicates that AF is a negative regulator of LPS-stimulated nuclear translocation of NF-κB and AP-1 (p-c-Jun) in RAW 264.7 macrophages, and specifically it targets p-ERK. Therefore, AF and ASC exert their effects in different ways, most probably because their structural differences allow for specific recognition and inhibition of their target MAPKs. Our results further suggest that AF could be a natural bioactive compound useful for treating inflammation-mediated pathological diseases.
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Affiliation(s)
- Jun-Young Park
- Molecular and Cellular Glycobiology Unit, Department of Biological Sciences, SungKyunKwan University, Seoburo 2066, Jangan-Gu, Suwon, Gyunggi-Do, Korea
| | - Tae-Wook Chung
- School of Korean Medicine and Healthy Aging Korean Medicine Research Center, Pusan National University, Yangsan City, Gyeongsangnam-Do, Republic of Korea
| | - Yun-Jeong Jeong
- Research Institute of Biomedical Engineering and Department of Medicine, Catholic University of Daegu School of Medicine, Daegu, Republic of Korea
| | - Choong-Hwan Kwak
- Molecular and Cellular Glycobiology Unit, Department of Biological Sciences, SungKyunKwan University, Seoburo 2066, Jangan-Gu, Suwon, Gyunggi-Do, Korea
| | - Sun-Hyung Ha
- Molecular and Cellular Glycobiology Unit, Department of Biological Sciences, SungKyunKwan University, Seoburo 2066, Jangan-Gu, Suwon, Gyunggi-Do, Korea
| | - Kyung-Min Kwon
- Molecular and Cellular Glycobiology Unit, Department of Biological Sciences, SungKyunKwan University, Seoburo 2066, Jangan-Gu, Suwon, Gyunggi-Do, Korea
| | - Fukushi Abekura
- Molecular and Cellular Glycobiology Unit, Department of Biological Sciences, SungKyunKwan University, Seoburo 2066, Jangan-Gu, Suwon, Gyunggi-Do, Korea
| | - Seung-Hak Cho
- Division of Enteric Diseases, Center for Infectious Diseases Research, Korea National Institute of Health, Heungdeok-gu, Cheongju, Korea
| | - Young-Choon Lee
- Faculty of Medicinal Biotechnology, Dong-A University, Busan, Republic of Korea
| | - Ki-Tae Ha
- School of Korean Medicine and Healthy Aging Korean Medicine Research Center, Pusan National University, Yangsan City, Gyeongsangnam-Do, Republic of Korea
| | - Junji Magae
- Magae Bioscience Institute, 49–4 Fujimidai, Tsukuba, Japan
| | - Young-Chae Chang
- Research Institute of Biomedical Engineering and Department of Medicine, Catholic University of Daegu School of Medicine, Daegu, Republic of Korea
- * E-mail: (CHM); (YCC)
| | - Cheorl-Ho Kim
- Molecular and Cellular Glycobiology Unit, Department of Biological Sciences, SungKyunKwan University, Seoburo 2066, Jangan-Gu, Suwon, Gyunggi-Do, Korea
- Samsung Advanced Institute for Health Sciences & Technology (SAIHST), Sungkyunkwan University, Seoul, South Korea
- * E-mail: (CHM); (YCC)
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19
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The Open Form Inducer Approach for Structure-Based Drug Design. PLoS One 2016; 11:e0167078. [PMID: 27893848 PMCID: PMC5125662 DOI: 10.1371/journal.pone.0167078] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 11/08/2016] [Indexed: 01/07/2023] Open
Abstract
Many open form (OF) structures of drug targets were obtained a posteriori by analysis of co-crystals with inhibitors. Therefore, obtaining the OF structure of a drug target a priori will accelerate development of potent inhibitors. In addition to its small active site, Trypanosoma cruzi dihydroorotate dehydrogenase (TcDHODH) is fully functional in its monomeric form, making drug design approaches targeting the active site and protein-protein interactions unrealistic. Therefore, a novel a priori approach was developed to determination the TcDHODH active site in OF. This approach consists of generating an "OF inducer" (predicted in silico) to bind the target and cause steric repulsion with flexible regions proximal to the active site that force it open. We provide the first proof-of-concept of this approach by predicting and crystallizing TcDHODH in complex with an OF inducer, thereby obtaining the OF a priori with its subsequent use in designing potent and selective inhibitors. Fourteen co-crystal structures of TcDHODH with the designed inhibitors are presented herein. This approach has potential to encourage drug design against diseases where the molecular targets are such difficult proteins possessing small AS volume. This approach can be extended to study open/close conformation of proteins in general, the identification of allosteric pockets and inhibitors for other drug targets where conventional drug design approaches are not applicable, as well as the effective exploitation of the increasing number of protein structures deposited in Protein Data Bank.
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20
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Re-identification of the ascofuranone-producing fungus Ascochyta viciae as Acremonium sclerotigenum. J Antibiot (Tokyo) 2016; 70:304-307. [PMID: 27804952 DOI: 10.1038/ja.2016.132] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 09/16/2016] [Accepted: 09/30/2016] [Indexed: 11/08/2022]
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21
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Balogun EO, Inaoka DK, Shiba T, Kido Y, Tsuge C, Nara T, Aoki T, Honma T, Tanaka A, Inoue M, Matsuoka S, Michels PAM, Kita K, Harada S. Molecular basis for the reverse reaction of African human trypanosomes glycerol kinase. Mol Microbiol 2014; 94:1315-29. [PMID: 25315291 DOI: 10.1111/mmi.12831] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/12/2014] [Indexed: 11/26/2022]
Abstract
The glycerol kinase (GK) of African human trypanosomes is compartmentalized in their glycosomes. Unlike the host GK, which under physiological conditions catalyzes only the forward reaction (ATP-dependent glycerol phosphorylation), trypanosome GK can additionally catalyze the reverse reaction. In fact, owing to this unique reverse catalysis, GK is potentially essential for the parasites survival in the human host, hence a promising drug target. The mechanism of its reverse catalysis was unknown; therefore, it was not clear if this ability was purely due to its localization in the organelles or whether structure-based catalytic differences also contribute. To investigate this lack of information, the X-ray crystal structure of this protein was determined up to 1.90 Å resolution, in its unligated form and in complex with three natural ligands. These data, in conjunction with results from structure-guided mutagenesis suggests that the trypanosome GK is possibly a transiently autophosphorylating threonine kinase, with the catalytic site formed by non-conserved residues. Our results provide a series of structural peculiarities of this enzyme, and gives unexpected insight into the reverse catalysis mechanism. Together, they provide an encouraging molecular framework for the development of trypanosome GK-specific inhibitors, which may lead to the design of new and safer trypanocidal drug(s).
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Affiliation(s)
- Emmanuel Oluwadare Balogun
- Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Sakyo-ku, Kyoto, 606-8585, Japan; Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan; Department of Biochemistry, Ahmadu Bello University, Zaria, 2222, Nigeria
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Drug discovery and human African trypanosomiasis: a disease less neglected? Future Med Chem 2014; 5:1801-41. [PMID: 24144414 DOI: 10.4155/fmc.13.162] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Human African trypanosomiasis (HAT) has been neglected for a long time. The most recent drug to treat this disease, eflornithine, was approved by the US FDA in 2000. Current treatments exhibit numerous problematic side effects and are often ineffective against the debilitating CNS resident stage of the disease. Fortunately, several partnerships and initiatives have been formed over the last 20 years in an effort to eradicate HAT, along with a number of other neglected diseases. This has led to an increasing number of foundations and research institutions that are currently working on the development of new drugs for HAT and tools with which to diagnose and treat patients. New biochemical pathways as therapeutic targets are emerging, accompanied by increasing numbers of new antitrypanosomal compound classes. The future looks promising that this collaborative approach will facilitate eagerly awaited breakthroughs in the treatment of HAT.
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Balogun EO, Inaoka DK, Shiba T, Kido Y, Nara T, Aoki T, Honma T, Tanaka A, Inoue M, Matsuoka S, Michels PA, Harada S, Kita K. Biochemical characterization of highly active Trypanosoma brucei gambiense glycerol kinase, a promising drug target. J Biochem 2013; 154:77-84. [DOI: 10.1093/jb/mvt037] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Shiba T, Kido Y, Sakamoto K, Inaoka DK, Tsuge C, Tatsumi R, Takahashi G, Balogun EO, Nara T, Aoki T, Honma T, Tanaka A, Inoue M, Matsuoka S, Saimoto H, Moore AL, Harada S, Kita K. Structure of the trypanosome cyanide-insensitive alternative oxidase. Proc Natl Acad Sci U S A 2013; 110:4580-5. [PMID: 23487766 PMCID: PMC3607012 DOI: 10.1073/pnas.1218386110] [Citation(s) in RCA: 128] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In addition to haem copper oxidases, all higher plants, some algae, yeasts, molds, metazoans, and pathogenic microorganisms such as Trypanosoma brucei contain an additional terminal oxidase, the cyanide-insensitive alternative oxidase (AOX). AOX is a diiron carboxylate protein that catalyzes the four-electron reduction of dioxygen to water by ubiquinol. In T. brucei, a parasite that causes human African sleeping sickness, AOX plays a critical role in the survival of the parasite in its bloodstream form. Because AOX is absent from mammals, this protein represents a unique and promising therapeutic target. Despite its bioenergetic and medical importance, however, structural features of any AOX are yet to be elucidated. Here we report crystal structures of the trypanosomal alternative oxidase in the absence and presence of ascofuranone derivatives. All structures reveal that the oxidase is a homodimer with the nonhaem diiron carboxylate active site buried within a four-helix bundle. Unusually, the active site is ligated solely by four glutamate residues in its oxidized inhibitor-free state; however, inhibitor binding induces the ligation of a histidine residue. A highly conserved Tyr220 is within 4 Å of the active site and is critical for catalytic activity. All structures also reveal that there are two hydrophobic cavities per monomer. Both inhibitors bind to one cavity within 4 Å and 5 Å of the active site and Tyr220, respectively. A second cavity interacts with the inhibitor-binding cavity at the diiron center. We suggest that both cavities bind ubiquinol and along with Tyr220 are required for the catalytic cycle for O2 reduction.
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Affiliation(s)
- Tomoo Shiba
- Department of Biomedical Chemistry, Graduate School of Medicine, and
| | - Yasutoshi Kido
- Department of Biomedical Chemistry, Graduate School of Medicine, and
| | | | - Daniel Ken Inaoka
- Department of Biomedical Chemistry, Graduate School of Medicine, and
| | - Chiaki Tsuge
- Department of Biomedical Chemistry, Graduate School of Medicine, and
| | - Ryoko Tatsumi
- Department of Biomedical Chemistry, Graduate School of Medicine, and
| | - Gen Takahashi
- Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Emmanuel Oluwadare Balogun
- Department of Biomedical Chemistry, Graduate School of Medicine, and
- Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Kyoto 606-8585, Japan
- Department of Biochemistry, Ahmadu Bello University, Zaria 2222, Nigeria
| | - Takeshi Nara
- Department of Molecular and Cellular Parasitology, Juntendo University School of Medicine, Tokyo 113-8421, Japan
| | - Takashi Aoki
- Department of Molecular and Cellular Parasitology, Juntendo University School of Medicine, Tokyo 113-8421, Japan
| | - Teruki Honma
- Systems and Structural Biology Center, RIKEN, Tsurumi, Yokohama 230-0045, Japan;
| | - Akiko Tanaka
- Systems and Structural Biology Center, RIKEN, Tsurumi, Yokohama 230-0045, Japan;
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Shigeru Matsuoka
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Hiroyuki Saimoto
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori 680-8552, Japan; and
| | - Anthony L. Moore
- Biochemistry and Molecular Biology, School of Life Sciences, University of Sussex, Brighton BN1 9QG, United Kingdom
| | - Shigeharu Harada
- Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Kiyoshi Kita
- Department of Biomedical Chemistry, Graduate School of Medicine, and
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Saimoto H, Kido Y, Haga Y, Sakamoto K, Kita K. Pharmacophore identification of ascofuranone, potent inhibitor of cyanide-insensitive alternative oxidase of Trypanosoma brucei. ACTA ACUST UNITED AC 2012. [DOI: 10.1093/jb/mvs135] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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26
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OHASHI-SUZUKI M, YABU Y, OHSHIMA S, NAKAMURA K, KIDO Y, SAKAMOTO K, KITA K, OHTA N, SUZUKI T. Differential Kinetic Activities of Glycerol Kinase among African Trypanosome Species: Phylogenetic and Therapeutic Implications. J Vet Med Sci 2011; 73:615-21. [DOI: 10.1292/jvms.10-0481] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Affiliation(s)
- Mitsuko OHASHI-SUZUKI
- Department of International Health Development, Division of Public Health, Graduate School of Tokyo Medical and Dental University
| | | | - Shigeru OHSHIMA
- Department of Core Laboratory, Nagoya City University Graduate School of Medical Sciences
| | - Kosuke NAKAMURA
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo
| | - Yasutoshi KIDO
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo
| | - Kimitoshi SAKAMOTO
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo
| | - Kiyoshi KITA
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo
| | - Nobuo OHTA
- Department of International Health Development, Division of Public Health, Graduate School of Tokyo Medical and Dental University
| | - Takashi SUZUKI
- Department of International Health Development, Division of Public Health, Graduate School of Tokyo Medical and Dental University
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Mallari JP, Zhu F, Lemoff A, Kaiser M, Lu M, Brun R, Guy RK. Optimization of purine-nitrile TbcatB inhibitors for use in vivo and evaluation of efficacy in murine models. Bioorg Med Chem 2010; 18:8302-9. [DOI: 10.1016/j.bmc.2010.09.073] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2010] [Revised: 09/24/2010] [Accepted: 09/30/2010] [Indexed: 11/25/2022]
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28
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Nakamura K, Fujioka S, Fukumoto S, Inoue N, Sakamoto K, Hirata H, Kido Y, Yabu Y, Suzuki T, Watanabe YI, Saimoto H, Akiyama H, Kita K. Trypanosome alternative oxidase, a potential therapeutic target for sleeping sickness, is conserved among Trypanosoma brucei subspecies. Parasitol Int 2010; 59:560-4. [PMID: 20688188 DOI: 10.1016/j.parint.2010.07.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2010] [Revised: 07/17/2010] [Accepted: 07/23/2010] [Indexed: 11/16/2022]
Abstract
Trypanosoma brucei rhodesiense and T. b. gambiense are known causes of human African trypanosomiasis (HAT), or "sleeping sickness," which is deadly if untreated. We previously reported that a specific inhibitor of trypanosome alternative oxidase (TAO), ascofuranone, quickly kills African trypanosomes in vitro and cures mice infected with another subspecies, non-human infective T. b. brucei, in in vivo trials. As an essential factor for trypanosome survival, TAO is a promising drug target due to the absence of alternative oxidases in the mammalian host. This study found TAO expression in HAT-causing trypanosomes; its amino acid sequence was identical to that in non-human infective T. b. brucei. The biochemical understanding of the TAO including its 3 dimensional structure and inhibitory compounds against TAO could therefore be applied to all three T. brucei subspecies in search of a cure for HAT. Our in vitro study using T. b. rhodesiense confirmed the effectiveness of ascofuranone (IC(50) value: 1 nM) to eliminate trypanosomes in human infective strain cultures.
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Affiliation(s)
- Kosuke Nakamura
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Tokyo 113-0033, Japan.
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Haga Y, Tonoi T, Anbiru Y, Takahashi Y, Tamura S, Yamamoto M, Ifuku S, Morimoto M, Saimoto H. A Short and Efficient Total Synthesis of (±)-Ascofuranone. CHEM LETT 2010. [DOI: 10.1246/cl.2010.622] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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30
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Kido Y, Sakamoto K, Nakamura K, Harada M, Suzuki T, Yabu Y, Saimoto H, Yamakura F, Ohmori D, Moore A, Harada S, Kita K. Purification and kinetic characterization of recombinant alternative oxidase from Trypanosoma brucei brucei. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:443-50. [DOI: 10.1016/j.bbabio.2009.12.021] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Revised: 12/23/2009] [Accepted: 12/25/2009] [Indexed: 10/20/2022]
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31
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Watts KR, Ratnam J, Ang KH, Tenney K, Compton JE, McKerrow J, Crews P. Assessing the trypanocidal potential of natural and semi-synthetic diketopiperazines from two deep water marine-derived fungi. Bioorg Med Chem 2010; 18:2566-74. [PMID: 20303767 PMCID: PMC2893881 DOI: 10.1016/j.bmc.2010.02.034] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Revised: 02/18/2010] [Accepted: 02/19/2010] [Indexed: 11/21/2022]
Abstract
Human African trypanosomiasis (HAT, commonly known as African sleeping sickness) is categorized as a neglected disease, as it afflicts >50,000 people annually in sub-saharan Africa, and there are few formal programs in the world focused on drug discovery approaches for this disease. In this study, we examined the crude extracts of two fungal strains (Aspergillus fumigatus and Nectria inventa) isolated from deep water sediment which provided >99% growth inhibition at 1microg/mL of Trypanosoma brucei, the causative parasite of HAT. A collection of fifteen natural products was supplemented with six semi-synthetic derivatives and one commercially available compound. Twelve of the compounds, each containing a diketopiperazine core, showed excellent activity against T. brucei (IC(50)=0.002-40microM), with selectivity over mammalian cells as great as 20-fold. The trypanocidal diketopiperazines were also tested against two cysteine protease targets Rhodesain and TbCatB, where five compounds showed inhibition activity at concentrations less than 20microM. A preliminary activity pattern is described and analyzed.
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Affiliation(s)
- Katharine R. Watts
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California 95064
| | - Joseline Ratnam
- Sandler Center for Basic Research in Parasitic Disease, University of California San Francisco, San Francisco,CA 94143, and Small Molecule Discovery Center, University of California San Francisco, San Francisco, CA 94158
| | - Kean-Hooi Ang
- Sandler Center for Basic Research in Parasitic Disease, University of California San Francisco, San Francisco,CA 94143, and Small Molecule Discovery Center, University of California San Francisco, San Francisco, CA 94158
| | - Karen Tenney
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California 95064
| | - Jennifer E. Compton
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California 95064
| | - James McKerrow
- Sandler Center for Basic Research in Parasitic Disease, University of California San Francisco, San Francisco,CA 94143, and Small Molecule Discovery Center, University of California San Francisco, San Francisco, CA 94158
| | - Phillip Crews
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California 95064
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Balogun EO, Inaoka DK, Kido Y, Shiba T, Nara T, Aoki T, Honma T, Tanaka A, Inoue M, Matsuoka S, Michels PAM, Harada S, Kita K. Overproduction, purification, crystallization and preliminary X-ray diffraction analysis of Trypanosoma brucei gambiense glycerol kinase. Acta Crystallogr Sect F Struct Biol Cryst Commun 2010; 66:304-8. [PMID: 20208167 PMCID: PMC2833043 DOI: 10.1107/s1744309110000369] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2009] [Accepted: 01/05/2010] [Indexed: 11/10/2022]
Abstract
In the bloodstream forms of human trypanosomes, glycerol kinase (GK; EC 2.7.1.30) is one of the nine glycosomally compartmentalized enzymes that are essential for energy metabolism. In this study, a recombinant Trypanosoma brucei gambiense GK (rTbgGK) with an N-terminal cleavable His(6) tag was overexpressed, purified to homogeneity and crystallized by the sitting-drop vapour-diffusion method using PEG 400 as a precipitant. A complete X-ray diffraction data set to 2.75 A resolution indicated that the crystals belonged to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 63.84, b = 121.50, c = 154.59 A. The presence of two rTbgGK molecules in the asymmetric unit gives a Matthews coefficient (V(M)) of 2.5 A(3) Da(-1), corresponding to 50% solvent content.
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Affiliation(s)
- Emmanuel Oluwadare Balogun
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- Department of Biochemistry, Ahmadu Bello University, Zaria, Nigeria
| | - Daniel Ken Inaoka
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yasutoshi Kido
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Tomoo Shiba
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takeshi Nara
- Department of Molecular and Cellular Parasitology, Juntendo University School of Medicine, Tokyo 113-8421, Japan
| | - Takashi Aoki
- Department of Molecular and Cellular Parasitology, Juntendo University School of Medicine, Tokyo 113-8421, Japan
| | - Teruki Honma
- Systems and Structural Biology Center, RIKEN, Tsurumi, Yokohama 230-0045, Japan
| | - Akiko Tanaka
- Systems and Structural Biology Center, RIKEN, Tsurumi, Yokohama 230-0045, Japan
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Shigeru Matsuoka
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Paul A. M. Michels
- Research Unit for Tropical Diseases, de Duve Institute and Laboratory of Biochemistry, Université Catholique de Louvain, Avenue Hippocrate 74, B-1200 Brussels, Belgium
| | - Shigeharu Harada
- Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585, Japan
| | - Kiyoshi Kita
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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Kido Y, Shiba T, Inaoka DK, Sakamoto K, Nara T, Aoki T, Honma T, Tanaka A, Inoue M, Matsuoka S, Moore A, Harada S, Kita K. Crystallization and preliminary crystallographic analysis of cyanide-insensitive alternative oxidase from Trypanosoma brucei brucei. Acta Crystallogr Sect F Struct Biol Cryst Commun 2010; 66:275-8. [PMID: 20208159 PMCID: PMC2833035 DOI: 10.1107/s1744309109054062] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2009] [Accepted: 12/15/2009] [Indexed: 04/24/2023]
Abstract
Cyanide-insensitive alternative oxidase (AOX) is a mitochondrial membrane protein and a non-proton-pumping ubiquinol oxidase that catalyzes the four-electron reduction of dioxygen to water. In the African trypanosomes, trypanosome alternative oxidase (TAO) functions as a cytochrome-independent terminal oxidase that is essential for survival in the mammalian host; hence, the enzyme is considered to be a promising drug target for the treatment of trypanosomiasis. In the present study, recombinant TAO (rTAO) overexpressed in haem-deficient Escherichia coli was purified and crystallized at 293 K by the hanging-drop vapour-diffusion method using polyethylene glycol 400 as a precipitant. X-ray diffraction data were collected at 100 K and were processed to 2.9 A resolution with 93.1% completeness and an overall R(merge) of 9.5%. The TAO crystals belonged to the orthorhombic space group I222 or I2(1)2(1)2(1), with unit-cell parameters a = 63.11, b = 136.44, c = 223.06 A. Assuming the presence of two rTAO molecules in the asymmetric unit (2 x 38 kDa), the calculated Matthews coefficient (V(M)) was 3.2 A(3) Da(-1), which corresponds to a solvent content of 61.0%. This is the first report of a crystal of the membrane-bound diiron proteins, which include AOXs.
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Affiliation(s)
- Yasutoshi Kido
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Tomoo Shiba
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Daniel Ken Inaoka
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Kimitoshi Sakamoto
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Takeshi Nara
- Department of Molecular and Cellular Parasitology, Juntendo University School of Medicine, Tokyo 113-8421, Japan
| | - Takashi Aoki
- Department of Molecular and Cellular Parasitology, Juntendo University School of Medicine, Tokyo 113-8421, Japan
| | - Teruki Honma
- Systems and Structural Biology Center, RIKEN, Tsurumi, Yokohama 230-0045, Japan
| | - Akiko Tanaka
- Systems and Structural Biology Center, RIKEN, Tsurumi, Yokohama 230-0045, Japan
| | - Masayuki Inoue
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Shigeru Matsuoka
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Anthony Moore
- Biochemistry and Biomedical Sciences, School of Life Sciences, University of Sussex, Falmer, Brighton, England
| | - Shigeharu Harada
- Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Kyoto 606-8585, Japan
| | - Kiyoshi Kita
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
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Williams BAP, Elliot C, Burri L, Kido Y, Kita K, Moore AL, Keeling PJ. A broad distribution of the alternative oxidase in microsporidian parasites. PLoS Pathog 2010; 6:e1000761. [PMID: 20169184 PMCID: PMC2820529 DOI: 10.1371/journal.ppat.1000761] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2009] [Accepted: 01/11/2010] [Indexed: 11/19/2022] Open
Abstract
Microsporidia are a group of obligate intracellular parasitic eukaryotes that were considered to be amitochondriate until the recent discovery of highly reduced mitochondrial organelles called mitosomes. Analysis of the complete genome of Encephalitozoon cuniculi revealed a highly reduced set of proteins in the organelle, mostly related to the assembly of iron-sulphur clusters. Oxidative phosphorylation and the Krebs cycle proteins were absent, in keeping with the notion that the microsporidia and their mitosomes are anaerobic, as is the case for other mitosome bearing eukaryotes, such as Giardia. Here we provide evidence opening the possibility that mitosomes in a number of microsporidian lineages are not completely anaerobic. Specifically, we have identified and characterized a gene encoding the alternative oxidase (AOX), a typically mitochondrial terminal oxidase in eukaryotes, in the genomes of several distantly related microsporidian species, even though this gene is absent from the complete genome of E. cuniculi. In order to confirm that these genes encode functional proteins, AOX genes from both A. locustae and T. hominis were over-expressed in E. coli and AOX activity measured spectrophotometrically using ubiquinol-1 (UQ-1) as substrate. Both A. locustae and T. hominis AOX proteins reduced UQ-1 in a cyanide and antimycin-resistant manner that was sensitive to ascofuranone, a potent inhibitor of the trypanosomal AOX. The physiological role of AOX microsporidia may be to reoxidise reducing equivalents produced by glycolysis, in a manner comparable to that observed in trypanosomes.
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Affiliation(s)
- Bryony A. P. Williams
- School of Biosciences, Geoffrey Pope Building, University of Exeter, Exeter, Devon, United Kingdom
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - Catherine Elliot
- Department of Biochemistry and Biomedical Sciences, School of Life Sciences, University of Sussex, Falmer, Brighton, United Kingdom
| | - Lena Burri
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - Yasutoshi Kido
- Department of Biomedical Chemistry, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - Kiyoshi Kita
- Department of Biomedical Chemistry, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - Anthony L. Moore
- Department of Biochemistry and Biomedical Sciences, School of Life Sciences, University of Sussex, Falmer, Brighton, United Kingdom
| | - Patrick J. Keeling
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
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Takashima E, Yamada H, Yajima A, Shiomi K, Ōmura S, Kiyoshi K. A quinol peroxidase inhibitor prevents secretion of a leukotoxin fromAggregatibacter actinomycetemcomitans. J Periodontal Res 2010; 45:123-8. [DOI: 10.1111/j.1600-0765.2009.01211.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Maréchal A, Kido Y, Kita K, Moore AL, Rich PR. Three redox states of Trypanosoma brucei alternative oxidase identified by infrared spectroscopy and electrochemistry. J Biol Chem 2009; 284:31827-33. [PMID: 19767647 DOI: 10.1074/jbc.m109.059980] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Electrochemistry coupled with Fourier transform infrared (IR) spectroscopy was used to investigate the redox properties of recombinant alternative ubiquinol oxidase from Trypanosoma brucei, the organism responsible for African sleeping sickness. Stepwise reduction of the fully oxidized resting state of recombinant alternative ubiquinol oxidase revealed two distinct IR redox difference spectra. The first of these, signal 1, titrates in the reductive direction as an n = 2 Nernstian component with an apparent midpoint potential of 80 mV at pH 7.0. However, reoxidation of signal 1 in the same potential range under anaerobic conditions did not occur and only began with potentials in excess of 500 mV. Reoxidation by introduction of oxygen was also unsuccessful. Signal 1 contained clear features that can be assigned to protonation of at least one carboxylate group, further perturbations of carboxylic and histidine residues, bound ubiquinone, and a negative band at 1554 cm(-1) that might arise from a radical in the fully oxidized protein. A second distinct IR redox difference spectrum, signal 2, appeared more slowly once signal 1 had been reduced. This component could be reoxidized with potentials above 100 mV. In addition, when both signals 1 and 2 were reduced, introduction of oxygen caused rapid oxidation of both components. These data are interpreted in terms of the possible active site structure and mechanism of oxygen reduction to water.
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Affiliation(s)
- Amandine Maréchal
- Glynn Laboratory of Bioenergetics, Institute of Structural and Molecular Biology, University College London, Gower Street, London WC1E 6BT, United Kingdom
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Liu FY, Luo KW, Yu ZM, Co NN, Wu SH, Wu P, Fung KP, Kwok TT. Suillin from the mushroom Suillus placidus as potent apoptosis inducer in human hepatoma HepG2 cells. Chem Biol Interact 2009; 181:168-74. [PMID: 19616521 DOI: 10.1016/j.cbi.2009.07.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Revised: 06/04/2009] [Accepted: 07/09/2009] [Indexed: 10/20/2022]
Abstract
During the search of new anti-cancer agent from high fungi, the ethyl acetate extract of the mushroom Suillus placidus was found to exhibit a significant cytotoxic activity against human hepatoma HepG2 cells. With bioassay-guided fractionation, a cytotoxic component suillin was isolated from the extract. The anti-cancer effect of suillin was subsequently examined in 8 human cancer cell lines by using MTT assay. It is of interest to note that human liver cancer cells (HepG2 cells, Hep3B cells, and SK-Hep-1) were preferentially killed by suillin with an IC(50) of approximately 2microM in a 48h treatment. Mechanistically. suillin was found for the first time to induce apoptosis in HepG2 cells as characterized by DNA fragmentation, phosphatidyl-serine (PS) externalization, activation of caspase-3, -8, -9, depolarization of mitochondrial membrane potential, as well as release of cytochrome c into the cytosol. Moreover, the apoptosis induced by suillin was suppressed by both caspase-8 and -9 inhibitors. Western blot analysis revealed significant increases in the protein levels of Fas death receptor, adaptor FADD protein, pro-apoptotic protein Bad and a decline of Bid. These results suggest that the induction of apoptosis by suillin is through both death receptor and mitochondrial pathways. Taken together, our results suggest that suillin might be an effective agent to treat liver cancer.
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Affiliation(s)
- Fei-yan Liu
- Zhejiang University, Research Centre of Siyuan Natural Pharmacy and Biotoxicology, Hangzhou, PR China.
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Mogi T, Ano Y, Nakatsuka T, Toyama H, Muroi A, Miyoshi H, Migita CT, Ui H, Shiomi K, Omura S, Kita K, Matsushita K. Biochemical and spectroscopic properties of cyanide-insensitive quinol oxidase from Gluconobacter oxydans. J Biochem 2009; 146:263-71. [PMID: 19416958 DOI: 10.1093/jb/mvp067] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Cyanide-insensitive quinol oxidase (CioAB), a relative of cytochrome bd, has no spectroscopic features of hemes b(595) and d in the wild-type bacteria and is difficult to purify for detailed characterization. Here we studied enzymatic and spectroscopic properties of CioAB from the acetic acid bacterium Gluconobacter oxydans. Gluconobacter oxydans CioAB showed the K(m) value for ubiquinol-1 comparable to that of Escherichia coli cytochrome bd but it was more resistant to KCN and quinone-analogue inhibitors except piericidin A and LL-Z1272gamma. We obtained the spectroscopic evidence for the presence of hemes b(595) and d. Heme b(595) showed the alpha peak at 587 nm in the reduced state and a rhombic high-spin signal at g = 6.3 and 5.5 in the air-oxidized state. Heme d showed the alpha peak at 626 and 644 nm in the reduced and air-oxidized state, respectively, and an axial high-spin signal at g = 6.0 and low-spin signals at g = 2.63, 2.37 and 2.32. We found also a broad low-spin signal at g = 3.2, attributable to heme b(558). Further, we identified the presence of heme D by mass spectrometry. In conclusion, CioAB binds all three ham species present in cytochrome bd quinol oxidase.
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Affiliation(s)
- Tatsushi Mogi
- Department of Biomedical Chemistry, the University of Tokyo, Bunkyo-ku, Japan.
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Antibiotics LL-Z1272 identified as novel inhibitors discriminating bacterial and mitochondrial quinol oxidases. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2009; 1787:129-33. [DOI: 10.1016/j.bbabio.2008.11.016] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2008] [Revised: 11/21/2008] [Accepted: 11/26/2008] [Indexed: 11/19/2022]
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Kawahara K, Mogi T, Tanaka TQ, Hata M, Miyoshi H, Kita K. Mitochondrial dehydrogenases in the aerobic respiratory chain of the rodent malaria parasite Plasmodium yoelii yoelii. J Biochem 2008; 145:229-37. [PMID: 19060309 DOI: 10.1093/jb/mvn161] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In the intraerythrocytic stages of malaria parasites, mitochondria lack obvious cristae and are assumed to derive energy through glycolysis. For understanding of parasite energy metabolism in mammalian hosts, we isolated rodent malaria mitochondria from Plasmodium yoelii yoelii grown in mice. As potential targets for antiplasmodial agents, we characterized two respiratory dehydrogenases, succinate:ubiquinone reductase (complex II) and alternative NADH dehydrogenase (NDH-II), which is absent in mammalian mitochondria. We found that P. y. yoelii complex II was a four-subunit enzyme and that kinetic properties were similar to those of mammalian enzymes, indicating that the Plasmodium complex II is favourable in catalysing the forward reaction of tricarboxylic acid cycle. Notably, Plasmodium complex II showed IC(50) value for atpenin A5 three-order of magnitudes higher than those of mammalian enzymes. Divergence of protist membrane anchor subunits from eukaryotic orthologs likely affects the inhibitor resistance. Kinetic properties and sensitivity to 2-heptyl-4-hydroxyquinoline-N-oxide and aurachin C of NADH: ubiquinone reductase activity of Plasmodium NDH-II were similar to those of plant and fungus enzymes but it can oxidize NADPH and deamino-NADH. Our findings are consistent with the notion that rodent malaria mitochondria are fully capable of oxidative phosphorylation and that these mitochondrial enzymes are potential targets for new antiplasmodials.
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Affiliation(s)
- Kenji Kawahara
- Department of Biomedical Chemistry, Graduate School of Medicine, the University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
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Lanteri CA, Tidwell RR, Meshnick SR. The mitochondrion is a site of trypanocidal action of the aromatic diamidine DB75 in bloodstream forms of Trypanosoma brucei. Antimicrob Agents Chemother 2008; 52:875-82. [PMID: 18086841 PMCID: PMC2258549 DOI: 10.1128/aac.00642-07] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2007] [Revised: 07/28/2007] [Accepted: 12/06/2007] [Indexed: 11/20/2022] Open
Abstract
Human African trypanosomiasis (HAT) is a fatal tropical disease caused by infection with protozoans of the species Trypanosoma brucei gambiense and T. b. rhodesiense. An oral prodrug, DB289, is a promising new therapy undergoing phase III clinical trials for early-stage HAT. DB289 is metabolically converted to the active trypanocidal diamidine DB75 [2,5-bis(4-amidinophenyl)furan]. We previously determined that DB75 inhibits yeast mitochondrial function (C. A. Lanteri, B. L. Trumpower, R. R. Tidwell, and S. R. Meshnick, Antimicrob. Agent Chemother. 48:3968-3974, 2004). The purpose of this study was to investigate if DB75 targets the mitochondrion of T. b. brucei bloodstream forms. DB75 rapidly accumulates within the mitochondria of living trypanosomes, as indicated by the fluorescent colocalization of DB75 with a mitochondrion-specific dye. Fluorescence-activated cell sorting analysis of rhodamine 123-stained living trypanosomes shows that DB75 and other trypanocidal diamidines (pentamidine and diminazene) collapse the mitochondrial membrane potential. DB75 inhibits ATP hydrolysis within T. brucei mitochondria and appears to inhibit the oligomycin-sensitive F 1 F 0-ATPase and perhaps other ATPases. DB75 is most likely not an inhibitor of electron transport within trypanosome mitochondria, since DB75 fails to inhibit mitochondrial respiration when glycerol-3-phosphate is used as the respiratory substrate. However, DB75 inhibits whole-cell respiration (50% inhibitory concentration, 20 microM) at drug concentrations and incubation durations that also result in the dissipation of the mitochondrial membrane potential. Taken together, these findings suggest that the mitochondrion is a target of the trypanocidal action of DB75.
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Affiliation(s)
- Charlotte A Lanteri
- Department of Pathology and Laboratory Medicine, University of North Carolina, 2102C McGavran/Greenberg Hall, Chapel Hill, NC 27599, USA
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42
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Hellemond JJV, Bakker BM, Tielens AGM. Energy metabolism and its compartmentation in Trypanosoma brucei. Adv Microb Physiol 2006; 50:199-226. [PMID: 16221581 DOI: 10.1016/s0065-2911(05)50005-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
African trypanosomes are parasitic protozoa of the order of Kinetoplastida, which cause sleeping sickness and nagana. Trypanosomes are not only of scientific interest because of their clinical importance, but also because these protozoa contain several very unusual biological features, such as their special energy metabolism. The energy metabolism of Trypanosoma brucei differs significantly from that of its host, not only because it comprises distinct enzymes and metabolic pathways, but also because some of the glycolytic enzymes are localized in organelles called glycosomes. Furthermore, the energy metabolism changes drastically during the complex life cycle of this parasite. This review will focus on the recent advances made in understanding the process of ATP production in T. brucei during its life cycle and the consequences of the special subcellular compartmentation.
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Affiliation(s)
- Jaap J van Hellemond
- Department of Biochemistry and Cell Biology, Faculty of Veterinary Medicine, Utrecht University, PO Box 80.176, 3508 TD Utrecht, The Netherlands
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Suzuki T, Hashimoto T, Yabu Y, Majiwa PAO, Ohshima S, Suzuki M, Lu S, Hato M, Kido Y, Sakamoto K, Nakamura K, Kita K, Ohta N. Alternative oxidase (AOX) genes of African trypanosomes: phylogeny and evolution of AOX and plastid terminal oxidase families. J Eukaryot Microbiol 2005; 52:374-81. [PMID: 16014016 DOI: 10.1111/j.1550-7408.2005.00050.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To clarify evolution and phylogenetic relationships of trypanosome alternative oxidase (AOX) molecules, AOX genes (cDNAs) of the African trypanosomes, Trypanosoma congolense and Trypanosoma evansi, were cloned by PCR. Both AOXs possess conserved consensus motifs (-E-, -EXXH-). The putative amino acid sequence of the AOX of T. evansi was exactly the same as that of T. brucei. A protein phylogeny of trypanosome AOXs revealed that three genetically and pathogenically distinct strains of T. congolense are closely related to each other. When all known AOX sequences collected from current databases were analyzed, the common ancestor of these three Trypanosoma species shared a sister-group position to T. brucei/T. evansi. Monophyly of Trypanosoma spp. was clearly supported (100% bootstrap value) with Trypanosoma vivax placed at the most basal position of the Trypanosoma clade. Monophyly of other eukaryotic lineages, terrestrial plants + red algae, Metazoa, diatoms, Alveolata, oomycetes, green algae, and Fungi, was reconstructed in the best AOX tree obtained from maximum likelihood analysis, although some of these clades were not strongly supported. The terrestrial plants + red algae clade showed the closest affinity with an alpha-proteobacterium, Novosphingobium aromaticivorans, and the common ancestor of these lineages, was separated from other eukaryotes. Although the root of the AOX subtree was not clearly determined, subsequent phylogenetic analysis of the composite tree for AOX and plastid terminal oxidase (PTOX) demonstrated that PTOX and related cyanobacterial sequences are of a monophyletic origin and their common ancestor is linked to AOX sequences.
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Affiliation(s)
- Takashi Suzuki
- Department of Molecular Parasitology, Nagoya City University, Graduate School of Medical Sciences, Kawasumi, Mizuho 467-8601 Nagoya, Japan.
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Nakamura K, Sakamoto K, Kido Y, Fujimoto Y, Suzuki T, Suzuki M, Yabu Y, Ohta N, Tsuda A, Onuma M, Kita K. Mutational analysis of the Trypanosoma vivax alternative oxidase: The E(X)6Y motif is conserved in both mitochondrial alternative oxidase and plastid terminal oxidase and is indispensable for enzyme activity. Biochem Biophys Res Commun 2005; 334:593-600. [PMID: 16009344 DOI: 10.1016/j.bbrc.2005.06.131] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2005] [Accepted: 06/23/2005] [Indexed: 11/16/2022]
Abstract
Based on amino acid sequence similarity and the ability to catalyze the four-electron reduction of oxygen to water using a quinol substrate, mitochondrial alternative oxidase (AOX) and plastid terminal oxidase (PTOX) appear to be two closely related members of the membrane-bound diiron carboxylate group of proteins. In the current studies, we took advantage of the high activity of Trypanosoma vivax AOX (TvAOX) to examine the importance of the conserved Glu and the Tyr residues around the predicted third helix region of AOXs and PTOXs. We first compared the amino acid sequences of TvAOX with AOXs and PTOXs from various taxa and then performed alanine-scanning mutagenesis of TvAOX between amino acids Y(199) and Y(247). We found that the ubiquinol oxidase activity of TvAOX is completely lost in the E214A mutant, whereas mutants E215A and E216A retained more than 30% of the wild-type activity. Among the Tyr mutants, a complete loss of activity was also observed for the Y221A mutant, whereas the activities were equivalent to wild-type for the Y199A, Y212A, and Y247A mutants. Finally, residues Glu(214) and Tyr(221) were found to be strictly conserved among AOXs and PTOXs. Based on these findings, it appears that AOXs and PTOXs are a novel subclass of diiron carboxylate proteins that require the conserved motif E(X)(6)Y for enzyme activity.
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Affiliation(s)
- Kosuke Nakamura
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
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Suzuki T, Nihei CI, Yabu Y, Hashimoto T, Suzuki M, Yoshida A, Nagai K, Hosokawa T, Minagawa N, Suzuki S, Kita K, Ohta N. Molecular cloning and characterization of Trypanosoma vivax alternative oxidase (AOX) gene, a target of the trypanocide ascofuranone. Parasitol Int 2004; 53:235-45. [PMID: 15468531 DOI: 10.1016/j.parint.2004.02.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Trypanosoma vivax causes nagana disease in cattle. Since T. vivax is transmitted not only by tsetse flies but also by other biting flies (non-cyclic transmission), the parasite has been distributed to and has had a significant economic impact on wide geographical areas, including Africa and South America. Our previous study on Trypanosoma brucei brucei showed that the trypanosome alternative oxidase (TAO, TbAOX) is a promising target of chemotherapy. For this reason, we also have cloned the T vivax AOX (TvAOX) gene and characterized the recombinant enzyme. The deduced amino acid sequence (328 a.a.) of TvAOX shares 76% identity with TbAOX and contains the diiron-coordination motifs (-E-, -EXXH-) that are conserved among AOXs. The Km of recombinant TvAOX (rTvAOX) expressed in Escherichia coli for ubiquinol (87.0 +/- 0.54 microM) was significantly lower than the value for recombinant TbAOX (rTbAOX) (714 +/- 4.5 microM). Ascofuranone, the most potent inhibitor of TbAOX, was a competitive inhibitor of rTvAOX with a Ki value (0.40 +/- 0.00 nM) significantly lower than that for rTbAOX (1.29 +/- 0.00 nM). The non-cyclic transmission ability of T. vivax and the in vivo chemotherapeutic efficacy of ascofuranone against T. vivax and T. b. brucei infection are discussed in terms of these Km and Ki values.
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Affiliation(s)
- Takashi Suzuki
- Department of Molecular Parasitology, Nagoya City University, Graduate School of Medical Sciences, Nagoya 467-8601, Japan.
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Nasirudeen AMA, Tan KSW. Isolation and characterization of the mitochondrion-like organelle from Blastocystis hominis. J Microbiol Methods 2004; 58:101-9. [PMID: 15177908 DOI: 10.1016/j.mimet.2004.03.008] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2003] [Revised: 03/06/2004] [Accepted: 03/11/2004] [Indexed: 11/18/2022]
Abstract
Blastocystis hominis in an unusual protozoan parasite of the human intestinal tract. Previous studies have described the presence of mitochondrial-like structures despite the anaerobic nature of the organism. In this study, we describe a simple and rapid technique to isolate and characterize mitochondrion-like organelles (MLO) from B. hominis. The parasite was disrupted using glass beads and the MLO were collected and purified using a sucrose gradient. Negative staining and transmission electron microscopy of the isolated organelles showed mitochondrial-like structures. B. hominis cells were stained with rhodamine 123 and MitoLight to show the presence of transmembrane potential of the MLO. DAPI staining of the cells suggested the presence of DNA in the MLO. Though brief reports have been made in literature, this study is the first to describe a technique for the isolation of the MLO from this organism. Using this technique of isolation, major metabolic functions of the organelle, their associated macromolecules and intra-mitochondrial location can be extensively studied. The role of MLO in this anaerobic protozoan can be widely investigated using this protocol.
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Affiliation(s)
- A M A Nasirudeen
- Laboratory of Molecular and Cellular Parasitology, Department of Microbiology, Faculty of Medicine, National University of Singapore, 5 Science Drive 2, 117597 Singapore
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Suzuki T, Hashimoto T, Yabu Y, Kido Y, Sakamoto K, Nihei CI, Hato M, Suzuki SI, Amano Y, Nagai K, Hosokawa T, Minagawa N, Ohta N, Kita K. Direct evidence for cyanide-insensitive quinol oxidase (alternative oxidase) in apicomplexan parasite Cryptosporidium parvum: phylogenetic and therapeutic implications. Biochem Biophys Res Commun 2004; 313:1044-52. [PMID: 14706648 DOI: 10.1016/j.bbrc.2003.12.038] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Cryptosporidium parvum is a parasitic protozoan that causes the diarrheal disease cryptosporidiosis, for which no satisfactory chemotherapy is currently available. Although the presence of mitochondria in this parasite has been suggested, its respiratory system is poorly understood due to difficulties in performing biochemical analyses. In order to better understand the respiratory chain of C. parvum, we surveyed its genomic DNA database in GenBank and identified a partial sequence encoding cyanide-insensitive alternative oxidase (AOX). Based on this sequence, we cloned C. parvum AOX (CpAOX) cDNA from the phylum apicomplexa for the first time. The deduced amino acid sequence (335 a.a.) of CpAOX contains diiron coordination motifs (-E-, -EXXH-) that are conserved among AOXs. Phylogenetic analysis suggested that CpAOX is a mitochondrial-type AOX, possibly derived from mitochondrial endosymbiont gene transfer. The recombinant enzyme expressed in Escherichia coli showed quinol oxidase activity. This activity was insensitive to cyanide and highly sensitive to ascofuranone, a specific inhibitor of trypanosome AOX.
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Affiliation(s)
- Takashi Suzuki
- Department of Molecular Parasitology, Nagoya City University, Graduate School of Medical Sciences, Nagoya 467-8601, Japan
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Schnaufer A, Domingo GJ, Stuart K. Natural and induced dyskinetoplastic trypanosomatids: how to live without mitochondrial DNA. Int J Parasitol 2002; 32:1071-84. [PMID: 12117490 DOI: 10.1016/s0020-7519(02)00020-6] [Citation(s) in RCA: 133] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Salivarian trypanosomes are the causative agents of several diseases of major social and economic impact. The most infamous parasites of this group are the African subspecies of the Trypanosoma brucei group, which cause sleeping sickness in humans and nagana in cattle. In terms of geographical distribution, however, Trypanosoma equiperdum and Trypanosoma evansi have been far more successful, causing disease in livestock in Africa, Asia, and South America. In these latter forms the mitochondrial DNA network, the kinetoplast, is altered or even completely lost. These natural dyskinetoplastic forms can be mimicked in bloodstream form T. brucei by inducing the loss of kinetoplast DNA (kDNA) with intercalating dyes. Dyskinetoplastic T. brucei are incapable of completing their usual developmental cycle in the insect vector, due to their inability to perform oxidative phosphorylation. Nevertheless, they are usually as virulent for their mammalian hosts as parasites with intact kDNA, thus questioning the therapeutic value of attempts to target mitochondrial gene expression with specific drugs. Recent experiments, however, have challenged this view. This review summarises the data available on dyskinetoplasty in trypanosomes and revisits the roles the mitochondrion and its genome play during the life cycle of T. brucei.
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Affiliation(s)
- Achim Schnaufer
- Seattle Biomedical Research Institute, 4 Nickerson Street, Suite 200, Seattle, WA 98109, USA.
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Natural products as potential antiparasitic drugs. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s1572-5995(02)80019-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2023]
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Helfert S, Estévez AM, Bakker B, Michels P, Clayton C. Roles of triosephosphate isomerase and aerobic metabolism in Trypanosoma brucei. Biochem J 2001; 357:117-25. [PMID: 11415442 PMCID: PMC1221934 DOI: 10.1042/0264-6021:3570117] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Kinetoplastid protozoa compartmentalize the first seven enzymes of glycolysis and two enzymes of glycerol metabolism in a microbody, the glycosome. While in its mammalian host, Trypanosoma brucei depends entirely on glucose for ATP generation. Under aerobic conditions, most of the glucose is metabolized to pyruvate. Aerobic metabolism depends on the activities of glycosomal triosephosphate isomerase and a mitochondrial glycerophosphate oxidase, and on glycerophosphate<-->dihydroxyacetone phosphate exchange across the glycosomal membrane. Using a combination of genetics and computer modelling, we show that triosephosphate isomerase is probably essential for bloodstream trypanosome survival, but not for the insect-dwelling procyclics, which preferentially use amino acids as an energy source. When the enzyme level decreased to about 15% of that of the wild-type, the growth rate was halved. Below this level, a lethal rise in dihydroxyacetone phosphate was predicted. Expression of cytosolic triosephosphate isomerase inhibited cell growth. Attempts to knockout the trypanosome alternative oxidase genes (which are needed for glycerophosphate oxidase activity) were unsuccessful, but when we lowered the level of the corresponding mRNA by expressing a homologous double-stranded RNA, oxygen consumption was reduced fourfold and the rate of trypanosome growth was halved.
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Affiliation(s)
- S Helfert
- Zentrum für Molekularbiologie der Universität Heidelberg (ZMBH), Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
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