1
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Dihydroorotate dehydrogenase inhibitors in anti-infective drug research. Eur J Med Chem 2019; 183:111681. [PMID: 31557612 DOI: 10.1016/j.ejmech.2019.111681] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 08/01/2019] [Accepted: 09/05/2019] [Indexed: 01/08/2023]
Abstract
Pyrimidines are essential for the cell survival and proliferation of living parasitic organisms, such as Helicobacter pylori, Plasmodium falciparum and Schistosoma mansoni, that are able to impact upon human health. Pyrimidine building blocks, in human cells, are synthesised via both de novo biosynthesis and salvage pathways, the latter of which is an effective way of recycling pre-existing nucleotides. As many parasitic organisms lack pyrimidine salvage pathways for pyrimidine nucleotides, blocking de novo biosynthesis is seen as an effective therapeutic means to selectively target the parasite without effecting the human host. Dihydroorotate dehydrogenase (DHODH), which is involved in the de novo biosynthesis of pyrimidines, is a validated target for anti-infective drug research. Recent advances in the DHODH microorganism field are discussed herein, as is the potential for the development of DHODH-targeted therapeutics.
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2
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Kumar V, Sharma M, Rakesh BR, Malik CK, Neelagiri S, Neerupudi KB, Garg P, Singh S. Pyridoxal kinase: A vitamin B6 salvage pathway enzyme from Leishmania donovani. Int J Biol Macromol 2018; 119:320-334. [DOI: 10.1016/j.ijbiomac.2018.07.095] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 07/13/2018] [Accepted: 07/14/2018] [Indexed: 12/21/2022]
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3
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The Oral Antimalarial Drug Tafenoquine Shows Activity against Trypanosoma brucei. Antimicrob Agents Chemother 2015. [PMID: 26195527 DOI: 10.1128/aac.00879-15] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The protozoan parasite Trypanosoma brucei causes human African trypanosomiasis, or sleeping sickness, a neglected tropical disease that requires new, safer, and more effective treatments. Repurposing oral drugs could reduce both the time and cost involved in sleeping sickness drug discovery. Tafenoquine (TFQ) is an oral antimalarial drug belonging to the 8-aminoquinoline family which is currently in clinical phase III. We show here that TFQ efficiently kills different T. brucei spp. in the submicromolar concentration range. Our results suggest that TFQ accumulates into acidic compartments and induces a necrotic process involving cell membrane disintegration and loss of cytoplasmic content, leading to parasite death. Cell lysis is preceded by a wide and multitarget drug action, affecting the lysosome, mitochondria, and acidocalcisomes and inducing a depolarization of the mitochondrial membrane potential, elevation of intracellular Ca(2+), and production of reactive oxygen species. This is the first report of an 8-aminoquinoline demonstrating significant in vitro activity against T. brucei.
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4
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Sola I, Castellà S, Viayna E, Galdeano C, Taylor MC, Gbedema SY, Pérez B, Clos MV, Jones DC, Fairlamb AH, Wright CW, Kelly JM, Muñoz-Torrero D. Synthesis, biological profiling and mechanistic studies of 4-aminoquinoline-based heterodimeric compounds with dual trypanocidal-antiplasmodial activity. Bioorg Med Chem 2015; 23:5156-67. [PMID: 25678015 DOI: 10.1016/j.bmc.2015.01.031] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Revised: 01/16/2015] [Accepted: 01/19/2015] [Indexed: 12/13/2022]
Abstract
Dual submicromolar trypanocidal-antiplasmodial compounds have been identified by screening and chemical synthesis of 4-aminoquinoline-based heterodimeric compounds of three different structural classes. In Trypanosoma brucei, inhibition of the enzyme trypanothione reductase seems to be involved in the potent trypanocidal activity of these heterodimers, although it is probably not the main biological target. Regarding antiplasmodial activity, the heterodimers seem to share the mode of action of the antimalarial drug chloroquine, which involves inhibition of the haem detoxification process. Interestingly, all of these heterodimers display good brain permeabilities, thereby being potentially useful for late stage human African trypanosomiasis. Future optimization of these compounds should focus mainly on decreasing cytotoxicity and acetylcholinesterase inhibitory activity.
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Affiliation(s)
- Irene Sola
- Laboratori de Química Farmacèutica (Unitat Associada al CSIC), Facultat de Farmàcia, and Institut de Biomedicina (IBUB), Universitat de Barcelona, Av. Joan XXIII, 27-31, E-08028 Barcelona, Spain
| | - Sílvia Castellà
- Laboratori de Química Farmacèutica (Unitat Associada al CSIC), Facultat de Farmàcia, and Institut de Biomedicina (IBUB), Universitat de Barcelona, Av. Joan XXIII, 27-31, E-08028 Barcelona, Spain
| | - Elisabet Viayna
- Laboratori de Química Farmacèutica (Unitat Associada al CSIC), Facultat de Farmàcia, and Institut de Biomedicina (IBUB), Universitat de Barcelona, Av. Joan XXIII, 27-31, E-08028 Barcelona, Spain
| | - Carles Galdeano
- Laboratori de Química Farmacèutica (Unitat Associada al CSIC), Facultat de Farmàcia, and Institut de Biomedicina (IBUB), Universitat de Barcelona, Av. Joan XXIII, 27-31, E-08028 Barcelona, Spain
| | - Martin C Taylor
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Stephen Y Gbedema
- Bradford School of Pharmacy, University of Bradford, West Yorkshire BD7 1 DP, United Kingdom; Department of Pharmaceutics, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Belén Pérez
- Departament de Farmacologia, de Terapèutica i de Toxicologia, Universitat Autònoma de Barcelona, 08193-Bellaterra, Barcelona, Spain
| | - M Victòria Clos
- Departament de Farmacologia, de Terapèutica i de Toxicologia, Universitat Autònoma de Barcelona, 08193-Bellaterra, Barcelona, Spain
| | - Deuan C Jones
- Division of Biological Chemistry & Drug Discovery, College of Life Sciences, University of Dundee, Dundee DD1 5EH, United Kingdom
| | - Alan H Fairlamb
- Division of Biological Chemistry & Drug Discovery, College of Life Sciences, University of Dundee, Dundee DD1 5EH, United Kingdom
| | - Colin W Wright
- Bradford School of Pharmacy, University of Bradford, West Yorkshire BD7 1 DP, United Kingdom
| | - John M Kelly
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, United Kingdom
| | - Diego Muñoz-Torrero
- Laboratori de Química Farmacèutica (Unitat Associada al CSIC), Facultat de Farmàcia, and Institut de Biomedicina (IBUB), Universitat de Barcelona, Av. Joan XXIII, 27-31, E-08028 Barcelona, Spain.
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5
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May B, Elliott C, Iwata M, Young L, Shearman J, Albury MS, Moore AL. Expression and crystallization of the plant alternative oxidase. Methods Mol Biol 2015; 1305:281-299. [PMID: 25910742 DOI: 10.1007/978-1-4939-2639-8_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The alternative oxidase (AOX) is an integral monotopic membrane protein located on the inner surface of the inner mitochondrial membrane. Branching from the traditional respiratory chain at the quinone pool, AOX is responsible for cyanide-resistant respiration in plants and fungi, heat generation in thermogenic plants, and survival of parasites, such as Trypanosoma brucei, in the human host. A recently solved AOX structure provides insight into its active site, thereby facilitating rational phytopathogenic and antiparasitic drug design. Here, we describe expression of recombinant AOX using two different expression systems. Purification protocols for the production of highly pure and stable AOX protein in sufficient quantities to facilitate further kinetic, biophysical, and structural analyses are also described.
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Affiliation(s)
- Benjamin May
- Department of Biochemistry and Molecular Biology, School of Life Sciences, University of Sussex, John Maynard Smith Building, Falmer, Brighton, BN1 9QG, UK
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6
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Sola I, Artigas A, Taylor MC, Gbedema SY, Pérez B, Clos MV, Wright CW, Kelly JM, Muñoz-Torrero D. Synthesis and antiprotozoal activity of oligomethylene- and p-phenylene-bis(methylene)-linked bis(+)-huprines. Bioorg Med Chem Lett 2014; 24:5435-8. [DOI: 10.1016/j.bmcl.2014.10.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Revised: 10/04/2014] [Accepted: 10/08/2014] [Indexed: 01/24/2023]
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7
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Chakraborty S. DOCLASP - Docking ligands to target proteins using spatial and electrostatic congruence extracted from a known holoenzyme and applying simple geometrical transformations. F1000Res 2014; 3:262. [PMID: 27429737 DOI: 10.12688/f1000research.5145.2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/10/2014] [Indexed: 02/04/2023] Open
Abstract
The ability to accurately and effectively predict the interaction between proteins and small drug-like compounds has long intrigued researchers for pedagogic, humanitarian and economic reasons. Protein docking methods (AutoDock, GOLD, DOCK, FlexX and Glide to name a few) rank a large number of possible conformations of protein-ligand complexes using fast algorithms. Previously, it has been shown that structural congruence leading to the same enzymatic function necessitates the congruence of electrostatic properties (CLASP). The current work presents a methodology for docking a ligand into a target protein, provided that there is at least one known holoenzyme with ligand bound - DOCLASP (Docking using CLASP). The contact points of the ligand in the holoenzyme defines a motif, which is used to query the target enzyme using CLASP. If there are significant matches, the holoenzyme and the target protein are superimposed based on congruent atoms. The same linear and rotational transformations are also applied to the ligand, thus creating a unified coordinate framework having the holoenzyme, the ligand and the target enzyme. In the current work, the dipeptidyl peptidase-IV inhibitor vildagliptin was docked to the PI-PLC structure complexed with myo-inositol using DOCLASP. Also, corroboration of the docking of phenylthiourea to the modelled structure of polyphenol oxidase (JrPPO1) from walnut is provided based on the subsequently solved structure of JrPPO1 (PDBid:5CE9). Analysis of the binding of the antitrypanosomial drug suramin to nine non-homologous proteins in the PDB database shows a diverse set of binding motifs, and multiple binding sites in the phospholipase A2-likeproteins from the Bothrops genus of pitvipers. The conformational changes in the suramin molecule on binding highlights the challenges in docking flexible ligands into an already 'plastic' binding site. Thus, DOCLASP presents a method for 'soft docking' ligands to proteins with low computational requirements.
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Affiliation(s)
- Sandeep Chakraborty
- Plant Sciences Department, University of California, Davis, CA, 95616, USA; Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, 400 005, India; Celia Engineers, Navi Mumbai, India
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8
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Chakraborty S. DOCLASP - Docking ligands to target proteins using spatial and electrostatic congruence extracted from a known holoenzyme and applying simple geometrical transformations. F1000Res 2014; 3:262. [PMID: 27429737 PMCID: PMC4934513 DOI: 10.12688/f1000research.5145.3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/14/2016] [Indexed: 12/01/2022] Open
Abstract
The ability to accurately and effectively predict the interaction between proteins and small drug-like compounds has long intrigued researchers for pedagogic, humanitarian and economic reasons. Protein docking methods (AutoDock, GOLD, DOCK, FlexX and Glide to name a few) rank a large number of possible conformations of protein-ligand complexes using fast algorithms. Previously, it has been shown that structural congruence leading to the same enzymatic function necessitates the congruence of electrostatic properties (CLASP). The current work presents a methodology for docking a ligand into a target protein, provided that there is at least one known holoenzyme with ligand bound - DOCLASP (Docking using CLASP). The contact points of the ligand in the holoenzyme defines a motif, which is used to query the target enzyme using CLASP. If there are significant matches, the holoenzyme and the target protein are superimposed based on congruent atoms. The same linear and rotational transformations are also applied to the ligand, thus creating a unified coordinate framework having the holoenzyme, the ligand and the target enzyme. In the current work, the dipeptidyl peptidase-IV inhibitor vildagliptin was docked to the PI-PLC structure complexed with myo-inositol using DOCLASP. Also, corroboration of the docking of phenylthiourea to the modelled structure of polyphenol oxidase (JrPPO1) from walnut is provided based on the subsequently solved structure of JrPPO1 (PDBid:5CE9). Analysis of the binding of the antitrypanosomial drug suramin to nine non-homologous proteins in the PDB database shows a diverse set of binding motifs, and multiple binding sites in the phospholipase A2-likeproteins from the Bothrops genus of pitvipers. The conformational changes in the suramin molecule on binding highlights the challenges in docking flexible ligands into an already ’plastic’ binding site. Thus, DOCLASP presents a method for ’soft docking’ ligands to proteins with low computational requirements.
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Affiliation(s)
- Sandeep Chakraborty
- Plant Sciences Department, University of California, Davis, CA, 95616, USA; Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, 400 005, India; Celia Engineers, Navi Mumbai, India
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9
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Njoroge M, Njuguna NM, Mutai P, Ongarora DSB, Smith PW, Chibale K. Recent approaches to chemical discovery and development against malaria and the neglected tropical diseases human African trypanosomiasis and schistosomiasis. Chem Rev 2014; 114:11138-63. [PMID: 25014712 DOI: 10.1021/cr500098f] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
| | | | | | | | - Paul W Smith
- Novartis Institute for Tropical Diseases , Singapore 138670, Singapore
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10
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Rashad AA, Jones AJ, Avery VM, Baell J, Keller PA. Facile Synthesis and Preliminary Structure-Activity Analysis of New Sulfonamides Against Trypanosoma brucei. ACS Med Chem Lett 2014; 5:496-500. [PMID: 24900868 DOI: 10.1021/ml400487t] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 03/10/2014] [Indexed: 12/17/2022] Open
Abstract
The high throughput screening of a library of over 87,000 drug-like compounds against the African sleeping sickness parasite resulted in the discovery of hits with a wide range of molecular diversity. We report here the medicinal chemistry development of one such hit, a tetrahydroisoquinoline disulfonamide, with the synthesis and testing of 26 derivatives against the trypanosome subspecies. Activities in the 2-4 μM range were revealed with a selectivity index suitable for further development.
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Affiliation(s)
- Adel A. Rashad
- School
of Chemistry, University of Wollongong, Wollongong 2522, Australia
| | - Amy J. Jones
- Eskitis
Institute for Drug Discovery, Griffith University, Brisbane Innovation Park, Don Young
Road, Nathan 4111, Australia
| | - Vicky M. Avery
- Eskitis
Institute for Drug Discovery, Griffith University, Brisbane Innovation Park, Don Young
Road, Nathan 4111, Australia
| | - Jonathan Baell
- Medicinal
Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Australia
| | - Paul A. Keller
- School
of Chemistry, University of Wollongong, Wollongong 2522, Australia
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11
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Chakraborty S. DOCLASP - Docking ligands to target proteins using spatial and electrostatic congruence extracted from a known holoenzyme and applying simple geometrical transformations. F1000Res 2014; 3:262. [PMID: 27429737 DOI: 10.12688/f1000research.5145.1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/27/2014] [Indexed: 12/20/2022] Open
Abstract
The ability to accurately and effectively predict the interaction between proteins and small drug-like compounds has long intrigued researchers for pedagogic, humanitarian and economic reasons. Protein docking methods (AutoDock, GOLD, DOCK, FlexX and Glide to name a few) rank a large number of possible conformations of protein-ligand complexes using fast algorithms. Previously, it has been shown that structural congruence leading to the same enzymatic function necessitates the congruence of electrostatic properties (CLASP). The current work presents a methodology for docking a ligand into a target protein, provided that there is at least one known holoenzyme with ligand bound - DOCLASP (Docking using CLASP). The contact points of the ligand in the holoenzyme defines a motif, which is used to query the target enzyme using CLASP. If there are significant matches, the holoenzyme and the target protein are superimposed based on congruent atoms. The same linear and rotational transformations are also applied to the ligand, thus creating a unified coordinate framework having the holoenzyme, the ligand and the target enzyme. In the current work, the dipeptidyl peptidase-IV inhibitor vildagliptin was docked to the PI-PLC structure complexed with myo-inositol using DOCLASP. Also, corroboration of the docking of phenylthiourea to the modelled structure of polyphenol oxidase (JrPPO1) from walnut is provided based on the subsequently solved structure of JrPPO1 (PDBid:5CE9). Analysis of the binding of the antitrypanosomial drug suramin to nine non-homologous proteins in the PDB database shows a diverse set of binding motifs, and multiple binding sites in the phospholipase A2-likeproteins from the Bothrops genus of pitvipers. The conformational changes in the suramin molecule on binding highlights the challenges in docking flexible ligands into an already 'plastic' binding site. Thus, DOCLASP presents a method for 'soft docking' ligands to proteins with low computational requirements.
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Affiliation(s)
- Sandeep Chakraborty
- Plant Sciences Department, University of California, Davis, CA, 95616, USA; Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, 400 005, India; Celia Engineers, Navi Mumbai, India
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12
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Sykes ML, Avery VM. Approaches to Protozoan Drug Discovery: Phenotypic Screening. J Med Chem 2013; 56:7727-40. [DOI: 10.1021/jm4004279] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Melissa L. Sykes
- Discovery Biology, Eskitis Institute
for Drug Discovery, Griffith University, Nathan, Queensland, Australia
| | - Vicky M. Avery
- Discovery Biology, Eskitis Institute
for Drug Discovery, Griffith University, Nathan, Queensland, Australia
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13
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Abstract
The discovery, development and optimal utilization of pharmaceuticals can be greatly enhanced by knowledge of their modes of action. However, many drugs currently on the market act by unknown mechanisms. Untargeted metabolomics offers the potential to discover modes of action for drugs that perturb cellular metabolism. Development of high resolution LC-MS methods and improved data analysis software now allows rapid detection of drug-induced changes to cellular metabolism in an untargeted manner. Several studies have demonstrated the ability of untargeted metabolomics to provide unbiased target discovery for antimicrobial drugs, in particular for antiprotozoal agents. Furthermore, the utilization of targeted metabolomics techniques has enabled validation of existing hypotheses regarding antiprotozoal drug mechanisms. Metabolomics approaches are likely to assist with optimization of new drug candidates by identification of drug targets, and by allowing detailed characterization of modes of action and resistance of existing and novel antiprotozoal drugs.
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14
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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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15
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Velez N, Brautigam CA, Phillips MA. Trypanosoma brucei S-adenosylmethionine decarboxylase N terminus is essential for allosteric activation by the regulatory subunit prozyme. J Biol Chem 2013; 288:5232-40. [PMID: 23288847 DOI: 10.1074/jbc.m112.442475] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human African trypanosomiasis is caused by a single-celled protozoan parasite, Trypanosoma brucei. Polyamine biosynthesis is a clinically validated target for the treatment of human African trypanosomiasis. Metabolic differences between the parasite and the human polyamine pathway are thought to contribute to species selectivity of pathway inhibitors. S-adenosylmethionine decarboxylase (AdoMetDC) catalyzes a key step in the production of the polyamine spermidine. We previously showed that trypanosomatid AdoMetDC differs from other eukaryotic enzymes in that it is regulated by heterodimer formation with a catalytically dead paralog, designated prozyme, which binds with high affinity to the enzyme and increases its activity by up to 10(3)-fold. Herein, we examine the role of specific residues involved in AdoMetDC activation by prozyme through deletion and site-directed mutagenesis. Results indicate that 12 key amino acids at the N terminus of AdoMetDC are essential for prozyme-mediated activation with Leu-8, Leu-10, Met-11, and Met-13 identified as the key residues. These N-terminal residues are fully conserved in the trypanosomatids but are absent from other eukaryotic homologs lacking the prozyme mechanism, suggesting co-evolution of these residues with the prozyme mechanism. Heterodimer formation between AdoMetDC and prozyme was not impaired by mutation of Leu-8 and Leu-10 to Ala, suggesting that these residues are involved in a conformational change that is essential for activation. Our findings provide the first insight into the mechanisms that influence catalytic regulation of AdoMetDC and may have potential implications for the development of new inhibitors against this enzyme.
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Affiliation(s)
- Nahir Velez
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9041, USA
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