1
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Lappalainen R, Kumar M, Duraisingh MT. Hungry for control: metabolite signaling to chromatin in Plasmodium falciparum. Curr Opin Microbiol 2024; 78:102430. [PMID: 38306915 PMCID: PMC11157454 DOI: 10.1016/j.mib.2024.102430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 12/18/2023] [Accepted: 01/08/2024] [Indexed: 02/04/2024]
Abstract
The human malaria parasite Plasmodium falciparum undergoes a complex life cycle in two hosts, mammalian and mosquito, where it is constantly subjected to environmental changes in nutrients. Epigenetic mechanisms govern transcriptional switches and are essential for parasite persistence and proliferation. Parasites infecting red blood cells are auxotrophic for several nutrients, and mounting evidence suggests that various metabolites act as direct substrates for epigenetic modifications, with their abundance directly relating to changes in parasite gene expression. Here, we review the latest understanding of metabolic changes that alter the histone code resulting in changes to transcriptional programmes in malaria parasites.
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Affiliation(s)
- Ruth Lappalainen
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston 02115, USA
| | - Manish Kumar
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston 02115, USA
| | - Manoj T Duraisingh
- Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston 02115, USA.
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2
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Vasquez M, Sica M, Namazzi R, Opoka RO, Sherman J, Datta D, Duran-Frigola M, Ssenkusu JM, John CC, Conroy AL, Rodriguez A. Xanthine oxidase levels and immune dysregulation are independently associated with anemia in Plasmodium falciparum malaria. Sci Rep 2023; 13:14720. [PMID: 37679382 PMCID: PMC10484935 DOI: 10.1038/s41598-023-41764-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 08/31/2023] [Indexed: 09/09/2023] Open
Abstract
Severe anemia is an important contributor to mortality in children with severe malaria. Anemia in malaria is a multi-factorial complication, since dyserythropoiesis, hemolysis and phagocytic clearance of uninfected red blood cells (RBCs) can contribute to this syndrome. High levels of oxidative stress and immune dysregulation have been proposed to contribute to severe malarial anemia, facilitating the clearance of uninfected RBCs. In a cohort of 552 Ugandan children with severe malaria, we measured the levels of xanthine oxidase (XO), an oxidative enzyme that is elevated in the plasma of malaria patients. The levels of XO in children with severe anemia were significantly higher compared to children with severe malaria not suffering from severe anemia. Levels of XO were inversely associated with RBC hemoglobin (ρ = - 0.25, p < 0.0001), indicating a relation between this enzyme and severe anemia. When compared with the levels of immune complexes and of autoimmune antibodies to phosphatidylserine, factors previously associated with severe anemia in malaria patients, we observed that XO is not associated with them, suggesting that XO is associated with severe anemia through an independent mechanism. XO was associated with prostration, acidosis, jaundice, respiratory distress, and kidney injury, which may reflect a broader relation of this enzyme with severe malaria pathology. Since inhibitors of XO are inexpensive and well-tolerated drugs already approved for use in humans, the validation of XO as a contributor to severe malarial anemia and other malaria complications may open new possibilities for much needed adjunctive therapy in malaria.
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Affiliation(s)
- Marilyn Vasquez
- New York University School of Medicine, 430E 29th St, New York, NY, 10016, USA
| | - Margaux Sica
- New York University School of Medicine, 430E 29th St, New York, NY, 10016, USA
| | - Ruth Namazzi
- Department of Paediatrics, Makerere University College of Health Sciences, Kampala, Uganda
- Global Health Uganda, Kampala, Uganda
| | - Robert O Opoka
- Department of Paediatrics, Makerere University College of Health Sciences, Kampala, Uganda
- Global Health Uganda, Kampala, Uganda
| | - Julian Sherman
- New York University School of Medicine, 430E 29th St, New York, NY, 10016, USA
| | - Dibyadyuti Datta
- Ryan White Center for Pediatric Infectious Disease and Global Health, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
- Center for Global Health, Indiana University, Indianapolis, IN, 46202, USA
| | | | - John M Ssenkusu
- Department of Epidemiology and Biostatistics, Makerere University School of Public Health, Kampala, Uganda
| | - Chandy C John
- Ryan White Center for Pediatric Infectious Disease and Global Health, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
- Center for Global Health, Indiana University, Indianapolis, IN, 46202, USA
| | - Andrea L Conroy
- Ryan White Center for Pediatric Infectious Disease and Global Health, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
- Center for Global Health, Indiana University, Indianapolis, IN, 46202, USA
| | - Ana Rodriguez
- New York University School of Medicine, 430E 29th St, New York, NY, 10016, USA.
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3
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Wang C, Yu L, Zhang J, Zhou Y, Sun B, Xiao Q, Zhang M, Liu H, Li J, Li J, Luo Y, Xu J, Lian Z, Lin J, Wang X, Zhang P, Guo L, Ren R, Deng D. Structural basis of the substrate recognition and inhibition mechanism of Plasmodium falciparum nucleoside transporter PfENT1. Nat Commun 2023; 14:1727. [PMID: 36977719 PMCID: PMC10050424 DOI: 10.1038/s41467-023-37411-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 03/16/2023] [Indexed: 03/30/2023] Open
Abstract
By lacking de novo purine biosynthesis enzymes, Plasmodium falciparum requires purine nucleoside uptake from host cells. The indispensable nucleoside transporter ENT1 of P. falciparum facilitates nucleoside uptake in the asexual blood stage. Specific inhibitors of PfENT1 prevent the proliferation of P. falciparum at submicromolar concentrations. However, the substrate recognition and inhibitory mechanism of PfENT1 are still elusive. Here, we report cryo-EM structures of PfENT1 in apo, inosine-bound, and inhibitor-bound states. Together with in vitro binding and uptake assays, we identify that inosine is the primary substrate of PfENT1 and that the inosine-binding site is located in the central cavity of PfENT1. The endofacial inhibitor GSK4 occupies the orthosteric site of PfENT1 and explores the allosteric site to block the conformational change of PfENT1. Furthermore, we propose a general "rocker switch" alternating access cycle for ENT transporters. Understanding the substrate recognition and inhibitory mechanisms of PfENT1 will greatly facilitate future efforts in the rational design of antimalarial drugs.
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Affiliation(s)
- Chen Wang
- Department of Obstetrics, Key Laboratory of Birth Defects and Related Disease of Women and Children of MOE, State Key Laboratory of Biotherapy, West China Second Hospital, Sichuan University, Chengdu, 610041, China
- Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Fudan University, Shanghai, 200438, China
| | - Leiye Yu
- Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Fudan University, Shanghai, 200438, China
- Warshal Institute of Computational Biology, School of Life and Health Sciences, the Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, China
| | - Jiying Zhang
- Department of Obstetrics, Key Laboratory of Birth Defects and Related Disease of Women and Children of MOE, State Key Laboratory of Biotherapy, West China Second Hospital, Sichuan University, Chengdu, 610041, China
| | - Yanxia Zhou
- Department of Obstetrics, Key Laboratory of Birth Defects and Related Disease of Women and Children of MOE, State Key Laboratory of Biotherapy, West China Second Hospital, Sichuan University, Chengdu, 610041, China
| | - Bo Sun
- Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201204, China
| | - Qingjie Xiao
- Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy of Sciences, Shanghai, 201204, China
| | - Minhua Zhang
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Huayi Liu
- Department of Obstetrics, Key Laboratory of Birth Defects and Related Disease of Women and Children of MOE, State Key Laboratory of Biotherapy, West China Second Hospital, Sichuan University, Chengdu, 610041, China
| | - Jinhong Li
- Department of Obstetrics, Key Laboratory of Birth Defects and Related Disease of Women and Children of MOE, State Key Laboratory of Biotherapy, West China Second Hospital, Sichuan University, Chengdu, 610041, China
| | - Jialu Li
- Department of Obstetrics, Key Laboratory of Birth Defects and Related Disease of Women and Children of MOE, State Key Laboratory of Biotherapy, West China Second Hospital, Sichuan University, Chengdu, 610041, China
| | - Yunzi Luo
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering of MOE, School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
| | - Jie Xu
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Zhong Lian
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Jingwen Lin
- Department of Obstetrics, Key Laboratory of Birth Defects and Related Disease of Women and Children of MOE, State Key Laboratory of Biotherapy, West China Second Hospital, Sichuan University, Chengdu, 610041, China
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Xiang Wang
- Department of Obstetrics, Key Laboratory of Birth Defects and Related Disease of Women and Children of MOE, State Key Laboratory of Biotherapy, West China Second Hospital, Sichuan University, Chengdu, 610041, China
| | - Peng Zhang
- National Key Laboratory of Plant Molecular Genetics, Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Li Guo
- Department of Obstetrics, Key Laboratory of Birth Defects and Related Disease of Women and Children of MOE, State Key Laboratory of Biotherapy, West China Second Hospital, Sichuan University, Chengdu, 610041, China.
| | - Ruobing Ren
- Shanghai Key Laboratory of Metabolic Remodeling and Health, Institute of Metabolism and Integrative Biology, Fudan University, Shanghai, 200438, China.
- Shanghai Qi Zhi Institute, Shanghai, 200030, China.
| | - Dong Deng
- Department of Obstetrics, Key Laboratory of Birth Defects and Related Disease of Women and Children of MOE, State Key Laboratory of Biotherapy, West China Second Hospital, Sichuan University, Chengdu, 610041, China.
- NHC key Laboratory of Chronobiology, Sichuan University, Chengdu, 610041, China.
- Development and Related Diseases of Women and Children Key Laboratory of Sichuan Province, Sichuan University, Chengdu, 610041, China.
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4
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Continuous In Vitro Culture of Babesia duncani in a Serum-Free Medium. Cells 2023; 12:cells12030482. [PMID: 36766823 PMCID: PMC9914146 DOI: 10.3390/cells12030482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/31/2023] [Accepted: 01/31/2023] [Indexed: 02/05/2023] Open
Abstract
Human babesiosis is an emerging tick-borne disease, caused by haemoprotozoa genus of Babesia. Cases of transfusion-transmitted and naturally acquired Babesia infection have been reported worldwide in recent years and causing a serious public health problem. Babesia duncani is one of the important pathogens of human babesiosis, which seriously endangers human health. The in vitro culture systems of B. duncani have been previously established, and it requires fetal bovine serum (FBS) to support long-term proliferation. However, there are no studies on serum-free in vitro culture of B. duncani. In this study, we reported that B. duncani achieved long-term serum-free culture in VP-SFM AGTTM (VP-SFM) supplemented with AlbuMaxTM I. The effect of adding different dilutions of AlbuMaxTM I to VP-SFM showed that 2 mg/mL AlbuMaxTM I had the best B. duncani growth curve with a maximum percentage of parasitized erythrocytes (PPE) of over 40%, and it can be used for long-term in vitro culture of B. duncani. However, the commonly used 20% serum-supplemented medium only achieves 20% PPE. Clearly, VP-SFM with 2 mg/mL AlbuMaxTM I (VP-SFMA) is more suitable for the in vitro proliferation of B. duncani. VP-SFM supplemented with CD lipid mixture was also tested, and the results showed it could support the parasite growth at 1:100 dilution with the highest PPE of 40%, which is similar to that of 2 mg/mL AlbuMaxTM I. However, the CD lipid mixture was only able to support the in vitro culture of B. duncani for 8 generations, while VP-SFMA could be used for long-term culture. To test the pathogenicity, the VP-SFMA cultured B. duncani was also subjected to hamster infection. Results showed that the hamster developed dyspnea and chills on day 7 with 30% PPE before treatment, which is similar to the symptoms with un-cultured B. duncani. This study develops a unique and reliable basis for further understanding of the physiological mechanisms, growth characteristics, and pathogenesis of babesiosis, and provides good laboratory material for the development of drugs or vaccines for human babesiosis and possibly other parasitic diseases.
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5
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Gai S, Suthagar K, Shaffer KJ, Jiao W, Minnow YVT, Glockzin K, Maatouk SW, Katzfuss A, Meek TD, Schramm VL, Tyler PC. The design of protozoan phosphoribosyltransferase inhibitors containing non-charged phosphate mimic residues. Bioorg Med Chem 2022; 74:117038. [PMID: 36209571 DOI: 10.1016/j.bmc.2022.117038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 09/22/2022] [Accepted: 09/23/2022] [Indexed: 01/11/2023]
Abstract
Phosphate groups play essential roles in biological processes, including retention inside biological membranes. Phosphodiesters link nucleic acids, and the reversible transfer of phosphate groups is essential in energy metabolism and cell-signalling processes. Phosphorylated metabolic intermediates are known targets for metabolic and disease-related disorders, and the enzymes involved in these pathways recognize phosphate groups in their catalytic sites. Therapeutics that target these enzymes can require charged (ionic) entities to capture the binding energy of ionic substrates. Such compounds are not cell-permeable and require pro-drug strategies for efficacy as therapeutics. Protozoan parasites such as Plasmodium and Trypanosoma spp. are unable to synthesise purines de novo and rely on the salvage of purines from the host cell to synthesise free purine bases. Purine phosphoribosyltransfereases (PPRTases) play a crucial role for purine salvage and are potential target for drug development. Here we present attempts to design inhibitors of PPRTases that are non-ionic and show affinity for the nucleotide 5'-phosphate binding site. Inhibitor design was based on known potent ionic inhibitors, reported phosphate mimics and computational modelling studies.
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Affiliation(s)
- Sinan Gai
- The Ferrier Research Institute, Victoria University of Wellington, Wellington, New Zealand
| | - Kajitha Suthagar
- The Ferrier Research Institute, Victoria University of Wellington, Wellington, New Zealand
| | - Karl J Shaffer
- The Ferrier Research Institute, Victoria University of Wellington, Wellington, New Zealand
| | - Wanting Jiao
- The Ferrier Research Institute, Victoria University of Wellington, Wellington, New Zealand
| | - Yacoba V T Minnow
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Kayla Glockzin
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
| | - Sean W Maatouk
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
| | - Ardala Katzfuss
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
| | - Thomas D Meek
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
| | - Vern L Schramm
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Peter C Tyler
- The Ferrier Research Institute, Victoria University of Wellington, Wellington, New Zealand.
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6
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Chhibber-Goel J, Shukla A, Shanmugam D, Sharma A. Profiling of metabolic alterations in mice infected with malaria parasites via high-resolution metabolomics. Mol Biochem Parasitol 2022; 252:111525. [PMID: 36209797 DOI: 10.1016/j.molbiopara.2022.111525] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 09/20/2022] [Accepted: 10/03/2022] [Indexed: 12/31/2022]
Abstract
BACKGROUND Malaria infection can result in distinct clinical outcomes from asymptomatic to severe. The association between patho-physiological changes and molecular changes in the host, and their correlation with severity of malaria progression is not fully understood. METHODS In this study, we addressed mass spectrometry-based temporal profiling of serum metabolite levels from mice infected with Plasmodium berhgei (strain ANKA). RESULTS We show global perturbations and identify changes in specific metabolites in correlation with disease progression. While metabolome-wide changes were apparent in late-stage malaria, a subset of metabolites exhibited highly correlated changes with disease progression. These metabolites changed early on following infection and either continued or maintained the change as mice developed severe disease. Some of these have the potential to be sentinel metabolites for severe malaria. Moreover, glycolytic metabolites, purine nucleotide precursors, tryptophan and its bioactive derivatives were many fold decreased in late-stage disease. Interestingly, uric acid, a metabolic waste reported to be elevated in severe human malaria, increased with disease progression, and subsequently appears to be detoxified into allantoin. This detoxification mechanism is absent in humans as they lack the enzyme uricase. CONCLUSIONS We have identified candidate marker metabolites that may be of relevance in the context of human malaria.
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Affiliation(s)
- Jyoti Chhibber-Goel
- Molecular Medicine, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Road, New Delhi 110067, India
| | - Anurag Shukla
- Biochemical Sciences Division, CSIR-National Chemical Laboratory, Pune 411008, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Dhanasekaran Shanmugam
- Biochemical Sciences Division, CSIR-National Chemical Laboratory, Pune 411008, India; Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
| | - Amit Sharma
- Molecular Medicine, International Centre for Genetic Engineering and Biotechnology (ICGEB), Aruna Asaf Ali Road, New Delhi 110067, India; ICMR-National institute of Malaria Research, New Delhi 110077, India.
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7
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Botnar A, Lawrence G, Maher SP, Vantaux A, Witkowski B, Shiau JC, Merino EF, De Vore D, Yang C, Murray C, Cassera MB, Leahy JW, Kyle DE. Alkyne modified purines for assessment of activation of Plasmodium vivax hypnozoites and growth of pre-erythrocytic and erythrocytic stages in Plasmodium spp. Int J Parasitol 2022; 52:733-744. [PMID: 35447149 PMCID: PMC9576819 DOI: 10.1016/j.ijpara.2022.03.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 03/28/2022] [Accepted: 03/28/2022] [Indexed: 12/26/2022]
Abstract
Malaria is a major global health problem which predominantly afflicts developing countries. Although many antimalarial therapies are currently available, the protozoan parasite causing this disease, Plasmodium spp., continues to evade eradication efforts. One biological phenomenon hampering eradication efforts is the parasite's ability to arrest development, transform into a drug-insensitive form, and then resume growth post-therapy. Currently, the mechanisms by which the parasite enters arrested development, or dormancy, and later recrudesces or reactivates to continue development, are unknown and the malaria field lacks techniques to study these elusive mechanisms. Since Plasmodium spp. salvage purines for DNA synthesis, we hypothesised that alkyne-containing purine nucleosides could be used to develop a DNA synthesis marker which could be used to investigate mechanisms behind dormancy. Using copper-catalysed click chemistry methods, we observe incorporation of alkyne modified adenosine, inosine, and hypoxanthine in actively replicating asexual blood stages of Plasmodium falciparum and incorporation of modified adenosine in actively replicating liver stage schizonts of Plasmodium vivax. Notably, these modified purines were not incorporated in dormant liver stage hypnozoites, suggesting this marker could be used as a tool to differentiate replicating and non-replicating liver forms and, more broadly, as a tool for advancing our understanding of Plasmodium dormancy mechanisms.
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Affiliation(s)
- Alona Botnar
- Department of Infectious Diseases, University of Georgia, Athens, GA, United States; Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, United States
| | - Grant Lawrence
- Department of Chemistry, University of South Florida, Tampa, FL, United States
| | - Steven P Maher
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, United States
| | - Amélie Vantaux
- Malaria Molecular Epidemiology Unit, Pasteur Institute of Cambodia, Phnom Penh, Cambodia
| | - Benoît Witkowski
- Malaria Molecular Epidemiology Unit, Pasteur Institute of Cambodia, Phnom Penh, Cambodia
| | - Justine C Shiau
- Department of Infectious Diseases, University of Georgia, Athens, GA, United States; Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, United States
| | - Emilio F Merino
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, United States; Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
| | - David De Vore
- Department of Chemistry, University of South Florida, Tampa, FL, United States
| | - Christian Yang
- Department of Chemistry, University of South Florida, Tampa, FL, United States
| | - Cameron Murray
- Department of Chemistry, University of South Florida, Tampa, FL, United States
| | - Maria B Cassera
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, United States; Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States
| | - James W Leahy
- Department of Chemistry, University of South Florida, Tampa, FL, United States; The Florida Center for Excellence for Drug Discovery and Innovation, University of South Florida, Tampa, GA, United States; Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, GA, United States
| | - Dennis E Kyle
- Department of Infectious Diseases, University of Georgia, Athens, GA, United States; Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, United States; Department of Cellular Biology, University of Georgia, Athens, GA, United States.
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8
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Singh P, Pal AC, Mamoun CB. An Alternative Culture Medium for Continuous In Vitro Propagation of the Human Pathogen Babesia duncani in Human Erythrocytes. Pathogens 2022; 11:599. [PMID: 35631120 PMCID: PMC9146245 DOI: 10.3390/pathogens11050599] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 05/17/2022] [Accepted: 05/19/2022] [Indexed: 02/01/2023] Open
Abstract
Continuous propagation of Babesia duncani in vitro in human erythrocytes and the availability of a mouse model of B. duncani lethal infection make this parasite an ideal model to study Babesia biology and pathogenesis. Two culture media, HL-1 and Claycomb, with proprietary formulations are the only culture media known to support the parasite growth in human erythrocytes; however, the HL-1 medium has been discontinued and the Claycomb medium is often unavailable leading to major interruptions in the study of this pathogen. To identify alternative media conditions, we evaluated the growth of B. duncani in various culture media with well-defined compositions. We report that the DMEM-F12 culture medium supports the continuous growth of the parasite in human erythrocytes to levels equal to those achieved in the HL-1 and Claycomb media. We generated new clones of B. duncani from the parental WA-1 clinical isolate after three consecutive subcloning events in this medium. All clones showed a multiplication rate in vitro similar to that of the WA-1 parental isolate and cause fatal infection in C3H/HeJ mice. The culture medium, which can be readily reconstituted from its individual components, and the tools and resources developed here will facilitate the study of B. duncani.
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Affiliation(s)
| | | | - Choukri Ben Mamoun
- Department of Internal Medicine, Section of Infectious Diseases, Yale School of Medicine, New Haven, CT 06519, USA; (P.S.); (A.C.P.)
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9
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Wu Z, Han Z, Zhou W, Sun X, Chen L, Yang S, Hu J, Li C. Insight into the Nucleoside Transport and Inhibition of Human ENT1. Curr Res Struct Biol 2022; 4:192-205. [PMID: 35677775 PMCID: PMC9168172 DOI: 10.1016/j.crstbi.2022.05.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 05/02/2022] [Accepted: 05/18/2022] [Indexed: 12/03/2022] Open
Abstract
The human equilibrative nucleoside transporter 1 (hENT1) is an effective controller of adenosine signaling by regulating its extracellular and intracellular concentration, and has become a solid drug target of clinical used adenosine reuptake inhibitors (AdoRIs). Currently, the mechanisms of adenosine transport and inhibition for hENT1 remain unclear, which greatly limits the in-depth understanding of its inner workings as well as the development of novel inhibitors. In this work, the dynamic details of hENT1 underlie adenosine transport and the inhibition mechanism of the non-nucleoside AdoRIs dilazep both were investigated by comparative long-time unbiased molecular dynamics simulations. The calculation results show that the conformational transitions of hENT1 from the outward open to metastable occluded state are mainly driven by TM1, TM2, TM7 and TM9. One of the trimethoxyphenyl rings in dilazep serves as the adenosyl moiety of the endogenous adenosine substrate to competitively occupy the orthosteric site of hENT1. Due to extensive and various VDW interactions with N30, M33, M84, P308 and F334, the other trimethoxyphenyl ring is stuck in the opportunistic site near the extracellular side preventing the complete occlusion of thin gate simultaneously. Obviously, dilazep shows significant inhibitory activity by disrupting the local induce-fit action in substrate binding cavity and blocking the transport cycle of whole protein. This study not only reveals the nucleoside transport mechanism by hENT1 at atomic level, but also provides structural guidance for the subsequent design of novel non-nucleoside AdoRIs with enhanced pharmacologic properties. The transitions of hENT1 from the outward open to metastable occluded state are mainly driven by TM1, TM2, TM7 and TM9. The induce-fit action by adenosine recognition precedes. inward contraction of the extracellular side. Dilazep exerts its special hENT1 inhibitory function through competitive binding and allosteric regulation. A gating strategy of extracellular loop is revealed to ensure adenosine is firmly located in the transport cavity.
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Affiliation(s)
- Zhixiang Wu
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing, China
| | - Zhongjie Han
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing, China
| | - Wenxue Zhou
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing, China
| | - Xiaohan Sun
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing, China
| | - Lei Chen
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing, China
| | - Shuang Yang
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing, China
| | - Jianping Hu
- Key Laboratory of Medicinal and Edible Plants Resources, Development of Sichuan Education Department, School of Pharmacy, Chengdu University, Chengdu, China
- Corresponding author. Key Laboratory of Medicinal and Edible Plants Resources, Development of Sichuan Education Department, School of Pharmacy, Chengdu University, Chengdu, 610106, China.
| | - Chunhua Li
- Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing, China
- Corresponding author. Faculty of Environmental and Life Sciences, Beijing University of Technology, Beijing, 100124, China.
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10
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Wang C, Krüger A, Du X, Wrenger C, Groves MR. Novel Highlight in Malarial Drug Discovery: Aspartate Transcarbamoylase. Front Cell Infect Microbiol 2022; 12:841833. [PMID: 35310840 PMCID: PMC8931299 DOI: 10.3389/fcimb.2022.841833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 02/15/2022] [Indexed: 11/16/2022] Open
Abstract
Malaria remains one of the most prominent and dangerous tropical diseases. While artemisinin and analogs have been used as first-line drugs for the past decades, due to the high mutational rate and rapid adaptation to the environment of the parasite, it remains urgent to develop new antimalarials. The pyrimidine biosynthesis pathway plays an important role in cell growth and proliferation. Unlike human host cells, the malarial parasite lacks a functional pyrimidine salvage pathway, meaning that RNA and DNA synthesis is highly dependent on the de novo synthesis pathway. Thus, direct or indirect blockage of the pyrimidine biosynthesis pathway can be lethal to the parasite. Aspartate transcarbamoylase (ATCase), catalyzes the second step of the pyrimidine biosynthesis pathway, the condensation of L-aspartate and carbamoyl phosphate to form N-carbamoyl aspartate and inorganic phosphate, and has been demonstrated to be a promising target both for anti-malaria and anti-cancer drug development. This is highlighted by the discovery that at least one of the targets of Torin2 – a potent, yet unselective, antimalarial – is the activity of the parasite transcarbamoylase. Additionally, the recent discovery of an allosteric pocket of the human homology raises the intriguing possibility of species selective ATCase inhibitors. We recently exploited the available crystal structures of the malarial aspartate transcarbamoylase to perform a fragment-based screening to identify hits. In this review, we summarize studies on the structure of Plasmodium falciparum ATCase by focusing on an allosteric pocket that supports the catalytic mechanisms.
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Affiliation(s)
- Chao Wang
- Department of Drug Design, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, Netherlands
| | - Arne Krüger
- Unit for Drug Discovery, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Xiaochen Du
- Department of Drug Design, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, Netherlands
| | - Carsten Wrenger
- Unit for Drug Discovery, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
- *Correspondence: Matthew R. Groves, ; Carsten Wrenger,
| | - Matthew R. Groves
- Department of Drug Design, Groningen Research Institute of Pharmacy, University of Groningen, Groningen, Netherlands
- *Correspondence: Matthew R. Groves, ; Carsten Wrenger,
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11
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Grube CD, Gill CP, Roy H. Development of a continuous assay for high throughput screening to identify inhibitors of the purine salvage pathway in Plasmodium falciparum. SLAS DISCOVERY : ADVANCING LIFE SCIENCES R & D 2022; 27:114-120. [PMID: 35058189 DOI: 10.1016/j.slasd.2021.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Malaria, an infectious disease caused by protozoan parasites from the genus Plasmodium, represents a serious global health threat. The continued emergence of drug resistant strains has severely decreased current antimalarial drug efficacy and led to a perpetual race for drug discovery. Most protozoan parasites, including Plasmodium spp., are unable to synthesize purines de novo and instead rely on an essential purine salvage pathway for acquisition of purines from the infected host. Because purines are essential for Plasmodium growth and survival, the enzymes of the purine salvage pathway represent promising targets for drug discovery. Target-based high-throughput screening (HTS) assays traditionally focus on a single target, which severely limits the screening power of this type of approach. To circumvent this limitation, we have reconstituted the purine salvage pathway from Plasmodium falciparum in an assay combining four drug targets. This assay was developed for HTS and optimized to detect partial inhibition of any of the four enzymes in the pathway. Inhibitors of several enzymes in the pathway were identified in a pilot screen, with several compounds exhibiting effective inhibition when provided in micromolar amounts.
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Affiliation(s)
- Christopher D Grube
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Cameron P Gill
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Hervé Roy
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA.
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12
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Kurian J, Kumari V, Chaluvalappil SV, Anas M, Manhas A, Kalluruttimmal R, Kumar N, Manheri MK. Adenine Modification at C7 as a Viable Strategy to Potentiate the Antimalarial Activity of Quinolones. ChemMedChem 2021; 17:e202100472. [PMID: 34717044 DOI: 10.1002/cmdc.202100472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/15/2021] [Indexed: 11/08/2022]
Abstract
Although many quinolones have shown promise as potent antimalarials, their clinical development has been slow due to poor performance in vivo. Insights into structural modifications that can improve their therapeutic potential will be very valuable in this vibrant area of research. Our studies involving a library of quinolones which vary in substitution pattern at N1, C3, C6 and C7 positions have shown that the presence of adenine moiety at C7 can bring a noticeable improvement in activity compared to other heterocyclic groups at this location. The most potent compound emerged from this study showed IC50 values of 0.38 μM and 0.75 μM against chloroquine-sensitive and -resistant (W2) strains, respectively. Docking analysis in the Qo site of cytochrome bc1 complex revealed the contribution of a key H-bonding interaction from the adenine unit in target binding. This corroborates with compound-induced loss of mitochondrial functions. These findings not only open avenues for further exploration of antimalarial potential of adenine-modified quinolones, but also suggests broader opportunities during lead-optimization against other antimalarial targets.
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Affiliation(s)
- Jais Kurian
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu, India
| | - Varsha Kumari
- Department of Molecular Microbiology and Immunology, CSIR-Central Drug Research Institute, Sector 10, Jankipuram extension, Sitapur road, Lucknow, 226031, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Saheer V Chaluvalappil
- Department of Chemistry, Krishna Menon Memorial Government Women's College, Kannur 670004, Kerala, India
| | - Mohammad Anas
- Department of Molecular Microbiology and Immunology, CSIR-Central Drug Research Institute, Sector 10, Jankipuram extension, Sitapur road, Lucknow, 226031, India
| | - Ashan Manhas
- Department of Molecular Microbiology and Immunology, CSIR-Central Drug Research Institute, Sector 10, Jankipuram extension, Sitapur road, Lucknow, 226031, India
| | - Ramshad Kalluruttimmal
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu, India
| | - Niti Kumar
- Department of Molecular Microbiology and Immunology, CSIR-Central Drug Research Institute, Sector 10, Jankipuram extension, Sitapur road, Lucknow, 226031, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India
| | - Muraleedharan K Manheri
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, Tamil Nadu, India
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13
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Martinez-Peinado N, Lorente-Macías Á, García-Salguero A, Cortes-Serra N, Fenollar-Collado Á, Ros-Lucas A, Gascon J, Pinazo MJ, Molina IJ, Unciti-Broceta A, Díaz-Mochón JJ, Pineda de las Infantas y Villatoro MJ, Izquierdo L, Alonso-Padilla J. Novel Purine Chemotypes with Activity against Plasmodium falciparum and Trypanosoma cruzi. Pharmaceuticals (Basel) 2021; 14:ph14070638. [PMID: 34358064 PMCID: PMC8308784 DOI: 10.3390/ph14070638] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/24/2021] [Accepted: 06/26/2021] [Indexed: 11/16/2022] Open
Abstract
Malaria and Chagas disease, caused by Plasmodium spp. and Trypanosoma cruzi parasites, remain important global health problems. Available treatments for those diseases present several limitations, such as lack of efficacy, toxic side effects, and drug resistance. Thus, new drugs are urgently needed. The discovery of new drugs may be benefited by considering the significant biological differences between hosts and parasites. One of the most striking differences is found in the purine metabolism, because most of the parasites are incapable of de novo purine biosynthesis. Herein, we have analyzed the in vitro anti-P. falciparum and anti-T. cruzi activity of a collection of 81 purine derivatives and pyrimidine analogs. We firstly used a primary screening at three fixed concentrations (100, 10, and 1 µM) and progressed those compounds that kept the growth of the parasites < 30% at 100 µM to dose–response assays. Then, we performed two different cytotoxicity assays on Vero cells and human HepG2 cells. Finally, compounds specifically active against T. cruzi were tested against intracellular amastigote forms. Purines 33 (IC50 = 19.19 µM) and 76 (IC50 = 18.27 µM) were the most potent against P. falciparum. On the other hand, 6D (IC50 = 3.78 µM) and 34 (IC50 = 4.24 µM) were identified as hit purines against T. cruzi amastigotes. Moreover, an in silico docking study revealed that P. falciparum and T. cruzi hypoxanthine guanine phosphoribosyltransferase enzymes could be the potential targets of those compounds. Our study identified two novel, purine-based chemotypes that could be further optimized to generate potent and diversified anti-parasitic drugs against both parasites.
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Affiliation(s)
- Nieves Martinez-Peinado
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic—University of Barcelona, 08036 Barcelona, Spain; (N.M.-P.); (A.G.-S.); (N.C.-S.); (Á.F.-C.); (A.R.-L.); (J.G.); (M.-J.P.)
| | - Álvaro Lorente-Macías
- Department of Medicinal & Organic Chemistry and Excellence Research Unit of “Chemistry Applied to Biomedicine and the Environment”, Faculty of Pharmacy, University of Granada, Campus de Cartuja s/n, 18071 Granada, Spain; (Á.L.-M.); (J.J.D.-M.)
- Institute of Biopathology and Regenerative Medicine, Centre for Biomedical Research, University of Granada, Avda. del Conocimiento s/n, 18100 Granada, Spain;
- Cancer Research UK Edinburgh Centre, Institute of Genetics & Cancer, University of Edinburgh, Crewe Road South, Edinburgh EH4 2XR, UK;
| | - Alejandro García-Salguero
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic—University of Barcelona, 08036 Barcelona, Spain; (N.M.-P.); (A.G.-S.); (N.C.-S.); (Á.F.-C.); (A.R.-L.); (J.G.); (M.-J.P.)
| | - Nuria Cortes-Serra
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic—University of Barcelona, 08036 Barcelona, Spain; (N.M.-P.); (A.G.-S.); (N.C.-S.); (Á.F.-C.); (A.R.-L.); (J.G.); (M.-J.P.)
| | - Ángel Fenollar-Collado
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic—University of Barcelona, 08036 Barcelona, Spain; (N.M.-P.); (A.G.-S.); (N.C.-S.); (Á.F.-C.); (A.R.-L.); (J.G.); (M.-J.P.)
| | - Albert Ros-Lucas
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic—University of Barcelona, 08036 Barcelona, Spain; (N.M.-P.); (A.G.-S.); (N.C.-S.); (Á.F.-C.); (A.R.-L.); (J.G.); (M.-J.P.)
| | - Joaquim Gascon
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic—University of Barcelona, 08036 Barcelona, Spain; (N.M.-P.); (A.G.-S.); (N.C.-S.); (Á.F.-C.); (A.R.-L.); (J.G.); (M.-J.P.)
| | - Maria-Jesus Pinazo
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic—University of Barcelona, 08036 Barcelona, Spain; (N.M.-P.); (A.G.-S.); (N.C.-S.); (Á.F.-C.); (A.R.-L.); (J.G.); (M.-J.P.)
| | - Ignacio J. Molina
- Institute of Biopathology and Regenerative Medicine, Centre for Biomedical Research, University of Granada, Avda. del Conocimiento s/n, 18100 Granada, Spain;
| | - Asier Unciti-Broceta
- Cancer Research UK Edinburgh Centre, Institute of Genetics & Cancer, University of Edinburgh, Crewe Road South, Edinburgh EH4 2XR, UK;
| | - Juan J. Díaz-Mochón
- Department of Medicinal & Organic Chemistry and Excellence Research Unit of “Chemistry Applied to Biomedicine and the Environment”, Faculty of Pharmacy, University of Granada, Campus de Cartuja s/n, 18071 Granada, Spain; (Á.L.-M.); (J.J.D.-M.)
| | - María J. Pineda de las Infantas y Villatoro
- Department of Medicinal & Organic Chemistry and Excellence Research Unit of “Chemistry Applied to Biomedicine and the Environment”, Faculty of Pharmacy, University of Granada, Campus de Cartuja s/n, 18071 Granada, Spain; (Á.L.-M.); (J.J.D.-M.)
- Correspondence: (M.J.P.d.l.I.y.V.); (L.I.); (J.A.-P.); Tel.: +34-958249360 (M.J.P.d.l.I.y.V.); +34-932275400 (ext. 4569) (L.I.); +34-932275400 (ext. 4569) (J.A.-P.)
| | - Luis Izquierdo
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic—University of Barcelona, 08036 Barcelona, Spain; (N.M.-P.); (A.G.-S.); (N.C.-S.); (Á.F.-C.); (A.R.-L.); (J.G.); (M.-J.P.)
- Correspondence: (M.J.P.d.l.I.y.V.); (L.I.); (J.A.-P.); Tel.: +34-958249360 (M.J.P.d.l.I.y.V.); +34-932275400 (ext. 4569) (L.I.); +34-932275400 (ext. 4569) (J.A.-P.)
| | - Julio Alonso-Padilla
- Barcelona Institute for Global Health (ISGlobal), Hospital Clínic—University of Barcelona, 08036 Barcelona, Spain; (N.M.-P.); (A.G.-S.); (N.C.-S.); (Á.F.-C.); (A.R.-L.); (J.G.); (M.-J.P.)
- Correspondence: (M.J.P.d.l.I.y.V.); (L.I.); (J.A.-P.); Tel.: +34-958249360 (M.J.P.d.l.I.y.V.); +34-932275400 (ext. 4569) (L.I.); +34-932275400 (ext. 4569) (J.A.-P.)
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14
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Counihan NA, Modak JK, de Koning-Ward TF. How Malaria Parasites Acquire Nutrients From Their Host. Front Cell Dev Biol 2021; 9:649184. [PMID: 33842474 PMCID: PMC8027349 DOI: 10.3389/fcell.2021.649184] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 02/24/2021] [Indexed: 01/01/2023] Open
Abstract
Plasmodium parasites responsible for the disease malaria reside within erythrocytes. Inside this niche host cell, parasites internalize and digest host hemoglobin to source amino acids required for protein production. However, hemoglobin does not contain isoleucine, an amino acid essential for Plasmodium growth, and the parasite cannot synthesize it de novo. The parasite is also more metabolically active than its host cell, and the rate at which some nutrients are consumed exceeds the rate at which they can be taken up by erythrocyte transporters. To overcome these constraints, Plasmodium parasites increase the permeability of the erythrocyte membrane to isoleucine and other low-molecular-weight solutes it requires for growth by forming new permeation pathways (NPPs). In addition to the erythrocyte membrane, host nutrients also need to cross the encasing parasitophorous vacuole membrane (PVM) and the parasite plasma membrane to access the parasite. This review outlines recent advances that have been made in identifying the molecular constituents of the NPPs, the PVM nutrient channel, and the endocytic apparatus that transports host hemoglobin and identifies key knowledge gaps that remain. Importantly, blocking the ability of Plasmodium to source essential nutrients is lethal to the parasite, and thus, components of these key pathways represent potential antimalaria drug targets.
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Affiliation(s)
| | - Joyanta K Modak
- School of Medicine, Deakin University, Waurn Ponds, VIC, Australia
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15
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Minnow YVT, Harijan RK, Schramm VL. A resistant mutant of Plasmodium falciparum purine nucleoside phosphorylase uses wild-type neighbors to maintain parasite survival. J Biol Chem 2021; 296:100342. [PMID: 33524395 PMCID: PMC7949152 DOI: 10.1016/j.jbc.2021.100342] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 01/16/2021] [Accepted: 01/21/2021] [Indexed: 12/14/2022] Open
Abstract
Plasmodium falciparum purine nucleoside phosphorylase (PfPNP) catalyzes an essential step in purine salvage for parasite growth. 4′-Deaza-1′-Aza-2′-Deoxy-1′-(9-Methylene)-Immucillin-G (DADMe-ImmG) is a transition state analog inhibitor of this enzyme, and P. falciparum infections in an Aotus primate malaria model can be cleared by oral administration of DADMe-ImmG. P. falciparum cultured under increasing DADMe-ImmG drug pressure exhibited PfPNP gene amplification, increased protein expression, and point mutations involved in DADMe-ImmG binding. However, the weak catalytic properties of the M183L resistance mutation (∼17,000-fold decrease in catalytic efficiency) are inconsistent with the essential function of PfPNP. We hypothesized that M183L subunits may form mixed oligomers of native and mutant PfPNP monomers to give hybrid hexameric enzymes with properties conferring DADMe-ImmG resistance. To test this hypothesis, we designed PfPNP constructs that covalently linked native and the catalytically weak M183L mutant subunits. Engineered hybrid PfPNP yielded trimer-of-dimer hexameric protein with alternating native and catalytically weak M183L subunits. This hybrid PfPNP gave near-native Km values for substrate, but the affinity for DADMe-ImmG and catalytic efficiency were both reduced approximately ninefold relative to a similar construct of native subunits. Contact between the relatively inactive M183L and native subunits is responsible for altered properties of the hybrid protein. Thus, gene amplification of PfPNP provides adequate catalytic activity while resistance to DADMe-ImmG occurs in the hybrid oligomer to promote parasite survival. Coupled with the slow development of drug resistance, this resistance mechanism highlights the potential for DADMe-ImmG use in antimalarial combination therapies.
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Affiliation(s)
- Yacoba V T Minnow
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Rajesh K Harijan
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Vern L Schramm
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, USA.
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16
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Xu G, van Bruggen R, Gualtieri CO, Moradin N, Fois A, Vallerand D, De Sa Tavares Russo M, Bassenden A, Lu W, Tam M, Lesage S, Girouard H, Avizonis DZ, Deblois G, Prchal JT, Stevenson M, Berghuis A, Muir T, Rabinowitz J, Vidal SM, Fodil N, Gros P. Bisphosphoglycerate Mutase Deficiency Protects against Cerebral Malaria and Severe Malaria-Induced Anemia. Cell Rep 2020; 32:108170. [PMID: 32966787 DOI: 10.1016/j.celrep.2020.108170] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 07/07/2020] [Accepted: 08/27/2020] [Indexed: 11/30/2022] Open
Abstract
The replication cycle and pathogenesis of the Plasmodium malarial parasite involves rapid expansion in red blood cells (RBCs), and variants of certain RBC-specific proteins protect against malaria in humans. In RBCs, bisphosphoglycerate mutase (BPGM) acts as a key allosteric regulator of hemoglobin/oxyhemoglobin. We demonstrate here that a loss-of-function mutation in the murine Bpgm (BpgmL166P) gene confers protection against both Plasmodium-induced cerebral malaria and blood-stage malaria. The malaria protection seen in BpgmL166P mutant mice is associated with reduced blood parasitemia levels, milder clinical symptoms, and increased survival. The protective effect of BpgmL166P involves a dual mechanism that enhances the host's stress erythroid response to Plasmodium-driven RBC loss and simultaneously alters the intracellular milieu of the RBCs, including increased oxyhemoglobin and reduced energy metabolism, reducing Plasmodium maturation, and replication. Overall, our study highlights the importance of BPGM as a regulator of hemoglobin/oxyhemoglobin in malaria pathogenesis and suggests a new potential malaria therapeutic target.
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Affiliation(s)
- Guoyue Xu
- Department of Human Genetics, McGill University, Montreal, QC H3A 0C7, Canada; McGill University Research Centre on Complex Traits, McGill University, Montreal, QC H3G 0B1, Canada
| | - Rebekah van Bruggen
- McGill University Research Centre on Complex Traits, McGill University, Montreal, QC H3G 0B1, Canada; Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada
| | - Christian O Gualtieri
- McGill University Research Centre on Complex Traits, McGill University, Montreal, QC H3G 0B1, Canada; Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada
| | - Neda Moradin
- McGill University Research Centre on Complex Traits, McGill University, Montreal, QC H3G 0B1, Canada
| | - Adrien Fois
- Immunology-Oncology Unit, Maisonneuve-Rosemont Hospital Research Center, Montréal, QC H1T 2M4, Canada; Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Diane Vallerand
- Université de Montréal, Département de Pharmacologie et Physiologie, Pav Roger-Gaudry, 2900 Édouard-Montpetit, Montréal, QC H3T 1J4, Canada
| | | | - Angelia Bassenden
- Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada
| | - Wenyun Lu
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA
| | - Mifong Tam
- Department of Microbiology and Immunology, McGill University, Montréal, QC H3A 2B4, Canada
| | - Sylvie Lesage
- Immunology-Oncology Unit, Maisonneuve-Rosemont Hospital Research Center, Montréal, QC H1T 2M4, Canada; Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, QC H3T 1J4, Canada
| | - Hélène Girouard
- Université de Montréal, Département de Pharmacologie et Physiologie, Pav Roger-Gaudry, 2900 Édouard-Montpetit, Montréal, QC H3T 1J4, Canada
| | - Daina Zofija Avizonis
- Rosalind and Morris Goodman Cancer Research Centre, 1160 Pin Avenue West, Montréal, QC H3A 1A3, Canada
| | - Geneviève Deblois
- Institute for Research in Immunology and Cancer, Université de Montréal, Montréal, QC H3T 1J4, Canada; Faculté de Pharmacie, Université de Montréal, Montréal, QC H3C 3J7, Canada
| | - Josef T Prchal
- Division of Hematology, School of Medicine, University of Utah, Salt Lake City, UT 84132, USA
| | - Mary Stevenson
- Department of Microbiology and Immunology, McGill University, Montréal, QC H3A 2B4, Canada
| | - Albert Berghuis
- Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada
| | - Tom Muir
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Joshua Rabinowitz
- Lewis Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Chemistry, Princeton University, Princeton, NJ 08544, USA
| | - Silvia M Vidal
- Department of Human Genetics, McGill University, Montreal, QC H3A 0C7, Canada; McGill University Research Centre on Complex Traits, McGill University, Montreal, QC H3G 0B1, Canada; Department of Microbiology and Immunology, McGill University, Montréal, QC H3A 2B4, Canada
| | - Nassima Fodil
- McGill University Research Centre on Complex Traits, McGill University, Montreal, QC H3G 0B1, Canada; Centre CERMO-FC Pavillon des Sciences Biologiques, 141 Avenue du Président Kennedy, Montréal, QC H2X 3Y7, Canada.
| | - Philippe Gros
- Department of Human Genetics, McGill University, Montreal, QC H3A 0C7, Canada; McGill University Research Centre on Complex Traits, McGill University, Montreal, QC H3G 0B1, Canada; Department of Biochemistry, McGill University, Montreal, QC H3A 1A3, Canada.
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17
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Chabanol E, Behrends V, Prévot G, Christophides GK, Gendrin M. Antibiotic Treatment in Anopheles coluzzii Affects Carbon and Nitrogen Metabolism. Pathogens 2020; 9:E679. [PMID: 32825534 PMCID: PMC7558193 DOI: 10.3390/pathogens9090679] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/13/2020] [Accepted: 08/17/2020] [Indexed: 01/04/2023] Open
Abstract
The mosquito microbiota reduces the vector competence of Anopheles to Plasmodium and affects host fitness; it is therefore considered as a potential target to reduce malaria transmission. While immune induction, secretion of antimicrobials and metabolic competition are three typical mechanisms of microbiota-mediated protection against invasive pathogens in mammals, the involvement of metabolic competition or mutualism in mosquito-microbiota and microbiota-Plasmodium interactions has not been investigated. Here, we describe a metabolome analysis of the midgut of Anopheles coluzzii provided with a sugar-meal or a non-infectious blood-meal, under conventional or antibiotic-treated conditions. We observed that the antibiotic treatment affects the tricarboxylic acid cycle and nitrogen metabolism, notably resulting in decreased abundance of free amino acids. Linking our results with published data, we identified pathways which may participate in microbiota-Plasmodium interactions via metabolic interactions or immune modulation and thus would be interesting candidates for future functional studies.
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Affiliation(s)
- Estelle Chabanol
- Microbiota of Insect Vectors Group, Institut Pasteur de Guyane, 97306 Cayenne, French Guiana;
- Ecole Doctorale Numéro 587, Diversités, Santé, et Développement en Amazonie, Université de Guyane, 97337 Cayenne, French Guiana
- Tropical Biome and Immunophysiopathology, Université de Guyane, 97300 Cayenne, French Guiana;
| | - Volker Behrends
- Health Sciences Research Centre, University of Roehampton, London SW15 4JD, UK;
| | - Ghislaine Prévot
- Tropical Biome and Immunophysiopathology, Université de Guyane, 97300 Cayenne, French Guiana;
- Univ. Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019—UMR9017—CIIL—Center for Infection and Immunity of Lille, F-59000 Lille, France
| | | | - Mathilde Gendrin
- Microbiota of Insect Vectors Group, Institut Pasteur de Guyane, 97306 Cayenne, French Guiana;
- Department of Life Sciences, Imperial College London, London SW7 2BU, UK;
- Department of Parasites and Insect Vectors, Institut Pasteur, 75015 Paris, France
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18
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Tewari SG, Swift RP, Reifman J, Prigge ST, Wallqvist A. Metabolic alterations in the erythrocyte during blood-stage development of the malaria parasite. Malar J 2020; 19:94. [PMID: 32103749 PMCID: PMC7045481 DOI: 10.1186/s12936-020-03174-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 02/20/2020] [Indexed: 02/08/2023] Open
Abstract
Background Human blood cells (erythrocytes) serve as hosts for the malaria parasite Plasmodium falciparum during its 48-h intraerythrocytic developmental cycle (IDC). Established in vitro protocols allow for the study of host–parasite interactions during this phase and, in particular, high-resolution metabolomics can provide a window into host–parasite interactions that support parasite development. Methods Uninfected and parasite-infected erythrocyte cultures were maintained at 2% haematocrit for the duration of the IDC, while parasitaemia was maintained at 7% in the infected cultures. The parasite-infected cultures were synchronized to obtain stage-dependent information of parasite development during the IDC. Samples were collected in quadruplicate at six time points from the uninfected and parasite-infected cultures and global metabolomics was used to analyse cell fractions of these cultures. Results In uninfected and parasite-infected cultures during the IDC, 501 intracellular metabolites, including 223 lipid metabolites, were successfully quantified. Of these, 19 distinct metabolites were present only in the parasite-infected culture, 10 of which increased to twofold in abundance during the IDC. This work quantified approximately five times the metabolites measured in previous studies of similar research scope, which allowed for more detailed analyses. Enrichment in lipid metabolism pathways exhibited a time-dependent association with different classes of lipids during the IDC. Specifically, enrichment occurred in sphingolipids at the earlier stages, and subsequently in lysophospholipid and phospholipid metabolites at the intermediate and end stages of the IDC, respectively. In addition, there was an accumulation of 18-, 20-, and 22-carbon polyunsaturated fatty acids, which produce eicosanoids and promote gametocytogenesis in infected erythrocyte cultures. Conclusions The current study revealed a number of heretofore unidentified metabolic components of the host–parasite system, which the parasite may exploit in a time-dependent manner to grow over the course of its development in the blood stage. Notably, the analyses identified components, such as precursors of immunomodulatory molecules, stage-dependent lipid dynamics, and metabolites, unique to parasite-infected cultures. These conclusions are reinforced by the metabolic alterations that were characterized during the IDC, which were in close agreement with those known from previous studies of blood-stage infection.
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Affiliation(s)
- Shivendra G Tewari
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Development Command, Ft. Detrick, MD, USA. .,The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, MD, USA.
| | - Russell P Swift
- Department of Molecular Microbiology and Immunology, Johns Hopkins University, Baltimore, MD, USA
| | - Jaques Reifman
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Development Command, Ft. Detrick, MD, USA
| | - Sean T Prigge
- Department of Molecular Microbiology and Immunology, Johns Hopkins University, Baltimore, MD, USA
| | - Anders Wallqvist
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Development Command, Ft. Detrick, MD, USA.
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19
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Sosa Y, Egbo D, Akabas MH. Impact of Field Isolate Identified Nonsynonymous Single Nucleotide Polymorphisms on Plasmodium falciparum Equilibrative Nucleoside Transporter 1 Inhibitor Efficacy. ACS Infect Dis 2020; 6:205-214. [PMID: 31876139 DOI: 10.1021/acsinfecdis.9b00203] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Plasmodium falciparum causes the most severe form of malaria and causes approximately 500 000 deaths per year. P. falciparum parasites resistant to current antimalarial treatments are spreading. Therefore, it is imperative to develop new antimalarial drugs. Malaria parasites are purine auxotrophic. They rely on purine import from the host erythrocyte via Equilibrative Nucleoside Transporters (ENTs). Recently, inhibitors of the P. falciparum ENT1 (PfENT1) that inhibit proliferation of malaria parasites in culture have been identified as promising starting points for antimalarial drug development. Genome sequencing of P. falciparum field isolates has identified nonsynonymous single nucleotide polymorphisms (SNPs) in the gene encoding PfENT1. Here we evaluate the impact of these PfENT1 SNPs on purine substrate affinity and inhibitor efficacy. We expressed each PfENT1-SNP in Saccharomyces cerevisiae. Using PfENT1-SNP-expressing yeast, we characterized the PfENT1 purine substrate affinity using radiolabeled substrate uptake inhibition experiments. Four of the 13 SNPs altered affinity for one or more purines by up to 7-fold. Three of the SNPs reduced the potency of a subset of the inhibitors by up to 7-fold. One SNP, Q284E, reduced the potency of all six inhibitor chemotypes. We tested drug efficacy in available parasite strains containing PfENT1 SNPs. While PfENT1-SNP-expressing yeast had decreased sensitivity to PfENT1 inhibitors, parasite strains containing SNPs showed similar or more potent inhibition of proliferation with all PfENT1 inhibitors. Thus, parasite strains bearing PfENT1 SNPs are not resistant to these PfENT1 inhibitors. This supports PfENT1 as a promising target for further development of novel antimalarial drugs.
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20
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Das D, Krishnan SR, Roy A, Bulusu G. A network-based approach reveals novel invasion and Maurer's clefts-related proteins in Plasmodium falciparum. Mol Omics 2019; 15:431-441. [PMID: 31631203 DOI: 10.1039/c9mo00124g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Malaria continues to be a major concern in developing countries despite continuous efforts to find a cure for the disease. Understanding the pathogenesis mechanism is necessary to identify more effective drug targets against malaria. Many years of experimental research have generated a large amount of data for the malarial parasite, Plasmodium falciparum. These data are useful to understand the importance of certain parasite proteins, but it often remains unclear how these proteins come together, interact with other proteins and carry out their function. Identification of all proteins involved in pathogenesis is an important step towards understanding the molecular mechanism of pathogenesis. In this study, dynamic stage-specific protein-protein interaction networks were created based on gene expression data during the parasite's intra-erythrocytic stages and static protein-protein interaction data. Using previously known proteins of a biological event as seed proteins, the random walk with restart (RWR) method was used on the dynamic protein-protein interaction networks to identify novel proteins related to that event. Two screening procedures namely, permutation test and GO enrichment test were performed to increase the reliability of the RWR predictions. The proposed method was first validated on Plasmodium falciparum proteins related to invasion, where it could reproduce the existing knowledge from a small set of seed proteins. It was then used to identify novel Maurer's clefts resident proteins, where it could identify 152 parasite proteins. We show that the current approach can annotate conserved proteins with unknown function. The predicted proteins can help build a mechanistic model for disease pathogenesis, which will be useful in identifying new drug targets.
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Affiliation(s)
- Dibyajyoti Das
- TCS Innovation Labs - Hyderabad (Life Sciences Division), Tata Consultancy Services Limited, Hyderabad, India.
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21
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Sosa Y, Deniskin R, Frame IJ, Steiginga MS, Bandyopadhyay D, Graybill TL, Kallal LA, Ouellette MT, Pope AJ, Widdowson KL, Young RJ, Akabas MH. Identification via a Parallel Hit Progression Strategy of Improved Small Molecule Inhibitors of the Malaria Purine Uptake Transporter that Inhibit Plasmodium falciparum Parasite Proliferation. ACS Infect Dis 2019; 5:1738-1753. [PMID: 31373203 DOI: 10.1021/acsinfecdis.9b00168] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Emerging resistance to current antimalarial medicines underscores the importance of identifying new drug targets and novel compounds. Malaria parasites are purine auxotrophic and import purines via the Plasmodium falciparum equilibrative nucleoside transporter type 1 (PfENT1). We previously showed that PfENT1 inhibitors block parasite proliferation in culture. Our goal was to identify additional, possibly more optimal chemical starting points for a drug discovery campaign. We performed a high throughput screen (HTS) of GlaxoSmithKline's 1.8 million compound library with a yeast-based assay to identify PfENT1 inhibitors. We used a parallel progression strategy for hit validation and expansion, with an emphasis on chemical properties in addition to potency. In one arm, the most active hits were tested for human cell toxicity; 201 had minimal toxicity. The second arm, hit expansion, used a scaffold-based substructure search with the HTS hits as templates to identify over 2000 compounds; 123 compounds had activity. Of these 324 compounds, 175 compounds inhibited proliferation of P. falciparum parasite strain 3D7 with IC50 values between 0.8 and ∼180 μM. One hundred forty-two compounds inhibited PfENT1 knockout (pfent1Δ) parasite growth, indicating they also hit secondary targets. Thirty-two hits inhibited growth of 3D7 but not pfent1Δ parasites. Thus, PfENT1 inhibition was sufficient to block parasite proliferation. Therefore, PfENT1 may be a viable target for antimalarial drug development. Six compounds with novel chemical scaffolds were extensively characterized in yeast-, parasite-, and human-erythrocyte-based assays. The inhibitors showed similar potencies against drug sensitive and resistant P. falciparum strains. They represent attractive starting points for development of novel antimalarial drugs.
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Affiliation(s)
| | | | | | - Matthew S. Steiginga
- Platform Technology & Science and Discovery Partners in Academia, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States
| | - Deepak Bandyopadhyay
- Platform Technology & Science and Discovery Partners in Academia, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States
| | - Todd L. Graybill
- Platform Technology & Science and Discovery Partners in Academia, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States
| | - Lorena A. Kallal
- Platform Technology & Science and Discovery Partners in Academia, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States
| | - Michael T. Ouellette
- Platform Technology & Science and Discovery Partners in Academia, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States
| | - Andrew J. Pope
- Platform Technology & Science and Discovery Partners in Academia, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States
| | - Katherine L. Widdowson
- Platform Technology & Science and Discovery Partners in Academia, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States
| | - Robert J. Young
- Platform Technology & Science and Discovery Partners in Academia, GlaxoSmithKline, 1250 South Collegeville Road, Collegeville, Pennsylvania 19426, United States
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22
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Kokina A, Ozolina Z, Liepins J. Purine auxotrophy: Possible applications beyond genetic marker. Yeast 2019; 36:649-656. [PMID: 31334866 DOI: 10.1002/yea.3434] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 07/12/2019] [Accepted: 07/16/2019] [Indexed: 01/09/2023] Open
Abstract
Exploring new drug candidates or drug targets against many illnesses is necessary as "traditional" treatments lose their effectivity. Cancer and sicknesses caused by protozoan parasites are among these diseases. Cell purine metabolism is an important drug target. Theoretically, inhibiting purine metabolism could stop the proliferation of unwanted cells. Purine metabolism is similar across all eukaryotes. However, some medically important organisms or cell lines rely on their host purine metabolism. Protozoans causing malaria, leishmaniasis, or toxoplasmosis are purine auxotrophs. Some cancer forms have also lost the ability to synthesize purines de novo. Budding yeast can serve as an effective model for eukaryotic purine metabolism, and thus, purine auxotrophic strains could be an important tool. In this review, we present the common principles of purine metabolism in eukaryotes, effects of purine starvation in eukaryotic cells, and purine-starved Saccharomyces cerevisiae as a model for purine depletion-elicited metabolic states with applications in evolution studies and pharmacology. Purine auxotrophic yeast strains behave differently when growing in media with sufficient supplementation with adenine or in media depleted of adenine (starvation). In the latter, they undergo cell cycle arrest at G1/G0 and become stress resistant. Importantly, similar effects have also been observed among parasitic protozoans or cancer cells. We consider that studies on metabolic changes caused by purine auxotrophy could reveal new options for parasite or cancer therapy. Further, knowledge on phenotypic changes will improve the use of auxotrophic strains in high-throughput screening for primary drug candidates.
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Affiliation(s)
- Agnese Kokina
- Institute of Microbiology and Biotechnology, University of Latvia, Riga, Latvia
| | - Zane Ozolina
- Institute of Microbiology and Biotechnology, University of Latvia, Riga, Latvia
| | - Janis Liepins
- Institute of Microbiology and Biotechnology, University of Latvia, Riga, Latvia
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23
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Nagappa LK, Singh D, Dey S, Kumar KA, Balaram H. Biochemical and physiological investigations on adenosine 5' monophosphate deaminase from Plasmodium spp. Mol Microbiol 2019; 112:699-717. [PMID: 31132185 DOI: 10.1111/mmi.14313] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/22/2019] [Indexed: 11/29/2022]
Abstract
The interplay between ATP generating and utilizing pathways in a cell is responsible for maintaining cellular ATP/energy homeostasis that is reflected by Adenylate Energy Charge (AEC) ratio. Adenylate kinase (AK), that catalyzes inter-conversion of ADP, ATP and AMP, plays a major role in maintaining AEC and is regulated by cellular AMP levels. Hence, the enzymes AMP deaminase (AMPD) and nucleotidases, which catabolize AMP, indirectly regulate AK activity and in-turn affect AEC. Here, we present the first report on AMPD from Plasmodium, the causative agent of malaria. The recombinant enzyme expressed in Saccharomyces cerevisiae was studied using functional complementation assay and residues vital for enzyme activity have been identified. Similarities and differences between Plasmodium falciparum AMPD (PfAMPD) and its homologs from yeast, Arabidopsis and humans are also discussed. The AMPD gene was deleted in the murine malaria parasite P. berghei and was found to be dispensable during all stages of the parasite life cycle. However, when episomal expression was attempted, viable parasites were not obtained, suggesting that perturbing AMP homeostasis by over-expressing AMPD might be lethal. As AMPD is known to be allosterically modulated by ATP, GTP and phosphate, allosteric activators of PfAMPD could be developed as anti-parasitic agents.
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Affiliation(s)
- Lakshmeesha Kempaiah Nagappa
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Bengaluru, India
| | - Dipti Singh
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Sandeep Dey
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Kota Arun Kumar
- Department of Animal Biology, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Hemalatha Balaram
- Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Bengaluru, India
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24
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Wang X, Miyazaki Y, Inaoka DK, Hartuti ED, Watanabe YI, Shiba T, Harada S, Saimoto H, Burrows JN, Benito FJG, Nozaki T, Kita K. Identification of Plasmodium falciparum Mitochondrial Malate: Quinone Oxidoreductase Inhibitors from the Pathogen Box. Genes (Basel) 2019; 10:genes10060471. [PMID: 31234346 PMCID: PMC6627850 DOI: 10.3390/genes10060471] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 06/14/2019] [Accepted: 06/17/2019] [Indexed: 12/25/2022] Open
Abstract
Malaria is one of the three major global health threats. Drug development for malaria, especially for its most dangerous form caused by Plasmodium falciparum, remains an urgent task due to the emerging drug-resistant parasites. Exploration of novel antimalarial drug targets identified a trifunctional enzyme, malate quinone oxidoreductase (MQO), located in the mitochondrial inner membrane of P. falciparum (PfMQO). PfMQO is involved in the pathways of mitochondrial electron transport chain, tricarboxylic acid cycle, and fumarate cycle. Recent studies have shown that MQO is essential for P. falciparum survival in asexual stage and for the development of experiment cerebral malaria in the murine parasite P. berghei, providing genetic validation of MQO as a drug target. However, chemical validation of MQO, as a target, remains unexplored. In this study, we used active recombinant protein rPfMQO overexpressed in bacterial membrane fractions to screen a total of 400 compounds from the Pathogen Box, released by Medicines for Malaria Venture. The screening identified seven hit compounds targeting rPfMQO with an IC50 of under 5 μM. We tested the activity of hit compounds against the growth of 3D7 wildtype strain of P. falciparum, among which four compounds showed an IC50 from low to sub-micromolar concentrations, suggesting that PfMQO is indeed a potential antimalarial drug target.
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Affiliation(s)
- Xinying Wang
- 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.
| | - Yukiko Miyazaki
- Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4, Sakamoto, Nagasaki 852-8523, Japan.
| | - 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.
- Department of Molecular Infection Dynamics, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4, Sakamoto, Nagasaki 852-8523, Japan.
| | - Endah Dwi Hartuti
- Graduate School of Biomedical Sciences, Nagasaki University, 1-12-4, Sakamoto, Nagasaki 852-8523, Japan.
| | - 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.
| | - Tomoo Shiba
- Department of Applied Biology, Graduate School of Science Technology, Kyoto Institute of Technology, Matsugasaki, Hashikamicho, Sakyo-ku, Kyoto 606-8585, Japan.
| | - Shigeharu Harada
- Department of Applied Biology, Graduate School of Science Technology, Kyoto Institute of Technology, Matsugasaki, Hashikamicho, Sakyo-ku, Kyoto 606-8585, Japan.
| | - Hiroyuki Saimoto
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, 4-101 Koyama-cho Minami, Tottori 680-8550, Japan.
| | | | | | - Tomoyoshi Nozaki
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-0033, 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.
- Department of Host-Defense Biochemistry, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4, Sakamoto, Nagasaki 852-8523, Japan.
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25
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Cheviet T, Lefebvre-Tournier I, Wein S, Peyrottes S. Plasmodium Purine Metabolism and Its Inhibition by Nucleoside and Nucleotide Analogues. J Med Chem 2019; 62:8365-8391. [PMID: 30964283 DOI: 10.1021/acs.jmedchem.9b00182] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Malaria still affects around 200 million people and is responsible for more than 400,000 deaths per year, mostly children in subequatorial areas. This disease is caused by parasites of the Plasmodium genus. Only a few WHO-recommended treatments are available to prevent or cure plasmodial infections, but genetic mutations in the causal parasites have led to onset of resistance against all commercial antimalarial drugs. New drugs and targets are being investigated to cope with this emerging problem, including enzymes belonging to the main metabolic pathways, while nucleoside and nucleotide analogues are also a promising class of potential drugs. This review highlights the main metabolic pathways targeted for the development of potential antiplasmodial therapies based on nucleos(t)ide analogues, as well as the different series of purine-containing nucleoside and nucleotide derivatives designed to inhibit Plasmodium falciparum purine metabolism.
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Affiliation(s)
- Thomas Cheviet
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247 UM-CNRS-ENSCM , Université Montpellier, Equipe Nucléosides & Effecteurs Phosphorylés , Place E. Bataillon, cc 1704 , 34095 Montpellier , France
| | - Isabelle Lefebvre-Tournier
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247 UM-CNRS-ENSCM , Université Montpellier, Equipe Nucléosides & Effecteurs Phosphorylés , Place E. Bataillon, cc 1704 , 34095 Montpellier , France
| | - Sharon Wein
- Dynamique des Interactions Membranaires Normales et Pathologiques (DIMNP), UMR 5235 UM-CNRS , Université Montpellier , Place E. Bataillon , 34095 Montpellier , France
| | - Suzanne Peyrottes
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247 UM-CNRS-ENSCM , Université Montpellier, Equipe Nucléosides & Effecteurs Phosphorylés , Place E. Bataillon, cc 1704 , 34095 Montpellier , France
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26
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Tewari SG, Rajaram K, Schyman P, Swift R, Reifman J, Prigge ST, Wallqvist A. Short-term metabolic adjustments in Plasmodium falciparum counter hypoxanthine deprivation at the expense of long-term viability. Malar J 2019; 18:86. [PMID: 30890151 PMCID: PMC6423861 DOI: 10.1186/s12936-019-2720-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 03/11/2019] [Indexed: 11/21/2022] Open
Abstract
Background The malarial parasite Plasmodium falciparum is an auxotroph for purines, which are required for nucleic acid synthesis during the intra-erythrocytic developmental cycle (IDC) of the parasite. The capabilities of the parasite and extent to which it can use compensatory mechanisms to adapt to purine deprivation were studied by examining changes in its metabolism under sub-optimal concentrations of hypoxanthine, the primary precursor utilized by the parasite for purine-based nucleic acid synthesis. Methods The concentration of hypoxanthine that caused a moderate growth defect over the course of one IDC was determined. At this concentration of hypoxanthine (0.5 μM), transcriptomic and metabolomic data were collected during one IDC at multiple time points. These data were integrated with a metabolic network model of the parasite embedded in a red blood cell (RBC) to interpret the metabolic adaptation of P. falciparum to hypoxanthine deprivation. Results At a hypoxanthine concentration of 0.5 μM, vacuole-like structures in the cytosol of many P. falciparum parasites were observed after the 24-h midpoint of the IDC. Parasites grown under these conditions experienced a slowdown in the progression of the IDC. After 72 h of deprivation, the parasite growth could not be recovered despite supplementation with 90 µM hypoxanthine. Simulations of P. falciparum metabolism suggested that alterations in ubiquinone, isoprenoid, shikimate, and mitochondrial metabolism occurred before the appearance of these vacuole-like structures. Alterations were found in metabolic reactions associated with fatty acid synthesis, the pentose phosphate pathway, methionine metabolism, and coenzyme A synthesis in the latter half of the IDC. Furthermore, gene set enrichment analysis revealed that P. falciparum activated genes associated with rosette formation, Maurer’s cleft and protein export under two different nutrient-deprivation conditions (hypoxanthine and isoleucine). Conclusions The metabolic network analysis presented here suggests that P. falciparum invokes specific purine-recycling pathways to compensate for hypoxanthine deprivation and maintains a hypoxanthine pool for purine-based nucleic acid synthesis. However, this compensatory mechanism is not sufficient to maintain long-term viability of the parasite. Although P. falciparum can complete a full IDC in low hypoxanthine conditions, subsequent cycles are disrupted. Electronic supplementary material The online version of this article (10.1186/s12936-019-2720-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Shivendra G Tewari
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, MD, USA. .,Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Ft. Detrick, MD, USA.
| | - Krithika Rajaram
- Department of Molecular Microbiology and Immunology, Johns Hopkins University, Baltimore, MD, USA
| | - Patric Schyman
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc. (HJF), Bethesda, MD, USA.,Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Ft. Detrick, MD, USA
| | - Russell Swift
- Department of Molecular Microbiology and Immunology, Johns Hopkins University, Baltimore, MD, USA
| | - Jaques Reifman
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Ft. Detrick, MD, USA
| | - Sean T Prigge
- Department of Molecular Microbiology and Immunology, Johns Hopkins University, Baltimore, MD, USA
| | - Anders Wallqvist
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Ft. Detrick, MD, USA.
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27
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Nishtala SN, Arora A, Reyes J, Akabas MH. Accessibility of substituted cysteines in TM2 and TM10 transmembrane segments in the Plasmodium falciparum equilibrative nucleoside transporter PfENT1. J Biol Chem 2019; 294:1924-1935. [PMID: 30541922 DOI: 10.1074/jbc.ra118.006547] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 11/30/2018] [Indexed: 11/06/2022] Open
Abstract
Infection with Plasmodium species parasites causes malaria. Plasmodium parasites are purine auxotrophic. They import purines via an equilibrative nucleoside transporter (ENT). In P. falciparum, the most virulent species, the equilibrative nucleoside transporter 1 (PfENT1) represents the primary purine uptake pathway. This transporter is a potential target for the development of antimalarial drugs. In the absence of a high-resolution structure for either PfENT1 or a homologous ENT, we used the substituted cysteine accessibility method (SCAM) to investigate the membrane-spanning domain structure of PfENT1 to identify potential inhibitor-binding sites. We previously used SCAM to identify water-accessible residues that line the permeation pathway in transmembrane segment 11 (TM11). TM2 and TM10 lie adjacent to TM11 in an ab initio model of a homologous Leishmania donovani nucleoside transporter. To identify TM2 and TM10 residues in PfENT1 that are at least transiently on the water-accessible transporter surface, we assayed the reactivity of single cysteine-substitution mutants with three methanethiosulfonate (MTS) derivatives. Cysteines substituted for 12 of 14 TM2 segment residues reacted with MTS-ethyl-ammonium-biotin (MTSEA-biotin). At eight positions, MTSEA-biotin inhibited transport, and at four positions substrate transport was potentiated. On an α helical wheel projection of TM2, the four positions where potentiation occurred were located in a cluster on one side of the helix. In contrast, although MTSEA-biotin inhibited 9 of 10 TM10 cysteine-substituted mutants, the reactive residues did not form a pattern consistent with either an α helix or β sheet. These results may help identify the binding site(s) of PfENT1 inhibitors.
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Affiliation(s)
| | - Avish Arora
- From the Departments of Physiology and Biophysics
| | - Jorge Reyes
- From the Departments of Physiology and Biophysics
| | - Myles H Akabas
- From the Departments of Physiology and Biophysics, .,Neuroscience, and.,Medicine, Albert Einstein College of Medicine, Bronx, New York 10461
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28
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Dziekan JM, Yu H, Chen D, Dai L, Wirjanata G, Larsson A, Prabhu N, Sobota RM, Bozdech Z, Nordlund P. Identifying purine nucleoside phosphorylase as the target of quinine using cellular thermal shift assay. Sci Transl Med 2019; 11. [DOI: 10.1126/scitranslmed.aau3174] [Citation(s) in RCA: 111] [Impact Index Per Article: 22.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Abstract
A cellular thermal shift assay (CETSA) protocol identifies and resolves antimalarial drug targets in
P. falciparum
.
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Affiliation(s)
- Jerzy M. Dziekan
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore
| | - Han Yu
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore
| | - Dan Chen
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore
| | - Lingyun Dai
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore
| | - Grennady Wirjanata
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore
| | - Andreas Larsson
- Department of Oncology and Pathology, Karolinska Institutet, Stockholm 17177, Sweden
| | - Nayana Prabhu
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore
| | - Radoslaw M. Sobota
- Institute of Molecular and Cell Biology, Functional Proteomics Laboratory, Agency for Science, Technology and Research (A*STAR), 138673, Singapore
- Institute of Medical Biology, Agency for Science, Technology and Research (A*STAR), 138648, Singapore
| | - Zbynek Bozdech
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore
| | - Pär Nordlund
- School of Biological Sciences, Nanyang Technological University, 637551, Singapore
- Department of Oncology and Pathology, Karolinska Institutet, Stockholm 17177, Sweden
- Institute of Molecular and Cell Biology, Functional Proteomics Laboratory, Agency for Science, Technology and Research (A*STAR), 138673, Singapore
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29
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Abstract
Transition state theory teaches that chemically stable mimics of enzymatic transition states will bind tightly to their cognate enzymes. Kinetic isotope effects combined with computational quantum chemistry provides enzymatic transition state information with sufficient fidelity to design transition state analogues. Examples are selected from various stages of drug development to demonstrate the application of transition state theory, inhibitor design, physicochemical characterization of transition state analogues, and their progress in drug development.
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Affiliation(s)
- Vern L. Schramm
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, United States
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30
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Ghosh S, Pathak S, Sonawat HM, Sharma S, Sengupta A. Metabolomic changes in vertebrate host during malaria disease progression. Cytokine 2018; 112:32-43. [PMID: 30057363 DOI: 10.1016/j.cyto.2018.07.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 07/16/2018] [Accepted: 07/17/2018] [Indexed: 12/24/2022]
Abstract
Metabolomics refers to top-down systems biological analysis of metabolites in biological specimens. Phenotypic proximity of metabolites makes them interesting candidates for studying biomarkers of environmental stressors such as parasitic infections. Moreover, the host-parasite interaction directly impinges upon metabolic pathways since the parasite uses the host metabolite pool as a biosynthetic resource. Malarial infection, although not recognized as a classic metabolic disorder, often leads to severe metabolic changes such as hypoglycemia and lactic acidosis. Thus, metabolomic analysis of the infection has become an invaluable tool for promoting a better understanding of the host-parasite interaction and for the development of novel therapeutics. In this review, we summarize the current knowledge obtained from metabolomic studies of malarial infection in rodent models and human patients. Metabolomic analysis of experimental rodent malaria has provided significant insights into the mechanisms of disease progression including utilization of host resources by the parasite, sexual dimorphism in metabolic phenotypes, and cellular changes in host metabolism. Moreover, these studies also provide proof of concept for prediction of cerebral malaria. On the other hand, metabolite analysis of patient biofluids generates extensive data that could be of use in identifying biomarkers of infection severity and in monitoring disease progression. Through the use of metabolomic datasets one hopes to assess crucial infection-specific issues such as clinical severity, drug resistance, therapeutic targets, and biomarkers. Also discussed are nascent or newly emerging areas of metabolomics such as pre-erythrocytic stages of the infection and the host immune response. This review is organized in four broad sections-methodologies for metabolomic analysis, rodent infection models, studies of human clinical specimens, and potential of immunometabolomics. Data summarized in this review should serve as a springboard for novel hypothesis testing and lead to a better understanding of malarial infection and parasite biology.
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Affiliation(s)
- Soumita Ghosh
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, PA 19104, USA.
| | - Sulabha Pathak
- Department of Biological Sciences, Tata Institute of Fundamental Research, 1, Homi Bhabha Road, Mumbai 400005, India
| | - Haripalsingh M Sonawat
- Department of Chemical Sciences, Tata Institute of Fundamental Research, 1, Homi Bhabha Road, Mumbai 400005, India
| | - Shobhona Sharma
- Department of Biological Sciences, Tata Institute of Fundamental Research, 1, Homi Bhabha Road, Mumbai 400005, India
| | - Arjun Sengupta
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, PA 19104, USA.
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31
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Raza M, Khan Z, Ahmad A, Raza S, Khan A, Mohammadzai IU, Zada S. In silico 3-D structure prediction and molecular docking studies of inosine monophosphate dehydrogenase from Plasmodium falciparum. Comput Biol Chem 2017; 71:10-19. [DOI: 10.1016/j.compbiolchem.2017.09.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2017] [Revised: 07/20/2017] [Accepted: 09/05/2017] [Indexed: 10/18/2022]
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32
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Chiu JE, Thekkiniath J, Choi JY, Perrin BA, Lawres L, Plummer M, Virji AZ, Abraham A, Toh JY, Zandt MV, Aly ASI, Voelker DR, Mamoun CB. The antimalarial activity of the pantothenamide α-PanAm is via inhibition of pantothenate phosphorylation. Sci Rep 2017; 7:14234. [PMID: 29079738 PMCID: PMC5660193 DOI: 10.1038/s41598-017-14074-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Accepted: 10/06/2017] [Indexed: 12/21/2022] Open
Abstract
The biosynthesis of the major acyl carrier Coenzyme A from pantothenic acid (PA) is critical for survival of Plasmodium falciparum within human erythrocytes. Accordingly, a PA analog α-PanAm showed potent activity against blood stage parasites in vitro; however, its efficacy in vivo and its mode of action remain unknown. We developed a new synthesis route for α-PanAm and showed that the compound is highly effective against blood stages of drug-sensitive and -resistant P. falciparum strains, inhibits development of P. berghei in hepatocytes, and at doses up to 100 mg/kg also inhibits blood stage development of P. chabaudi in mice. We used yeast and its pantothenate kinase Cab1 as models to characterize mode of action of α-PanAm and found that α-PanAm inhibits yeast growth in a PA-dependent manner, and its potency increases dramatically in a yeast mutant with defective pantothenate kinase activity. Biochemical analyses using 14C-PA as a substrate demonstrated that α-PanAm is a competitive inhibitor of Cab1. Interestingly, biochemical and mass spectrometry analyses also showed that the compound is phosphorylated by Cab1. Together, these data suggest that α-PanAm exerts its antimicrobial activity by direct competition with the natural substrate PA for phosphorylation by the pantothenate kinase.
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Affiliation(s)
- Joy E Chiu
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Jose Thekkiniath
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Jae-Yeon Choi
- Basic Science Section, Department of Medicine, National Jewish Health, 1400 Jackson St, Denver, Colorado, 80206, USA
| | - Benjamin A Perrin
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Lauren Lawres
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Mark Plummer
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Azan Z Virji
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Amanah Abraham
- Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, 70112, USA
| | - Justin Y Toh
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | | | - Ahmed S I Aly
- Department of Tropical Medicine, Tulane University School of Public Health and Tropical Medicine, New Orleans, LA, 70112, USA
| | - Dennis R Voelker
- Basic Science Section, Department of Medicine, National Jewish Health, 1400 Jackson St, Denver, Colorado, 80206, USA
| | - Choukri Ben Mamoun
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA.
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33
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Tang Y, Gupta A, Garimalla S, Galinski MR, Styczynski MP, Fonseca LL, Voit EO. Metabolic modeling helps interpret transcriptomic changes during malaria. Biochim Biophys Acta Mol Basis Dis 2017; 1864:2329-2340. [PMID: 29069611 DOI: 10.1016/j.bbadis.2017.10.023] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Revised: 09/27/2017] [Accepted: 10/17/2017] [Indexed: 10/18/2022]
Abstract
Disease represents a specific case of malfunctioning within a complex system. Whereas it is often feasible to observe and possibly treat the symptoms of a disease, it is much more challenging to identify and characterize its molecular root causes. Even in infectious diseases that are caused by a known parasite, it is often impossible to pinpoint exactly which molecular profiles of components or processes are directly or indirectly altered. However, a deep understanding of such profiles is a prerequisite for rational, efficacious treatments. Modern omics methodologies are permitting large-scale scans of some molecular profiles, but these scans often yield results that are not intuitive and difficult to interpret. For instance, the comparison of healthy and diseased transcriptome profiles may point to certain sets of involved genes, but a host of post-transcriptional processes and regulatory mechanisms renders predictions regarding metabolic or physiological consequences of the observed changes in gene expression unreliable. Here we present proof of concept that dynamic models of metabolic pathway systems may offer a tool for interpreting transcriptomic profiles measured during disease. We illustrate this strategy with the interpretation of expression data of genes coding for enzymes associated with purine metabolism. These data were obtained during infections of rhesus macaques (Macaca mulatta) with the malaria parasite Plasmodium cynomolgi or P. coatneyi. The model-based interpretation reveals clear patterns of flux redistribution within the purine pathway that are consistent between the two malaria pathogens and are even reflected in data from humans infected with P. falciparum. This article is part of a Special Issue entitled: Accelerating Precision Medicine through Genetic and Genomic Big Data Analysis edited by Yudong Cai & Tao Huang.
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Affiliation(s)
- Yan Tang
- School of Chemical and Biomolecular Engineering, Georgia Tech, Atlanta, GA 30332, USA
| | - Anuj Gupta
- Department of Biomedical Engineering, Georgia Tech, Atlanta, GA 30332, USA
| | - Swetha Garimalla
- School of Biological Sciences, Georgia Tech, Atlanta, GA 30332, USA
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- Malaria Host-Pathogen Interaction Center, USA
| | - Mary R Galinski
- Emory Vaccine Center at Yerkes, Emory University, 954 Gatewood Road, EVC 003, Atlanta, GA 30329, USA; Department of Medicine, Division of Infectious Diseases, Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30329, USA
| | - Mark P Styczynski
- School of Chemical and Biomolecular Engineering, Georgia Tech, Atlanta, GA 30332, USA
| | - Luis L Fonseca
- Department of Biomedical Engineering, Georgia Tech, Atlanta, GA 30332, USA
| | - Eberhard O Voit
- Department of Biomedical Engineering, Georgia Tech, Atlanta, GA 30332, USA.
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34
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Ansari MY, Ahsan MJ, Yasmin S, Sahoo GC, Saini V, Das P. In silico identification of novel antagonists and binding insights by structural and functional analyses of guanylate kinase of Leishmania donovani and interaction with inhibitors. GENE REPORTS 2017. [DOI: 10.1016/j.genrep.2017.07.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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35
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Kaiser MM, Baszczyňski O, Hocková D, Poštová-Slavětínská L, Dračínský M, Keough DT, Guddat LW, Janeba Z. Acyclic Nucleoside Phosphonates Containing 9-Deazahypoxanthine and a Five-Membered Heterocycle as Selective Inhibitors of Plasmodial 6-Oxopurine Phosphoribosyltransferases. ChemMedChem 2017. [DOI: 10.1002/cmdc.201700293] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Martin Maxmilian Kaiser
- The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences; Flemingovo nám. 2 16610 Prague 6 Czech Republic
| | - Ondřej Baszczyňski
- The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences; Flemingovo nám. 2 16610 Prague 6 Czech Republic
| | - Dana Hocková
- The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences; Flemingovo nám. 2 16610 Prague 6 Czech Republic
| | - Lenka Poštová-Slavětínská
- The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences; Flemingovo nám. 2 16610 Prague 6 Czech Republic
| | - Martin Dračínský
- The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences; Flemingovo nám. 2 16610 Prague 6 Czech Republic
| | - Dianne T. Keough
- School of Chemistry and Molecular Biosciences; The University of Queensland; Brisbane Queensland 4068 Australia
| | - Luke W. Guddat
- School of Chemistry and Molecular Biosciences; The University of Queensland; Brisbane Queensland 4068 Australia
| | - Zlatko Janeba
- The Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences; Flemingovo nám. 2 16610 Prague 6 Czech Republic
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36
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Single-molecule analysis reveals that DNA replication dynamics vary across the course of schizogony in the malaria parasite Plasmodium falciparum. Sci Rep 2017. [PMID: 28638076 PMCID: PMC5479783 DOI: 10.1038/s41598-017-04407-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The mechanics of DNA replication and cell cycling are well-characterized in model organisms, but less is known about these basic aspects of cell biology in early-diverging Apicomplexan parasites, which do not divide by canonical binary fission but undergo unconventional cycles. Schizogony in the malaria parasite, Plasmodium, generates ~16–24 new nuclei via independent, asynchronous rounds of genome replication prior to cytokinesis and little is known about the control of DNA replication that facilitates this. We have characterised replication dynamics in P. falciparum throughout schizogony, using DNA fibre labelling and combing to visualise replication forks at a single-molecule level. We show that origins are very closely spaced in Plasmodium compared to most model systems, and that replication dynamics vary across the course of schizogony, from faster synthesis rates and more widely-spaced origins through to slower synthesis rates and closer-spaced origins. This is the opposite of the pattern usually seen across S-phase in human cells, when a single genome is replicated. Replication forks also appear to stall at an unusually high rate throughout schizogony. Our work explores Plasmodium DNA replication in unprecedented detail and opens up tremendous scope for analysing cell cycle dynamics and developing interventions targetting this unique aspect of malaria biology.
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37
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González-López L, Carballar-Lejarazú R, Arrevillaga Boni G, Cortés-Martínez L, Cázares-Raga FE, Trujillo-Ocampo A, Rodríguez MH, James AA, Hernández-Hernández FDLC. Lys48 ubiquitination during the intraerythrocytic cycle of the rodent malaria parasite, Plasmodium chabaudi. PLoS One 2017; 12:e0176533. [PMID: 28604779 PMCID: PMC5467854 DOI: 10.1371/journal.pone.0176533] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 04/12/2017] [Indexed: 12/26/2022] Open
Abstract
Ubiquitination tags proteins for different functions within the cell. One of the most abundant and studied ubiquitin modification is the Lys48 polyubiquitin chain that modifies proteins for their destruction by proteasome. In Plasmodium is proposed that post-translational regulation is fundamental for parasite development during its complex life-cycle; thus, the objective of this work was to analyze the ubiquitination during Plasmodium chabaudi intraerythrocytic stages. Ubiquitinated proteins were detected during intraerythrocytic stages of Plasmodium chabaudi by immunofluorescent microscopy, bidimensional electrophoresis (2-DE) combined with immunoblotting and mass spectrometry. All the studied stages presented protein ubiquitination and Lys48 polyubiquitination with more abundance during the schizont stage. Three ubiquitinated proteins were identified for rings, five for trophozoites and twenty for schizonts. Only proteins detected with a specific anti- Lys48 polyubiquitin antibody were selected for Mass Spectrometry analysis and two of these identified proteins were selected in order to detect the specific amino acid residues where ubiquitin is placed. Ubiquitinated proteins during the ring and trophozoite stages were related with the invasion process and in schizont proteins were related with nucleic acid metabolism, glycolysis and protein biosynthesis. Most of the ubiquitin detection was during the schizont stage and the Lys48 polyubiquitination during this stage was related to proteins that are expected to be abundant during the trophozoite stage. The evidence that these Lys48 polyubiquitinated proteins are tagged for destruction by the proteasome complex suggests that this type of post-translational modification is important in the regulation of protein abundance during the life-cycle and may also contribute to the parasite cell-cycle progression.
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Affiliation(s)
- Lorena González-López
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México, D.F., México
| | - Rebeca Carballar-Lejarazú
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México, D.F., México
- Departments of Molecular Biology & Biochemistry and Microbiology & Molecular Genetics, University of California, Irvine, California, United States of America
| | - Gerardo Arrevillaga Boni
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México, D.F., México
| | - Leticia Cortés-Martínez
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México, D.F., México
| | - Febe Elena Cázares-Raga
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México, D.F., México
| | - Abel Trujillo-Ocampo
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México, D.F., México
| | - Mario H. Rodríguez
- Centro de Investigación Sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México
| | - Anthony A. James
- Departments of Molecular Biology & Biochemistry and Microbiology & Molecular Genetics, University of California, Irvine, California, United States of America
| | - Fidel de la Cruz Hernández-Hernández
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV-IPN), México, D.F., México
- * E-mail:
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38
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Reddy PL, Khan SI, Ponnan P, Tripathi M, Rawat DS. Design, synthesis and evaluation of 4-aminoquinoline-purine hybrids as potential antiplasmodial agents. Eur J Med Chem 2017; 126:675-686. [DOI: 10.1016/j.ejmech.2016.11.057] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 11/28/2016] [Accepted: 11/29/2016] [Indexed: 11/25/2022]
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39
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Blundell RD, Williams SJ, Arras SDM, Chitty JL, Blake KL, Ericsson DJ, Tibrewal N, Rohr J, Koh YQAE, Kappler U, Robertson AAB, Butler MS, Cooper MA, Kobe B, Fraser JA. Disruption of de Novo Adenosine Triphosphate (ATP) Biosynthesis Abolishes Virulence in Cryptococcus neoformans. ACS Infect Dis 2016; 2:651-663. [PMID: 27759389 DOI: 10.1021/acsinfecdis.6b00121] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Opportunistic fungal pathogens such as Cryptococcus neoformans are a growing cause of morbidity and mortality among immunocompromised populations worldwide. To address the current paucity of antifungal therapeutic agents, further research into fungal-specific drug targets is required. Adenylosuccinate synthetase (AdSS) is a crucial enzyme in the adeosine triphosphate (ATP) biosynthetic pathway, catalyzing the formation of adenylosuccinate from inosine monophosphate and aspartate. We have investigated the potential of this enzyme as an antifungal drug target, finding that loss of function results in adenine auxotrophy in C. neoformans, as well as complete loss of virulence in a murine model. Cryptococcal AdSS was expressed and purified in Escherichia coli and the enzyme's crystal structure determined, the first example of a structure of this enzyme from fungi. Together with enzyme kinetic studies, this structural information enabled comparison of the fungal enzyme with the human orthologue and revealed species-specific differences potentially exploitable via rational drug design. These results validate AdSS as a promising antifungal drug target and lay a foundation for future in silico and in vitro screens for novel antifungal compounds.
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Affiliation(s)
- Ross D. Blundell
- Australian Infectious Diseases Research
Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Simon J. Williams
- Australian Infectious Diseases Research
Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
- Institute for Molecular
Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Samantha D. M. Arras
- Australian Infectious Diseases Research
Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Jessica L. Chitty
- Australian Infectious Diseases Research
Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Kirsten L. Blake
- Australian Infectious Diseases Research
Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Daniel J. Ericsson
- Australian Infectious Diseases Research
Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
- Institute for Molecular
Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
- MX Beamlines, Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
| | - Nidhi Tibrewal
- College of Pharmacy, University of Kentucky, Lexington, Kentucky 40536-0596, United States
| | - Jurgen Rohr
- College of Pharmacy, University of Kentucky, Lexington, Kentucky 40536-0596, United States
| | - Y. Q. Andre E. Koh
- Australian Infectious Diseases Research
Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Ulrike Kappler
- Australian Infectious Diseases Research
Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
- Centre for Metals in Biology, School of
Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Avril A. B. Robertson
- Institute for Molecular
Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Mark S. Butler
- Institute for Molecular
Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Matthew A. Cooper
- Institute for Molecular
Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Bostjan Kobe
- Australian Infectious Diseases Research
Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
- Institute for Molecular
Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - James A. Fraser
- Australian Infectious Diseases Research
Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
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40
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Lunev S, Bosch SS, Batista FDA, Wrenger C, Groves MR. Crystal structure of truncated aspartate transcarbamoylase from Plasmodium falciparum. Acta Crystallogr F Struct Biol Commun 2016; 72:523-33. [PMID: 27380369 PMCID: PMC4933002 DOI: 10.1107/s2053230x16008475] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 05/25/2016] [Indexed: 11/10/2022] Open
Abstract
The de novo pyrimidine-biosynthesis pathway of Plasmodium falciparum is a promising target for antimalarial drug discovery. The parasite requires a supply of purines and pyrimidines for growth and proliferation and is unable to take up pyrimidines from the host. Direct (or indirect) inhibition of de novo pyrimidine biosynthesis via dihydroorotate dehydrogenase (PfDHODH), the fourth enzyme of the pathway, has already been shown to be lethal to the parasite. In the second step of the plasmodial pyrimidine-synthesis pathway, aspartate and carbamoyl phosphate are condensed to N-carbamoyl-L-aspartate and inorganic phosphate by aspartate transcarbamoylase (PfATC). In this paper, the 2.5 Å resolution crystal structure of PfATC is reported. The space group of the PfATC crystals was determined to be monoclinic P21, with unit-cell parameters a = 87.0, b = 103.8, c = 87.1 Å, α = 90.0, β = 117.7, γ = 90.0°. The presented PfATC model shares a high degree of homology with the catalytic domain of Escherichia coli ATC. There is as yet no evidence of the existence of a regulatory domain in PfATC. Similarly to E. coli ATC, PfATC was modelled as a homotrimer in which each of the three active sites is formed at the oligomeric interface. Each active site comprises residues from two adjacent subunits in the trimer with a high degree of evolutional conservation. Here, the activity loss owing to mutagenesis of the key active-site residues is also described.
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Affiliation(s)
- Sergey Lunev
- Department of Drug Design, Groningen Research Institute of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9700 AD Groningen, The Netherlands
| | - Soraya S. Bosch
- Unit for Drug Discovery, Department of Parasitology, Institute of Biomedical Science, University of São Paulo, Avenida Professor Lineu Prestes 1374, 05508-000 São Paulo-SP, Brazil
| | - Fernando de Assis Batista
- Department of Drug Design, Groningen Research Institute of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9700 AD Groningen, The Netherlands
| | - Carsten Wrenger
- Unit for Drug Discovery, Department of Parasitology, Institute of Biomedical Science, University of São Paulo, Avenida Professor Lineu Prestes 1374, 05508-000 São Paulo-SP, Brazil
| | - Matthew R. Groves
- Department of Drug Design, Groningen Research Institute of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9700 AD Groningen, The Netherlands
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41
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Krungkrai SR, Krungkrai J. Insights into the pyrimidine biosynthetic pathway of human malaria parasite Plasmodium falciparum as chemotherapeutic target. ASIAN PAC J TROP MED 2016; 9:525-34. [PMID: 27262062 DOI: 10.1016/j.apjtm.2016.04.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 03/16/2016] [Accepted: 04/08/2016] [Indexed: 11/25/2022] Open
Abstract
Malaria is a major cause of morbidity and mortality in humans. Artemisinins remain as the first-line treatment for Plasmodium falciparum (P. falciparum) malaria although drug resistance has already emerged and spread in Southeast Asia. Thus, to fight this disease, there is an urgent need to develop new antimalarial drugs for malaria chemotherapy. Unlike human host cells, P. falciparum cannot salvage preformed pyrimidine bases or nucleosides from the extracellular environment and relies solely on nucleotides synthesized through the de novo biosynthetic pathway. This review presents significant progress on understanding the de novo pyrimidine pathway and the functional enzymes in the human parasite P. falciparum. Current knowledge in genomics and metabolomics are described, particularly focusing on the parasite purine and pyrimidine nucleotide metabolism. These include gene annotation, characterization and molecular mechanism of the enzymes that are different from the human host pathway. Recent elucidation of the three-dimensional crystal structures and the catalytic reactions of three enzymes: dihydroorotate dehydrogenase, orotate phosphoribosyltransferase, and orotidine 5'-monophosphate decarboxylase, as well as their inhibitors are reviewed in the context of their therapeutic potential against malaria.
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Affiliation(s)
- Sudaratana R Krungkrai
- Unit of Biochemistry, Department of Medical Science, Faculty of Science, Rangsit University, Pathumthani 12000, Thailand
| | - Jerapan Krungkrai
- Department of Biochemistry, Faculty of Medicine, Chulalongkorn University, Pathumwan, Bangkok 10330, Thailand.
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Tseng TS, Lee YC, Hsiao NW, Liu YR, Tsai KC. Comparative study between 3D-QSAR and Docking-Based Pharmacophore models for potent Plasomodium falciparum dihydroorotate dehydrogenase inhibitors. Bioorg Med Chem Lett 2016; 26:265-271. [DOI: 10.1016/j.bmcl.2015.12.043] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Revised: 11/03/2015] [Accepted: 12/12/2015] [Indexed: 12/17/2022]
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Targeting the Plasmodium vivax equilibrative nucleoside transporter 1 (PvENT1) for antimalarial drug development. INTERNATIONAL JOURNAL FOR PARASITOLOGY-DRUGS AND DRUG RESISTANCE 2015; 6:1-11. [PMID: 26862473 PMCID: PMC4706624 DOI: 10.1016/j.ijpddr.2015.11.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Revised: 11/18/2015] [Accepted: 11/25/2015] [Indexed: 11/26/2022]
Abstract
Infection with Plasmodium falciparum and vivax cause most cases of malaria. Emerging resistance to current antimalarial medications makes new drug development imperative. Ideally a new antimalarial drug should treat both falciparum and vivax malaria. Because malaria parasites are purine auxotrophic, they rely on purines imported from the host erythrocyte via Equilibrative Nucleoside Transporters (ENTs). Thus, the purine import transporters represent a potential target for antimalarial drug development. For falciparum parasites the primary purine transporter is the P. falciparum Equilibrative Nucleoside Transporter Type 1 (PfENT1). Recently we identified potent PfENT1 inhibitors with nanomolar IC50 values using a robust, yeast-based high throughput screening assay. In the current work we characterized the Plasmodium vivax ENT1 (PvENT1) homologue and its sensitivity to the PfENT1 inhibitors. We expressed a yeast codon-optimized PvENT1 gene in Saccharomyces cerevisiae. PvENT1-expressing yeast imported both purines ([3H]adenosine) and pyrimidines ([3H]uridine), whereas wild type (fui1Δ) yeast did not. Based on radiolabel substrate uptake inhibition experiments, inosine had the lowest IC50 (3.8 μM), compared to guanosine (14.9 μM) and adenosine (142 μM). For pyrimidines, thymidine had an IC50 of 183 μM (vs. cytidine and uridine; mM range). IC50 values were higher for nucleobases compared to the corresponding nucleosides; hypoxanthine had a 25-fold higher IC50 than inosine. The archetypal human ENT1 inhibitor 4-nitrobenzylthioinosine (NBMPR) had no effect on PvENT1, whereas dipyridamole inhibited PvENT1, albeit with a 40 μM IC50, a 1000-fold less sensitive than human ENT1 (hENT1). The PfENT1 inhibitors blocked transport activity of PvENT1 and the five known naturally occurring non-synonymous single nucleotide polymorphisms (SNPs) with similar IC50 values. Thus, the PfENT1 inhibitors also target PvENT1. This implies that development of novel antimalarial drugs that target both falciparum and vivax ENT1 may be feasible. PvENT1 can be functionally expressed in Saccharomyces cerevisiae. PvENT1 transports purine and pyrimidine nucleosides and nucleobases but does not transport nucleotides. PvENT1 is inhibited by recently described PfENT1 inhibitors with similar potency. Identified PvENT1 non-synonymous SNPs do not change PfENT1 inhibitor potency. Plasmodium ENTs may be feasible target for development of novel antimalarial drugs.
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Key Words
- ACT, Artemisinin-based Combination Therapies
- CQ, chloroquine
- Drug development
- EC50, concentration causing 50% of maximal effect
- ENT, equilibrative nucleoside transporter
- EV, empty vector
- HTS, high throughput screen
- IC50, concentration causing 50% inhibition
- Malaria
- NBMPR, 4-nitrobenzylthioinosine
- Nucleoside/nucleobase transport
- Parasite
- PfENT1, P. falciparum ENT type 1
- Plasmodium vivax
- Purines
- PvENT1, P. vivax ENT type 1
- SDM, synthetic defined media
- SNP, single nucleotide polymorphism
- Single-nucleotide polymorphism (SNP)
- Transporter
- WHO, World Health Organization
- WT, wild type
- hENT1, human ENT type 1
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Active site coupling in Plasmodium falciparum GMP synthetase is triggered by domain rotation. Nat Commun 2015; 6:8930. [PMID: 26592566 PMCID: PMC4673825 DOI: 10.1038/ncomms9930] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 10/19/2015] [Indexed: 11/24/2022] Open
Abstract
GMP synthetase (GMPS), a key enzyme in the purine biosynthetic pathway performs catalysis through a coordinated process across two catalytic pockets for which the mechanism remains unclear. Crystal structures of Plasmodium falciparum GMPS in conjunction with mutational and enzyme kinetic studies reported here provide evidence that an 85° rotation of the GATase domain is required for ammonia channelling and thus for the catalytic activity of this two-domain enzyme. We suggest that conformational changes in helix 371–375 holding catalytic residues and in loop 376–401 along the rotation trajectory trigger the different steps of catalysis, and establish the central role of Glu374 in allostery and inter-domain crosstalk. These studies reveal the mechanism of domain rotation and inter-domain communication, providing a molecular framework for the function of all single polypeptide GMPSs and form a solid basis for rational drug design targeting this therapeutically important enzyme. GMP synthetase, a key enzyme in purine biosynthesis, is of interest for understanding purine metabolism processes and for developing therapeutic applications. Here, the authors propose a molecular mechanism and the structural basis for the catalytic activity of this enzyme.
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Ansari MY, Equbal A, Dikhit MR, Mansuri R, Rana S, Ali V, Sahoo GC, Das P. Establishment of correlation between in-silico and in-vitro test analysis against Leishmania HGPRT to inhibitors. Int J Biol Macromol 2015; 83:78-96. [PMID: 26616453 DOI: 10.1016/j.ijbiomac.2015.11.051] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 11/13/2015] [Accepted: 11/18/2015] [Indexed: 10/22/2022]
Abstract
Hypoxanthine Phosphoribosyltransferase (HGPRT; EC 2.4.2.8) is a central enzyme in the purine recycling pathway of all protozoan parasites. Protozoan parasites cannot synthesize purine bases (DNA/RNA) which is essential for survival as lack of de-novo pathway. Thus its good target for drug design and discovery as inhibition leads to cessation of replication. PRTase (transferase enzyme) has common PRTase type I folding pattern domain for its activities. Genomic studies revealed the sequence pattern and identified highly conserved residues that catalyzed the reaction in protozoan parasites. A recombinant protein has 24 kDa molecular mass (rLdHGPRT) was cloned, expressed and purified for testing of guanosine monophosphate (GMP) analogous compounds in-vitro by spectroscopically to the rLdHGPRT, lysates protein and MTT assay on Leishmania donovani. The predicted inhibitors of different libraries were screen into FlexX. The reported inhibitors were tested in-vitro. The 2'-deoxyguanosine 5'-diphosphate (DGD) (IC50 value 12.5 μM) is two times more effective when compared to guanosine-5'-diphosphate sodium (GD). Interestingly, LdHGPRT complex has shown stable after 24 ns in molecular dynamics simulation with interacting amino acids are Glu125, Ile127, Lys87 and Val186. QSAR studies revealed the correlation between predicted and experimental values has shown R2 0.998. Concludes that inversely proportional to their docked score with activities.
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Affiliation(s)
- Md Yousuf Ansari
- Pharmacoinformatics Department, National Institute of Pharmaceutical Education and Research (NIPER), Hajipur 844102, India; BioMedical Informatics Division, Rajendra Memorial Research Institute of Medical Sciences, Agam Kuan, Patna 800007, India
| | - Asif Equbal
- Biochemistry Department, Rajendra Memorial Research Institute of Medical Sciences, Agam Kuan, Patna 800007, India
| | - Manas Ranjan Dikhit
- BioMedical Informatics Division, Rajendra Memorial Research Institute of Medical Sciences, Agam Kuan, Patna 800007, India
| | - Rani Mansuri
- Pharmacoinformatics Department, National Institute of Pharmaceutical Education and Research (NIPER), Hajipur 844102, India; BioMedical Informatics Division, Rajendra Memorial Research Institute of Medical Sciences, Agam Kuan, Patna 800007, India
| | - Sindhuprava Rana
- BioMedical Informatics Division, Rajendra Memorial Research Institute of Medical Sciences, Agam Kuan, Patna 800007, India
| | - Vahab Ali
- Biochemistry Department, Rajendra Memorial Research Institute of Medical Sciences, Agam Kuan, Patna 800007, India
| | - Ganesh Chandra Sahoo
- BioMedical Informatics Division, Rajendra Memorial Research Institute of Medical Sciences, Agam Kuan, Patna 800007, India.
| | - Pradeep Das
- Pharmacoinformatics Department, National Institute of Pharmaceutical Education and Research (NIPER), Hajipur 844102, India; BioMedical Informatics Division, Rajendra Memorial Research Institute of Medical Sciences, Agam Kuan, Patna 800007, India
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Primon-Barros M, Rigo GV, Frasson AP, Santos OD, Smiderle L, Almeida S, Macedo AJ, Tasca T. Modulatory effect of iron chelators on adenosine deaminase activity and gene expression in Trichomonas vaginalis. Mem Inst Oswaldo Cruz 2015; 110:877-83. [PMID: 26517498 PMCID: PMC4660616 DOI: 10.1590/0074-02760150076] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 08/12/2015] [Indexed: 01/29/2023] Open
Abstract
Trichomonas vaginalis is a flagellate protozoan that parasitises the
urogenital human tract and causes trichomoniasis. During the infection, the
acquisition of nutrients, such as iron and purine and pyrimidine nucleosides, is
essential for the survival of the parasite. The enzymes for purinergic signalling,
including adenosine deaminase (ADA), which degrades adenosine to inosine, have been
characterised in T. vaginalis. In the evaluation of the ADA profile
in different T. vaginalis isolates treated with different iron
sources or with limited iron availability, a decrease in activity and an increase in
ADA gene expression after iron limitation by 2,2-bipyridyl and ferrozine chelators
were observed. This supported the hypothesis that iron can modulate the activity of
the enzymes involved in purinergic signalling. Under bovine serum limitation
conditions, no significant differences were observed. The results obtained in this
study allow for the assessment of important aspects of ADA and contribute to a better
understanding of the purinergic system in T. vaginalis and the role
of iron in establishing infection and parasite survival.
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Affiliation(s)
- Muriel Primon-Barros
- Laboratório de Pesquisa em Parasitologia, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil
| | - Graziela Vargas Rigo
- Laboratório de Pesquisa em Parasitologia, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil
| | - Amanda Piccoli Frasson
- Laboratório de Pesquisa em Parasitologia, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil
| | - Odelta dos Santos
- Laboratório de Pesquisa em Parasitologia, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil
| | - Lisiane Smiderle
- Laboratório de Biologia Molecular, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, Brasil
| | - Silvana Almeida
- Laboratório de Biologia Molecular, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, Brasil
| | - Alexandre José Macedo
- Laboratório de Tecnologia Bioquímica, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil
| | - Tiana Tasca
- Laboratório de Pesquisa em Parasitologia, Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brasil
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Hocková D, Janeba Z, Naesens L, Edstein MD, Chavchich M, Keough DT, Guddat LW. Antimalarial activity of prodrugs of N-branched acyclic nucleoside phosphonate inhibitors of 6-oxopurine phosphoribosyltransferases. Bioorg Med Chem 2015; 23:5502-10. [PMID: 26275679 DOI: 10.1016/j.bmc.2015.07.038] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 07/17/2015] [Accepted: 07/19/2015] [Indexed: 11/25/2022]
Abstract
Acyclic nucleoside phosphonates (ANPs) that contain a 6-oxopurine base are good inhibitors of the human and Plasmodium falciparum 6-oxopurine phosphoribosyltransferases (PRTs), key enzymes of the purine salvage pathway. Chemical modifications, based on the crystal structures of several inhibitors in complex with the human PRTase, led to the design of a new class of inhibitors--the aza-ANPs. Because of the negative charges of the phosphonic acid moiety, their ability to cross cell membranes is, however, limited. Thus, phosphoramidate prodrugs of the aza-ANPs were prepared to improve permeability. These prodrugs arrest parasitemia with IC50 values in the micromolar range against Plasmodium falciparum-infected erythrocyte cultures (both chloroquine-sensitive and chloroquine-resistant Pf strains). The prodrugs exhibit low cytotoxicity in several human cell lines. Thus, they fulfill two essential criteria to qualify them as promising antimalarial drug leads.
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Affiliation(s)
- Dana Hocková
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i. Flemingovo nám. 2, CZ-166 10 Prague 6, Czech Republic.
| | - Zlatko Janeba
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, v.v.i. Flemingovo nám. 2, CZ-166 10 Prague 6, Czech Republic
| | - Lieve Naesens
- Rega Institute for Medical Research, KU Leuven-University of Leuven, Minderbroedersstraat 10, B-3000 Leuven, Belgium
| | - Michael D Edstein
- Department of Drug Evaluation, Australian Army Malaria Institute, Enoggera, Brisbane, QLD 4051, Australia
| | - Marina Chavchich
- Department of Drug Evaluation, Australian Army Malaria Institute, Enoggera, Brisbane, QLD 4051, Australia
| | - Dianne T Keough
- The School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane 4072, QLD, Australia
| | - Luke W Guddat
- The School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane 4072, QLD, Australia.
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Chen N, Zhao Y, Lu J, Wu R, Cao Z. Mechanistic Insights into the Rate-Limiting Step in Purine-Specific Nucleoside Hydrolase. J Chem Theory Comput 2015; 11:3180-8. [DOI: 10.1021/acs.jctc.5b00045] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Nanhao Chen
- School
of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, People’s Republic of China
| | - Yuan Zhao
- State
Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian
Provincial Key Laboratory of Theoretical and Computational Chemistry,
College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 360015, People’s Republic of China
| | - Jianing Lu
- State
Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian
Provincial Key Laboratory of Theoretical and Computational Chemistry,
College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 360015, People’s Republic of China
| | - Ruibo Wu
- School
of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, 510006, People’s Republic of China
| | - Zexing Cao
- State
Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian
Provincial Key Laboratory of Theoretical and Computational Chemistry,
College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 360015, People’s Republic of China
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Srivastava A, Creek DJ, Evans KJ, De Souza D, Schofield L, Müller S, Barrett MP, McConville MJ, Waters AP. Host reticulocytes provide metabolic reservoirs that can be exploited by malaria parasites. PLoS Pathog 2015; 11:e1004882. [PMID: 26042734 PMCID: PMC4456406 DOI: 10.1371/journal.ppat.1004882] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 04/14/2015] [Indexed: 11/18/2022] Open
Abstract
Human malaria parasites proliferate in different erythroid cell types during infection. Whilst Plasmodium vivax exhibits a strong preference for immature reticulocytes, the more pathogenic P. falciparum primarily infects mature erythrocytes. In order to assess if these two cell types offer different growth conditions and relate them to parasite preference, we compared the metabolomes of human and rodent reticulocytes with those of their mature erythrocyte counterparts. Reticulocytes were found to have a more complex, enriched metabolic profile than mature erythrocytes and a higher level of metabolic overlap between reticulocyte resident parasite stages and their host cell. This redundancy was assessed by generating a panel of mutants of the rodent malaria parasite P. berghei with defects in intermediary carbon metabolism (ICM) and pyrimidine biosynthesis known to be important for P. falciparum growth and survival in vitro in mature erythrocytes. P. berghei ICM mutants (pbpepc-, phosphoenolpyruvate carboxylase and pbmdh-, malate dehydrogenase) multiplied in reticulocytes and committed to sexual development like wild type parasites. However, P. berghei pyrimidine biosynthesis mutants (pboprt-, orotate phosphoribosyltransferase and pbompdc-, orotidine 5'-monophosphate decarboxylase) were restricted to growth in the youngest forms of reticulocytes and had a severe slow growth phenotype in part resulting from reduced merozoite production. The pbpepc-, pboprt- and pbompdc- mutants retained virulence in mice implying that malaria parasites can partially salvage pyrimidines but failed to complete differentiation to various stages in mosquitoes. These findings suggest that species-specific differences in Plasmodium host cell tropism result in marked differences in the necessity for parasite intrinsic metabolism. These data have implications for drug design when targeting mature erythrocyte or reticulocyte resident parasites.
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Affiliation(s)
- Anubhav Srivastava
- Wellcome Trust Centre for Molecular Parasitology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Scotland, United Kingdom
- Institute of Infection, Immunity & Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Scotland, United Kingdom
| | - Darren J. Creek
- Wellcome Trust Centre for Molecular Parasitology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Scotland, United Kingdom
- Institute of Infection, Immunity & Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Scotland, United Kingdom
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Australia
| | - Krystal J. Evans
- Walter and Eliza Hall Institute of Medical Research, Division of Infection and Immunity, Parkville, Victoria, Australia
| | - David De Souza
- Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Louis Schofield
- Walter and Eliza Hall Institute of Medical Research, Division of Infection and Immunity, Parkville, Victoria, Australia
- Australian Institute of Tropical Health and Medicine, Centre for Biodiscovery and Molecular Development of Therapeutics, James Cook University, Townsville, Australia
| | - Sylke Müller
- Institute of Infection, Immunity & Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Scotland, United Kingdom
| | - Michael P. Barrett
- Wellcome Trust Centre for Molecular Parasitology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Scotland, United Kingdom
- Institute of Infection, Immunity & Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Scotland, United Kingdom
| | - Malcolm J. McConville
- Metabolomics Australia, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
- Department of Biochemistry and Molecular Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Andrew P. Waters
- Wellcome Trust Centre for Molecular Parasitology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Scotland, United Kingdom
- Institute of Infection, Immunity & Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Scotland, United Kingdom
- * E-mail:
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50
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Bullard KM, Broccardo C, Keenan SM. Effects of cyclin-dependent kinase inhibitor Purvalanol B application on protein expression and developmental progression in intra-erythrocytic Plasmodium falciparum parasites. Malar J 2015; 14:147. [PMID: 25879664 PMCID: PMC4403934 DOI: 10.1186/s12936-015-0655-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 03/17/2015] [Indexed: 11/10/2022] Open
Abstract
Background The 2013 Malaria World Report indicated that in 2012 there were approximately 207 million cases of malaria, which resulted in an estimated 627,000 malaria-related deaths. Due to the alarming resistance of these parasites to traditional anti-malarial treatments there is a pressing need to not only identify new anti-malarial compounds, but also to characterize the effect of compounds known to have an effect on the parasite life cycle. This study reports on effects of kinase inhibitor Purvalanol B administration on the growth and protein expression of Plasmodium falciparum late-stage trophozoites. Methods A SYBR® Green I parasite growth assay was used to measure the IC50 of Purvalanol B with P. falciparum (strain W2). Purvalanol B or DMSO control were applied to synchronized parasites 36 hours post invasion and parasites were incubated for 12 hours. Giemsa-stained blood smears were used to determine the effect of Purvalanol B on parasite growth, global quantitative proteomic analysis was used to examine differences in protein expression between Purvalanol B-treated and control parasites and results were confirmed by qPCR. Results There were no differences in parasitaemia between inhibitor-treated and control parasites. However, the ability of Purvalanol B-treated parasites to form schizonts was significantly reduced. Proteomic analysis detected 76 human proteins and 518 P. falciparum proteins (63 in control cultures only, 56 proteins in Purvalanol B cultures only, and 399 proteins in both cultures). Quantitative analysis of protein extracts revealed eight proteins that were up-regulated in the inhibitor-treated cultures, including several components of the parasite’s proteasome complex and thioredoxin reductase. Two proteins appeared to be down-regulated, including a helicase and an RNA-binding protein. Conclusion Purvalanol B application decreases the ability of late-stage P. falciparum trophozoites to form multinucleated schizonts and up-regulates proteasome subunits and proteins that contribute to redox homeostasis, which may indicate an increase in oxidative stress as a result of inhibitor application. While the efficacy of Purvalanol B is relatively low for use as an anti-malarial therapy, quantitative proteomic analysis may serve as a method of examining the action of drugs on the parasite and indicate the likelihood of future resistance development. Electronic supplementary material The online version of this article (doi:10.1186/s12936-015-0655-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Kristen M Bullard
- School of Biological Sciences, University of Northern Colorado, Greeley, CO, 80639, USA.
| | - Carolyn Broccardo
- Proteomics and Metabolomics Facility, Colorado State University, Fort ColliHns, CO, 80523, USA.
| | - Susan M Keenan
- School of Biological Sciences, University of Northern Colorado, Greeley, CO, 80639, USA.
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