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Tsakem Nangap MJ, Walbadet L, Mbock MA, Adjieufack AI, Ongagna JM, Fokou R, Tenlep LN, Tchatat MB, Tsouh Fokou PV, Boyom FF, Gounoue Kamkumo R, Tsofack FN, Dimo T. In vitro, in vivo and in silico antiplasmodial profiling of the aqueous extract of Hibiscus asper HOOK F. Leaf (Malvaceae). JOURNAL OF ETHNOPHARMACOLOGY 2024; 335:118536. [PMID: 39004192 DOI: 10.1016/j.jep.2024.118536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 06/28/2024] [Accepted: 07/05/2024] [Indexed: 07/16/2024]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Plasmodium resistance to antimalarial drugs raises the urgent need to seek for alternative treatments. Aqueous extract of Hibiscus asper leaves is currently used in malaria management but remains less documented. AIM OF THE STUDY The study aims to evaluate antimalarial effects of the aqueous extract of Hibiscus asper. UHPLC/MS, was used to identify some likely compounds present in the plant that were thereafter docked to some malaria parasite proteins. STUDY DESIGN In vitro anti-plasmodium and antioxidant, UHPLC/Ms analysis, in vivo antimalarial of the plant extract, and in silico molecular docking prediction of some identified compounds were performed to investigate the pharmacological effects of H. asper. MATERIAL AND METHODS The in vitro antiplasmodial activity of the extract was carried out on Plasmodium falciparum strains using SYBR-green dye; then, the curative antimalarial activity was conducted on Plasmodium berghei NK65-infected male Wistar rats. The UHPLC/MS analysis was used to identify plant compounds, followed by interactions (docking affinity) between some compounds and parasitic enzymes such as P. falciparum purine nucleoside phosphorylase (2BSX) and 6-phosphogluconate dehydrogenase (6FQY) to explore potential mechanisms of action at the molecular level. RESULTS No hemolysis effect of the extract was observed at concentrations up to 100 mg/mL. In vitro test of the aqueous leaves extract of H. asper showed inhibitory activity against P. falciparum Dd2 and 3D7 strains with IC50 values of 19.75 and 21.97 μg/mL, respectively. The curative antimalarial test of the H. asper extract in infected rats exhibited significant inhibition of the parasite growth (p < 0.001) with inhibition percentage of 95.11%, 97.68% and 95.59% at all the doses (50, 100 and 200 mg/kg) respectively. The extract corrected major physiological alterations such as liver and kidney impairments, oxidative stress and architectural disorganization in liver, spleen and kidneys tissues. The UHPLC/MS analysis identified 7 compounds, namely chlorogenic acid, azulene, quercetin, rhodine, 1-ethyl-2,4-dimethyl benzene and phthalan. Out of seven compounds identified in the extract quercetin and phthalan showed higher in silico inhibitory activity against P. falciparum purine nucleoside phosphorylase and Plasmodium falciparum 6-phosphosgluconate dehydrogenase parasite enzymes. CONCLUSION These findings indicate that H. asper could be a promising complementary medicine to manage malaria. Meanwhile, the affinity of annoted compounds with these enzymes should be further confirmed.
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Affiliation(s)
- Marius Jaurès Tsakem Nangap
- Laboratory of Animal Physiology, Faculty of Science, University of Yaoundé I, Cameroon; Laboratory for Phytobiochemistry and Medicinal Plants Studies, Antimicrobial and Biocontrol Agents Unit, Faculty of Science, University of Yaounde I, Cameroon
| | - Lucain Walbadet
- Laboratory of Animal Physiology, Faculty of Science, University of Yaoundé I, Cameroon; Laboratory for Phytobiochemistry and Medicinal Plants Studies, Antimicrobial and Biocontrol Agents Unit, Faculty of Science, University of Yaounde I, Cameroon; Département des Sciences de La Vie et de La Terre, Ecole Normale Supérieure de N'Djamena, BP 206, N'Djamena, Chad
| | - Michel Arnaud Mbock
- Laboratory of Animal Physiology, Faculty of Science, University of Yaoundé I, Cameroon; Laboratory for Phytobiochemistry and Medicinal Plants Studies, Antimicrobial and Biocontrol Agents Unit, Faculty of Science, University of Yaounde I, Cameroon; Department of Biochemistry, Laboratory of Biochemistry, Faculty of Science, University of Douala, Cameroon
| | - Abel Idrice Adjieufack
- Physical and Theoretical Chemistry Laboratory, Faculty of Science, University of Yaoundé I, Cameroon
| | - Jean Moto Ongagna
- Chemistry Unit, Department of Chemistry, Faculty of Science, University of Douala, Cameroon
| | - Roberto Fokou
- Laboratory of Animal Physiology, Faculty of Science, University of Yaoundé I, Cameroon; Laboratory for Phytobiochemistry and Medicinal Plants Studies, Antimicrobial and Biocontrol Agents Unit, Faculty of Science, University of Yaounde I, Cameroon
| | - Loïc Ngwem Tenlep
- Laboratory of Animal Physiology, Faculty of Science, University of Yaoundé I, Cameroon; Laboratory for Phytobiochemistry and Medicinal Plants Studies, Antimicrobial and Biocontrol Agents Unit, Faculty of Science, University of Yaounde I, Cameroon
| | - Mariscal Brice Tchatat
- Laboratory for Phytobiochemistry and Medicinal Plants Studies, Antimicrobial and Biocontrol Agents Unit, Faculty of Science, University of Yaounde I, Cameroon
| | - Patrick Valère Tsouh Fokou
- Laboratory for Phytobiochemistry and Medicinal Plants Studies, Antimicrobial and Biocontrol Agents Unit, Faculty of Science, University of Yaounde I, Cameroon; Department of Biochemistry, Laboratory of Biochemistry, Faculty of Science, University of Bamenda, Cameroon
| | - Fabrice Fekam Boyom
- Laboratory for Phytobiochemistry and Medicinal Plants Studies, Antimicrobial and Biocontrol Agents Unit, Faculty of Science, University of Yaounde I, Cameroon
| | - Raceline Gounoue Kamkumo
- Laboratory of Animal Physiology, Faculty of Science, University of Yaoundé I, Cameroon; Laboratory for Phytobiochemistry and Medicinal Plants Studies, Antimicrobial and Biocontrol Agents Unit, Faculty of Science, University of Yaounde I, Cameroon.
| | | | - Théophile Dimo
- Laboratory of Animal Physiology, Faculty of Science, University of Yaoundé I, Cameroon
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Qu SY, Liu YH, Liu JT, Li PF, Liu TQ, Wang GX, Yu Q, Ling F. Catechol compounds as dual-targeting agents for fish protection against Ichthyophthirius multifiliis infections. FISH & SHELLFISH IMMUNOLOGY 2024; 151:109717. [PMID: 38914179 DOI: 10.1016/j.fsi.2024.109717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 06/15/2024] [Accepted: 06/21/2024] [Indexed: 06/26/2024]
Abstract
Aquaculture is one of the fastest growing sectors in global food production, recognized as a significant contributor to poverty alleviation, food security, and income generation. However, the frequent occurrence of diseases caused by pathogen infections result in reduced yields and economic losses, posing a substantial constraint to the sustainable development of aquaculture. Here, our study identified that four catechol compounds, quercetin, luteolin, caffeic acid, and chlorogenic acid, exhibited potent antiparasitic effects against Ichthyophthirius multifiliis in both, in vitro and in vivo. The parasite is recognized as one of the most pathogenic to fish worldwide. Using a combination of in silico methods, the dipeptidyl peptidase (DPP) was identified as a critical target for catechol compounds. The two hydroxyl radicals of the catechol group were essential for its binding to and interacting with the DPP protein. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses indicated that catechol compounds disrupt pathways associated with the metabolism and growth of I. multifiliis, thereby exerting antiparasitic effects. Furthermore, these compounds attenuated the expression of proinflammatory cytokines in vivo in fish and promoted macrophage polarization toward M2 phenotype by inhibiting the STAT1 signaling pathway. The dual activity of catechol compounds, acting as both direct antiparasitic and anti-inflammatory agents in fish, offers a promising therapeutic approach for combating I. multifiliis infections in aquaculture.
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Affiliation(s)
- Shen-Ye Qu
- Northwest A&F University, Xinong Road, Yangling, Shaanxi, 712100, China; Engineering Research Center of the Innovation and Development of Green Fishery Drugs, Universities of Shaanxi Province, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Yi-Hang Liu
- Northwest A&F University, Xinong Road, Yangling, Shaanxi, 712100, China; Engineering Research Center of the Innovation and Development of Green Fishery Drugs, Universities of Shaanxi Province, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Jie-Tao Liu
- Northwest A&F University, Xinong Road, Yangling, Shaanxi, 712100, China; Engineering Research Center of the Innovation and Development of Green Fishery Drugs, Universities of Shaanxi Province, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Peng-Fei Li
- Guangxi Academy of Sciences, Nanning, 530000, China
| | - Tian-Qiang Liu
- Northwest A&F University, Xinong Road, Yangling, Shaanxi, 712100, China; Engineering Research Center of the Innovation and Development of Green Fishery Drugs, Universities of Shaanxi Province, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Gao-Xue Wang
- Northwest A&F University, Xinong Road, Yangling, Shaanxi, 712100, China; Engineering Research Center of the Innovation and Development of Green Fishery Drugs, Universities of Shaanxi Province, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Qing Yu
- Guangxi Academy of Sciences, Nanning, 530000, China.
| | - Fei Ling
- Northwest A&F University, Xinong Road, Yangling, Shaanxi, 712100, China; Engineering Research Center of the Innovation and Development of Green Fishery Drugs, Universities of Shaanxi Province, Northwest A&F University, Yangling, Shaanxi, 712100, China.
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3
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González JEH, Salas-Sarduy E, Alvarez LH, Valiente PA, Arni RK, Pascutti PG. Three Decades of Targeting Falcipains to Develop Antiplasmodial Agents: What have we Learned and What can be Done Next? Curr Med Chem 2024; 31:2234-2263. [PMID: 37711130 DOI: 10.2174/0929867331666230913165219] [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: 03/28/2023] [Revised: 05/06/2023] [Accepted: 07/25/2023] [Indexed: 09/16/2023]
Abstract
Malaria is a devastating infectious disease that affects large swathes of human populations across the planet's tropical regions. It is caused by parasites of the genus Plasmodium, with Plasmodium falciparum being responsible for the most lethal form of the disease. During the intraerythrocytic stage in the human hosts, malaria parasites multiply and degrade hemoglobin (Hb) using a battery of proteases, which include two cysteine proteases, falcipains 2 and 3 (FP-2 and FP-3). Due to their role as major hemoglobinases, FP-2 and FP-3 have been targeted in studies aiming to discover new antimalarials and numerous inhibitors with activity against these enzymes, and parasites in culture have been identified. Nonetheless, cross-inhibition of human cysteine cathepsins remains a serious hurdle to overcome for these compounds to be used clinically. In this article, we have reviewed key functional and structural properties of FP-2/3 and described different compound series reported as inhibitors of these proteases during decades of active research in the field. Special attention is also paid to the wide range of computer-aided drug design (CADD) techniques successfully applied to discover new active compounds. Finally, we provide guidelines that, in our understanding, will help advance the rational discovery of new FP-2/3 inhibitors.
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Affiliation(s)
- Jorge Enrique Hernández González
- Multiuser Center for Biomolecular Innovation, IBILCE/UNESP, São José do Rio Preto, SP, Brazil
- Department of Pharmaceutical Sciences, UZA II, University of Vienna, Vienna, 1090, Austria
| | - Emir Salas-Sarduy
- Instituto de Investigaciones Biotecnológicas Dr. Rodolfo Ugalde, Universidad Nacional de San Martín, CONICET, San Martín, Buenos Aires, Argentina
- Escuela de Bio y Nanotecnología (EByN), Universidad de San Martín (UNSAM), San Martín, Buenos Aires, Argentina
| | | | - Pedro Alberto Valiente
- Donnelly Centre for Cellular & Biomolecular Research, University of Toronto, Toronto, Canada
| | | | - Pedro Geraldo Pascutti
- Laboratório de Modelagem e Dinâmica Molecular, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, RJ, Brazil
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Verma K, Lahariya AK, Verma G, Kumari M, Gupta D, Maurya N, Verma AK, Mani A, Schneider KA, Bharti PK. Screening of potential antiplasmodial agents targeting cysteine protease-Falcipain 2: a computational pipeline. J Biomol Struct Dyn 2023; 41:8121-8164. [PMID: 36218071 DOI: 10.1080/07391102.2022.2130984] [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: 07/13/2022] [Accepted: 09/24/2022] [Indexed: 10/17/2022]
Abstract
The spread of antimalarial drug resistance is a substantial challenge in achieving global malaria elimination. Consequently, the identification of novel therapeutic candidates is a global health priority. Malaria parasite necessitates hemoglobin degradation for its survival, which is mediated by Falcipain 2 (FP2), a promising antimalarial target. In particular, FP2 is a key enzyme in the erythrocytic stage of the parasite's life cycle. Here, we report the screening of approved drugs listed in DrugBank using a computational pipeline that includes drug-likeness, toxicity assessments, oral toxicity evaluation, oral bioavailability, docking analysis, maximum common substructure (MCS) and molecular dynamics (MD) Simulations analysis to identify capable FP2 inhibitors, which are hence potential antiplasmodial agents. A total of 45 drugs were identified, which have positive drug-likeness, no toxic features and good bioavailability. Among these, six drugs showed good binding affinity towards FP2 compared to E64, an epoxide known to inhibit FP2. Notably, two of them, Cefalotin and Cefoxitin, shared the highest MCS with E64, which suggests that they possess similar biological activity as E64. In an investigation using MD for 100 ns, Cefalotin and Cefoxitin showed adequate protein compactness as well as satisfactory complex stability. Overall, these computational approach findings can be applied for designing and developing specific inhibitors or new antimalarial agents for the treatment of malaria infections.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Kanika Verma
- Division of Vector-Borne Diseases, ICMR-National Institute of Research in Tribal Health, Jabalpur, Madhya Pradesh, India
| | - Ayush Kumar Lahariya
- Division of Vector-Borne Diseases, ICMR-National Institute of Research in Tribal Health, Jabalpur, Madhya Pradesh, India
| | - Garima Verma
- Division of Vector-Borne Diseases, ICMR-National Institute of Research in Tribal Health, Jabalpur, Madhya Pradesh, India
- School of Studies in Microbiology, Jiwaji University, Gwalior, Madhya Pradesh, India
| | - Monika Kumari
- Division of Vector-Borne Diseases, ICMR-National Institute of Research in Tribal Health, Jabalpur, Madhya Pradesh, India
- Department of Biotechnology, St. Aloysius' (Autonomous) College, Affiliated to Rani Durgawati University, Jabalpur, Madhya Pradesh, Jabalpur, India
| | - Divanshi Gupta
- Division of Vector-Borne Diseases, ICMR-National Institute of Research in Tribal Health, Jabalpur, Madhya Pradesh, India
- Department of Biological Sciences, Rani Durgawati University, Jabalpur, Madhya Pradesh, India
| | - Neha Maurya
- Department of Biotechnology, Motilal Nehru National Institute of Technology, Allahabad, Prayagraj, India
| | - Anil Kumar Verma
- Division of Vector-Borne Diseases, ICMR-National Institute of Research in Tribal Health, Jabalpur, Madhya Pradesh, India
| | - Ashutosh Mani
- Department of Biotechnology, Motilal Nehru National Institute of Technology, Allahabad, Prayagraj, India
| | | | - Praveen Kumar Bharti
- Division of Vector-Borne Diseases, ICMR-National Institute of Research in Tribal Health, Jabalpur, Madhya Pradesh, India
- Department of Parasite Host Biology, National Institute of Malaria Research, Delhi, India
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5
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Berger F, Gomez GM, Sanchez CP, Posch B, Planelles G, Sohraby F, Nunes-Alves A, Lanzer M. pH-dependence of the Plasmodium falciparum chloroquine resistance transporter is linked to the transport cycle. Nat Commun 2023; 14:4234. [PMID: 37454114 PMCID: PMC10349806 DOI: 10.1038/s41467-023-39969-2] [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: 11/16/2022] [Accepted: 07/05/2023] [Indexed: 07/18/2023] Open
Abstract
The chloroquine resistance transporter, PfCRT, of the human malaria parasite Plasmodium falciparum is sensitive to acidic pH. Consequently, PfCRT operates at 60% of its maximal drug transport activity at the pH of 5.2 of the digestive vacuole, a proteolytic organelle from which PfCRT expels drugs interfering with heme detoxification. Here we show by alanine-scanning mutagenesis that E207 is critical for pH sensing. The E207A mutation abrogates pH-sensitivity, while preserving drug substrate specificity. Substituting E207 with Asp or His, but not other amino acids, restores pH-sensitivity. Molecular dynamics simulations and kinetics analyses suggest an allosteric binding model in which PfCRT can accept both protons and chloroquine in a partial noncompetitive manner, with increased proton concentrations decreasing drug transport. Further simulations reveal that E207 relocates from a peripheral to an engaged location during the transport cycle, forming a salt bridge with residue K80. We propose that the ionized carboxyl group of E207 acts as a hydrogen acceptor, facilitating transport cycle progression, with pH sensing as a by-product.
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Affiliation(s)
- Fiona Berger
- Center of Infectious Diseases, Parasitology, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany
| | - Guillermo M Gomez
- Center of Infectious Diseases, Parasitology, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany
| | - Cecilia P Sanchez
- Center of Infectious Diseases, Parasitology, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany
| | - Britta Posch
- Center of Infectious Diseases, Parasitology, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany
| | - Gabrielle Planelles
- INSERM, Centre de Recherche des Cordeliers, Unité 1138, CNRS ERL8228, Université Pierre et Marie Curie and Université Paris-Descartes, Paris, 75006, France
| | - Farzin Sohraby
- Institute of Chemistry, Technische Universität Berlin, Straße des 17. Juni 135, 10623, Berlin, Germany
| | - Ariane Nunes-Alves
- Institute of Chemistry, Technische Universität Berlin, Straße des 17. Juni 135, 10623, Berlin, Germany.
| | - Michael Lanzer
- Center of Infectious Diseases, Parasitology, Universitätsklinikum Heidelberg, Im Neuenheimer Feld 324, 69120, Heidelberg, Germany.
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6
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Patra J, Rana D, Arora S, Pal M, Mahindroo N. Falcipains: Biochemistry, target validation and structure-activity relationship studies of inhibitors as antimalarials. Eur J Med Chem 2023; 252:115299. [PMID: 36996716 DOI: 10.1016/j.ejmech.2023.115299] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 03/04/2023] [Accepted: 03/17/2023] [Indexed: 03/29/2023]
Abstract
Malaria is a tropical disease with significant morbidity and mortality burden caused by Plasmodium species in Africa, the Middle East, Asia, and South America. Pathogenic Plasmodium species have lately become increasingly resistant to approved chemotherapeutics and combination therapies. Therefore, there is an emergent need for identifying new druggable targets and novel chemical classes against the parasite. Falcipains, cysteine proteases required for heme metabolism in the erythrocytic stage, have emerged as promising drug targets against Plasmodium species that infect humans. This perspective discusses the biology, biochemistry, structural features, and genetics of falcipains. The efforts to identify selective or dual inhibitors and their structure-activity relationships are reviewed to give a perspective on the design of novel compounds targeting falcipains for antimalarial activity evaluating reasons for hits and misses for this important target.
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Affiliation(s)
- Jeevan Patra
- School of Health Sciences and Technology, University of Petroleum and Energy Studies, Energy Acres, Bidholi, Via Prem Nagar, Uttarakhand, 248007, India
| | - Devika Rana
- School of Pharmaceutical Sciences, Shoolini University of Biotechnology and Management Sciences, Bajhol, Solan, Himachal Pradesh, 173229, India
| | - Smriti Arora
- School of Health Sciences and Technology, University of Petroleum and Energy Studies, Energy Acres, Bidholi, Via Prem Nagar, Uttarakhand, 248007, India
| | - Mintu Pal
- Department of Pharmacology, All India Institute of Medical Sciences (AIIMS), Bathinda, Punjab, 151001, India
| | - Neeraj Mahindroo
- School of Health Sciences and Technology, University of Petroleum and Energy Studies, Energy Acres, Bidholi, Via Prem Nagar, Uttarakhand, 248007, India; School of Health Sciences and Technology, Dr. Vishwanath Karad MIT World Peace University, 124 Paud Road, Kothrud, Pune, Maharashtra, 411038, India.
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7
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Hitting drug-resistant malaria infection with triazole-linked flavonoid-chloroquine hybrid compounds. Future Med Chem 2022; 14:1865-1880. [PMID: 36622669 DOI: 10.4155/fmc-2022-0173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background: Malaria represents the major parasitic disease in tropical regions, and the development of new potent drugs is of pivotal importance. In this study, a series of hybrid molecules were designed by linking the 7-chloroquinoline core of chloroquine to different fluorinated flavonoid-related scaffolds. Materials & methods: Compounds were prepared by exploiting the click chemistry approach, allowing the introduction of a 1,2,3-triazole, a privileged structural motif in antiparasitic dug discovery. Results: Compounds 1b and 1c were the most interesting and were endowed with the highest in vitro activity, mainly against a resistant Plasmodium falciparum strain. They also inhibited hemozoin formation, and 1c was more effective than chloroquine against stage V gametocytes. Conclusion: The homoisoflavone core is a new, promising antimalarial scaffold that deserves further investigation.
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8
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Stasic AJ, Moreno SNJ, Carruthers VB, Dou Z. The Toxoplasma plant-like vacuolar compartment (PLVAC). J Eukaryot Microbiol 2022; 69:e12951. [PMID: 36218001 PMCID: PMC10576567 DOI: 10.1111/jeu.12951] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 10/06/2022] [Accepted: 10/07/2022] [Indexed: 11/28/2022]
Abstract
Toxoplasma gondii belongs to the phylum Apicomplexa and is an important cause of congenital disease and infection in immunocompromised patients. T. gondii shares several characteristics with plants including a nonphotosynthetic plastid termed apicoplast and a multivesicular organelle that was named the plant-like vacuole (PLV) or vacuolar compartment (VAC). The name plant-like vacuole was selected based on its resemblance in composition and function to plant vacuoles. The name VAC represents its general vacuolar characteristics. We will refer to the organelle as PLVAC in this review. New findings in recent years have revealed that the PLVAC represents the lysosomal compartment of T. gondii which has adapted peculiarities to fulfill specific Toxoplasma needs. In this review, we discuss the composition and functions of the PLVAC highlighting its roles in ion storage and homeostasis, endocytosis, exocytosis, and autophagy.
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Affiliation(s)
- Andrew J Stasic
- Department of Microbiology, Heartland FPG, Carmel, Indiana, USA
| | - Silvia N J Moreno
- Department of Cellular Biology, University of Georgia, Georgia, Athens, USA
- Center for Tropical and Emerging Global Diseases and Department of Cellular Biology, University of Georgia, Georgia, Athens, USA
| | - Vern B Carruthers
- Department of Microbiology & Immunology, University of Michigan Medical School, Michigan, Ann Arbor, USA
| | - Zhicheng Dou
- Department of Biological Sciences, Clemson University, South Carolina, Clemson, USA
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9
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Sanchez CP, Manson EDT, Moliner Cubel S, Mandel L, Weidt SK, Barrett MP, Lanzer M. The Knock-Down of the Chloroquine Resistance Transporter PfCRT Is Linked to Oligopeptide Handling in Plasmodium falciparum. Microbiol Spectr 2022; 10:e0110122. [PMID: 35867395 PMCID: PMC9431119 DOI: 10.1128/spectrum.01101-22] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Accepted: 06/27/2022] [Indexed: 11/20/2022] Open
Abstract
The chloroquine resistance transporter, PfCRT, is an essential factor during intraerythrocytic development of the human malaria parasite Plasmodium falciparum. PfCRT resides at the digestive vacuole of the parasite, where hemoglobin taken up by the parasite from its host cell is degraded. PfCRT can acquire several mutations that render PfCRT a drug transporting system expelling compounds targeting hemoglobin degradation from the digestive vacuole. The non-drug related function of PfCRT is less clear, although a recent study has suggested a role in oligopeptide transport based on studies conducted in a heterologous expression system. The uncertainty about the natural function of PfCRT is partly due to a lack of a null mutant and a dearth of functional assays in the parasite. Here, we report on the generation of a conditional PfCRT knock-down mutant in P. falciparum. The mutant accumulated oligopeptides 2 to at least 8 residues in length under knock-down conditions, as shown by comparative global metabolomics. The accumulated oligopeptides were structurally diverse, had an isoelectric point between 4.0 and 5.4 and were electrically neutral or carried a single charge at the digestive vacuolar pH of 5.2. Fluorescently labeled dipeptides and live cell imaging identified the digestive vacuole as the compartment where oligopeptides accumulated. Our findings suggest a function of PfCRT in oligopeptide transport across the digestive vacuolar membrane in P. falciparum and associated with it a role in nutrient acquisition and the maintenance of the colloid osmotic balance. IMPORTANCE The chloroquine resistance transporter, PfCRT, is important for the survival of the human malaria parasite Plasmodium falciparum. It increases the tolerance to many antimalarial drugs, and it is essential for the development of the parasite within red blood cells. While we understand the role of PfCRT in drug resistance in ever increasing detail, the non-drug resistance functions are still debated. Identifying the natural substrate of PfCRT has been hampered by a paucity of functional assays to test putative substrates in the parasite system and the absence of a parasite mutant deficient for the PfCRT encoding gene. By generating a conditional PfCRT knock-down mutant, together with comparative metabolomics and uptake studies using fluorescently labeled oligopeptides, we could show that PfCRT is an oligopeptide transporter. The oligopeptides were structurally diverse and were electrically neutral or carried a single charge. Our data support a function of PfCRT in oligopeptide transport.
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Affiliation(s)
- Cecilia P. Sanchez
- Center of Infectious Diseases, Parasitology, Universitätsklinikum Heidelberg, Heidelberg, Germany
| | | | - Sonia Moliner Cubel
- Center of Infectious Diseases, Parasitology, Universitätsklinikum Heidelberg, Heidelberg, Germany
| | | | - Stefan K. Weidt
- Glasgow Polyomics, University of Glasgow, Wolfson Wohl Cancer Research Centre, Glasgow, United Kingdom
| | - Michael P. Barrett
- Glasgow Polyomics, University of Glasgow, Wolfson Wohl Cancer Research Centre, Glasgow, United Kingdom
- The Wellcome Centre for Integrative Parasitology, Institute for Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Michael Lanzer
- Center of Infectious Diseases, Parasitology, Universitätsklinikum Heidelberg, Heidelberg, Germany
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10
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Ruberto AA, Maher SP, Vantaux A, Joyner CJ, Bourke C, Balan B, Jex A, Mueller I, Witkowski B, Kyle DE. Single-cell RNA profiling of Plasmodium vivax-infected hepatocytes reveals parasite- and host- specific transcriptomic signatures and therapeutic targets. Front Cell Infect Microbiol 2022; 12:986314. [PMID: 36093191 PMCID: PMC9453201 DOI: 10.3389/fcimb.2022.986314] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 08/08/2022] [Indexed: 12/12/2022] Open
Abstract
The resilience of Plasmodium vivax, the most widely-distributed malaria-causing parasite in humans, is attributed to its ability to produce dormant liver forms known as hypnozoites, which can activate weeks, months, or even years after an initial mosquito bite. The factors underlying hypnozoite formation and activation are poorly understood, as is the parasite's influence on the host hepatocyte. Here, we shed light on transcriptome-wide signatures of both the parasite and the infected host cell by sequencing over 1,000 P. vivax-infected hepatocytes at single-cell resolution. We distinguish between replicating schizonts and hypnozoites at the transcriptional level, identifying key differences in transcripts encoding for RNA-binding proteins associated with cell fate. In infected hepatocytes, we show that genes associated with energy metabolism and antioxidant stress response are upregulated, and those involved in the host immune response downregulated, suggesting both schizonts and hypnozoites alter the host intracellular environment. The transcriptional markers in schizonts, hypnozoites, and infected hepatocytes revealed here pinpoint potential factors underlying dormancy and can inform therapeutic targets against P. vivax liver-stage infection.
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Affiliation(s)
- Anthony A. Ruberto
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, 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, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Chester J. Joyner
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, United States
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA, United States
| | - Caitlin Bourke
- Population Health & Immunity Division, Walter and Eliza Hall Institute, Parkville, VIC, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, Australia
| | - Balu Balan
- Population Health & Immunity Division, Walter and Eliza Hall Institute, Parkville, VIC, Australia
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC, Australia
| | - Aaron Jex
- Population Health & Immunity Division, Walter and Eliza Hall Institute, Parkville, VIC, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, Australia
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Parkville, VIC, Australia
| | - Ivo Mueller
- Population Health & Immunity Division, Walter and Eliza Hall Institute, Parkville, VIC, Australia
- Department of Medical Biology, The University of Melbourne, Parkville, VIC, Australia
| | - Benoit Witkowski
- Malaria Molecular Epidemiology Unit, Institut Pasteur du Cambodge, Phnom Penh, Cambodia
| | - Dennis E. Kyle
- Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, GA, United States
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11
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Inhibitor of Cysteine Protease of Plasmodium malariae Regulates Malapains, Endogenous Cysteine Proteases of the Parasite. Pathogens 2022; 11:pathogens11050605. [PMID: 35631126 PMCID: PMC9142985 DOI: 10.3390/pathogens11050605] [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: 04/15/2022] [Revised: 05/13/2022] [Accepted: 05/16/2022] [Indexed: 02/05/2023] Open
Abstract
Cysteine proteases of malaria parasites have been recognized as potential targets in antimalarial drug development as they play pivotal roles in the biology of these parasites. However, strict regulation of their activities is also necessary to minimize or prevent deleterious damage to the parasite and the host. Previously, we have characterized falcipain family cysteine proteases of Plasmodium malariae, named as malapains (MPs). MPs are active hemoglobinases. They also may participate in the release of merozoites from mature schizonts by facilitating remodeling of erythrocyte skeleton proteins. In this study, we identified and characterized an endogenous inhibitor of cysteine protease of P. malariae (PmICP). PmICP shared similar structural and biochemical properties with ICPs from other Plasmodium species. Recombinant PmICP showed a broad range of inhibitory activities against diverse cysteine proteases such as falcipain family enzymes (MP-2, MP-4, VX-3, VX-4, and FP-3), papain, and human cathepsins B and L, with stronger inhibitory activities against falcipain family enzymes. The inhibitory activity of PmICP was not affected by pH. PmICP was thermo-labile, resulting in rapid loss of its inhibitory activity at a high temperature. PmICP effectively inhibited hemoglobin hydrolysis by MPs and regulated maturation of MPs, suggesting its role as a functional regulator of MPs.
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12
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Lê HG, Kang JM, Võ TC, Yoo WG, Lee KH, Na BK. Biochemical Properties of Two Plasmodium malariae Cysteine Proteases, Malapain-2 and Malapain-4. Microorganisms 2022; 10:microorganisms10010193. [PMID: 35056641 PMCID: PMC8780100 DOI: 10.3390/microorganisms10010193] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 01/12/2022] [Accepted: 01/13/2022] [Indexed: 11/25/2022] Open
Abstract
Cysteine proteases belonging to the falcipain (FP) family play a pivotal role in the biology of malaria parasites and have been extensively investigated as potential antimalarial drug targets. Three paralogous FP-family cysteine proteases of Plasmodium malariae, termed malapains 2–4 (MP2–4), were identified in PlasmoDB. The three MPs share similar structural properties with the FP-2/FP-3 subfamily enzymes and exhibit a close phylogenetic lineage with vivapains (VXs) and knowpains (KPs), FP orthologues of P. vivax and P. knowlesi. Recombinant MP-2 and MP-4 were produced in a bacterial expression system, and their biochemical properties were characterized. Both recombinant MP-2 and MP-4 showed enzyme activity across a broad range of pH values with an optimum activity at pH 5.0 and relative stability at neutral pHs. Similar to the FP-2/FP-3 subfamily enzymes in other Plasmodium species, recombinant MP-2 and MP-4 effectively hydrolyzed hemoglobin at acidic pHs. They also degraded erythrocyte cytoskeletal proteins, such as spectrin and band 3, at a neutral pH. These results imply that MP-2 and MP-4 are redundant hemoglobinases of P. malariae and may also participate in merozoite egression by degrading erythrocyte cytoskeletal proteins. However, compared with other FP-2/FP-3 enzymes, MP-2 showed a strong preference for arginine at the P2 position. Meanwhile, MP-4 showed a primary preference for leucine at the P2 position but a partial preference for phenylalanine. These different substrate preferences of MPs underscore careful consideration in the design of optimized inhibitors targeting the FP-family cysteine proteases of human malaria parasites.
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Affiliation(s)
- Hương Giang Lê
- Department of Parasitology and Tropical Medicine, Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju 52727, Korea
- Department of Convergence Medical Science, Gyeongsang National University, Jinju 52727, Korea
| | - Jung-Mi Kang
- Department of Parasitology and Tropical Medicine, Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju 52727, Korea
- Department of Convergence Medical Science, Gyeongsang National University, Jinju 52727, Korea
| | - Tuấn Cường Võ
- Department of Parasitology and Tropical Medicine, Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju 52727, Korea
- Department of Convergence Medical Science, Gyeongsang National University, Jinju 52727, Korea
| | - Won Gi Yoo
- Department of Parasitology and Tropical Medicine, Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju 52727, Korea
- Department of Convergence Medical Science, Gyeongsang National University, Jinju 52727, Korea
| | - Kon Ho Lee
- Department of Convergence Medical Science, Gyeongsang National University, Jinju 52727, Korea
- Department of Microbiology, Gyeongsang National University College of Medicine, Jinju 52727, Korea
| | - Byoung-Kuk Na
- Department of Parasitology and Tropical Medicine, Institute of Health Sciences, Gyeongsang National University College of Medicine, Jinju 52727, Korea
- Department of Convergence Medical Science, Gyeongsang National University, Jinju 52727, Korea
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13
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Okeke CJ, Musyoka TM, Sheik Amamuddy O, Barozi V, Tastan Bishop Ö. Allosteric pockets and dynamic residue network hubs of falcipain 2 in mutations including those linked to artemisinin resistance. Comput Struct Biotechnol J 2021; 19:5647-5666. [PMID: 34745456 PMCID: PMC8545671 DOI: 10.1016/j.csbj.2021.10.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 09/30/2021] [Accepted: 10/03/2021] [Indexed: 10/29/2022] Open
Abstract
Continually emerging resistant strains of malarial parasites to current drugs present challenges. Understanding the underlying resistance mechanisms, especially those linked to allostery is, thus, highly crucial for drug design. This forms the main concern of the paper through a case study of falcipain 2 (FP-2) and its mutations, some of which are linked to artemisinin (ART) drug resistance. Here, we applied a variety of in silico approaches and tools that we developed recently, together with existing computational tools. This included novel essential dynamics and dynamic residue network (DRN) analysis algorithms. We identified six pockets demonstrating dynamic differences in the presence of some mutations. We observed striking allosteric effects in two mutant proteins. In the presence of M245I, a cryptic pocket was detected via a unique mechanism in which Pocket 2 fused with Pocket 6. In the presence of the A353T mutation, which is located at Pocket 2, the pocket became the most rigid among all protein systems analyzed. Pocket 6 was also highly stable in all cases, except in the presence of M245I mutation. The effect of ART linked mutations was more subtle, and the changes were at residue level. Importantly, we identified an allosteric communication path formed by four unique averaged BC hubs going from the mutated residue to the catalytic site and passing through the interface of three identified pockets. Collectively, we established and demonstrated that we have robust tools and a pipeline that can be applicable to the analysis of mutations.
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Affiliation(s)
| | | | - Olivier Sheik Amamuddy
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, Makhanda 6140, South Africa
| | - Victor Barozi
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, Makhanda 6140, South Africa
| | - Özlem Tastan Bishop
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, Makhanda 6140, South Africa
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14
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Hernández González JE, Salas-Sarduy E, Hernández Alvarez L, Barreto Gomes DE, Pascutti PG, Oostenbrink C, Leite VBP. In silico identification of noncompetitive inhibitors targeting an uncharacterized allosteric site of falcipain-2. J Comput Aided Mol Des 2021; 35:1067-1079. [PMID: 34617191 DOI: 10.1007/s10822-021-00420-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 09/24/2021] [Indexed: 01/05/2023]
Abstract
Falcipain-2 (FP-2) is a Plasmodium falciparum hemoglobinase widely targeted in the search for antimalarials. FP-2 can be allosterically modulated by various noncompetitive inhibitors that have been serendipitously identified. Moreover, the crystal structures of two inhibitors bound to an allosteric site, termed site 6, of the homolog enzyme human cathepsin K (hCatK) suggest that the equivalent region in FP-2 might play a similar role. Here, we conduct the rational identification of FP-2 inhibitors through virtual screenings (VS) of compounds into several pocket-like conformations of site 6, sampled during molecular dynamics (MD) simulations of the free enzyme. Two noncompetitive inhibitors, ZINC03225317 and ZINC72290660, were confirmed using in vitro enzymatic assays and their poses into site 6 led to calculated binding free energies matching the experimental ones. Our results provide strong evidence about the allosteric inhibition of FP-2 through binding of small molecules to site 6, thus opening the way toward the discovery of new inhibitors against this enzyme.
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Affiliation(s)
- Jorge Enrique Hernández González
- Departamento de Física, Instituto de Biociências, Letras e Ciências Exatas - Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Rua Cristóvão Colombo 2265, Jardim Nazareth, São José do Rio Preto, SP, CEP 15054-000, Brazil. .,Laboratório de Modelagem e Dinâmica Molecular, Instituto de Biofı́sica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Ave. Carlos Chagas Filho - Universidade Federal do Rio de Janeiro (UFRJ), Ave. Carlos Chagas Filho, 373, CCS-Bloco D sala 30, Cidade Universitária Ilha de Fundão, Rio de Janeiro, RJ, CEP 21941-902, Brazil. .,Institute for Molecular Modeling and Simulation, Department for Material Sciences and Process Engineering - University of Natural Resources and Life Sciences (BOKU), Vienna, Muthgasse 18, 1190, Vienna, Austria.
| | - Emir Salas-Sarduy
- Instituto de Investigaciones Biotecnológicas Dr. Rodolfo Ugalde, Universidad Nacional de San Martín, CONICET, San Martín, Buenos Aires, Argentina
| | - Lilian Hernández Alvarez
- Departamento de Física, Instituto de Biociências, Letras e Ciências Exatas - Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Rua Cristóvão Colombo 2265, Jardim Nazareth, São José do Rio Preto, SP, CEP 15054-000, Brazil
| | - Diego Enry Barreto Gomes
- Laboratório de Modelagem e Dinâmica Molecular, Instituto de Biofı́sica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Ave. Carlos Chagas Filho - Universidade Federal do Rio de Janeiro (UFRJ), Ave. Carlos Chagas Filho, 373, CCS-Bloco D sala 30, Cidade Universitária Ilha de Fundão, Rio de Janeiro, RJ, CEP 21941-902, Brazil.,Instituto de Ciências Exatas, Universidade Federal de Juiz de Fora (UFJF), Rua José Lourenço Kelmer, s/n - Campus Universitário, Bairro São Pedro, Juiz de Fora, MG, CEP 36036-900, Brazil
| | - Pedro Geraldo Pascutti
- Laboratório de Modelagem e Dinâmica Molecular, Instituto de Biofı́sica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Ave. Carlos Chagas Filho - Universidade Federal do Rio de Janeiro (UFRJ), Ave. Carlos Chagas Filho, 373, CCS-Bloco D sala 30, Cidade Universitária Ilha de Fundão, Rio de Janeiro, RJ, CEP 21941-902, Brazil
| | - Chris Oostenbrink
- Institute for Molecular Modeling and Simulation, Department for Material Sciences and Process Engineering - University of Natural Resources and Life Sciences (BOKU), Vienna, Muthgasse 18, 1190, Vienna, Austria
| | - Vitor B P Leite
- Departamento de Física, Instituto de Biociências, Letras e Ciências Exatas - Universidade Estadual Paulista Júlio de Mesquita Filho (UNESP), Rua Cristóvão Colombo 2265, Jardim Nazareth, São José do Rio Preto, SP, CEP 15054-000, Brazil
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15
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Adejoh J, Inyang BA, Egua MO, Nwachukwu KC, Alli LA, Okoh MP. In-vivo anti-plasmodial activity of phosphate buffer extract of Calotropis procera latex in mice infected with Plasmodium berghei. JOURNAL OF ETHNOPHARMACOLOGY 2021; 277:114237. [PMID: 34051335 DOI: 10.1016/j.jep.2021.114237] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/02/2021] [Accepted: 05/21/2021] [Indexed: 06/12/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Malaria is a global health problem with the greatest burden in sub-Saharan Africa (sSA). The resistance to available antimalarial agents necessitate for the development of new and safe drugs for which medicinal plants provides credible alternative sources for discovering new and cheap therapeutic agents. Calotropis procera is used in several folk or traditional medicines for the treatment of various diseases across different regions of the world. In Nigeria traditional medicine, C. procera latex is used either alone or in combination with other herbs to cure common diseases including malaria. In Malaka district (Indonesia), Calotropis gigantea (a member of Apocyanceae), is one of the most used herbs to treat malaria patient via the massage method. AIM OF THE STUDY This study aimed to evaluate the anti-plasmodial activity of phosphate buffer extract of Calotropis procera latex in mice infected with Plasmodium berghei. MATERIALS AND METHODS The plant's anti-plasmodial agent was extracted using 0.2 M-phosphate buffer (pH 7.0), followed by precipitation using acetone. 90 (ninety) mice were divided into three main groups of 30 (thirty) mice each, used for the curative, suppressive and prophylactic tests, respectively. The 30 (thirty) mice in each of the main groups were sub-divided into five groups of 6 (six) mice. The mice in the group 1, 2 and 3 (test groups) were made to receive graded doses of 25 mg/kg, 50 mg/kg and 75 mg/kg of the extract of C. procera latex intraperitoneally; group 4 (negative control group) received 0.2 ml of normal saline; while group 5 (positive control group) were administered with 5 mg/kg chloroquine. The phytochemical constituents of the plant and its intraperitoneal median lethal dose (LD50) were also undertaken. RESULTS The freeze-dried acetone extract exhibited acute toxicity with median lethal dose (LD50) of 745 mg/kg body weight in mice. The highest percentage parasite suppression (61.85%), percentage parasite cure (50.26%), and percentage parasite prophylaxis (65.47%), were obtained for the groups treated with 75 mg/kg bodyweight/day of the extract. The least percentage parasite suppression (44.74%), percentage parasite cure (35.21%), and percentage parasite prophylaxis (45.21%), were obtained for the groups treated with 25 mg/kg body weight of the extract. Also, a dose-dependent percentage parasite suppression (53.03%), percentage parasite cure (39.70%), and percentage parasite prophylaxis (49.82%) were obtained for the groups treated with 50 mg/kg body weight. This is comparable to the groups treated with standard chloroquine. The extract also produced a significant elevation in body weight of the animals for suppressive and curative tests. However, there were observable significant decreases in body weight of the animals in the case of prophylactic test. CONCLUSION This study showed that the phosphate buffer extract of C. procera latex possess anti-plasmodial activity. The results of this study can be used as a basis for further phytochemical investigations in the search for new and locally affordable antimalarial agents.
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Affiliation(s)
- Johnson Adejoh
- Department of Medical Biochemistry, Faculty of Basic Medical Sciences, College of Health Sciences, University of Abuja, P.M.B 117 FCT, Abuja, Nigeria
| | - Bassey A Inyang
- Department of Medical Biochemistry, Faculty of Basic Medical Sciences, College of Health Sciences, University of Abuja, P.M.B 117 FCT, Abuja, Nigeria
| | - Maxwell O Egua
- Department of Pharmacology and Therapeutics, Faculty of Basic Clinical Sciences, College of Health Sciences, University of Abuja, P.M.B 117 FCT, Abuja, Nigeria
| | - Kenneth C Nwachukwu
- Department of Medical Biochemistry, Faculty of Basic Medical Sciences, College of Health Sciences, University of Abuja, P.M.B 117 FCT, Abuja, Nigeria
| | - Lukman A Alli
- Department of Medical Biochemistry, Faculty of Basic Medical Sciences, College of Health Sciences, University of Abuja, P.M.B 117 FCT, Abuja, Nigeria
| | - Michael P Okoh
- Department of Medical Biochemistry, Faculty of Basic Medical Sciences, College of Health Sciences, University of Abuja, P.M.B 117 FCT, Abuja, Nigeria.
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16
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Purification and Characterization of a Novel Thermostable Papain Inhibitor from Moringa oleifera with Antimicrobial and Anticoagulant Properties. Pharmaceutics 2021; 13:pharmaceutics13040512. [PMID: 33917878 PMCID: PMC8068210 DOI: 10.3390/pharmaceutics13040512] [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: 02/23/2021] [Revised: 03/31/2021] [Accepted: 04/01/2021] [Indexed: 11/26/2022] Open
Abstract
Plant cystatins (or phytocystatins) comprise a large superfamily of natural bioactive small proteins that typically act as protein inhibitors of papain-like cysteine proteases. In this report, we present the purification and characterization of the first phytocystatin isolated from Moringa oleifera (MoPI). MoPI has a molecular mass of 19 kDa and showed an extraordinary physicochemical stability against acidic pHs and high temperatures. Our findings also revealed that MoPI is one of the most potent cysteine protease inhibitors reported to date, with Ki and IC50 values of 2.1 nM and 5.7 nM, respectively. More interestingly, MoPI presents a strong antimicrobial activity against human pathogens such as Enterococcus faecalis and Staphylococcus aureus. In addition, MoPI also showed important anticoagulant activity, which is an unprecedented property for this family of protease inhibitors. These results highlight the pharmaceutical potential of this plant and its derived bioactive molecules.
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17
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Mishra M, Singh V, Tellis MB, Joshi RS, Singh S. Repurposing the McoTI-II Rigid Molecular Scaffold in to Inhibitor of 'Papain Superfamily' Cysteine Proteases. Pharmaceuticals (Basel) 2020; 14:ph14010007. [PMID: 33374547 PMCID: PMC7822474 DOI: 10.3390/ph14010007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 11/30/2020] [Indexed: 01/19/2023] Open
Abstract
Clan C1A or ‘papain superfamily’ cysteine proteases are key players in many important physiological processes and diseases in most living systems. Novel approaches towards the development of their inhibitors can open new avenues in translational medicine. Here, we report a novel design of a re-engineered chimera inhibitor Mco-cysteine protease inhibitor (CPI) to inhibit the activity of C1A cysteine proteases. This was accomplished by grafting the cystatin first hairpin loop conserved motif (QVVAG) onto loop 1 of the ultrastable cyclic peptide scaffold McoTI-II. The recombinantly expressed Mco-CPI protein was able to bind with micromolar affinity to papain and showed remarkable thermostability owing to the formation of multi-disulphide bonds. Using an in silico approach based on homology modelling, protein–protein docking, the calculation of the free-energy of binding, the mechanism of inhibition of Mco-CPI against representative C1A cysteine proteases (papain and cathepsin L) was validated. Furthermore, molecular dynamics simulation of the Mco-CPI–papain complex validated the interaction as stable. To conclude, in this McoTI-II analogue, the specificity had been successfully redirected towards C1A cysteine proteases while retaining the moderate affinity. The outcomes of this study pave the way for further modifications of the Mco-CPI design for realizing its full potential in therapeutics. This study also demonstrates the relevance of ultrastable peptide-based scaffolds for the development of novel inhibitors via grafting.
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Affiliation(s)
- Manasi Mishra
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Gautam Buddha Nagar 201314, India;
- Correspondence: (M.M.); (S.S.)
| | - Vigyasa Singh
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Gautam Buddha Nagar 201314, India;
- Special Centre for Molecular Medicine, Jawahar Lal Nehru University, New Delhi 110067, India
| | - Meenakshi B. Tellis
- Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India; (M.B.T.); (R.S.J.)
| | - Rakesh S. Joshi
- Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune 411008, India; (M.B.T.); (R.S.J.)
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Shailja Singh
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Gautam Buddha Nagar 201314, India;
- Special Centre for Molecular Medicine, Jawahar Lal Nehru University, New Delhi 110067, India
- Correspondence: (M.M.); (S.S.)
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18
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Mishra M, Singh V, Tellis MB, Joshi RS, Pandey KC, Singh S. Cyclic peptide engineered from phytocystatin inhibitory hairpin loop as an effective modulator of falcipains and potent antimalarial. J Biomol Struct Dyn 2020; 40:3642-3654. [PMID: 33292080 DOI: 10.1080/07391102.2020.1848629] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Cystatins are classical competitive inhibitors of C1 family cysteine proteases (papain family). Phytocystatin superfamily shares high sequence homology and typical tertiary structure with conserved glutamine-valine-glycine (Q-X-V-X-G) loop blocking the active site of C1 proteases. Here, we develop a cysteine-bounded cyclic peptide (CYS-cIHL) and linear peptide (CYS-IHL), using the conserved inhibitory hairpin loop amino acid sequence. Using an in silico approach based on modeling, protein-peptide docking, molecular dynamics simulations and calculation of free energy of binding, we designed and validated inhibitory peptides against falcipain-2 (FP-2) and -3 (FP-3), cysteine proteases from the malarial parasite Plasmodium falciparum. Falcipains are critical hemoglobinases of P. falciparum that are validated targets for the development of antimalarial therapies. CYS-cIHL was able to bind with micromolar affinity to FP-2 and modulate its binding with its substrate, hemoglobin in in vitro and in vivo assays. CYS-cIHL could effectively block parasite growth and displayed antimalarial activity in culture assays with no cytotoxicity towards human cells. These results indicated that cyclization can substantially increase the peptide affinity to the target. Furthermore, this can be applied as an effective strategy for engineering peptide inhibitory potency against proteases.
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Affiliation(s)
- Manasi Mishra
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Uttar Pradesh, India
| | - Vigyasa Singh
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Meenakshi B Tellis
- Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, India
| | - Rakesh S Joshi
- Division of Biochemical Sciences, CSIR-National Chemical Laboratory, Pune, India.,Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Kailash C Pandey
- Parasite-Host Biology Group, ICMR National Institute of Malaria Research, Dwarka, India
| | - Shailja Singh
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Uttar Pradesh, India.,Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
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19
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Singh V, Hada RS, Uddin A, Aneja B, Abid M, Pandey KC, Singh S. Inhibition of Hemoglobin Degrading Protease Falcipain-2 as a Mechanism for Anti-Malarial Activity of Triazole-Amino Acid Hybrids. Curr Top Med Chem 2020; 20:377-389. [PMID: 32000644 DOI: 10.2174/1568026620666200130162347] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 08/20/2019] [Accepted: 10/20/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND Novel drug development against malaria parasite over old conventional antimalarial drugs is essential due to rapid and indiscriminate use of drugs, which led to the emergence of resistant strains. METHODS In this study, previously reported triazole-amino acid hybrids (13-18) are explored against Plasmodium falciparum as antimalarial agents. Among six compounds, 15 and 18 exhibited antimalarial activity against P. falciparum with insignificant hemolytic activity and cytotoxicity towards HepG2 mammalian cells. In molecular docking studies, both compounds bind into the active site of PfFP-2 and block its accessibility to the substrate that leads to the inhibition of target protein further supported by in vitro analysis. RESULTS Antimalarial half-maximal inhibitory concentration (IC50) of 15 and 18 compounds were found to be 9.26 μM and 20.62 μM, respectively. Blood stage specific studies showed that compounds, 15 and 18 are effective at late trophozoite stage and block egress pathway of parasites. Decreased level of free monomeric heme was found in a dose dependent manner after the treatment with compounds 15 and 18, which was further evidenced by the reduction in percent of hemoglobin hydrolysis. Compounds 15 and 18 hindered hemoglobin degradation via intra- and extracellular cysteine protease falcipain-2 (PfFP-2) inhibitory activity both in in vitro and in vivo in P. falciparum. CONCLUSION We report antimalarial potential of triazole-amino acid hybrids and their role in the inhibition of cysteine protease PfFP-2 as its mechanistic aspect.
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Affiliation(s)
- Vigyasa Singh
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Rahul Singh Hada
- Department of Life Sciences, Shiv Nadar University, Gautam Buddha Nagar UP, 201314, India
| | - Amad Uddin
- Medicinal Chemistry Laboratory, Department of Biosciences, Jamia Millia Islamia, Jamia Nagar, New Delhi, 110025, India
| | - Babita Aneja
- Medicinal Chemistry Laboratory, Department of Biosciences, Jamia Millia Islamia, Jamia Nagar, New Delhi, 110025, India.,Department of Organic Chemistry, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Mohammad Abid
- Medicinal Chemistry Laboratory, Department of Biosciences, Jamia Millia Islamia, Jamia Nagar, New Delhi, 110025, India
| | - Kailash C Pandey
- Host-Parasite Interaction Biology Group, National Institute of Malaria Research, Indian Council of Medical Research, Sector-8, Dwarka, New Delhi 110077, India
| | - Shailja Singh
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, 110067, India
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20
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Hernández González JE, Hernández Alvarez L, Leite VBP, Pascutti PG. Water Bridges Play a Key Role in Affinity and Selectivity for Malarial Protease Falcipain-2. J Chem Inf Model 2020; 60:5499-5512. [PMID: 32634311 DOI: 10.1021/acs.jcim.0c00294] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Falcipain-2 (FP-2) is hemoglobinase considered an attractive drug target of Plasmodium falciparum. Recently, it has been shown that peptidomimetic nitriles containing a 3-pyridyl (3Pyr) moiety at P2 display high affinity and selectivity for FP-2 with respect to human cysteine cathepsins (hCats), outperforming other P2-Pyr isomers and analogs. Further characterization demonstrated that certain P3 variants of these compounds possess micromolar inhibition of parasite growth in vitro and no cytotoxicity against human cell lines. However, the structural determinants underlying the selectivity of the 3Pyr-containing nitriles for FP-2 remain unknown. In this work, we conduct a thorough computational study combining MD simulations and free energy calculations to decipher the bases of the selectivity of the aforementioned nitriles. Our results reveal that water bridges involving the nitrogen and one carboxyl oxygen of I85 and D234 of FP-2, respectively, and the nitrogen of the neutral 3Pyr moiety, which are either less prevalent or nonexistent in the other complexes, explain the experimental activity profiles. The presence of crystallographic waters close to the bridging water positions in the studied proteases strongly supports the occurrence of such interactions. Overall, our findings suggest that selective FP-2 inhibitors can be designed by promoting water bridge formation at the bottom of the S2 subsite and/or by introducing complementary groups that displace the bridging water.
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Affiliation(s)
- Jorge Enrique Hernández González
- Departamento de Fı́sica, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista Júlio de Mesquita Filho, Rua Cristóvão Colombo, 2265, Jardim Nazareth, São José do Rio Preto, São Paulo CEP 15054-000, Brazil
| | - Lilian Hernández Alvarez
- Departamento de Fı́sica, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista Júlio de Mesquita Filho, Rua Cristóvão Colombo, 2265, Jardim Nazareth, São José do Rio Preto, São Paulo CEP 15054-000, Brazil.,Skaggs School of Pharmacy and Pharmaceutical Sciences, Center for Discovery and Innovation in Parasitic Diseases, University of California San Diego, La Jolla, California 92093, United States
| | - Vitor B P Leite
- Departamento de Fı́sica, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista Júlio de Mesquita Filho, Rua Cristóvão Colombo, 2265, Jardim Nazareth, São José do Rio Preto, São Paulo CEP 15054-000, Brazil
| | - Pedro Geraldo Pascutti
- Laboratório de Modelagem e Dinâmica Molecular, Instituto de Biofı́sica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Ave. Carlos Chagas Filho, 373, CCS-Bloco D sala 30, Cidade Universitária Ilha de Fundão Rio de Janeiro, CEP 21941-902, Brazil
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21
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Shafik SH, Cobbold SA, Barkat K, Richards SN, Lancaster NS, Llinás M, Hogg SJ, Summers RL, McConville MJ, Martin RE. The natural function of the malaria parasite's chloroquine resistance transporter. Nat Commun 2020; 11:3922. [PMID: 32764664 PMCID: PMC7413254 DOI: 10.1038/s41467-020-17781-6] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 07/15/2020] [Indexed: 01/27/2023] Open
Abstract
The Plasmodium falciparum chloroquine resistance transporter (PfCRT) is a key contributor to multidrug resistance and is also essential for the survival of the malaria parasite, yet its natural function remains unresolved. We identify host-derived peptides of 4-11 residues, varying in both charge and composition, as the substrates of PfCRT in vitro and in situ, and show that PfCRT does not mediate the non-specific transport of other metabolites and/or ions. We find that drug-resistance-conferring mutations reduce both the peptide transport capacity and substrate range of PfCRT, explaining the impaired fitness of drug-resistant parasites. Our results indicate that PfCRT transports peptides from the lumen of the parasite's digestive vacuole to the cytosol, thereby providing a source of amino acids for parasite metabolism and preventing osmotic stress of this organelle. The resolution of PfCRT's native substrates will aid the development of drugs that target PfCRT and/or restore the efficacy of existing antimalarials.
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Affiliation(s)
- Sarah H Shafik
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Simon A Cobbold
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, VIC, 3052, Australia
| | - Kawthar Barkat
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Sashika N Richards
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Nicole S Lancaster
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Manuel Llinás
- Department of Biochemistry and Molecular Biology, Department of Chemistry, and Huck Center for Malaria Research, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Simon J Hogg
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Robert L Summers
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia
| | - Malcolm J McConville
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, VIC, 3052, Australia
| | - Rowena E Martin
- Research School of Biology, The Australian National University, Canberra, ACT, 2601, Australia.
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22
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Florentin A, Cobb DW, Kudyba HM, Muralidharan V. Directing traffic: Chaperone-mediated protein transport in malaria parasites. Cell Microbiol 2020; 22:e13215. [PMID: 32388921 PMCID: PMC7282954 DOI: 10.1111/cmi.13215] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 04/12/2020] [Accepted: 04/14/2020] [Indexed: 12/16/2022]
Abstract
The ability of eukaryotic parasites from the phylum Apicomplexa to cause devastating diseases is predicated upon their ability to maintain faithful and precise protein trafficking mechanisms. Their parasitic life cycle depends on the trafficking of effector proteins to the infected host cell, transport of proteins to several critical organelles required for survival, as well as transport of parasite and host proteins to the digestive organelles to generate the building blocks for parasite growth. Several recent studies have shed light on the molecular mechanisms parasites utilise to transform the infected host cells, transport proteins to essential metabolic organelles and for biogenesis of organelles required for continuation of their life cycle. Here, we review key pathways of protein transport originating and branching from the endoplasmic reticulum, focusing on the essential roles of chaperones in these processes. Further, we highlight key gaps in our knowledge that prevents us from building a holistic view of protein trafficking in these deadly human pathogens.
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Affiliation(s)
- Anat Florentin
- Department of Cellular Biology, University of Georgia, Athens, Georgia, USA.,Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
| | - David W Cobb
- Department of Cellular Biology, University of Georgia, Athens, Georgia, USA.,Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
| | - Heather M Kudyba
- Department of Cellular Biology, University of Georgia, Athens, Georgia, USA.,Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
| | - Vasant Muralidharan
- Department of Cellular Biology, University of Georgia, Athens, Georgia, USA.,Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia, USA
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23
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Rosenthal PJ. Falcipain cysteine proteases of malaria parasites: An update. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2020; 1868:140362. [DOI: 10.1016/j.bbapap.2020.140362] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 01/04/2020] [Accepted: 01/07/2020] [Indexed: 02/06/2023]
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24
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Toxoplasma Cathepsin Protease B and Aspartyl Protease 1 Are Dispensable for Endolysosomal Protein Digestion. mSphere 2020; 5:5/1/e00869-19. [PMID: 32051238 PMCID: PMC7021471 DOI: 10.1128/msphere.00869-19] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Roughly one-third of the human population is chronically infected with the intracellular single-celled parasite Toxoplasma gondii, but little is known about how this organism persists inside people. Previous research suggested that a parasite proteolytic enzyme, termed cathepsin protease L, is important for Toxoplasma persistence; however, it remained possible that other associated proteolytic enzymes could also be involved in the long-term survival of the parasite during infection. Here, we show that two proteolytic enzymes associated with cathepsin protease L play dispensable roles and are dependent on cathepsin L to reach maturity, which differs from the corresponding enzymes in humans. These findings establish a divergent hierarchy of proteases and help focus attention principally on cathepsin protease L as a potential target for interrupting Toxoplasma chronic infection. The lysosome-like vacuolar compartment (VAC) is a major site of proteolysis in the intracellular parasite Toxoplasma gondii. Previous studies have shown that genetic ablation of a VAC-residing cysteine protease, cathepsin protease L (CPL), resulted in the accumulation of undigested protein in the VAC and loss of parasite viability during the chronic stage of infection. However, since the maturation of another VAC localizing protease, cathepsin protease B (CPB), is dependent on CPL, it remained unknown whether these defects result directly from ablation of CPL or indirectly from a lack of CPB maturation. Likewise, although a previously described cathepsin D-like aspartyl protease 1 (ASP1) could also play a role in proteolysis, its definitive residence and function in the Toxoplasma endolysosomal system were not well defined. Here, we demonstrate that CPB is not necessary for protein turnover in the VAC and that CPB-deficient parasites have normal growth and viability in both the acute and chronic stages of infection. We also show that ASP1 depends on CPL for correct maturation, and it resides in the T. gondii VAC, where, similar to CPB, it plays a dispensable role in protein digestion. Taken together with previous work, our findings suggest that CPL is the dominant protease in a hierarchy of proteolytic enzymes within the VAC. This unusual lack of redundancy for CPL in T. gondii makes it a single exploitable target for disrupting chronic toxoplasmosis. IMPORTANCE Roughly one-third of the human population is chronically infected with the intracellular single-celled parasite Toxoplasma gondii, but little is known about how this organism persists inside people. Previous research suggested that a parasite proteolytic enzyme, termed cathepsin protease L, is important for Toxoplasma persistence; however, it remained possible that other associated proteolytic enzymes could also be involved in the long-term survival of the parasite during infection. Here, we show that two proteolytic enzymes associated with cathepsin protease L play dispensable roles and are dependent on cathepsin L to reach maturity, which differs from the corresponding enzymes in humans. These findings establish a divergent hierarchy of proteases and help focus attention principally on cathepsin protease L as a potential target for interrupting Toxoplasma chronic infection.
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25
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Musyoka T, Bishop ÖT. South African Abietane Diterpenoids and Their Analogs as Potential Antimalarials: Novel Insights from Hybrid Computational Approaches. Molecules 2019; 24:E4036. [PMID: 31703388 PMCID: PMC6891524 DOI: 10.3390/molecules24224036] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 10/28/2019] [Accepted: 10/31/2019] [Indexed: 12/31/2022] Open
Abstract
The hemoglobin degradation process in Plasmodium parasites is vital for nutrient acquisition required for their growth and proliferation. In P. falciparum, falcipains (FP-2 and FP-3) are the major hemoglobinases, and remain attractive antimalarial drug targets. Other Plasmodium species also possess highly homologous proteins to FP-2 and FP-3. Although several inhibitors have been designed against these proteins, none has been commercialized due to associated toxicity on human cathepsins (Cat-K, Cat-L and Cat-S). Despite the two enzyme groups sharing a common structural fold and catalytic mechanism, distinct active site variations have been identified, and can be exploited for drug development. Here, we utilize in silico approaches to screen 628 compounds from the South African natural sources to identify potential hits that can selectively inhibit the plasmodial proteases. Using docking studies, seven abietane diterpenoids, binding strongly to the plasmodial proteases, and three additional analogs from PubChem were identified. Important residues involved in ligand stabilization were identified for all potential hits through binding pose analysis and their energetic contribution determined by binding free energy calculations. The identified compounds present important scaffolds that could be further developed as plasmodial protease inhibitors. Previous laboratory assays showed the effect of the seven diterpenoids as antimalarials. Here, for the first time, we demonstrate that their possible mechanism of action could be by interacting with falcipains and their plasmodial homologs. Dynamic residue network (DRN) analysis on the plasmodial proteases identified functionally important residues, including a region with high betweenness centrality, which had previously been proposed as a potential allosteric site in FP-2.
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Affiliation(s)
| | - Özlem Tastan Bishop
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown 6140, South Africa;
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26
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Vieira RP, Santos VC, Ferreira RS. Structure-based Approaches Targeting Parasite Cysteine Proteases. Curr Med Chem 2019; 26:4435-4453. [PMID: 28799498 DOI: 10.2174/0929867324666170810165302] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 07/18/2017] [Accepted: 07/18/2017] [Indexed: 12/17/2022]
Abstract
Cysteine proteases are essential hydrolytic enzymes present in the majority of organisms, including viruses and unicellular parasites. Despite the high sequence identity displayed among these proteins, specific structural features across different species grant distinct functions to these biomolecules, frequently related to pathological conditions. Consequently, their relevance as promising targets for potential specific inhibitors has been highlighted and occasionally validated in recent decades. In this review, we discuss the recent outcomes of structure-based campaigns aiming the discovery of new inhibitor prototypes against cruzain and falcipain, as alternative therapeutic tools for Chagas disease and malaria treatments, respectively. Computational and synthetic approaches have been combined on hit optimization strategies and are also discussed herein. These rationales are extended to additional tropical infectious and neglected pathologies, such as schistosomiasis, leishmaniasis and babesiosis, and also to Alzheimer's Disease, a widespread neurodegenerative disease poorly managed by currently available drugs and recently linked to particular physiopathological roles of human cysteine proteases.
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Affiliation(s)
- Rafael Pinto Vieira
- Departamento de Bioquimica e Imunologia, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG, Brazil.,CAPES Foundation, Ministry of Education of Brazil, 70040-020 Brasília, DF, Brazil
| | - Viviane Corrêa Santos
- Departamento de Bioquimica e Imunologia, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG, Brazil
| | - Rafaela Salgado Ferreira
- Departamento de Bioquimica e Imunologia, Instituto de Ciencias Biologicas, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG, Brazil
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27
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Herraiz T, Guillén H, González-Peña D, Arán VJ. Antimalarial Quinoline Drugs Inhibit β-Hematin and Increase Free Hemin Catalyzing Peroxidative Reactions and Inhibition of Cysteine Proteases. Sci Rep 2019; 9:15398. [PMID: 31659177 PMCID: PMC6817881 DOI: 10.1038/s41598-019-51604-z] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 10/03/2019] [Indexed: 01/06/2023] Open
Abstract
Malaria caused by Plasmodium affects millions people worldwide. Plasmodium consumes hemoglobin during its intraerythrocytic stage leaving toxic heme. Parasite detoxifies free heme through formation of hemozoin (β-hematin) pigment. Proteolysis of hemoglobin and formation of hemozoin are two main targets for antimalarial drugs. Quinoline antimarial drugs and analogs (β-carbolines or nitroindazoles) were studied as inhibitors of β-hematin formation. The most potent inhibitors were quinacrine, chloroquine, and amodiaquine followed by quinidine, mefloquine and quinine whereas 8-hydroxyquinoline and β-carbolines had no effect. Compounds that inhibited β-hematin increased free hemin that promoted peroxidative reactions as determined with TMB and ABTS substrates. Hemin-catalyzed peroxidative reactions were potentiated in presence of proteins (i.e. globin or BSA) while antioxidants and peroxidase inhibitors decreased peroxidation. Free hemin increased by chloroquine action promoted oxidative reactions resulting in inhibition of proteolysis by three cysteine proteases: papain, ficin and cathepsin B. Glutathione reversed inhibition of proteolysis. These results show that active quinolines inhibit hemozoin and increase free hemin which in presence of H2O2 that abounds in parasite digestive vacuole catalyzes peroxidative reactions and inhibition of cysteine proteases. This work suggests a link between the action of quinoline drugs with biochemical processes of peroxidation and inhibition of proteolysis.
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Affiliation(s)
- Tomás Herraiz
- Instituto de Ciencia y Tecnología de Alimentos y Nutrición (ICTAN). Spanish National Research Council (CSIC), Juan de la Cierva 3, 28006, Madrid, Spain.
| | - Hugo Guillén
- Instituto de Ciencia y Tecnología de Alimentos y Nutrición (ICTAN). Spanish National Research Council (CSIC), Juan de la Cierva 3, 28006, Madrid, Spain
| | - Diana González-Peña
- Instituto de Ciencia y Tecnología de Alimentos y Nutrición (ICTAN). Spanish National Research Council (CSIC), Juan de la Cierva 3, 28006, Madrid, Spain
| | - Vicente J Arán
- Instituto de Química Médica (IQM-CSIC), Juan de la Cierva 3, 28006, Madrid, Spain
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28
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Musyoka TM, Njuguna JN, Tastan Bishop Ö. Comparing sequence and structure of falcipains and human homologs at prodomain and catalytic active site for malarial peptide based inhibitor design. Malar J 2019; 18:159. [PMID: 31053072 PMCID: PMC6500056 DOI: 10.1186/s12936-019-2790-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 04/23/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Falcipains are major cysteine proteases of Plasmodium falciparum involved in haemoglobin degradation and remain attractive anti-malarial drug targets. Several inhibitors against these proteases have been identified, yet none of them has been approved for malaria treatment. Other Plasmodium species also possess highly homologous proteins to falcipains. For selective therapeutic targeting, identification of sequence and structure differences with homologous human cathepsins is necessary. The substrate processing activity of these proteins is tightly controlled via a prodomain segment occluding the active site which is chopped under low pH conditions exposing the catalytic site. Current work characterizes these proteases to identify residues mediating the prodomain regulatory function for the design of peptide based anti-malarial inhibitors. METHODS Sequence and structure variations between prodomain regions of plasmodial proteins and human cathepsins were determined using in silico approaches. Additionally, evolutionary clustering of these proteins was evaluated using phylogenetic analysis. High quality partial zymogen protein structures were modelled using homology modelling and residue interaction analysis performed between the prodomain segment and mature domain to identify key interacting residues between these two domains. The resulting information was used to determine short peptide sequences which could mimic the inherent regulatory function of the prodomain regions. Through flexible docking, the binding affinity of proposed peptides on the proteins studied was evaluated. RESULTS Sequence, evolutionary and motif analyses showed important differences between plasmodial and human proteins. Residue interaction analysis identified important residues crucial for maintaining prodomain integrity across the different proteins as well as the pro-segment responsible for inhibitory mechanism. Binding affinity of suggested peptides was highly dependent on their residue composition and length. CONCLUSIONS Despite the conserved structural and catalytic mechanism between human cathepsins and plasmodial proteases, current work revealed significant differences between the two protein groups which may provide valuable information for selective anti-malarial inhibitor development. Part of this study aimed to design peptide inhibitors based on endogenous inhibitory portions of protease prodomains as a novel aspect. Even though peptide inhibitors may not be practical solutions to malaria at this stage, the approach followed and results offer a promising means to find new malarial inhibitors.
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Affiliation(s)
- Thommas Mutemi Musyoka
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, P.O. Box 94, Grahamstown, 6140, South Africa
| | - Joyce Njoki Njuguna
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, P.O. Box 94, Grahamstown, 6140, South Africa
| | - Özlem Tastan Bishop
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, P.O. Box 94, Grahamstown, 6140, South Africa.
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29
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Istvan ES, Das S, Bhatnagar S, Beck JR, Owen E, Llinas M, Ganesan SM, Niles JC, Winzeler E, Vaidya AB, Goldberg DE. Plasmodium Niemann-Pick type C1-related protein is a druggable target required for parasite membrane homeostasis. eLife 2019; 8:40529. [PMID: 30888318 PMCID: PMC6424564 DOI: 10.7554/elife.40529] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 02/05/2019] [Indexed: 01/05/2023] Open
Abstract
Plasmodium parasites possess a protein with homology to Niemann-Pick Type C1 proteins (Niemann-Pick Type C1-Related protein, NCR1). We isolated parasites with resistance-conferring mutations in Plasmodium falciparum NCR1 (PfNCR1) during selections with three diverse small-molecule antimalarial compounds and show that the mutations are causative for compound resistance. PfNCR1 protein knockdown results in severely attenuated growth and confers hypersensitivity to the compounds. Compound treatment or protein knockdown leads to increased sensitivity of the parasite plasma membrane (PPM) to the amphipathic glycoside saponin and engenders digestive vacuoles (DVs) that are small and malformed. Immuno-electron microscopy and split-GFP experiments localize PfNCR1 to the PPM. Our experiments show that PfNCR1 activity is critically important for the composition of the PPM and is required for DV biogenesis, suggesting PfNCR1 as a novel antimalarial drug target. Editorial note: This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (see decision letter).
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Affiliation(s)
- Eva S Istvan
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, Saint Louis, United States.,Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - Sudipta Das
- Department of Microbiology and Immunology, Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, United States
| | - Suyash Bhatnagar
- Department of Microbiology and Immunology, Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, United States
| | - Josh R Beck
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, Saint Louis, United States.,Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
| | - Edward Owen
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, United States.,Huck Center for Malaria Research, Pennsylvania State University, University Park, United States.,Department of Chemistry, Pennsylvania State University, University Park, United States
| | - Manuel Llinas
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, United States.,Huck Center for Malaria Research, Pennsylvania State University, University Park, United States.,Department of Chemistry, Pennsylvania State University, University Park, United States
| | - Suresh M Ganesan
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, United States
| | - Jacquin C Niles
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, United States
| | - Elizabeth Winzeler
- Department of Pediatrics, University of California San Diego School of Medicine, La Jolla, United States
| | - Akhil B Vaidya
- Department of Microbiology and Immunology, Center for Molecular Parasitology, Drexel University College of Medicine, Philadelphia, United States
| | - Daniel E Goldberg
- Department of Medicine, Division of Infectious Diseases, Washington University School of Medicine, Saint Louis, United States.,Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, United States
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30
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Mishra M, Singh V, Singh S. Structural Insights Into Key Plasmodium Proteases as Therapeutic Drug Targets. Front Microbiol 2019; 10:394. [PMID: 30891019 PMCID: PMC6411711 DOI: 10.3389/fmicb.2019.00394] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 02/14/2019] [Indexed: 11/13/2022] Open
Abstract
Malaria, caused by protozoan of genus Plasmodium, remains one of the highest mortality infectious diseases. Malaria parasites have a complex life cycle, easily adapt to their host’s immune system and have evolved with an arsenal of unique proteases which play crucial roles in proliferation and survival within the host cells. Owing to the existing knowledge of enzymatic mechanisms, 3D structures and active sites of proteases, they have been proven to be opportune for target based drug development. Here, we discuss in depth the crucial roles of essential proteases in Plasmodium life cycle and particularly focus on highlighting the atypical “structural signatures” of key parasite proteases which have been exploited for drug development. These features, on one hand aid parasites pathogenicity while on the other hand could be effective in designing targeted and very specific inhibitors for counteracting them. We conclude that Plasmodium proteases are suitable as multistage targets for designing novel drugs with new modes of action to combat malaria.
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Affiliation(s)
- Manasi Mishra
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Dadri, India
| | - Vigyasa Singh
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Shailja Singh
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Dadri, India.,Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
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31
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Veale CGL. Unpacking the Pathogen Box-An Open Source Tool for Fighting Neglected Tropical Disease. ChemMedChem 2019; 14:386-453. [PMID: 30614200 DOI: 10.1002/cmdc.201800755] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Indexed: 12/13/2022]
Abstract
The Pathogen Box is a 400-strong collection of drug-like compounds, selected for their potential against several of the world's most important neglected tropical diseases, including trypanosomiasis, leishmaniasis, cryptosporidiosis, toxoplasmosis, filariasis, schistosomiasis, dengue virus and trichuriasis, in addition to malaria and tuberculosis. This library represents an ensemble of numerous successful drug discovery programmes from around the globe, aimed at providing a powerful resource to stimulate open source drug discovery for diseases threatening the most vulnerable communities in the world. This review seeks to provide an in-depth analysis of the literature pertaining to the compounds in the Pathogen Box, including structure-activity relationship highlights, mechanisms of action, related compounds with reported activity against different diseases, and, where appropriate, discussion on the known and putative targets of compounds, thereby providing context and increasing the accessibility of the Pathogen Box to the drug discovery community.
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Affiliation(s)
- Clinton G L Veale
- School of Chemistry and Physics, Pietermaritzburg Campus, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, South Africa
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Subramanian G, Sadeer A, Mukherjee K, Kojima T, Tripathi P, Naidu R, Tay SW, Pang JH, Pullarkat SA, Chandramohanadas R. Evaluation of ferrocenyl phosphines as potent antimalarials targeting the digestive vacuole function of Plasmodium falciparum. Dalton Trans 2019; 48:1108-1117. [DOI: 10.1039/c8dt04263b] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Ferrocenyl phosphines targeting the digestive vacuole function of the malaria parasite, Plasmodium falciparum.
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Affiliation(s)
- Gowtham Subramanian
- Pillar of Engineering Product Development (EPD)
- Singapore University of Technology and Design (SUTD)
- Singapore 487372
- Singapore
| | - Abdul Sadeer
- Division of Chemistry & Biological Chemistry
- School of Physical and Mathematical Sciences
- Nanyang Technological University Singapore
- Singapore
| | - Kalyani Mukherjee
- Pillar of Engineering Product Development (EPD)
- Singapore University of Technology and Design (SUTD)
- Singapore 487372
- Singapore
| | - Tadayuki Kojima
- Division of Chemistry & Biological Chemistry
- School of Physical and Mathematical Sciences
- Nanyang Technological University Singapore
- Singapore
| | - Pallavi Tripathi
- Pillar of Engineering Product Development (EPD)
- Singapore University of Technology and Design (SUTD)
- Singapore 487372
- Singapore
| | - Renugah Naidu
- Pillar of Engineering Product Development (EPD)
- Singapore University of Technology and Design (SUTD)
- Singapore 487372
- Singapore
| | - Shan Wen Tay
- Division of Chemistry & Biological Chemistry
- School of Physical and Mathematical Sciences
- Nanyang Technological University Singapore
- Singapore
| | - Jia Hao Pang
- Division of Chemistry & Biological Chemistry
- School of Physical and Mathematical Sciences
- Nanyang Technological University Singapore
- Singapore
| | - Sumod A. Pullarkat
- Division of Chemistry & Biological Chemistry
- School of Physical and Mathematical Sciences
- Nanyang Technological University Singapore
- Singapore
| | - Rajesh Chandramohanadas
- Pillar of Engineering Product Development (EPD)
- Singapore University of Technology and Design (SUTD)
- Singapore 487372
- Singapore
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Siqueira-Neto JL, Debnath A, McCall LI, Bernatchez JA, Ndao M, Reed SL, Rosenthal PJ. Cysteine proteases in protozoan parasites. PLoS Negl Trop Dis 2018; 12:e0006512. [PMID: 30138453 PMCID: PMC6107107 DOI: 10.1371/journal.pntd.0006512] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Cysteine proteases (CPs) play key roles in the pathogenesis of protozoan parasites, including cell/tissue penetration, hydrolysis of host or parasite proteins, autophagy, and evasion or modulation of the host immune response, making them attractive chemotherapeutic and vaccine targets. This review highlights current knowledge on clan CA cysteine proteases, the best-characterized group of cysteine proteases, from 7 protozoan organisms causing human diseases with significant impact: Entamoeba histolytica, Leishmania species (sp.), Trypanosoma brucei, T. cruzi, Cryptosporidium sp., Plasmodium sp., and Toxoplasma gondii. Clan CA proteases from three organisms (T. brucei, T. cruzi, and Plasmodium sp.) are well characterized as druggable targets based on in vitro and in vivo models. A number of candidate inhibitors are under development. CPs from these organisms and from other protozoan parasites should be further characterized to improve our understanding of their biological functions and identify novel targets for chemotherapy.
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Affiliation(s)
- Jair L. Siqueira-Neto
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
- * E-mail:
| | - Anjan Debnath
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Laura-Isobel McCall
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Jean A. Bernatchez
- Center for Discovery and Innovation in Parasitic Diseases, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Momar Ndao
- National Reference Centre for Parasitology, The Research Institute of the McGill University Health Center, Montreal, Canada
- Program in Infectious Diseases and Immunity in Global Health, The Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada
| | - Sharon L. Reed
- Departments of Pathology and Medicine, University of California San Diego School of Medicine, La Jolla, California, United States of America
| | - Philip J. Rosenthal
- Department of Medicine, University of California, San Francisco, San Francisco, California, United States of America
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Targeted Phenotypic Screening in Plasmodium falciparum and Toxoplasma gondii Reveals Novel Modes of Action of Medicines for Malaria Venture Malaria Box Molecules. mSphere 2018; 3:mSphere00534-17. [PMID: 29359192 PMCID: PMC5770543 DOI: 10.1128/msphere.00534-17] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 12/20/2017] [Indexed: 01/23/2023] Open
Abstract
The Malaria Box collection includes 400 chemically diverse small molecules with documented potency against malaria parasite growth, but the underlying modes of action are largely unknown. Using complementary phenotypic screens against Plasmodium falciparum and Toxoplasma gondii, we report phenotype-specific hits based on inhibition of overall parasite growth, apicoplast segregation, and egress or host invasion, providing hitherto unavailable insights into the possible mechanisms affected. First, the Malaria Box library was screened against tachyzoite stage T. gondii and the half-maximal effective concentrations (EC50s) of molecules showing ≥80% growth inhibition at 10 µM were determined. Comparison of the EC50s for T. gondii and P. falciparum identified a subset of 24 molecules with nanomolar potency against both parasites. Thirty molecules that failed to induce acute growth inhibition in T. gondii tachyzoites in a 2-day assay caused delayed parasite death upon extended exposure, with at least three molecules interfering with apicoplast segregation during daughter cell formation. Using flow cytometry and microscopy-based examinations, we prioritized 26 molecules with the potential to inhibit host cell egress/invasion during asexual developmental stages of P. falciparum. None of the inhibitors affected digestive vacuole integrity, ruling out a mechanism mediated by broadly specific protease inhibitor activity. Interestingly, five of the plasmodial egress inhibitors inhibited ionophore-induced egress of T. gondii tachyzoites. These findings highlight the advantage of comparative and targeted phenotypic screens in related species as a means to identify lead molecules with a conserved mode of action. Further work on target identification and mechanism analysis will facilitate the development of antiparasitic compounds with cross-species efficacy. IMPORTANCE The phylum Apicomplexa includes many human and animal pathogens, such as Plasmodium falciparum (human malaria) and Toxoplasma gondii (human and animal toxoplasmosis). Widespread resistance to current antimalarials and the lack of a commercial vaccine necessitate novel pharmacological interventions with distinct modes of action against malaria. For toxoplasmosis, new drugs to effectively eliminate tissue-dwelling latent cysts of the parasite are needed. The Malaria Box antimalarial collection, managed and distributed by the Medicines for Malaria Venture, includes molecules of novel chemical classes with proven antimalarial efficacy. Using targeted phenotypic assays of P. falciparum and T. gondii, we have identified a subset of the Malaria Box molecules as potent inhibitors of plastid segregation and parasite invasion and egress, thereby providing early insights into their probable mode of action. Five molecules that inhibit the egress of both parasites have been identified for further mechanistic studies. Thus, the approach we have used to identify novel molecules with defined modes of action in multiple parasites can expedite the development of pan-active antiparasitic agents.
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Abstract
The coevolution of intracellular bacteria with their eukaryotic hosts has presented these pathogens with numerous challenges for their evolutionary progress and survival. Chief among these is the ability to exit from host cells, an event that is fundamentally linked to pathogen dissemination and transmission. Recent years have witnessed a major expansion of research in this area, and this chapter summarizes our current understanding of the spectrum of exit strategies that are exploited by intracellular pathogens. Clear themes regarding the mechanisms of microbial exit have emerged and are most easily conceptualized as (i) lysis of the host cell, (ii) nonlytic exit of free bacteria, and (iii) release of microorganisms into membrane-encased compartments. The adaptation of particular exit strategies is closely linked with additional themes in microbial pathogenesis, including host cell death, manipulation of host signaling pathways, and coincident activation of proinflammatory responses. This chapter will explore the molecular determinants used by intracellular pathogens to promote host cell escape and the infectious advantages each exit pathway may confer, and it will provide an evolutionary framework for the adaptation of these mechanisms.
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Hopp CS, Bennett BL, Mishra S, Lehmann C, Hanson KK, Lin JW, Rousseau K, Carvalho FA, van der Linden WA, Santos NC, Bogyo M, Khan SM, Heussler V, Sinnis P. Deletion of the rodent malaria ortholog for falcipain-1 highlights differences between hepatic and blood stage merozoites. PLoS Pathog 2017; 13:e1006586. [PMID: 28922424 PMCID: PMC5602738 DOI: 10.1371/journal.ppat.1006586] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 08/16/2017] [Indexed: 01/10/2023] Open
Abstract
Proteases have been implicated in a variety of developmental processes during the malaria parasite lifecycle. In particular, invasion and egress of the parasite from the infected hepatocyte and erythrocyte, critically depend on protease activity. Although falcipain-1 was the first cysteine protease to be characterized in P. falciparum, its role in the lifecycle of the parasite has been the subject of some controversy. While an inhibitor of falcipain-1 blocked erythrocyte invasion by merozoites, two independent studies showed that falcipain-1 disruption did not affect growth of blood stage parasites. To shed light on the role of this protease over the entire Plasmodium lifecycle, we disrupted berghepain-1, its ortholog in the rodent parasite P. berghei. We found that this mutant parasite displays a pronounced delay in blood stage infection after inoculation of sporozoites. Experiments designed to pinpoint the defect of berghepain-1 knockout parasites found that it was not due to alterations in gliding motility, hepatocyte invasion or liver stage development and that injection of berghepain-1 knockout merosomes replicated the phenotype of delayed blood stage growth after sporozoite inoculation. We identified an additional role for berghepain-1 in preparing blood stage merozoites for infection of erythrocytes and observed that berghepain-1 knockout parasites exhibit a reticulocyte restriction, suggesting that berghepain-1 activity broadens the erythrocyte repertoire of the parasite. The lack of berghepain-1 expression resulted in a greater reduction in erythrocyte infectivity in hepatocyte-derived merozoites than it did in erythrocyte-derived merozoites. These observations indicate a role for berghepain-1 in processing ligands important for merozoite infectivity and provide evidence supporting the notion that hepatic and erythrocytic merozoites, though structurally similar, are not identical. Malaria affects hundreds of millions of people and is the cause of hundreds of thousands of deaths each year. Infection begins with the inoculation of sporozoites into the skin during the bite of an infected mosquito. Sporozoites subsequently travel to the liver, where they invade and replicate in hepatocytes, eventually releasing the stage of the parasite that is infectious for red blood cells, termed merozoites. Hepatic merozoites initiate blood stage infection, the stage that is responsible for the clinical symptoms of malaria. The blood stage of the parasite grows through repeated rounds of invasion, development and egress of blood stage merozoites, which then continue the cycle. Proteases are among the enzymes that are essential for parasite survival and their functions range from invasion of red blood cells, to the breakdown of red cell hemoglobin, to the release of parasites from red cells. As the function of the cysteine protease falcipain-1 in the lifecycle of the human malaria parasite Plasmodium falciparum remains poorly understood, we decided to study berghepain-1, the orthologue of the rodent malaria parasite P. berghei by generating a berghepain-1 deletion parasite. Using this mutant, we demonstrate that berghepain-1 has a critical role in both hepatic and erythrocytic merozoite infectivity. Little is known about differences between these two types of merozoites and our data leads us to conclude that these merozoites are not identical.
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Affiliation(s)
- Christine S. Hopp
- Department of Molecular Microbiology & Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- * E-mail: (CSH); (BLB); (PS)
| | - Brandy L. Bennett
- Department of Microbiology, New York University School of Medicine, New York, New York, United States of America
- * E-mail: (CSH); (BLB); (PS)
| | - Satish Mishra
- Department of Molecular Microbiology & Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | | | - Kirsten K. Hanson
- Instituto de Medicina Molecular, Faculdade de Medicina Universidade de Lisboa, Lisbon, Portugal
| | - Jing-wen Lin
- Department of Parasitology, Leiden Malaria Research Group, Leiden University Medical Center, Leiden ZA, The Netherlands
| | - Kimberly Rousseau
- Department of Molecular Microbiology & Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Filomena A. Carvalho
- Instituto de Medicina Molecular, Faculdade de Medicina Universidade de Lisboa, Lisbon, Portugal
| | - Wouter A. van der Linden
- Departments of Pathology and Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, United States of America
| | - Nuno C. Santos
- Instituto de Medicina Molecular, Faculdade de Medicina Universidade de Lisboa, Lisbon, Portugal
| | - Matthew Bogyo
- Departments of Pathology and Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, United States of America
| | - Shahid M. Khan
- Department of Parasitology, Leiden Malaria Research Group, Leiden University Medical Center, Leiden ZA, The Netherlands
| | - Volker Heussler
- Institute of Cell Biology, University of Bern, Bern, Switzerland
| | - Photini Sinnis
- Department of Molecular Microbiology & Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- Department of Microbiology, New York University School of Medicine, New York, New York, United States of America
- * E-mail: (CSH); (BLB); (PS)
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Previti S, Ettari R, Cosconati S, Amendola G, Chouchene K, Wagner A, Hellmich UA, Ulrich K, Krauth-Siegel RL, Wich PR, Schmid I, Schirmeister T, Gut J, Rosenthal PJ, Grasso S, Zappalà M. Development of Novel Peptide-Based Michael Acceptors Targeting Rhodesain and Falcipain-2 for the Treatment of Neglected Tropical Diseases (NTDs). J Med Chem 2017; 60:6911-6923. [PMID: 28763614 DOI: 10.1021/acs.jmedchem.7b00405] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
This paper describes the development of a class of peptide-based inhibitors as novel antitrypanosomal and antimalarial agents. The inhibitors are based on a characteristic peptide sequence for the inhibition of the cysteine proteases rhodesain of Trypanosoma brucei rhodesiense and falcipain-2 of Plasmodium falciparum. We exploited the reactivity of novel unsaturated electrophilic functions such as vinyl-sulfones, -ketones, -esters, and -nitriles. The Michael acceptors inhibited both rhodesain and falcipain-2, at nanomolar and micromolar levels, respectively. In particular, the vinyl ketone 3b has emerged as a potent rhodesain inhibitor (k2nd = 67 × 106 M-1 min-1), endowed with a picomolar binding affinity (Ki = 38 pM), coupled with a single-digit micromolar activity against Trypanosoma brucei brucei (EC50 = 2.97 μM), thus being considered as a novel lead compound for the discovery of novel effective antitrypanosomal agents.
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Affiliation(s)
- Santo Previti
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina , Viale Annunziata, 98168 Messina, Italy
| | - Roberta Ettari
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina , Viale Annunziata, 98168 Messina, Italy
| | - Sandro Cosconati
- DiSTABiF, University of Campania Luigi Vanvitelli , Via Vivaldi 43, 81100 Caserta, Italy
| | - Giorgio Amendola
- DiSTABiF, University of Campania Luigi Vanvitelli , Via Vivaldi 43, 81100 Caserta, Italy
| | - Khawla Chouchene
- Laboratoire de Chimie des Substances Naturelles UR/11-ES-74, Faculté des Sciences de Sfax, Université de Sfax , Route de l'aeroport, 3000 Sfax, Tunisia
| | - Annika Wagner
- Institute of Pharmacy and Biochemistry, University of Mainz , Johann-Joachim-Becherweg 30, DE 55128 Mainz, Germany.,Centre for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt , Max-von-Laue-Strasse 9, DE 60438 Frankfurt am Main, Germany
| | - Ute A Hellmich
- Institute of Pharmacy and Biochemistry, University of Mainz , Johann-Joachim-Becherweg 30, DE 55128 Mainz, Germany.,Centre for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt , Max-von-Laue-Strasse 9, DE 60438 Frankfurt am Main, Germany
| | - Kathrin Ulrich
- Biochemistry Center, Heidelberg University , Im Neuenheimer Feld 328, DE 69120 Heidelberg, Germany
| | - R Luise Krauth-Siegel
- Biochemistry Center, Heidelberg University , Im Neuenheimer Feld 328, DE 69120 Heidelberg, Germany
| | - Peter R Wich
- Institute of Pharmacy and Biochemistry, University of Mainz , Staudingerweg 5, DE 55128 Mainz, Germany
| | - Ira Schmid
- Institute of Pharmacy and Biochemistry, University of Mainz , Staudingerweg 5, DE 55128 Mainz, Germany
| | - Tanja Schirmeister
- Institute of Pharmacy and Biochemistry, University of Mainz , Staudingerweg 5, DE 55128 Mainz, Germany
| | - Jiri Gut
- Department of Medicine, San Francisco General Hospital, University of California , 1001 Potrero Avenue, San Francisco, California 94110, United States
| | - Philip J Rosenthal
- Department of Medicine, San Francisco General Hospital, University of California , 1001 Potrero Avenue, San Francisco, California 94110, United States
| | - Silvana Grasso
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina , Viale Annunziata, 98168 Messina, Italy
| | - Maria Zappalà
- Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina , Viale Annunziata, 98168 Messina, Italy
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Roy KK. Targeting the active sites of malarial proteases for antimalarial drug discovery: approaches, progress and challenges. Int J Antimicrob Agents 2017; 50:287-302. [PMID: 28668681 DOI: 10.1016/j.ijantimicag.2017.04.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 04/12/2017] [Accepted: 04/27/2017] [Indexed: 02/08/2023]
Abstract
Malaria is an infectious disease causing vast mortality and morbidity worldwide. Although antimalarial drugs are effective in several parts of the world, there is a serious threat to malaria control as malaria parasites are continuously developing widespread resistance against currently available antimalarial drugs, including artemisinin. Such widespread antimalarial drug resistance confirms the need to improve the efficacy of existing or new drugs as well as to develop alternative treatments through the identification of novel drug targets and the development of candidate drugs. Similar to proteases in other parasitic diseases such as leishmaniasis, schistosomiasis, Chagas disease and African sleeping sickness, malarial proteases constitute the major virulence factors in malaria. Malarial proteases belong to several classes and many of them have been targeted for the design and discovery of antimalarial agents. This review summarises the approaches, progress and challenges in the design of small-molecule inhibitors as antimalarial drugs targeting the inhibition of various malarial proteases.
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Affiliation(s)
- Kuldeep K Roy
- National Institute of Pharmaceutical Education and Research (NIPER), 4 Raja S.C. Mullick Road, Jadavpur, Kolkata 700032, West Bengal, India.
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Hernández González JE, Hernández Alvarez L, Pascutti PG, Valiente PA. Predicting binding modes of reversible peptide-based inhibitors of falcipain-2 consistent with structure-activity relationships. Proteins 2017; 85:1666-1683. [DOI: 10.1002/prot.25322] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 05/05/2017] [Accepted: 05/17/2017] [Indexed: 12/17/2022]
Affiliation(s)
- Jorge Enrique Hernández González
- Departamento de Física; Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista Júlio de Mesquita Filho; Rua Cristóvão Colombo, 2265, Jardim Nazareth, São José do Rio Preto São Paulo CEP 15054-000 Brazil
- Centro de Estudios de Proteínas, Facultad de Biología, Universidad de La Habana; Calle 25 No. 455, entre J e I, Vedado, Plaza de la Revolución La Habana CP 10400 Cuba
| | - Lilian Hernández Alvarez
- Departamento de Física; Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual Paulista Júlio de Mesquita Filho; Rua Cristóvão Colombo, 2265, Jardim Nazareth, São José do Rio Preto São Paulo CEP 15054-000 Brazil
| | - Pedro Geraldo Pascutti
- Laboratório de Dinâmica e Modelagem Molecular, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Ave. Carlos Chagas Filho, 373, CCS-Bloco D sala 30, Cidade Universitária Ilha de Fundão; Rio de Janeiro CEP 21941-902 Brazil
| | - Pedro A. Valiente
- Centro de Estudios de Proteínas, Facultad de Biología, Universidad de La Habana; Calle 25 No. 455, entre J e I, Vedado, Plaza de la Revolución La Habana CP 10400 Cuba
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Purification and antiparasitic activity of a few legume serine proteinase inhibitors: Effect on erythrocyte invasion, schizont rupture and proteolytic processing of the Plasmodium falciparum AMA1 protein. Process Biochem 2017. [DOI: 10.1016/j.procbio.2017.03.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Bacherikov VA, Chittiboyina AG, Avery MA. Design, Synthesis, and Biological Evaluation of Peptidomimetic N-Substituted Cbz-4-Hyp-Hpa-Amides as Novel Inhibitors of Plasmodium falciparum. Chem Biodivers 2017; 14. [PMID: 28498611 DOI: 10.1002/cbdv.201700037] [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: 01/29/2017] [Accepted: 05/08/2017] [Indexed: 11/10/2022]
Abstract
A new series of peptidomimetic N-substituted Cbz-4-Hyp-Hpa-amides were designed, synthesized, and evaluated for inhibition of the Plasmodium falciparum. Substituents on the N-atom of the amide group were selected alkyl-, allyl-, aryl-, 2-hydroxyethyl-, 2-cyanoethyl-, cyanomethyl-, 2-hydroxyethyl-, 2,2-diethoxyethyl-, or 2-ethoxy-2-oxoethylamino groups, and about of 40 new compounds were synthesized and evaluated for antiplasmodial activity in vitro. Antimalarial activity has been investigated as for the final peptide mimetics, and their immediate predecessors, carrying TBDMS or TBDPS protecting groups on 4-hydroxyproline residue and 18 derivatives exhibited toxicity against P. falciparum. Of these agents, compound 23e was shown to have potent antimalarial activity with IC50 528 ng/ml.
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Affiliation(s)
- Valeriy A Bacherikov
- Department of Medicinal Chemistry and Biology, Odessa Medical Institute, International Humanitarian University, Fontanskaya road, 33, Odessa, 65009, Ukraine
| | - Amar G Chittiboyina
- National Center for Natural Products Research, University of Mississippi, Oxford, MS, 38677, USA.,Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, Oxford, MS, 38677, USA
| | - Mitchell A Avery
- National Center for Natural Products Research, University of Mississippi, Oxford, MS, 38677, USA.,Department of BioMolecular Sciences, School of Pharmacy, University of Mississippi, Oxford, MS, 38677, USA
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42
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Ono Y, Saido TC, Sorimachi H. Calpain research for drug discovery: challenges and potential. Nat Rev Drug Discov 2016; 15:854-876. [PMID: 27833121 DOI: 10.1038/nrd.2016.212] [Citation(s) in RCA: 191] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Calpains are a family of proteases that were scientifically recognized earlier than proteasomes and caspases, but remain enigmatic. However, they are known to participate in a multitude of physiological and pathological processes, performing 'limited proteolysis' whereby they do not destroy but rather modulate the functions of their substrates. Calpains are therefore referred to as 'modulator proteases'. Multidisciplinary research on calpains has begun to elucidate their involvement in pathophysiological mechanisms. Therapeutic strategies targeting malfunctions of calpains have been developed, driven primarily by improvements in the specificity and bioavailability of calpain inhibitors. Here, we review the calpain superfamily and calpain-related disorders, and discuss emerging calpain-targeted therapeutic strategies.
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Affiliation(s)
- Yasuko Ono
- Calpain Project, Department of Advanced Science for Biomolecules, Tokyo Metropolitan Institute of Medical Science (IGAKUKEN), 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
| | - Takaomi C Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Brain Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Hiroyuki Sorimachi
- Calpain Project, Department of Advanced Science for Biomolecules, Tokyo Metropolitan Institute of Medical Science (IGAKUKEN), 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan
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43
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Binding affinity models for Falcipain inhibition based on the Linear Interaction Energy method. J Mol Graph Model 2016; 70:236-245. [DOI: 10.1016/j.jmgm.2016.06.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 06/06/2016] [Accepted: 06/15/2016] [Indexed: 02/04/2023]
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Kesely KR, Pantaleo A, Turrini FM, Olupot-Olupot P, Low PS. Inhibition of an Erythrocyte Tyrosine Kinase with Imatinib Prevents Plasmodium falciparum Egress and Terminates Parasitemia. PLoS One 2016; 11:e0164895. [PMID: 27768734 PMCID: PMC5074466 DOI: 10.1371/journal.pone.0164895] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 10/03/2016] [Indexed: 11/18/2022] Open
Abstract
With half of the world's population at risk for malaria infection and with drug resistance on the rise, the search for mutation-resistant therapies has intensified. We report here a therapy for Plasmodium falciparum malaria that acts by inhibiting the phosphorylation of erythrocyte membrane band 3 by an erythrocyte tyrosine kinase. Because tyrosine phosphorylation of band 3 causes a destabilization of the erythrocyte membrane required for parasite egress, inhibition of the erythrocyte tyrosine kinase leads to parasite entrapment and termination of the infection. Moreover, because one of the kinase inhibitors to demonstrate antimalarial activity is imatinib, i.e. an FDA-approved drug authorized for use in children, translation of the therapy into the clinic will be facilitated. At a time when drug resistant strains of P. falciparum are emerging, a strategy that targets a host enzyme that cannot be mutated by the parasite should constitute a therapeutic mechanism that will retard evolution of resistance.
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Affiliation(s)
- Kristina R. Kesely
- Purdue Institute for Drug Discovery, Purdue University, West Lafayette, 47907, United States of America
- Purdue Department of Chemistry, Purdue University, West Lafayette, 47907, United States of America
| | - Antonella Pantaleo
- Department of Biomedical Sciences, University of Sassari, Sassari, Italy
| | - Francesco M. Turrini
- Department of Genetics, Biology and Biochemistry, University of Turin, Turin, Italy
| | - Peter Olupot-Olupot
- Department of Paediatrics/Research Unit, Mbale Regional Referral Hospital, Mbale, Uganda
| | - Philip S. Low
- Purdue Institute for Drug Discovery, Purdue University, West Lafayette, 47907, United States of America
- Purdue Department of Chemistry, Purdue University, West Lafayette, 47907, United States of America
- * E-mail:
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Musyoka TM, Kanzi AM, Lobb KA, Bishop ÖT. Analysis of non-peptidic compounds as potential malarial inhibitors against Plasmodial cysteine proteases via integrated virtual screening workflow. J Biomol Struct Dyn 2016; 34:2084-101. [PMID: 26471975 PMCID: PMC5035544 DOI: 10.1080/07391102.2015.1108231] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 10/08/2015] [Indexed: 10/22/2022]
Abstract
Falcipain-2 (FP-2) and falcipain-3 (FP-3), haemoglobin-degrading enzymes in Plasmodium falciparum, are validated drug targets for the development of effective inhibitors against malaria. However, no commercial drug-targeting falcipains has been developed despite their central role in the life cycle of the parasites. In this work, in silico approaches are used to identify key structural elements that control the binding and selectivity of a diverse set of non-peptidic compounds onto FP-2, FP-3 and homologues from other Plasmodium species as well as human cathepsins. Hotspot residues and the underlying non-covalent interactions, important for the binding of ligands, are identified by interaction fingerprint analysis between the proteases and 2-cyanopyridine derivatives (best hits). It is observed that the size and chemical type of substituent groups within 2-cyanopyridine derivatives determine the strength of protein-ligand interactions. This research presents novel results that can further be exploited in the structure-based molecular-guided design of more potent antimalarial drugs.
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Affiliation(s)
- Thommas M. Musyoka
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, South Africa
| | - Aquillah M. Kanzi
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, South Africa
- Department of Genetics, Forestry and Agricultural Biotechnology Institute (FABI), Faculty of Natural and Agricultural Sciences, University of Pretoria, Pretoria, South Africa
| | - Kevin A. Lobb
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, South Africa
- Department of Chemistry, Rhodes University, Grahamstown, South Africa
| | - Özlem Tastan Bishop
- Research Unit in Bioinformatics (RUBi), Department of Biochemistry and Microbiology, Rhodes University, Grahamstown, South Africa
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On Blastocystis secreted cysteine proteases: a legumain-activated cathepsin B increases paracellular permeability of intestinal Caco-2 cell monolayers. Parasitology 2016; 143:1713-1722. [PMID: 27609526 DOI: 10.1017/s0031182016001396] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Blastocystis spp. pathogenic potential remains unclear as these anaerobic parasitic protozoa are frequently isolated from stools of both symptomatic and asymptomatic subjects. In silico analysis of the whole genome sequence of Blastocystis subtype 7 revealed the presence of numerous proteolytic enzymes including cysteine proteases predicted to be secreted. To assess the potential impact of proteases on intestinal cells and gut function, we focused our study on two cysteine proteases, a legumain and a cathepsin B, which were previously identified in Blastocystis subtype 7 culture supernatants. Both cysteine proteases were produced as active recombinant proteins. Activation of the recombinant legumain was shown to be autocatalytic and triggered by acidic pH, whereas proteolytic activity of the recombinant cathepsin B was only recorded after co-incubation with the legumain. We then measured the diffusion of 4-kDa FITC-labelled dextran across Caco-2 cell monolayers following exposition to either Blastocystis culture supernatants or each recombinant protease. Both Blastocystis culture supernatants and recombinant activated cathepsin B induced an increase of Caco-2 cell monolayer permeability, and this effect was significantly inhibited by E-64, a specific cysteine protease inhibitor. Our results suggest that cathepsin B might play a role in pathogenesis of Blastocystis by increasing intestinal cell permeability.
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47
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Waldecker M, Dasanna AK, Lansche C, Linke M, Srismith S, Cyrklaff M, Sanchez CP, Schwarz US, Lanzer M. Differential time-dependent volumetric and surface area changes and delayed induction of new permeation pathways in P. falciparum-infected hemoglobinopathic erythrocytes. Cell Microbiol 2016; 19. [PMID: 27450804 PMCID: PMC5298026 DOI: 10.1111/cmi.12650] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 07/01/2016] [Accepted: 07/15/2016] [Indexed: 12/31/2022]
Abstract
During intraerythrocytic development, Plasmodium falciparum increases the ion permeability of the erythrocyte plasma membrane to an extent that jeopardizes the osmotic stability of the host cell. A previously formulated numeric model has suggested that the parasite prevents premature rupture of the host cell by consuming hemoglobin (Hb) in excess of its own anabolic needs. Here, we have tested the colloid‐osmotic model on the grounds of time‐resolved experimental measurements on cell surface area and volume. We have further verified whether the colloid‐osmotic model can predict time‐dependent volumetric changes when parasites are grown in erythrocytes containing the hemoglobin variants S or C. A good agreement between model‐predicted and empirical data on both infected erythrocyte and intracellular parasite volume was found for parasitized HbAA and HbAC erythrocytes. However, a delayed induction of the new permeation pathways needed to be taken into consideration for the latter case. For parasitized HbAS erythrocyte, volumes diverged from model predictions, and infected erythrocytes showed excessive vesiculation during the replication cycle. We conclude that the colloid‐osmotic model provides a plausible and experimentally supported explanation of the volume expansion and osmotic stability of P. falciparum‐infected erythrocytes. The contribution of vesiculation to the malaria‐protective function of hemoglobin S is discussed.
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Affiliation(s)
- Mailin Waldecker
- Department of Infectious Diseases, Parasitology, Heidelberg University, Medical School, Im Neuenheimer Feld 324, Heidelberg, 69120, Baden-Württemberg, Germany
| | - Anil K Dasanna
- BioQuant, Heidelberg University, Im Neuenheimer Feld 267, Heidelberg, 69120, Baden-Württemberg, Germany.,Institute for Theoretical Physics, Heidelberg University, Philosophenweg 19, Heidelberg, 69120, Baden-Württemberg, Germany
| | - Christine Lansche
- Department of Infectious Diseases, Parasitology, Heidelberg University, Medical School, Im Neuenheimer Feld 324, Heidelberg, 69120, Baden-Württemberg, Germany
| | - Marco Linke
- BioQuant, Heidelberg University, Im Neuenheimer Feld 267, Heidelberg, 69120, Baden-Württemberg, Germany.,Institute for Theoretical Physics, Heidelberg University, Philosophenweg 19, Heidelberg, 69120, Baden-Württemberg, Germany
| | - Sirikamol Srismith
- Department of Infectious Diseases, Parasitology, Heidelberg University, Medical School, Im Neuenheimer Feld 324, Heidelberg, 69120, Baden-Württemberg, Germany
| | - Marek Cyrklaff
- Department of Infectious Diseases, Parasitology, Heidelberg University, Medical School, Im Neuenheimer Feld 324, Heidelberg, 69120, Baden-Württemberg, Germany
| | - Cecilia P Sanchez
- Department of Infectious Diseases, Parasitology, Heidelberg University, Medical School, Im Neuenheimer Feld 324, Heidelberg, 69120, Baden-Württemberg, Germany
| | - Ulrich S Schwarz
- BioQuant, Heidelberg University, Im Neuenheimer Feld 267, Heidelberg, 69120, Baden-Württemberg, Germany.,Institute for Theoretical Physics, Heidelberg University, Philosophenweg 19, Heidelberg, 69120, Baden-Württemberg, Germany
| | - Michael Lanzer
- Department of Infectious Diseases, Parasitology, Heidelberg University, Medical School, Im Neuenheimer Feld 324, Heidelberg, 69120, Baden-Württemberg, Germany
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48
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Carrasco MP, Machado M, Gonçalves L, Sharma M, Gut J, Lukens AK, Wirth DF, André V, Duarte MT, Guedes RC, Dos Santos DJVA, Rosenthal PJ, Mazitschek R, Prudêncio M, Moreira R. Probing the Azaaurone Scaffold against the Hepatic and Erythrocytic Stages of Malaria Parasites. ChemMedChem 2016; 11:2194-2204. [PMID: 27538856 DOI: 10.1002/cmdc.201600327] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Indexed: 11/09/2022]
Abstract
The potential of azaaurones as dual-stage antimalarial agents was investigated by assessing the effect of a small library of azaaurones on the inhibition of liver and intraerythrocytic lifecycle stages of the malaria parasite. The whole series was screened against the blood stage of a chloroquine-resistant Plasmodium falciparum strain and the liver stage of P. berghei, yielding compounds with dual-stage activity and sub-micromolar potency against erythrocytic parasites. Studies with genetically modified parasites, using a phenotypic assay based on the P. falciparum Dd2-ScDHODH line, which expresses yeast dihydroorotate dehydrogenase (DHODH), showed that one of the azaaurone derivatives has the potential to inhibit the parasite mitochondrial electron-transport chain. The global urgency in finding new therapies for malaria, especially against the underexplored liver stage, associated with chemical tractability of azaaurones, warrants further development of this chemotype. Overall, these results emphasize the azaaurone chemotype as a promising scaffold for dual-stage antimalarials.
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Affiliation(s)
- Marta P Carrasco
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisboa, Portugal. .,Department of Chemistry and Molecular Biology, University of Gothenburg, 412 96, Göteborg, Sweden.
| | - Marta Machado
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028, Lisboa, Portugal
| | - Lídia Gonçalves
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisboa, Portugal
| | - Moni Sharma
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisboa, Portugal
| | - Jiri Gut
- Department of Medicine, San Francisco General Hospital, University of California San Francisco, 1001 Potrero Avenue, San Francisco, CA, 94110, USA
| | - Amanda K Lukens
- The Broad Institute, Infectious Diseases Program, Cambridge, MA, 02142, USA.,Department of Immunology and Infectious Disease, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Dyann F Wirth
- The Broad Institute, Infectious Diseases Program, Cambridge, MA, 02142, USA.,Department of Immunology and Infectious Disease, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA
| | - Vânia André
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, 1049-001, Lisboa, Portugal
| | - Maria Teresa Duarte
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, 1049-001, Lisboa, Portugal
| | - Rita C Guedes
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisboa, Portugal
| | - Daniel J V A Dos Santos
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisboa, Portugal.,LAQV@REQUIMTE, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, Portugal
| | - Philip J Rosenthal
- Department of Medicine, San Francisco General Hospital, University of California San Francisco, 1001 Potrero Avenue, San Francisco, CA, 94110, USA
| | - Ralph Mazitschek
- The Broad Institute, Infectious Diseases Program, Cambridge, MA, 02142, USA.,Department of Immunology and Infectious Disease, Harvard T.H. Chan School of Public Health, Boston, MA, 02115, USA.,Center for System Biology, Massachusetts General Hospital and Harvard Medical School, Richard B. Simches Research Center, 185 Cambridge Street, Boston, MA, 02114, USA
| | - Miguel Prudêncio
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028, Lisboa, Portugal.
| | - Rui Moreira
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisboa, Portugal
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49
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Tilley L, Straimer J, Gnädig NF, Ralph SA, Fidock DA. Artemisinin Action and Resistance in Plasmodium falciparum. Trends Parasitol 2016; 32:682-696. [PMID: 27289273 DOI: 10.1016/j.pt.2016.05.010] [Citation(s) in RCA: 206] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 05/10/2016] [Accepted: 05/13/2016] [Indexed: 12/16/2022]
Abstract
The worldwide use of artemisinin-based combination therapies (ACTs) has contributed in recent years to a substantial reduction in deaths resulting from Plasmodium falciparum malaria. Resistance to artemisinins, however, has emerged in Southeast Asia. Clinically, resistance is defined as a slower rate of parasite clearance in patients treated with an artemisinin derivative or an ACT. These slow clearance rates associate with enhanced survival rates of ring-stage parasites briefly exposed in vitro to dihydroartemisinin. We describe recent progress made in defining the molecular basis of artemisinin resistance, which has identified a primary role for the P. falciparum K13 protein. Using K13 mutations as molecular markers, epidemiological studies are now tracking the emergence and spread of artemisinin resistance. Mechanistic studies suggest potential ways to overcome resistance.
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Affiliation(s)
- Leann Tilley
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Australia.
| | - Judith Straimer
- Department of Microbiology and Immunology, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Nina F Gnädig
- Department of Microbiology and Immunology, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Stuart A Ralph
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, Australia
| | - David A Fidock
- Department of Microbiology and Immunology, Columbia University College of Physicians and Surgeons, New York, NY, USA; Division of Infectious Diseases, Department of Medicine, Columbia University College of Physicians and Surgeons, New York, NY, USA.
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50
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Verma S, Dixit R, Pandey KC. Cysteine Proteases: Modes of Activation and Future Prospects as Pharmacological Targets. Front Pharmacol 2016; 7:107. [PMID: 27199750 PMCID: PMC4842899 DOI: 10.3389/fphar.2016.00107] [Citation(s) in RCA: 164] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 04/08/2016] [Indexed: 02/05/2023] Open
Abstract
Proteolytic enzymes are crucial for a variety of biological processes in organisms ranging from lower (virus, bacteria, and parasite) to the higher organisms (mammals). Proteases cleave proteins into smaller fragments by catalyzing peptide bonds hydrolysis. Proteases are classified according to their catalytic site, and distributed into four major classes: cysteine proteases, serine proteases, aspartic proteases, and metalloproteases. This review will cover only cysteine proteases, papain family enzymes which are involved in multiple functions such as extracellular matrix turnover, antigen presentation, processing events, digestion, immune invasion, hemoglobin hydrolysis, parasite invasion, parasite egress, and processing surface proteins. Therefore, they are promising drug targets for various diseases. For preventing unwanted digestion, cysteine proteases are synthesized as zymogens, and contain a prodomain (regulatory) and a mature domain (catalytic). The prodomain acts as an endogenous inhibitor of the mature enzyme. For activation of the mature enzyme, removal of the prodomain is necessary and achieved by different modes. The pro-mature domain interaction can be categorized as protein-protein interactions (PPIs) and may be targeted in a range of diseases. Cysteine protease inhibitors are available that can block the active site but no such inhibitor available yet that can be targeted to block the pro-mature domain interactions and prevent it activation. This review specifically highlights the modes of activation (processing) of papain family enzymes, which involve auto-activation, trans-activation and also clarifies the future aspects of targeting PPIs to prevent the activation of cysteine proteases.
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Affiliation(s)
- Sonia Verma
- Host-Parasite Interaction Biology Group, National Institute of Malaria Research, Indian Council of Medical Research New Delhi, India
| | - Rajnikant Dixit
- Host-Parasite Interaction Biology Group, National Institute of Malaria Research, Indian Council of Medical Research New Delhi, India
| | - Kailash C Pandey
- Department of Biochemistry, National Institute for Research in Environmental Health, Indian Council of Medical Research Bhopal, India
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