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Shukla M, Rathi K, Hassam M, Yadav DK, Karnatak M, Rawat V, Verma VP. An overview on the antimalarial activity of 1,2,4-trioxanes, 1,2,4-trioxolanes and 1,2,4,5-tetraoxanes. Med Res Rev 2024; 44:66-137. [PMID: 37222435 DOI: 10.1002/med.21979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 05/04/2023] [Accepted: 05/08/2023] [Indexed: 05/25/2023]
Abstract
The demand for novel, fast-acting, and effective antimalarial medications is increasing exponentially. Multidrug resistant forms of malarial parasites, which are rapidly spreading, pose a serious threat to global health. Drug resistance has been addressed using a variety of strategies, such as targeted therapies, the hybrid drug idea, the development of advanced analogues of pre-existing drugs, and the hybrid model of resistant strains control mechanisms. Additionally, the demand for discovering new potent drugs grows due to the prolonged life cycle of conventional therapy brought on by the emergence of resistant strains and ongoing changes in existing therapies. The 1,2,4-trioxane ring system in artemisinin (ART) is the most significant endoperoxide structural scaffold and is thought to be the key pharmacophoric moiety required for the pharmacodynamic potential of endoperoxide-based antimalarials. Several derivatives of artemisinin have also been found as potential treatments for multidrug-resistant strain in this area. Many 1,2,4-trioxanes, 1,2,4-trioxolanes, and 1,2,4,5-tetraoxanes derivatives have been synthesised as a result, and many of these have shown promise antimalarial activity both in vivo and in vitro against Plasmodium parasites. As a consequence, efforts to develop a functionally straight-forward, less expensive, and vastly more effective synthetic pathway to trioxanes continue. This study aims to give a thorough examination of the biological properties and mode of action of endoperoxide compounds derived from 1,2,4-trioxane-based functional scaffolds. The present system of 1,2,4-trioxane, 1,2,4-trioxolane, and 1,2,4,5-tetraoxane compounds and dimers with potentially antimalarial activity will be highlighted in this systematic review (January 1963-December 2022).
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Affiliation(s)
- Monika Shukla
- Department of Chemistry, Banasthali University, Newai, Rajasthan, India
| | - Komal Rathi
- Department of Chemistry, Banasthali University, Newai, Rajasthan, India
| | - Mohammad Hassam
- Department of Chemistry, Chemveda Life Sciences Pvt Ltd, Hyderabad, Telangana, India
| | - Dinesh Kumar Yadav
- Department of Chemistry, Mohanlal Sukhadia University, Udaipur, Rajasthan, India
| | - Manvika Karnatak
- Department of Chemistry, Banasthali University, Newai, Rajasthan, India
| | - Varun Rawat
- School of Chemistry, Tel Aviv University, Tel Aviv, Israel
| | - Ved Prakash Verma
- Department of Chemistry, Banasthali University, Newai, Rajasthan, India
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2
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Sakata K, Lowe MA, Xuan M, Bruffaerts J, Stasi LP, Lallemand B, Cardenas A, Taylor RD, Vidler LR, King L, Valentin JP, Laleu B, de Haro T. Design of Novel Series of Antimalarial PMX Inhibitors with Increased Half-Life via Molecular Property Optimization. ACS Med Chem Lett 2023; 14:1582-1588. [PMID: 37974949 PMCID: PMC10641918 DOI: 10.1021/acsmedchemlett.3c00404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 10/14/2023] [Accepted: 10/16/2023] [Indexed: 11/19/2023] Open
Abstract
Plasmepsin X (PMX) has been identified as a multistage antimalarial target. PMX is a malarial aspartyl protease essential for merozoite egress from infected red blood cells and invasion of the host erythrocytes. Previously, we reported the identification of PMX inhibitors by structure-based optimization of a cyclic guanidine core. Preclinical assessment of UCB7362, which displayed both in vitro and in vivo antimalarial activity, revealed a suboptimal dose paradigm (once daily dosing of 50 mg for 7 days for treatment of uncomplicated malaria) relative to current standard of care (three-dose regime). We report here the efforts toward extending the half-life (t1/2) by reducing metabolic clearance and increasing volume of distribution (Vss). Our efforts culminated in the identification of a biaryl series, with an expected longer t1/2 in human than UCB7362 while maintaining a similar in vitro off-target hit rate.
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Affiliation(s)
- Komei Sakata
- UCB, 216 Bath Road, Slough SL1 3WE, United
Kingdom
| | | | | | | | | | | | | | | | | | - Lloyd King
- UCB, 216 Bath Road, Slough SL1 3WE, United
Kingdom
| | | | - Benoît Laleu
- Medicines
for Malaria Venture, ICC, Route de Pré-Bois 20, 1215 Geneva, Switzerland
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3
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Comparative Degradome Analysis of the Bovine Piroplasmid Pathogens Babesia bovis and Theileria annulata. Pathogens 2023; 12:pathogens12020237. [PMID: 36839509 PMCID: PMC9965338 DOI: 10.3390/pathogens12020237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 01/30/2023] [Accepted: 02/01/2023] [Indexed: 02/05/2023] Open
Abstract
Babesia bovis and Theileria annulata are tick-borne hemoprotozoans that impact bovine health and are responsible for considerable fatalities in tropical and subtropical regions around the world. Both pathogens infect the same vertebrate host, are closely related, and contain similar-sized genomes; however, they differ in invertebrate host specificity, absence vs. presence of a schizont stage, erythrocyte invasion mechanism, and transovarial vs. transstadial transmission. Phylogenetic analysis and bidirectional best hit (BBH) identified a similar number of aspartic, metallo, and threonine proteinases and nonproteinase homologs. In contrast, a considerably increased number of S54 serine rhomboid proteinases and S9 nonproteinase homologs were identified in B. bovis, whereas C1A cysteine proteinases and A1 aspartic nonproteinase homologs were found to be expanded in T. annulata. Furthermore, a single proteinase of families S8 (subtilisin-like protein) and C12 (ubiquitin carboxyl-terminal hydrolase), as well as four nonproteinase homologs, one with dual domains M23-M23 and three with S9-S9, were exclusively present in B. bovis. Finally, a pronounced difference in species-specific ancillary domains was observed between both species. We hypothesize that the observed degradome differences represent functional correlates of the dissimilar life history features of B. bovis and T. annulata. The presented improved classification of piroplasmid proteinases will facilitate an informed choice for future in-depth functional studies.
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Lowe MA, Cardenas A, Valentin JP, Zhu Z, Abendroth J, Castro JL, Class R, Delaunois A, Fleurance R, Gerets H, Gryshkova V, King L, Lorimer DD, MacCoss M, Rowley JH, Rosseels ML, Royer L, Taylor RD, Wong M, Zaccheo O, Chavan VP, Ghule GA, Tapkir BK, Burrows JN, Duffey M, Rottmann M, Wittlin S, Angulo-Barturen I, Jiménez-Díaz MB, Striepen J, Fairhurst KJ, Yeo T, Fidock DA, Cowman AF, Favuzza P, Crespo-Fernandez B, Gamo FJ, Goldberg DE, Soldati-Favre D, Laleu B, de Haro T. Discovery and Characterization of Potent, Efficacious, Orally Available Antimalarial Plasmepsin X Inhibitors and Preclinical Safety Assessment of UCB7362. J Med Chem 2022; 65:14121-14143. [PMID: 36216349 DOI: 10.1021/acs.jmedchem.2c01336] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Plasmepsin X (PMX) is an essential aspartyl protease controlling malaria parasite egress and invasion of erythrocytes, development of functional liver merozoites (prophylactic activity), and blocking transmission to mosquitoes, making it a potential multistage drug target. We report the optimization of an aspartyl protease binding scaffold and the discovery of potent, orally active PMX inhibitors with in vivo antimalarial efficacy. Incorporation of safety evaluation early in the characterization of PMX inhibitors precluded compounds with a long human half-life (t1/2) to be developed. Optimization focused on improving the off-target safety profile led to the identification of UCB7362 that had an improved in vitro and in vivo safety profile but a shorter predicted human t1/2. UCB7362 is estimated to achieve 9 log 10 unit reduction in asexual blood-stage parasites with once-daily dosing of 50 mg for 7 days. This work demonstrates the potential to deliver PMX inhibitors with in vivo efficacy to treat malaria.
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Affiliation(s)
| | | | | | - Zhaoning Zhu
- UCB, 216 Bath Road, Slough SL1 3WE, United Kingdom
| | - Jan Abendroth
- UCB, 7869 NE Day Road West, Bainbridge Island, Washington 98110, United States
| | | | - Reiner Class
- UCB, Chem. du Foriest 1, 1420 Braine-l'Alleud, Belgium
| | | | | | - Helga Gerets
- UCB, Chem. du Foriest 1, 1420 Braine-l'Alleud, Belgium
| | | | - Lloyd King
- UCB, 216 Bath Road, Slough SL1 3WE, United Kingdom
| | - Donald D Lorimer
- UCB, 7869 NE Day Road West, Bainbridge Island, Washington 98110, United States
| | - Malcolm MacCoss
- Bohicket Pharma Consulting LLC, 2556 Seabrook Island Road, Seabrook Island, South Carolina 29455, United States
| | | | | | - Leandro Royer
- UCB, Chem. du Foriest 1, 1420 Braine-l'Alleud, Belgium
| | | | - Melanie Wong
- UCB, 216 Bath Road, Slough SL1 3WE, United Kingdom
| | | | - Vishal P Chavan
- Sai Life Sciences Limited, Plot DS-7, IKP Knowledge Park, Genome Valley, Turkapally, Hyderabad 500078, Telangana, India
| | - Gokul A Ghule
- Sai Life Sciences Limited, Plot DS-7, IKP Knowledge Park, Genome Valley, Turkapally, Hyderabad 500078, Telangana, India
| | - Bapusaheb K Tapkir
- Sai Life Sciences Limited, Plot DS-7, IKP Knowledge Park, Genome Valley, Turkapally, Hyderabad 500078, Telangana, India
| | - Jeremy N Burrows
- Medicines for Malaria Venture, ICC, Route de Pré-Bois 20, 1215 Geneva, Switzerland
| | - Maëlle Duffey
- Medicines for Malaria Venture, ICC, Route de Pré-Bois 20, 1215 Geneva, Switzerland
| | - Matthias Rottmann
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, CH-4123 Allschwil, Switzerland.,University of Basel, 4002 Basel, Switzerland
| | - Sergio Wittlin
- Swiss Tropical and Public Health Institute, Kreuzstrasse 2, CH-4123 Allschwil, Switzerland.,University of Basel, 4002 Basel, Switzerland
| | - Iñigo Angulo-Barturen
- The Art of Discovery, SL Biscay Science and Technology Park, Astondo Bidea, BIC Bizkaia Building, no. 612, Derio 48160, Bizkaia, Basque Country, Spain
| | - María Belén Jiménez-Díaz
- The Art of Discovery, SL Biscay Science and Technology Park, Astondo Bidea, BIC Bizkaia Building, no. 612, Derio 48160, Bizkaia, Basque Country, Spain
| | - Josefine Striepen
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, New York 10032, United States
| | - Kate J Fairhurst
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, New York 10032, United States
| | - Tomas Yeo
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, New York 10032, United States
| | - David A Fidock
- Department of Microbiology & Immunology, Columbia University Irving Medical Center, New York, New York 10032, United States.,Center for Malaria Therapeutics and Antimicrobial Resistance, Division of Infectious Diseases, Department of Medicine, Columbia University Irving Medical Center, New York, New York 10032, United States
| | - Alan F Cowman
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC 3052, Australia
| | - Paola Favuzza
- The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC 3052, Australia
| | | | | | - Daniel E Goldberg
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, 660 South Euclid Avenue, Campus Box 8051, St. Louis, Missouri 63110, United States
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, CMU, 1 rue Michel-Servet, CH-1211 Genève 4, Switzerland
| | - Benoît Laleu
- Medicines for Malaria Venture, ICC, Route de Pré-Bois 20, 1215 Geneva, Switzerland
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5
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Catalytic Properties of Caseinolytic Protease Subunit of Plasmodium knowlesi and Its Inhibition by a Member of δ-Lactone, Hyptolide. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27123787. [PMID: 35744912 PMCID: PMC9228282 DOI: 10.3390/molecules27123787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 06/05/2022] [Accepted: 06/08/2022] [Indexed: 11/17/2022]
Abstract
The caseinolytic protease (Clp) system plays an essential role in the protein homeostasis of the malaria parasite, particularly at the stage of apicoplast development. The inhibition of this protein is known to have a lethal effect on the parasite and is therefore considered an interesting avenue for antimalaria drugs discovery. The catalytic activity of the Clp system is modulated by its proteolytic subunit (ClpP), which belongs to the serine protease family member and is therefore extensively studied for further inhibitors development. Among many inhibitors, the group of β-lactone is known to be a specific inhibitor for ClpP. Nevertheless, other groups of lactones have never been studied. This study aims to characterize the catalytic properties of ClpP of Plasmodium knowlesi (Pk-ClpP) and the inhibition properties of a δ-lactone hyptolide against this protein. Accordingly, a codon-optimized synthetic gene encoding Pk-ClpP was expressed in Escherichia coli BL21(DE3) and purified under a single step of Ni2+-affinity chromatography, yielding a 2.20 mg from 1 L culture. Meanwhile, size-exclusion chromatography indicated that Pk-ClpP migrated primarily as homoheptameric with a size of 205 kDa. The specific activity of pure Pk-ClpP was 0.73 U µg-1, with a catalytic efficiency kcat/KM of 0.05 µM-1 s-1, with optimum temperature and pH of 50 °C and 7.0-7.5, respectively. Interestingly, hyptolide, a member of δ-lactone, was shown to inhibit Pk-ClpP with an IC50 value of 17.36 ± 1.44 nM. Structural homology modelling, secondary structure prediction, and far-UV CD spectra revealed that helical structures dominate this protein. In addition, the structural homology modeling showed that this protein forms a barrel-shaped homoheptamer. Docking simulation revealed that the inhibition was found to be a competitive inhibition in which hyptolide was able to dock into the catalytic site and block the substrate. The competitiveness of hyptolide is due to the higher binding affinity of this molecule than the substrate.
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6
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Florin-Christensen M, Wieser SN, Suarez CE, Schnittger L. In Silico Survey and Characterization of Babesia microti Functional and Non-Functional Proteases. Pathogens 2021; 10:1457. [PMID: 34832610 PMCID: PMC8621943 DOI: 10.3390/pathogens10111457] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Revised: 10/29/2021] [Accepted: 11/06/2021] [Indexed: 12/23/2022] Open
Abstract
Human babesiosis caused by the intraerythrocytic apicomplexan Babesia microti is an expanding tick-borne zoonotic disease that may cause severe symptoms and death in elderly or immunocompromised individuals. In light of an increasing resistance of B. microti to drugs, there is a lack of therapeutic alternatives. Species-specific proteases are essential for parasite survival and possible chemotherapeutic targets. However, the repertoire of proteases in B. microti remains poorly investigated. Herein, we employed several combined bioinformatics tools and strategies to organize and identify genes encoding for the full repertoire of proteases in the B. microti genome. We identified 64 active proteases and 25 nonactive protease homologs. These proteases can be classified into cysteine (n = 28), serine (n = 21), threonine (n = 14), asparagine (n = 7), and metallopeptidases (n = 19), which, in turn, are assigned to a total of 38 peptidase families. Comparative studies between the repertoire of B. bovis and B. microti proteases revealed differences among sensu stricto and sensu lato Babesia parasites that reflect their distinct evolutionary history. Overall, this data may help direct future research towards our understanding of the biology and pathogenicity of Babesia parasites and to explore proteases as targets for developing novel therapeutic interventions.
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Affiliation(s)
- Monica Florin-Christensen
- Instituto de Patobiologia Veterinaria (IPVET), Centro de Investigaciones en Ciencias Veterinarias y Agronomicas, Instituto Nacional de Tecnología Agropecuaria (INTA), Hurlingham C1033AAE, Argentina; (S.N.W.); (L.S.)
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires C1033AAJ, Argentina
| | - Sarah N. Wieser
- Instituto de Patobiologia Veterinaria (IPVET), Centro de Investigaciones en Ciencias Veterinarias y Agronomicas, Instituto Nacional de Tecnología Agropecuaria (INTA), Hurlingham C1033AAE, Argentina; (S.N.W.); (L.S.)
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires C1033AAJ, Argentina
| | - Carlos E. Suarez
- Animal Disease Research Unit, USDA-ARS, Pullman, WA 99163, USA;
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99163, USA
| | - Leonhard Schnittger
- Instituto de Patobiologia Veterinaria (IPVET), Centro de Investigaciones en Ciencias Veterinarias y Agronomicas, Instituto Nacional de Tecnología Agropecuaria (INTA), Hurlingham C1033AAE, Argentina; (S.N.W.); (L.S.)
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires C1033AAJ, Argentina
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Artemisinin-Based Drugs Target the Plasmodium falciparum Heme Detoxification Pathway. Antimicrob Agents Chemother 2021; 65:AAC.02137-20. [PMID: 33495226 DOI: 10.1128/aac.02137-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 01/16/2021] [Indexed: 12/18/2022] Open
Abstract
Artemisinin (ART)-based antimalarial drugs are believed to exert lethal effects on malarial parasites by alkylating a variety of intracellular molecular targets. Recent work with live parasites has shown that one of the alkylated targets is free heme within the parasite digestive vacuole, which is liberated upon hemoglobin catabolism by the intraerythrocytic parasite, and that reduced levels of heme alkylation occur in artemisinin-resistant parasites. One implication of heme alkylation is that these drugs may inhibit parasite detoxification of free heme via inhibition of heme-to-hemozoin crystallization; however, previous reports that have investigated this hypothesis present conflicting data. By controlling reducing conditions and, hence, the availability of ferrous versus ferric forms of free heme, we modify a previously reported hemozoin inhibition assay to quantify the ability of ART-based drugs to target the heme detoxification pathway under reduced versus oxidizing conditions. Contrary to some previous reports, we find that artemisinins are potent inhibitors of hemozoin crystallization, with effective half-maximal concentrations approximately an order of magnitude lower than those for most quinoline-based antimalarial drugs. We also examine hemozoin and in vitro parasite growth inhibition for drug pairs found in the most commonly used ART-based combination therapies (ACTs). All ACTs examined inhibit hemozoin crystallization in an additive fashion, and all but one inhibit parasite growth in an additive fashion.
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8
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Barber J, Sikakana P, Sadler C, Baud D, Valentin JP, Roberts R. A target safety assessment of the potential toxicological risks of targeting plasmepsin IX/X for the treatment of malaria. Toxicol Res (Camb) 2021; 10:203-213. [PMID: 33884171 DOI: 10.1093/toxres/tfaa106] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 11/30/2020] [Accepted: 12/07/2020] [Indexed: 12/28/2022] Open
Abstract
The aspartic proteases plasmepsin IX/X are important antimalarial drug targets due to their specificity to the malaria parasite and their vital role as mediators of disease progression. Focusing on parasite-specific targets where no human homologue exists reduces the possibility of on-target drug toxicity. However, there is a risk of toxicity driven by inadequate selectivity for plasmepsins IX/X in Plasmodium over related mammalian aspartic proteases. Of these, CatD/E may be of most toxicological relevance as CatD is a ubiquitous lysosomal enzyme present in most cell types and CatE is found in the gut and in erythrocytes, the clinically significant site of malarial infection. Based on mammalian aspartic protease physiology and adverse drug reactions (ADRs) to FDA-approved human immunodeficiency virus (HIV) aspartic protease inhibitors, we predicted several potential toxicities including β-cell and congenital abnormalities, hypotension, hypopigmentation, hyperlipidaemia, increased infection risk and respiratory, renal, gastrointestinal, dermatological, and other epithelial tissue toxicities. These ADRs to the HIV treatments are likely to be a result of host aspartic protease inhibition due a lack of specificity for the HIV protease; plasmepsins are much more closely related to human CatD than to HIV proteinase. Plasmepsin IX/X inhibition presents an opportunity to specifically target Plasmodium as an effective antimalarial treatment, providing adequate selectivity can be obtained. Potential plasmepsin IX/X inhibitors should be assayed for inhibitory activity against the main human aspartic proteases and particularly CatD/E. An investigative rodent study conducted early in drug discovery would serve as an initial risk assessment of the potential hazards identified.
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Affiliation(s)
- Jane Barber
- ApconiX, Alderley Park, Alderley Edge, SK10 4TG, UK
| | | | | | - Delphine Baud
- Medicines for Malaria Venture, 20 Route de Pré-Bois, Geneva 1215, Switzerland
| | - Jean-Pierre Valentin
- UCB Biopharma SRL, Building R9, Chemin du Foriest, 1420 Braine-l'Alleud, Belgium
| | - Ruth Roberts
- ApconiX, Alderley Park, Alderley Edge, SK10 4TG, UK
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9
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Cheuka PM, Dziwornu G, Okombo J, Chibale K. Plasmepsin Inhibitors in Antimalarial Drug Discovery: Medicinal Chemistry and Target Validation (2000 to Present). J Med Chem 2020; 63:4445-4467. [PMID: 31913032 DOI: 10.1021/acs.jmedchem.9b01622] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Plasmepsins represent novel antimalarial drug targets. However, plasmepsin-based antimalarial drug discovery efforts in the past 2 decades have generally suffered some drawbacks including lack of translatability of target inhibition to potent parasite inhibition in vitro and in vivo as well as poor selectivity over the related human aspartic proteases. Most studies reported in this period have over-relied on the use of hemoglobinase plasmepsins I-IV (particularly I and II) as targets for the new inhibitors even though these are known to be nonessential at the asexual stage of parasite development. Therefore, future antimalarial drug discovery efforts seeking to identify plasmepsin inhibitors should focus on incorporating non-hemoglobinase plasmepsins such as V, IX, and X in their screening in order to maximize chances of success. Additionally, there is need to go beyond just target enzymatic activity profiling to establishing cellular activity, physicochemical as well as drug metabolism and pharmacokinetics properties and finally in vivo proof-of-concept while ensuring selectivity over related human host proteases.
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Affiliation(s)
- Peter Mubanga Cheuka
- Department of Chemistry, University of Zambia, Great East Road Campus, P.O. Box 32379, Lusaka, Zambia
| | - Godwin Dziwornu
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
| | - John Okombo
- Department of Microbiology and Immunology, Columbia University, 701 West 168th Street, New York, New York 10032, United States
| | - Kelly Chibale
- Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa.,Drug Discovery and Development Centre (H3D), Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa.,Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 7701, South Africa.,South African Medical Research Council Drug Discovery and Development Research Unit, University of Cape Town, Rondebosch 7701, South Africa
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10
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Munsamy G, Agoni C, Soliman MES. A dual target of Plasmepsin IX and X: Unveiling the atomistic superiority of a core chemical scaffold in malaria therapy. J Cell Biochem 2019; 120:7876-7887. [PMID: 30430636 DOI: 10.1002/jcb.28062] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 10/22/2018] [Indexed: 01/24/2023]
Abstract
Plasmepsin IX and X, members of the prominent aspartic family of proteases whose function were hitherto unknown have only recently been established as key mediators of erythrocyte invasion and egress of the virulent malarial parasite. Inhibitor 49c, a potent antimalarial peptidomimetic inhibitor initially developed to target Plasmepsin II has lately been proven to exhibit potent inhibitory activity against Plasmepsin IX and X. However, the molecular and structural dynamics supporting its inhibitory activity remain inconclusive. Hindering the motion of the flap and hinge region of an aspartic protease remains essential for disabling the catalytic activity of the enzyme. Integrating molecular dynamic simulations coupled with other advanced biocomputational tools, we reveal the enhanced structural mechanistic competence of 49c in complex with Plasmepsin IX and X relative to Pepstatin. Pepstatin, a known aspartic protease inhibitor which actively hinders the opening and closing of the flap tip and flexible loop and consequently limits access to the catalytic aspartic residues, however, its administration has been related to elevated levels of toxicity. Thermodynamic calculations reveal a higher relative binding free energy associated with Plasmepsin IX and X in complex with 49c as opposed to Pepstatin. A relatively compact and structurally rigid 49c bound complexes sequel into the restriction of the flap and hinge residues by restraining cohesive movement, consequently hindering their "twisting motion" from transpiring. Findings unveil an atomistic perspective into the structural superiority of 49c in complex with Plasmepsin IX and X.
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Affiliation(s)
- Geraldene Munsamy
- Department of Pharmaceutical Chemistry, Molecular Bio-Computation and Drug Design Laboratory, School of Health Sciences, Westville Campus, University of KwaZulu-Natal, Durban, South Africa
| | - Clement Agoni
- Department of Pharmaceutical Chemistry, Molecular Bio-Computation and Drug Design Laboratory, School of Health Sciences, Westville Campus, University of KwaZulu-Natal, Durban, South Africa
| | - Mahmoud E S Soliman
- Department of Pharmaceutical Chemistry, Molecular Bio-Computation and Drug Design Laboratory, School of Health Sciences, Westville Campus, University of KwaZulu-Natal, Durban, South Africa
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11
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Munsamy G, Ramharack P, Soliman MES. Egress and invasion machinery of malaria: an in-depth look into the structural and functional features of the flap dynamics of plasmepsin IX and X. RSC Adv 2018; 8:21829-21840. [PMID: 35541758 PMCID: PMC9081207 DOI: 10.1039/c8ra04360d] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 06/07/2018] [Indexed: 02/05/2023] Open
Abstract
Plasmepsins, a family of aspartic proteases expressed by Plasmodium falciparum parasite, have been identified as key mediators in the onset of lethal malaria. Precedence has been placed on this family of enzymes due their essential role in the virulence of the parasite, thus highlighting their importance as novel drug targets. A previously published study by our group proposed a set of parameters used to define the flap motion of aspartic proteases. These parameters were used in the study of Plm I-V and focused on the flap flexibility as well as structural dynamics. Recent studies have highlighted the essential role played by Plm IX and X in egress and invasion of the malarial parasite. This study aims to close the gap on the latter family, investigating the flap dynamics of Plms IX and X. Molecular dynamics simulations demonstrated an "open and close" mechanism at the region of the catalytic site. Further computation of the dihedral angles at the catalytic region revealed tractability at both the flap tip and flexible loop. This structural versatility enhances the interaction of variant ligand sizes, in comparison to other Plm family members. The results obtained from this study signify the essential role of structural flap dynamics and its resultant effect on the binding landscapes of Plm IX and X. We believe that this unique structural mechanism may be integrated in the design and development of effective anti-malarial drugs.
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Affiliation(s)
- Geraldene Munsamy
- Molecular Bio-computation and Drug Design Laboratory, School of Health Sciences, University of KwaZulu-Natal Westville Campus Durban 4001 South Africa +27 (0) 31 260 7872 +27 (0) 31 260 8048
| | - Pritika Ramharack
- Molecular Bio-computation and Drug Design Laboratory, School of Health Sciences, University of KwaZulu-Natal Westville Campus Durban 4001 South Africa +27 (0) 31 260 7872 +27 (0) 31 260 8048
| | - Mahmoud E S Soliman
- Molecular Bio-computation and Drug Design Laboratory, School of Health Sciences, University of KwaZulu-Natal Westville Campus Durban 4001 South Africa +27 (0) 31 260 7872 +27 (0) 31 260 8048
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Bounaadja L, Schmitt M, Albrecht S, Mouray E, Tarnus C, Florent I. Selective inhibition of PfA-M1, over PfA-M17, by an amino-benzosuberone derivative blocks malaria parasites development in vitro and in vivo. Malar J 2017; 16:382. [PMID: 28934959 PMCID: PMC5609037 DOI: 10.1186/s12936-017-2032-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Accepted: 09/18/2017] [Indexed: 01/09/2023] Open
Abstract
Background Plasmodium falciparum M1 family aminopeptidase is currently considered as a promising target for anti-malarial chemotherapy. Several series of inhibitors developed by various research groups display IC50/Ki values down to nM range on native PfA-M1 or recombinant forms and block the parasite development in culture at µM to sub-µM concentrations. A handful of these inhibitors has been tested on murine models of malaria and has shown anti plasmodial in vivo activity. However, most of these inhibitors do also target the other neutral malarial aminopeptidase, PfA-M17, often with lower Ki values, which questions the relative involvement and importance of each enzyme in the parasite biology. Results An amino-benzosuberone derivative from a previously published collection of chemicals targeting specifically the M1-aminopeptidases has been identified; it is highly potent on PfA-M1 (Ki = 50 nM) and devoid of inhibitory activity on PfA-M17 (no inhibition up to 100 µM). This amino-benzosuberone derivative (T5) inhibits, in the µM range, the in vitro growth of two P. falciparum strains, 3D7 and FcB1, respectively chloroquino-sensitive and resistant. Evaluated in vivo, on the murine non-lethal model of malaria Plasmodium chabaudi chabaudi, this amino-benzosuberone derivative was able to reduce the parasite burden by 44 and 40% in a typical 4-day Peters assay at a daily dose of 12 and 24 mg/kg by intraperitoneal route of administration. Conclusions The evaluation of a highly selective inhibitor of PfA-M1, over PfA-M17, active on Plasmodium parasites in vitro and in vivo, highlights the relevance of PfA-M1 in the biological development of the parasite as well as in the list of promising anti-malarial targets to be considered in combination with current or future anti-malarial drugs. Electronic supplementary material The online version of this article (doi:10.1186/s12936-017-2032-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Lotfi Bounaadja
- Molécules de Communication et Adaptation des Microorganismes, (MCAM, UMR7245), Muséum National Histoire Naturelle, Sorbonne Universités, CNRS, CP 52, 57 Rue Cuvier, 75005, Paris, France
| | - Marjorie Schmitt
- Laboratoire de Chimie Moléculaire, CNRS-UMR7509, Université de Strasbourg, 67037, Strasbourg Cedex 2, France
| | - Sébastien Albrecht
- Laboratoire de Chimie Organique et Bioorganique, EA4566, Université de Haute Alsace, 68093, Mulhouse Cedex, France
| | - Elisabeth Mouray
- Molécules de Communication et Adaptation des Microorganismes, (MCAM, UMR7245), Muséum National Histoire Naturelle, Sorbonne Universités, CNRS, CP 52, 57 Rue Cuvier, 75005, Paris, France
| | - Céline Tarnus
- Laboratoire de Chimie Organique et Bioorganique, EA4566, Université de Haute Alsace, 68093, Mulhouse Cedex, France
| | - Isabelle Florent
- Molécules de Communication et Adaptation des Microorganismes, (MCAM, UMR7245), Muséum National Histoire Naturelle, Sorbonne Universités, CNRS, CP 52, 57 Rue Cuvier, 75005, Paris, France.
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Milton ME, Nelson SW. Replication and maintenance of the Plasmodium falciparum apicoplast genome. Mol Biochem Parasitol 2016; 208:56-64. [PMID: 27338018 DOI: 10.1016/j.molbiopara.2016.06.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Revised: 06/14/2016] [Accepted: 06/19/2016] [Indexed: 12/18/2022]
Abstract
Members of the phylum Apicomplexa are responsible for many devastating diseases including malaria (Plasmodium spp.), toxoplasmosis (Toxoplasma gondii), babesiosis (Babesia bovis), and cyclosporiasis (Cyclospora cayetanensis). Most Apicomplexans contain a unique and essential organelle called the apicoplast. Derived from an ancient chloroplast, the apicoplast replicates and maintains a 35 kilobase (kb) circular genome. Due to its essential nature within the parasite, drugs targeted to proteins involved in DNA replication and repair of the apicoplast should be potent and specific. This review summarizes the current knowledge surrounding the replication and repair of the Plasmodium falciparum apicoplast genome and identifies several putative proteins involved in replication and repair pathways.
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Affiliation(s)
- Morgan E Milton
- Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames IA 50011, USA
| | - Scott W Nelson
- Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames IA 50011, USA.
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Phagocytic uptake of oxidized heme polymer is highly cytotoxic to macrophages. PLoS One 2014; 9:e103706. [PMID: 25078090 PMCID: PMC4117526 DOI: 10.1371/journal.pone.0103706] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 07/06/2014] [Indexed: 11/26/2022] Open
Abstract
Apoptosis in macrophages is responsible for immune-depression and pathological effects during malaria. Phagocytosis of PRBC causes induction of apoptosis in macrophages through release of cytosolic factors from infected cells. Heme polymer or β-hematin causes dose-dependent death of macrophages with LC50 of 132 µg/ml and 182 µg/ml respectively. The toxicity of hemin or heme polymer was amplified several folds in the presence of non-toxic concentration of methemoglobin. β-hematin uptake in macrophage through phagocytosis is crucial for enhanced toxicological effects in the presence of methemoglobin. Higher accumulation of β-hematin is observed in macrophages treated with β-hematin along with methemoglobin. Light and scanning electron microscopic observations further confirm accumulation of β-hematin with cellular toxicity. Toxicological potentiation of pro-oxidant molecules toward macrophages depends on generation of H2O2 and independent to release of free iron from pro-oxidant molecules. Methemoglobin oxidizes β-hematin to form oxidized β-hematin (βH*) through single electron transfer mechanism. Pre-treatment of reaction mixture with spin-trap Phenyl-N-t-butyl-nitrone dose-dependently reverses the β-hematin toxicity, indicates crucial role of βH* generation with the toxicological potentiation. Acridine orange/ethidium bromide staining and DNA fragmentation analysis indicate that macrophage follows an oxidative stress dependent apoptotic pathway to cause death. In summary, current work highlights mutual co-operation between methemoglobin and different pro-oxidant molecules to enhance toxicity towards macrophages. Hence, methemoglobin peroxidase activity can be probed for subduing cellular toxicity of pro-oxidant molecules and it may in-turn make up for host immune response against the malaria parasite.
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Insight into structural and biochemical determinants of substrate specificity of PFI1625c: Correlation analysis of protein-peptide molecular models. J Mol Graph Model 2013; 43:21-30. [DOI: 10.1016/j.jmgm.2013.03.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Revised: 03/18/2013] [Accepted: 03/28/2013] [Indexed: 11/21/2022]
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Abdelmohsen UR, Szesny M, Othman EM, Schirmeister T, Grond S, Stopper H, Hentschel U. Antioxidant and anti-protease activities of diazepinomicin from the sponge-associated Micromonospora strain RV115. Mar Drugs 2012; 10:2208-2221. [PMID: 23170078 PMCID: PMC3497017 DOI: 10.3390/md10102208] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 09/06/2012] [Accepted: 09/17/2012] [Indexed: 11/17/2022] Open
Abstract
Diazepinomicin is a dibenzodiazepine alkaloid with an unusual structure among the known microbial metabolites discovered so far. Diazepinomicin was isolated from the marine sponge-associated strain Micromonospora sp. RV115 and was identified by spectroscopic analysis and by comparison to literature data. In addition to its interesting preclinical broad-spectrum antitumor potential, we report here new antioxidant and anti-protease activities for this compound. Using the ferric reducing antioxidant power (FRAP) assay, a strong antioxidant potential of diazepinomicin was demonstrated. Moreover, diazepinomicin showed a significant antioxidant and protective capacity from genomic damage induced by the reactive oxygen species hydrogen peroxide in human kidney (HK-2) and human promyelocytic (HL-60) cell lines. Additionally, diazepinomicin inhibited the proteases rhodesain and cathepsin L at an IC50 of 70–90 µM. It also showed antiparasitic activity against trypomastigote forms of Trypanosoma brucei with an IC50 of 13.5 µM. These results showed unprecedented antioxidant and anti-protease activities of diazepinomicin, thus further highlighting its potential as a future drug candidate.
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Affiliation(s)
- Usama Ramadan Abdelmohsen
- Julius-von-Sachs-Institute for Biological Sciences, University of Würzburg, Julius-von-Sachs-Platz 3, Würzburg 97082, Germany;
- Author to whom correspondence should be addressed; ; Tel.: +49-931-318-0297; Fax: +49-931-888-6235
| | - Matthias Szesny
- Institute of Organic Chemistry, Eberhard-Karls-Universität, Auf der Morgenstelle 18, Tübingen 72076, Germany; (M.S.); (S.G.)
| | - Eman Maher Othman
- Department of Toxicology, University of Würzburg, Würzburg 97078, Germany; (E.M.O.); (H.S.)
| | - Tanja Schirmeister
- Institute of Pharmacy and Biochemistry, University of Mainz, Staudinger Weg 5, Mainz 55128, Germany;
| | - Stephanie Grond
- Institute of Organic Chemistry, Eberhard-Karls-Universität, Auf der Morgenstelle 18, Tübingen 72076, Germany; (M.S.); (S.G.)
| | - Helga Stopper
- Department of Toxicology, University of Würzburg, Würzburg 97078, Germany; (E.M.O.); (H.S.)
| | - Ute Hentschel
- Julius-von-Sachs-Institute for Biological Sciences, University of Würzburg, Julius-von-Sachs-Platz 3, Würzburg 97082, Germany;
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