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Mishra V, Rathore I, Arekar A, Sthanam LK, Xiao H, Kiso Y, Sen S, Patankar S, Gustchina A, Hidaka K, Wlodawer A, Yada RY, Bhaumik P. Deciphering the mechanism of potent peptidomimetic inhibitors targeting plasmepsins - biochemical and structural insights. FEBS J 2018; 285:3077-3096. [PMID: 29943906 DOI: 10.1111/febs.14598] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 06/10/2018] [Accepted: 06/22/2018] [Indexed: 11/28/2022]
Abstract
Malaria is a deadly disease killing worldwide hundreds of thousands people each year and the responsible parasite has acquired resistance to the available drug combinations. The four vacuolar plasmepsins (PMs) in Plasmodium falciparum involved in hemoglobin (Hb) catabolism represent promising targets to combat drug resistance. High antimalarial activities can be achieved by developing a single drug that would simultaneously target all the vacuolar PMs. We have demonstrated for the first time the use of soluble recombinant plasmepsin II (PMII) for structure-guided drug discovery with KNI inhibitors. Compounds used in this study (KNI-10742, 10743, 10395, 10333, and 10343) exhibit nanomolar inhibition against PMII and are also effective in blocking the activities of PMI and PMIV with the low nanomolar Ki values. The high-resolution crystal structures of PMII-KNI inhibitor complexes reveal interesting features modulating their differential potency. Important individual characteristics of the inhibitors and their importance for potency have been established. The alkylamino analog, KNI-10743, shows intrinsic flexibility at the P2 position that potentiates its interactions with Asp132, Leu133, and Ser134. The phenylacetyl tripeptides, KNI-10333 and KNI-10343, accommodate different ρ-substituents at the P3 phenylacetyl ring that determine the orientation of the ring, thus creating novel hydrogen-bonding contacts. KNI-10743 and KNI-10333 possess significant antimalarial activity, block Hb degradation inside the food vacuole, and show no cytotoxicity on human cells; thus, they can be considered as promising candidates for further optimization. Based on our structural data, novel KNI derivatives with improved antimalarial activity could be designed for potential clinical use. DATABASE: Structural data are available in the PDB under the accession numbers 5YIE, 5YIB, 5YID, 5YIC, and 5YIA.
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Affiliation(s)
- Vandana Mishra
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Ishan Rathore
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Anagha Arekar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Lakshmi Kavitha Sthanam
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Huogen Xiao
- Department of Molecular and Cellular Biology, University of Guelph, ON, Canada
| | - Yoshiaki Kiso
- Laboratory of Peptide Sciences, Nagahama Institute of Bio-Science and Technology, Japan
| | - Shamik Sen
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Swati Patankar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Alla Gustchina
- Protein Structure Section, Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, MD, USA
| | - Koushi Hidaka
- Division of Pharmaceutical Chemistry, Faculty of Pharmaceutical Sciences, Kobe Gakuin University, Japan
| | - Alexander Wlodawer
- Protein Structure Section, Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, MD, USA
| | - Rickey Y Yada
- Faculty of Land and Food Systems, University of British Columbia, Vancouver, BC, Canada
| | - Prasenjit Bhaumik
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
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Nguyen W, Hodder AN, de Lezongard RB, Czabotar PE, Jarman KE, O'Neill MT, Thompson JK, Jousset Sabroux H, Cowman AF, Boddey JA, Sleebs BE. Enhanced antimalarial activity of plasmepsin V inhibitors by modification of the P 2 position of PEXEL peptidomimetics. Eur J Med Chem 2018; 154:182-198. [PMID: 29800827 DOI: 10.1016/j.ejmech.2018.05.022] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Revised: 05/14/2018] [Accepted: 05/14/2018] [Indexed: 12/26/2022]
Abstract
Plasmepsin V is an aspartyl protease that plays a critical role in the export of proteins bearing the Plasmodium export element (PEXEL) motif (RxLxQ/E/D) to the infected host erythrocyte, and thus the survival of the malaria parasite. Previously, development of transition state PEXEL mimetic inhibitors of plasmepsin V have primarily focused on demonstrating the importance of the P3 Arg and P1 Leu in binding affinity and selectivity. Here, we investigate the importance of the P2 position by incorporating both natural and non-natural amino acids into this position and show disubstituted beta-carbon amino acids convey the greatest potency. Consequently, we show analogues with either cyclohexylglycine or phenylglycine in the P2 position are the most potent inhibitors of plasmepsin V that impair processing of the PEXEL motif in exported proteins resulting in death of P. falciparum asexual stage parasites.
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Affiliation(s)
- William Nguyen
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, 3010, Australia
| | - Anthony N Hodder
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, 3010, Australia
| | - Richard Bestel de Lezongard
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, 3010, Australia
| | - Peter E Czabotar
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, 3010, Australia
| | - Kate E Jarman
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, 3010, Australia
| | - Matthew T O'Neill
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Australia
| | - Jennifer K Thompson
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Australia
| | - Helene Jousset Sabroux
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, 3010, Australia
| | - Alan F Cowman
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, 3010, Australia
| | - Justin A Boddey
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, 3010, Australia
| | - Brad E Sleebs
- The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Australia; Department of Medical Biology, The University of Melbourne, Parkville, 3010, Australia.
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3
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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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Saini D, Jain S, Kumar A, Jain N. Synthesis and antimalarial potential of some novel quinoline-pyrazolopyridine derivatives. EXCLI JOURNAL 2016; 15:730-737. [PMID: 28337104 PMCID: PMC5318676 DOI: 10.17179/excli2016-677] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 11/02/2016] [Indexed: 01/28/2023]
Abstract
A series of 1-(4-methylquinolin-2-yl)-4,6-diaryl-1H-pyrazolo[3,4-b]pyridin-3-amine derivatives was synthesized by the reaction of 3-cinnamoyl-4-hydroxy-6-methyl-2H-pyran-2-ones with 2-chloro-4,6-diphenylnicotinonitrile analogues in the presence of 2-hydrazino-4-methyl quinoline and ethanol. The newly synthesized compounds were characterized by IR, 1H NMR and mass spectral data. The synthetic series of novel quinoline-pyrazolopyridine hybrids were screened for in vitro schizont maturation assay against chloroquine sensitive 3D7 strain of Plasmodium falciparum, from which the most five active analogues were further evaluated for in vivo 4-day suppressive test in Swiss albino mice. Among the series, 5p (containing 4-Cl substituent attached to both aryl ring) portrayed considerable potent antimalarial activity during in vitro as well as in vivo study.
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Affiliation(s)
- Deepika Saini
- Drug Discovery and Research Laboratory, Department of Pharmaceutical Sciences, Guru Jambheshwar University of Science and Technology, Hisar-125001
| | - Sandeep Jain
- Drug Discovery and Research Laboratory, Department of Pharmaceutical Sciences, Guru Jambheshwar University of Science and Technology, Hisar-125001
| | - Ajay Kumar
- Institute of Pharmaceutical Sciences, Kurukshetra University, Kurukshetra 136119
| | - Neelam Jain
- Department of Pharmaceutical Education and Research, Bhagat Singh Phool Mahila Vishwavidyalaya, Khanpur Kalan, Sonepat-131305
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Aneja B, Kumar B, Jairajpuri MA, Abid M. A structure guided drug-discovery approach towards identification of Plasmodium inhibitors. RSC Adv 2016. [DOI: 10.1039/c5ra19673f] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
This article provides a comprehensive review of inhibitors from natural, semisynthetic or synthetic sources against key targets ofPlasmodium falciparum.
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Affiliation(s)
- Babita Aneja
- Medicinal Chemistry Lab
- Department of Biosciences
- Jamia Millia Islamia (A Central University)
- New Delhi 110025
- India
| | - Bhumika Kumar
- Medicinal Chemistry Lab
- Department of Biosciences
- Jamia Millia Islamia (A Central University)
- New Delhi 110025
- India
| | - Mohamad Aman Jairajpuri
- Protein Conformation and Enzymology Lab
- Department of Biosciences
- Jamia Millia Islamia (A Central University)
- New Delhi 110025
- India
| | - Mohammad Abid
- Medicinal Chemistry Lab
- Department of Biosciences
- Jamia Millia Islamia (A Central University)
- New Delhi 110025
- India
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6
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Recacha R, Leitans J, Akopjana I, Aprupe L, Trapencieris P, Jaudzems K, Jirgensons A, Tars K. Structures of plasmepsin II from Plasmodium falciparum in complex with two hydroxyethylamine-based inhibitors. Acta Crystallogr F Struct Biol Commun 2015; 71:1531-9. [PMID: 26625296 PMCID: PMC4666482 DOI: 10.1107/s2053230x15022049] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 11/18/2015] [Indexed: 11/10/2022] Open
Abstract
Plasmepsin II (PMII) is one of the ten plasmepsins (PMs) identified in the genome of Plasmodium falciparum, the causative agent of the most severe and deadliest form of malaria. Owing to the emergence of P. falciparum strains that are resistant to current antimalarial agents such as chloroquine and sulfadoxine/pyrimethamine, there is a constant pressure to find new and lasting chemotherapeutic drug therapies. Previously, the crystal structure of PMII in complex with NU655, a potent antimalarial hydroxyethylamine-based inhibitor, and the design of new compounds based on it have been reported. In the current study, two of these newly designed hydroxyethylamine-based inhibitors, PG418 and PG394, were cocrystallized with PMII and their structures were solved, analyzed and compared with that of the PMII-NU655 complex. Structural analysis of the PMII-PG418 complex revealed that the flap loop can adopt a fully closed conformation, stabilized by interactions with the inhibitor, and a fully open conformation, causing an overall expansion in the active-site cavity, which in turn causes unstable binding of the inhibitor. PG418 also stabilizes the flexible loop Gln275-Met286 of another monomer in the asymmetric unit of PMII, which is disordered in the PMII-NU655 complex structure. The crystal structure of PMII in complex with the inhibitor PG418 demonstrates the conformational flexibility of the active-site cavity of the plasmepsins. The interactions of the different moieties in the P1' position of PG418 and PG394 with Thr217 have to be taken into account in the design of new potent plasmepsin inhibitors.
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Affiliation(s)
- Rosario Recacha
- Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga, LV-1006, Latvia
| | - Janis Leitans
- Biomedical Research and Study Centre, Ratsupites 1, Riga, LV-1067, Latvia
| | - Inara Akopjana
- Biomedical Research and Study Centre, Ratsupites 1, Riga, LV-1067, Latvia
| | - Lilija Aprupe
- Biomedical Research and Study Centre, Ratsupites 1, Riga, LV-1067, Latvia
| | | | - Kristaps Jaudzems
- Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga, LV-1006, Latvia
| | - Aigars Jirgensons
- Latvian Institute of Organic Synthesis, Aizkraukles 21, Riga, LV-1006, Latvia
| | - Kaspars Tars
- Biomedical Research and Study Centre, Ratsupites 1, Riga, LV-1067, Latvia
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7
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New paradigm of an old target: an update on structural biology and current progress in drug design towards plasmepsin II. Eur J Med Chem 2015; 95:324-48. [PMID: 25827401 DOI: 10.1016/j.ejmech.2015.03.049] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Revised: 03/09/2015] [Accepted: 03/20/2015] [Indexed: 11/20/2022]
Abstract
Malaria is one of the major parasitic disease whose rapid spreading and mortality rate affects all parts of the world especially several parts of Asia as well as Africa. The emergence of multi-drug resistant strains hamper the progress of current antimalarial therapy and displayed an urgent need for new antimalarials by targeting novel drug targets. Until now, several promising targets were explored in order to develop a promising Achilles hill to counter malaria. Plasmepsin, an aspartic protease, which is involved in the hemoglobin breakdown into smaller peptides emerged as a crucial target to develop new chemical entities to counter malaria. Due to early crystallographic evidence, plasmepsin II (Plm II) emerged as well explored target to develop novel antimalarials as well as a starting point to develop inhibitors targeting some other subtypes of plasmepsins i.e. Plm I, II, IV and V. With the advancements in drug discovery, several computational and synthetic approaches were employed in order to develop novel inhibitors targeting Plm II. Strategies such as fragment based drug design, molecular dynamics simulation, double drug approach etc. were employed in order to develop new chemical entities targeting Plm II. But majority of Plm II inhibitors suffered from poor selectivity over cathepsin D as well as other subtypes of plasmepsins. This review highlights an updated account of drug discovery efforts targeting plasmepsin II from a medicinal chemistry perspective.
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8
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Xiao H, Bryksa BC, Bhaumik P, Gustchina A, Kiso Y, Yao SQ, Wlodawer A, Yada RY. The zymogen of plasmepsin V from Plasmodium falciparum is enzymatically active. Mol Biochem Parasitol 2014; 197:56-63. [PMID: 25447707 PMCID: PMC6310130 DOI: 10.1016/j.molbiopara.2014.10.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 10/15/2014] [Accepted: 10/16/2014] [Indexed: 10/24/2022]
Abstract
Plasmepsin V, a membrane-bound aspartic protease present in Plasmodium falciparum, is involved in the export of malaria parasite effector proteins into host erythrocytes and therefore is a potential target for antimalarial drug development. The present study reports the bacterial recombinant expression and initial characterization of zymogenic and mature plasmepsin V. A 484-residue truncated form of proplasmepsin (Glu37-Asn521) was fused to a fragment of thioredoxin and expressed as inclusion bodies. Refolding conditions were optimized and zymogen was processed into a mature form via cleavage at the Asn80-Ala81 peptide bond. Mature plasmepsin V exhibited a pH optimum of 5.5-7.0 with Km and kcat of 4.6 μM and 0.24s(-1), respectively, at pH 6.0 using the substrate DABCYL-LNKRLLHETQ-E(EDANS). Furthermore, the prosegment of proplasmepsin V was shown to be nonessential for refolding and inhibition. Unexpectedly, unprocessed proplasmepsin V was enzymatically active with slightly reduced substrate affinity (∼ 2-fold), and similar pH optimum as well as turnover compared to the mature form. Both zymogenic and mature plasmepsin V were partially inhibited by pepstatin A as well as several KNI aspartic protease inhibitors while certain metals strongly inhibited activity. Overall, the present study provides the first report on the nonessentiality of the prosegment for plasmepsin V folding and activity, and therefore, subsequent characterization of its structure-function relationships of both zymogen and mature forms in the development of novel inhibitors with potential antimalarial activities is warranted.
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Affiliation(s)
- Huogen Xiao
- Department of Food Science, University of Guelph, 50 Stone Road East, Guelph, ON, Canada N1G2W1
| | - Brian C Bryksa
- Department of Food Science, University of Guelph, 50 Stone Road East, Guelph, ON, Canada N1G2W1
| | - Prasenjit Bhaumik
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Alla Gustchina
- Protein Structure Section, Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - Yoshiaki Kiso
- Laboratory of Peptide Science, Nagahama Institute of Bio-Science and Technology, Nagahama, Shiga 526-0829, Japan
| | - Shao Q Yao
- Department of Chemistry, National University of Singapore, 3 Science Drive, Singapore 117543, Singapore
| | - Alexander Wlodawer
- Protein Structure Section, Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - Rickey Y Yada
- Department of Food Science, University of Guelph, 50 Stone Road East, Guelph, ON, Canada N1G2W1; Faculty of Land and Food Systems, University of British Columbia 248-2357 Main Mall Vancouver, BC V6T 1Z4.
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9
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Miura T, Hidaka K, Azai Y, Kashimoto K, Kawasaki Y, Chen SE, de Freitas RF, Freire E, Kiso Y. Optimization of plasmepsin inhibitor by focusing on similar structural feature with chloroquine to avoid drug-resistant mechanism of Plasmodium falciparum. Bioorg Med Chem Lett 2014; 24:1698-701. [DOI: 10.1016/j.bmcl.2014.02.051] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 02/12/2014] [Accepted: 02/19/2014] [Indexed: 11/17/2022]
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Trafficked Proteins-Druggable in Plasmodium falciparum? Int J Cell Biol 2013; 2013:435981. [PMID: 23710183 PMCID: PMC3655585 DOI: 10.1155/2013/435981] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2013] [Accepted: 03/12/2013] [Indexed: 01/09/2023] Open
Abstract
Malaria is an infectious disease that results in serious health problems in the countries in which it is endemic. Annually this parasitic disease leads to more than half a million deaths; most of these are children in Africa. An effective vaccine is not available, and the treatment of the disease is solely dependent on chemotherapy. However, drug resistance is spreading, and the identification of new drug targets as well as the development of new antimalarials is urgently required. Attention has been drawn to a variety of essential plasmodial proteins, which are targeted to intra- or extracellular destinations, such as the digestive vacuole, the apicoplast, or into the host cell. Interfering with the action or the transport of these proteins will impede proliferation of the parasite. In this mini review, we will shed light on the present discovery of chemotherapeutics and potential drug targets involved in protein trafficking processes in the malaria parasite.
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McConnell RM, Inapudi K, Kadasala N, Yarlagadda K, Velusamy P, McConnell MS, Green A, Trana C, Sayyar K, McConnell JS. New cathepsin D inhibitor library utilizing hydroxyethyl isosteres with cyclic tertiary amines. Med Chem 2013; 8:1146-54. [PMID: 22830497 DOI: 10.2174/1573406411208061146] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Revised: 05/10/2012] [Accepted: 05/21/2012] [Indexed: 12/23/2022]
Abstract
The design and synthesis of hydroxyethylamine isosteres as inhibitors of cathepsin D based on SAR data have been accomplished. A library of 96 of these hydroxyethylamine isosteres are described and many have proven to be very potent inhibitors of human cathepsin D activity as measured using a fluorometric assay technique, via peptide substrate Ac-Glu-Glu(Edans)-Lys-Pro-Ile-Cys-Phe-Phe-Arg-Leu-Gly-Lys(Methyl Red)-Glu-NH(2). Compounds showing strongest inhibition of cathepsin D activity were those that contain a hydroxyethyl-N'-2- or N'-(4-chlorophenyl)piperazine moiety (IC(50) values range from 0.55 to 8.5 nM), with N'-(2-pyrimidyl)piperizine (IC(50) values range from 0.5 to 21.6 nM), with N-N'- L-piperazinocolinamide (IC(50) values range from 0.001 - 0.25 nM), or N-N'-L-piperazinocolin-N-methylamide (IC(50) values range from 0.015 - 7.3 nM).
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Affiliation(s)
- Rose M McConnell
- Department of Chemistry, Western Illinois University, Macomb, IL 61455, USA.
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12
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Song Y, Jin H, Liu X, Zhu L, Huang J, Li H. Discovery of non-peptide inhibitors of Plasmepsin II by structure-based virtual screening. Bioorg Med Chem Lett 2013; 23:2078-82. [DOI: 10.1016/j.bmcl.2013.01.128] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Revised: 01/26/2013] [Accepted: 01/30/2013] [Indexed: 10/27/2022]
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13
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Bhaumik P, Gustchina A, Wlodawer A. Structural studies of vacuolar plasmepsins. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1824:207-23. [PMID: 21540129 PMCID: PMC3154504 DOI: 10.1016/j.bbapap.2011.04.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/12/2011] [Revised: 04/11/2011] [Accepted: 04/12/2011] [Indexed: 10/18/2022]
Abstract
Plasmepsins (PMs) are pepsin-like aspartic proteases present in different species of parasite Plasmodium. Four Plasmodium spp. (P. vivax, P. ovale, P. malariae, and the most lethal P. falciparum) are mainly responsible for causing human malaria that affects millions worldwide. Due to the complexity and rate of parasite mutation coupled with regional variations, and the emergence of P. falciparum strains which are resistant to antimalarial agents such as chloroquine and sulfadoxine/pyrimethamine, there is constant pressure to find new and lasting chemotherapeutic drug therapies. Since many proteases represent therapeutic targets and PMs have been shown to play an important role in the survival of parasite, these enzymes have recently been identified as promising targets for the development of novel antimalarial drugs. The genome of P. falciparum encodes 10 PMs (PMI, PMII, PMIV-X and histo-aspartic protease (HAP)), 4 of which (PMI, PMII, PMIV and HAP) reside within the food vacuole, are directly involved in degradation of human hemoglobin, and share 50-79% amino acid sequence identity. This review focuses on structural studies of only these four enzymes, including their orthologs in other Plasmodium spp.. Almost all original crystallographic studies were performed with PMII, but more recent work on PMIV, PMI, and HAP resulted in a more complete picture of the structure-function relationship of vacuolar PMs. Many structures of inhibitor complexes of vacuolar plasmepsins, as well as their zymogens, have been reported in the last 15 years. Information gained by such studies will be helpful for the development of better inhibitors that could become a new class of potent antimalarial drugs. This article is part of a Special Issue entitled: Proteolysis 50 years after the discovery of lysosome.
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Affiliation(s)
- Prasenjit Bhaumik
- Protein Structure Section, Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - Alla Gustchina
- Protein Structure Section, Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, MD 21702, USA
| | - Alexander Wlodawer
- Protein Structure Section, Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, MD 21702, USA
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14
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Lilburn TG, Cai H, Zhou Z, Wang Y. Protease-associated cellular networks in malaria parasite Plasmodium falciparum. BMC Genomics 2011; 12 Suppl 5:S9. [PMID: 22369208 PMCID: PMC3287505 DOI: 10.1186/1471-2164-12-s5-s9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Background Malaria continues to be one of the most severe global infectious diseases, responsible for 1-2 million deaths yearly. The rapid evolution and spread of drug resistance in parasites has led to an urgent need for the development of novel antimalarial targets. Proteases are a group of enzymes that play essential roles in parasite growth and invasion. The possibility of designing specific inhibitors for proteases makes them promising drug targets. Previously, combining a comparative genomics approach and a machine learning approach, we identified the complement of proteases (degradome) in the malaria parasite Plasmodium falciparum and its sibling species [1-3], providing a catalog of targets for functional characterization and rational inhibitor design. Network analysis represents another route to revealing the role of proteins in the biology of parasites and we use this approach here to expand our understanding of the systems involving the proteases of P. falciparum. Results We investigated the roles of proteases in the parasite life cycle by constructing a network using protein-protein association data from the STRING database [4], and analyzing these data, in conjunction with the data from protein-protein interaction assays using the yeast 2-hybrid (Y2H) system [5], blood stage microarray experiments [6-8], proteomics [9-12], literature text mining, and sequence homology analysis. Seventy-seven (77) out of 124 predicted proteases were associated with at least one other protein, constituting 2,431 protein-protein interactions (PPIs). These proteases appear to play diverse roles in metabolism, cell cycle regulation, invasion and infection. Their degrees of connectivity (i.e., connections to other proteins), range from one to 143. The largest protease-associated sub-network is the ubiquitin-proteasome system which is crucial for protein recycling and stress response. Proteases are also implicated in heat shock response, signal peptide processing, cell cycle progression, transcriptional regulation, and signal transduction networks. Conclusions Our network analysis of proteases from P. falciparum uses a so-called guilt-by-association approach to extract sets of proteins from the proteome that are candidates for further study. Novel protease targets and previously unrecognized members of the protease-associated sub-systems provide new insights into the mechanisms underlying parasitism, pathogenesis and virulence.
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Affiliation(s)
- Timothy G Lilburn
- Department of Biology, University of Texas at San Antonio, San Antonio, TX 78249, USA
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