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Madhav H, Reddy GS, Rizvi Z, Jameel E, Patel TS, Rahman A, Yadav V, Fatima S, Heyat F, Pal K, Minju-Op A, Subbarao N, Bhattacharjee S, Dixit BC, Sijwali PS, Hoda N. Reinvestigation of diphenylmethylpiperazine analogues of pyrazine as new class of Plasmodial cysteine protease inhibitors for the treatment of malaria. RSC Med Chem 2024; 15:1022-1037. [PMID: 38516592 PMCID: PMC10953474 DOI: 10.1039/d3md00490b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 12/19/2023] [Indexed: 03/23/2024] Open
Abstract
Malaria eradication is still a global challenge due to the lack of a broadly effective vaccine and the emergence of drug resistance to most of the currently available drugs as part of the mainline artemisinin-based combination therapy. A variety of experimental approaches are quite successful in identifying and synthesizing new promising pharmacophore hybrids with distinct mechanisms of action. Based on our recent findings, the current study demonstrates the reinvestigation of a series of diphenylmethylpiperazine and pyrazine-derived molecular hybrids. Pyrazine-derived molecular hybrids were screened to investigate the antiplasmodial activity on drug-susceptible Pf3D7 and drug-resistant PfW2 strains. The selected compounds were shown to be potent dual inhibitors of cysteine protease PfFP2 and PfFP3. Time-course parasitic development study demonstrated that compounds were able to arrest the growth of the parasite at the early trophozoite stage. The compounds did not show hemolysis of red blood cells and showed selectivity to the parasite compared with the mammalian Vero and A5489 cell lines. The study underlined HR5 and HR15 as a new class of Plasmodial falcipain inhibitors with an IC50 of 6.2 μM and 5.9 μM for PfFP2 and 6.8 μM and 6.4 μM for PfFP3, respectively. Both compounds have antimalarial efficacy with IC50 values of 3.05 μM and 2.80 μM for the Pf3D7 strain, and 4.35 μM and 3.39 μM for the PfW2 strain, respectively. Further structural optimization may turn them into potential Plasmodial falcipain inhibitors for malaria therapeutics.
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Affiliation(s)
- Hari Madhav
- Drug Design and Synthesis Laboratory, Department of Chemistry, Jamia Millia Islamia (A Central University) New Delhi-110025 India
| | - G Srinivas Reddy
- CSIR-Centre for Cellular and Molecular Biology Hyderabad-500007 TS India
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad-201002 UP India
| | - Zeba Rizvi
- CSIR-Centre for Cellular and Molecular Biology Hyderabad-500007 TS India
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad-201002 UP India
| | - Ehtesham Jameel
- Drug Design and Synthesis Laboratory, Department of Chemistry, Jamia Millia Islamia (A Central University) New Delhi-110025 India
| | - Tarosh S Patel
- Chemistry Department, V. P. & R. P. T. P Science College, Affiliated to Sardar Patel University Vallabh Vidyanagar-388120 Gujarat India
| | - Abdur Rahman
- Special Centre for Molecular Medicine, Jawaharlal Nehru University New Delhi-110067 India
| | - Vikas Yadav
- School of Computational and Integrative Sciences, Jawaharlal Nehru University New Delhi-110067 India
| | - Sadaf Fatima
- Drug Design and Synthesis Laboratory, Department of Chemistry, Jamia Millia Islamia (A Central University) New Delhi-110025 India
| | - Fatima Heyat
- Drug Design and Synthesis Laboratory, Department of Chemistry, Jamia Millia Islamia (A Central University) New Delhi-110025 India
| | - Kavita Pal
- Drug Design and Synthesis Laboratory, Department of Chemistry, Jamia Millia Islamia (A Central University) New Delhi-110025 India
| | - Amisha Minju-Op
- CSIR-Centre for Cellular and Molecular Biology Hyderabad-500007 TS India
| | - Naidu Subbarao
- School of Computational and Integrative Sciences, Jawaharlal Nehru University New Delhi-110067 India
| | - Souvik Bhattacharjee
- Special Centre for Molecular Medicine, Jawaharlal Nehru University New Delhi-110067 India
| | - Bharat C Dixit
- CSIR-Centre for Cellular and Molecular Biology Hyderabad-500007 TS India
| | - Puran Singh Sijwali
- CSIR-Centre for Cellular and Molecular Biology Hyderabad-500007 TS India
- Academy of Scientific and Innovative Research (AcSIR) Ghaziabad-201002 UP India
| | - Nasimul Hoda
- Drug Design and Synthesis Laboratory, Department of Chemistry, Jamia Millia Islamia (A Central University) New Delhi-110025 India
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2
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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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3
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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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Nwanna E, Inumisan PD, Olawuyi TS, Oboh G. Assessment of Sperm Quality in Plasmodium berghei NK65 Infected Mice Treated with Brimstone (Morinda lucida Benth) Tree Plant. SCIENTIFIC AFRICAN 2023. [DOI: 10.1016/j.sciaf.2023.e01625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023] Open
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Chauke E, Pelle R, Coetzer THT. A single exon-encoded Theileria parva strain Muguga cysteine protease (ThpCP): Molecular modelling and characterisation. Biochimie 2023; 206:24-35. [PMID: 36198333 DOI: 10.1016/j.biochi.2022.09.018] [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: 06/24/2022] [Revised: 09/01/2022] [Accepted: 09/26/2022] [Indexed: 11/27/2022]
Abstract
The tick-transmitted apicomplexan Theileria parva causes East Coast fever, a bovine disease of great economic and veterinary importance in Africa. Papain-like cysteine proteases play important roles in protozoan parasite host cell entry and egress, nutrition and host immune evasion. This study reports the identification and characterisation of a T. parva strain Muguga cathepsin L-like (C1A subfamily) cysteine protease (ThpCP). Molecular modelling confirmed the papain-like fold of ThpCP, hydrophobic character of the S2 substrate binding pocket and non-covalent interaction between the pro- and catalytic domains preceding low pH autoactivation. ThpCP was recombinantly expressed in a protease deficient E. coli (Rosetta (DE3)pLysS strain) expression host as a 46 kDa proenzyme. Following Ni-chelate affinity chromatography and acidification, the 27 kDa mature ThpCP was purified by cation-exchange chromatography. Purified ThpCP hydrolysed typical cathepsin L substrates N-α-benzyloxycarbonyl (Z)-Phe-Arg-7-amino-4-methyl-coumarin (AMC) (kcat/Km = 4.49 × 105 s-1M-1) and Z-Leu-Arg-AMC (kcat/Km = 4.20 × 105 s-1M-1), but showed no activity against the cathepsin B-selective substrate Z-Arg-Arg-AMC. Recombinant ThpCP was active over a broad pH range from pH 4.5 to 7.5, thereby showing potential activity in the acidic parasite food vacuole and close to neutral pH of the host lymphocyte cytoplasm. Recombinant ThpCP was inhibited by the cysteine protease inhibitors E64, iodoacetate, leupeptin, chymostatin, Z-Phe-Ala-diazomethylketone (DMK) and Z-Phe-Phe-DMK and hydrolysed bovine proteins: haemoglobin, immunoglobulin G, serum albumin and fibrinogen as well as goat IgG at pH 6 and 7. Functional expression and characterisation of Theileria cysteine proteases should enable high throughput screening of cysteine protease inhibitor libraries against these proteases.
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Affiliation(s)
- Ephraim Chauke
- Biochemistry, School of Life Sciences, University of KwaZulu-Natal (Pietermaritzburg Campus), Private Bag X01, Scottsville, 3209, South Africa
| | - Roger Pelle
- Biosciences Eastern and Central Africa, International Livestock Research Institute (BecA-ILRI) Hub, P.O. Box, 30709-00100, Nairobi, Kenya
| | - Theresa H T Coetzer
- Biochemistry, School of Life Sciences, University of KwaZulu-Natal (Pietermaritzburg Campus), Private Bag X01, Scottsville, 3209, South Africa.
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6
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Nema S, Verma K, Mani A, Maurya NS, Tiwari A, Bharti PK. Identification of Potential Antimalarial Drug Candidates Targeting Falcipain-2 Protein of Malaria Parasite-A Computational Strategy. BIOTECH (BASEL (SWITZERLAND)) 2022; 11:biotech11040054. [PMID: 36546908 PMCID: PMC9775493 DOI: 10.3390/biotech11040054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 11/28/2022] [Accepted: 11/28/2022] [Indexed: 12/02/2022]
Abstract
Falcipain-2 (FP-2) is one of the main haemoglobinase of P. falciparum which is an important molecular target for the treatment of malaria. In this study, we have screened alkaloids to identify potential inhibitors against FP-2 since alkaloids possess great potential as anti-malarial agents. A total of 340 alkaloids were considered for the study using a series of computational pipelines. Initially, pharmacokinetics and toxicity risk assessment parameters were applied to screen compounds. Subsequently, molecular docking algorithms were utilised to understand the binding efficiency of alkaloids against FP-2. Further, oral toxicity prediction was done using the pkCSM tool, and 3D pharmacophore features were analysed using the PharmaGist server. Finally, MD simulation was performed for Artemisinin and the top 3 drug candidates (Noscapine, Reticuline, Aclidinium) based on docking scores to understand the functional impact of the complexes, followed by a binding site interaction residues study. Overall analysis suggests that Noscapine conceded good pharmacokinetics and oral bioavailability properties. Also, it showed better binding efficiency with FP-2 when compared to Artemisinin. Interestingly, structure alignment analysis with artemisinin revealed that Noscapine, Reticuline, and Aclidinium might possess similar biological action. Molecular dynamics and free energy calculations revealed that Noscapine could be a potent antimalarial agent targeting FP-2 that can be used for the treatment of malaria and need to be studied experimentally in the future.
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Affiliation(s)
- Shrikant Nema
- Division of Vector-Borne Diseases, ICMR-National Institute of Research in Tribal Health, Jabalpur 482 003, Madhya Pradesh, India
- School of Biotechnology, Rajiv Gandhi Proudyogiki Vishwavidyalaya (State Technological University of Madhya Pradesh), Bhopal 462 023, Madhya Pradesh, India
| | - Kanika Verma
- Division of Vector-Borne Diseases, ICMR-National Institute of Research in Tribal Health, Jabalpur 482 003, Madhya Pradesh, India
| | - Ashutosh Mani
- Department of Biotechnology, Motilal Nehru National Institute of Technology, Allahabad 211 004, Uttar Pradesh, India
| | - Neha Shree Maurya
- Department of Biotechnology, Motilal Nehru National Institute of Technology, Allahabad 211 004, Uttar Pradesh, India
| | - Archana Tiwari
- School of Biotechnology, Rajiv Gandhi Proudyogiki Vishwavidyalaya (State Technological University of Madhya Pradesh), Bhopal 462 023, Madhya Pradesh, India
| | - Praveen Kumar Bharti
- Division of Vector-Borne Diseases, ICMR-National Institute of Research in Tribal Health, Jabalpur 482 003, Madhya Pradesh, India
- Correspondence:
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7
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Chakraborty S, Alam B, Biswas S. New insights of falcipain 2 structure from Plasmodium falciparum 3D7 strain. Biochem Biophys Res Commun 2022; 590:145-151. [PMID: 34974303 DOI: 10.1016/j.bbrc.2021.12.080] [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: 12/03/2021] [Accepted: 12/21/2021] [Indexed: 11/29/2022]
Abstract
Malaria identifies as a tropical hallmark, conforming to the burgeoning notion of escalating drug resistance among virulent strains, with the burdensome Plasmodium falciparum under its wing. The cysteine protease Falcipain-2 (FP2) is released in the parasite's food vacuole in the trophozoite stage and contributes to disease progression through its hemoglobinase activity. In the present study, we have determined the crystal structure of FP2 from a drug resistant P. falciparum 3D7 strain. FP2-3D7 sequence has detected four amino acid variants, R12K, E14 N, P100T and G102D, in the mature domain of the protease, when compared with other reported structures. FP2-3D7 protease has been crystallized in the presence of two inhibitors E-64 and Iodoacetamide, which diffracted up to 3.5 Å and 3.4 Å respectively. Structural analyses of the mature domain helped unveil two solvent-exposed pockets with bound ligands where one is structurally homologous to the allosteric binding site of human Cathepsin-K and thus, could be exploited for designing allosteric modifiers of FP2. The structure has also revealed (poly)ethylene glycol molecules along the catalytic cleft, providing interesting insights for exploring FP2 as a chemotherapeutic target and for PEGylation in drug delivery. The side-chains of P2 and P3 residues of E-64 also adopt different rotamer conformations, compared with previously reported structure, emphasizing strain-specific multiple binding-modes of active-site targeted inhibitors. Docking studies, along with normal mode analyses, highlight the mode of hemoglobin binding and the active/inactive switch in hemoglobinase activity, conjecturing the formation of a stable dimeric state with a symmetry related copy in crystal packing.
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Affiliation(s)
- Subhoja Chakraborty
- Crystallography and Molecular Biology Division, Saha Institute of Nuclear Physics, HBNI, Kolkata, 700064, India
| | - Benazir Alam
- Crystallography and Molecular Biology Division, Saha Institute of Nuclear Physics, HBNI, Kolkata, 700064, India
| | - Sampa Biswas
- Crystallography and Molecular Biology Division, Saha Institute of Nuclear Physics, HBNI, Kolkata, 700064, India.
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8
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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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9
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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: 42] [Impact Index Per Article: 10.5] [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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10
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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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11
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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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12
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South African Abietane Diterpenoids and Their Analogs as Potential Antimalarials: Novel Insights from Hybrid Computational Approaches. Molecules 2019; 24:molecules24224036. [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] [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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Alberca LN, Chuguransky SR, Álvarez CL, Talevi A, Salas-Sarduy E. In silico Guided Drug Repurposing: Discovery of New Competitive and Non-competitive Inhibitors of Falcipain-2. Front Chem 2019; 7:534. [PMID: 31448257 PMCID: PMC6691349 DOI: 10.3389/fchem.2019.00534] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 07/12/2019] [Indexed: 11/13/2022] Open
Abstract
Malaria is among the leading causes of death worldwide. The emergence of Plasmodium falciparum resistant strains with reduced sensitivity to the first line combination therapy and suboptimal responses to insecticides used for Anopheles vector management have led to renewed interest in novel therapeutic options. Here, we report the development and validation of an ensemble of ligand-based computational models capable of identifying falcipain-2 inhibitors, and their subsequent application in the virtual screening of DrugBank and Sweetlead libraries. Among four hits submitted to enzymatic assays, two (odanacatib, an abandoned investigational treatment for osteoporosis and bone metastasis, and the antibiotic methacycline) confirmed inhibitory effects on falcipain-2, with Ki of 98.2 nM and 84.4 μM. Interestingly, Methacycline proved to be a non-competitive inhibitor (α = 1.42) of falcipain-2. The effects of both hits on falcipain-2 hemoglobinase activity and on the development of P. falciparum were also studied.
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Affiliation(s)
- Lucas N Alberca
- Laboratory of Bioactive Compounds Research and Development (LIDeB), Department of Biological Sciences, Exact Sciences College, Universidad Nacional de La Plata, La Plata, Argentina
| | - Sara R Chuguransky
- Laboratory of Bioactive Compounds Research and Development (LIDeB), Department of Biological Sciences, Exact Sciences College, Universidad Nacional de La Plata, La Plata, Argentina
| | - Cora L Álvarez
- Departamento de Biodiversidad y Biología Experimental, Facultad de Farmacia y Bioquímica, Facultad de Ciencias Exactas y Naturales, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Química y Fisico-Química Biológicas (IQUIFIB) "Prof. Alejandro C. Paladini", Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Alan Talevi
- Laboratory of Bioactive Compounds Research and Development (LIDeB), Department of Biological Sciences, Exact Sciences College, Universidad Nacional de La Plata, La Plata, Argentina
| | - Emir Salas-Sarduy
- Instituto de Investigaciones Biotecnológicas "Dr. Rodolfo Ugalde", Universidad Nacional de San Martín, CONICET, Buenos Aires, Argentina
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Cianni L, Feldmann CW, Gilberg E, Gütschow M, Juliano L, Leitão A, Bajorath J, Montanari CA. Can Cysteine Protease Cross-Class Inhibitors Achieve Selectivity? J Med Chem 2019; 62:10497-10525. [DOI: 10.1021/acs.jmedchem.9b00683] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Lorenzo Cianni
- Medicinal Chemistry Group, Institute of Chemistry of São Carlos, University of São Paulo, Avenue Trabalhador Sancarlense, 400, 23566-590 São Carlos, SP, Brazil
- Pharmaceutical Institute, Pharmaceutical Chemistry I, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
- Department of Life Science Informatics, B-IT, LIMES Program Unit Chemical Biology and Medicinal Chemistry, Rheinische Friedrich-Wilhelms-Universität, Endenicher Allee 19c, D-53115 Bonn, Germany
| | - Christian Wolfgang Feldmann
- Department of Life Science Informatics, B-IT, LIMES Program Unit Chemical Biology and Medicinal Chemistry, Rheinische Friedrich-Wilhelms-Universität, Endenicher Allee 19c, D-53115 Bonn, Germany
| | - Erik Gilberg
- Pharmaceutical Institute, Pharmaceutical Chemistry I, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
- Department of Life Science Informatics, B-IT, LIMES Program Unit Chemical Biology and Medicinal Chemistry, Rheinische Friedrich-Wilhelms-Universität, Endenicher Allee 19c, D-53115 Bonn, Germany
| | - Michael Gütschow
- Pharmaceutical Institute, Pharmaceutical Chemistry I, University of Bonn, An der Immenburg 4, D-53121 Bonn, Germany
| | - Luiz Juliano
- A. C. Camargo Cancer Center and São Paulo Medical School of Federal University of São Paulo, Rua Professor Antônio Prudente, 211, 01509-010 São Paulo, SP, Brazil
| | - Andrei Leitão
- Medicinal Chemistry Group, Institute of Chemistry of São Carlos, University of São Paulo, Avenue Trabalhador Sancarlense, 400, 23566-590 São Carlos, SP, Brazil
| | - Jürgen Bajorath
- Department of Life Science Informatics, B-IT, LIMES Program Unit Chemical Biology and Medicinal Chemistry, Rheinische Friedrich-Wilhelms-Universität, Endenicher Allee 19c, D-53115 Bonn, Germany
| | - Carlos A. Montanari
- Medicinal Chemistry Group, Institute of Chemistry of São Carlos, University of São Paulo, Avenue Trabalhador Sancarlense, 400, 23566-590 São Carlos, SP, Brazil
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Kannan D, Yadav N, Ahmad S, Namdev P, Bhattacharjee S, Lochab B, Singh S. Pre-clinical study of iron oxide nanoparticles fortified artesunate for efficient targeting of malarial parasite. EBioMedicine 2019; 45:261-277. [PMID: 31255656 PMCID: PMC6642363 DOI: 10.1016/j.ebiom.2019.06.026] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 06/01/2019] [Accepted: 06/13/2019] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Artesunate the most potent antimalarial is widely used for the treatment of multidrug-resistant malaria. The antimalarial cytotoxicity of artesunate has been mainly attributed to its selective, irreversible and iron- radical-mediated damage of parasite biomolecules. In the present research, iron oxide nanoparticle fortified artesunate was tested in P. falciparum and in an experimental malaria mouse model for enhancement in the selectivity and toxicity of artesunate towards parasite. Artesunate was fortified with nontoxic biocompatible surface modified iron oxide nanoparticle which is specially designed and synthesized for the sustained pH-dependent release of Fe2+ within the parasitic food vacuole for enhanced ROS spurt. METHODS Antimalarial efficacy of Iron oxide nanoparticle fortified artesunate was evaluated in wild type and artemisinin-resistant Plasmodium falciparum (R539T) grown in O + ve human blood and in Plasmodium berghei ANKA infected swiss albino mice. Internalization of nanoparticles, the pH-dependent release of Fe2+, production of reactive oxygen species and parasite biomolecule damage by iron oxide nanoparticle fortified artesunate was studied using various biochemical, biophysical, ultra-structural and fluorescence microscopy. For determining the efficacy of ATA-IONP+ART on resistant parasite ring survival assay was performed. RESULTS The nanoparticle fortified artesunate was highly efficient in the 1/8th concentration of artesunate IC50 and led to retarded growth of P. falciparum with significant damage to macromolecules mediated via enhanced ROS production. Similarly, preclinical In vivo studies also signified a radical reduction in parasitemia with ~8-10-fold reduced dosage of artesunate when fortified with iron oxide nanoparticles. Importantly, the ATA-IONP combination was efficacious against artemisinin-resistant parasites. INTERPRETATION Surface coated iron-oxide nanoparticle fortified artesunate can be developed into a potent therapeutic agent towards multidrug-resistant and artemisinin-resistant malaria in humans. FUND: This study is supported by the Centre for Study of Complex Malaria in India funded by the National Institute of Health, USA.
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Affiliation(s)
- Deepika Kannan
- Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Gautam Buddha Nagar, India
| | - Nisha Yadav
- Department of Chemistry, School of Natural Sciences, Shiv Nadar University, Gautam Buddha Nagar, India
| | - Shakeel Ahmad
- Special Center for Molecular Medicine, Jawaharlal Nehru University, New Mehrauli Road, New Delhi, India
| | - Pragya Namdev
- Special Center for Molecular Medicine, Jawaharlal Nehru University, New Mehrauli Road, New Delhi, India
| | - Souvik Bhattacharjee
- Special Center for Molecular Medicine, Jawaharlal Nehru University, New Mehrauli Road, New Delhi, India
| | - Bimlesh Lochab
- Department of Chemistry, School of Natural Sciences, Shiv Nadar University, Gautam Buddha Nagar, India.
| | - Shailja Singh
- Special Center for Molecular Medicine, Jawaharlal Nehru University, New Mehrauli Road, New Delhi, India.
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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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Crucial residues in falcipains that mediate hemoglobin hydrolysis. Exp Parasitol 2019; 197:43-50. [PMID: 30648557 DOI: 10.1016/j.exppara.2019.01.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 11/03/2018] [Accepted: 01/11/2019] [Indexed: 02/08/2023]
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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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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: 149] [Impact Index Per Article: 18.6] [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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Independent amino acid residues in the S2 pocket of falcipain-3 determine its specificity for P2 residues in substrates. Mol Biochem Parasitol 2015; 202:11-22. [DOI: 10.1016/j.molbiopara.2015.09.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 09/24/2015] [Accepted: 09/28/2015] [Indexed: 12/23/2022]
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21
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Fang X, Reifman J, Wallqvist A. Modeling metabolism and stage-specific growth of Plasmodium falciparum HB3 during the intraerythrocytic developmental cycle. MOLECULAR BIOSYSTEMS 2015; 10:2526-37. [PMID: 25001103 DOI: 10.1039/c4mb00115j] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The human malaria parasite Plasmodium falciparum goes through a complex life cycle, including a roughly 48-hour-long intraerythrocytic developmental cycle (IDC) in human red blood cells. A better understanding of the metabolic processes required during the asexual blood-stage reproduction will enhance our basic knowledge of P. falciparum and help identify critical metabolic reactions and pathways associated with blood-stage malaria. We developed a metabolic network model that mechanistically links time-dependent gene expression, metabolism, and stage-specific growth, allowing us to predict the metabolic fluxes, the biomass production rates, and the timing of production of the different biomass components during the IDC. We predicted time- and stage-specific production of precursors and macromolecules for P. falciparum (strain HB3), allowing us to link specific metabolites to specific physiological functions. For example, we hypothesized that coenzyme A might be involved in late-IDC DNA replication and cell division. Moreover, the predicted ATP metabolism indicated that energy was mainly produced from glycolysis and utilized for non-metabolic processes. Finally, we used the model to classify the entire tricarboxylic acid cycle into segments, each with a distinct function, such as superoxide detoxification, glutamate/glutamine processing, and metabolism of fumarate as a byproduct of purine biosynthesis. By capturing the normal metabolic and growth progression in P. falciparum during the IDC, our model provides a starting point for further elucidation of strain-specific metabolic activity, host-parasite interactions, stress-induced metabolic responses, and metabolic responses to antimalarial drugs and drug candidates.
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Affiliation(s)
- Xin Fang
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Ft. Detrick, MD 21702, USA.
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Lin JW, Spaccapelo R, Schwarzer E, Sajid M, Annoura T, Deroost K, Ravelli RBG, Aime E, Capuccini B, Mommaas-Kienhuis AM, O'Toole T, Prins F, Franke-Fayard BMD, Ramesar J, Chevalley-Maurel S, Kroeze H, Koster AJ, Tanke HJ, Crisanti A, Langhorne J, Arese P, Van den Steen PE, Janse CJ, Khan SM. Replication of Plasmodium in reticulocytes can occur without hemozoin formation, resulting in chloroquine resistance. ACTA ACUST UNITED AC 2015; 212:893-903. [PMID: 25941254 PMCID: PMC4451122 DOI: 10.1084/jem.20141731] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2014] [Accepted: 04/08/2015] [Indexed: 01/03/2023]
Abstract
Lin et al. generate Plasmodium berghei mutants lacking enzymes critical to hemoglobin digestion. A double gene deletion mutant lacking enzymes involved in the initial steps of hemoglobin proteolysis is able to replicate inside reticulocytes of infected mice with limited hemoglobin degradation and no hemozoin formation, and moreover, is resistant to the antimalarial drug chloroquine. Most studies on malaria-parasite digestion of hemoglobin (Hb) have been performed using P. falciparum maintained in mature erythrocytes, in vitro. In this study, we examine Plasmodium Hb degradation in vivo in mice, using the parasite P. berghei, and show that it is possible to create mutant parasites lacking enzymes involved in the initial steps of Hb proteolysis. These mutants only complete development in reticulocytes and mature into both schizonts and gametocytes. Hb degradation is severely impaired and large amounts of undigested Hb remains in the reticulocyte cytoplasm and in vesicles in the parasite. The mutants produce little or no hemozoin (Hz), the detoxification by-product of Hb degradation. Further, they are resistant to chloroquine, an antimalarial drug that interferes with Hz formation, but their sensitivity to artesunate, also thought to be dependent on Hb degradation, is retained. Survival in reticulocytes with reduced or absent Hb digestion may imply a novel mechanism of drug resistance. These findings have implications for drug development against human-malaria parasites, such as P. vivax and P. ovale, which develop inside reticulocytes.
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Affiliation(s)
- Jing-Wen Lin
- Leiden Malaria Research Group, Department of Parasitology, Department of Molecular Cell Biology, and Department of Pathology, Leiden University Medical Centre, 2333 ZA Leiden, Netherlands Division of Parasitology, MRC National Institute for Medical Research, London NW7 1AA, England, UK
| | - Roberta Spaccapelo
- Department of Experimental Medicine, University of Perugia, Piazzale Gambuli, 06132 Perugia, Italy
| | - Evelin Schwarzer
- Department of Oncology, University of Torino, 10124 Torino, Italy
| | - Mohammed Sajid
- Leiden Malaria Research Group, Department of Parasitology, Department of Molecular Cell Biology, and Department of Pathology, Leiden University Medical Centre, 2333 ZA Leiden, Netherlands
| | - Takeshi Annoura
- Leiden Malaria Research Group, Department of Parasitology, Department of Molecular Cell Biology, and Department of Pathology, Leiden University Medical Centre, 2333 ZA Leiden, Netherlands
| | - Katrien Deroost
- Laboratory of Immunobiology, Rega Institute for Medical Research, KU Leuven - University of Leuven, 3000 Leuven, Belgium
| | - Raimond B G Ravelli
- Leiden Malaria Research Group, Department of Parasitology, Department of Molecular Cell Biology, and Department of Pathology, Leiden University Medical Centre, 2333 ZA Leiden, Netherlands
| | - Elena Aime
- Department of Experimental Medicine, University of Perugia, Piazzale Gambuli, 06132 Perugia, Italy
| | - Barbara Capuccini
- Department of Experimental Medicine, University of Perugia, Piazzale Gambuli, 06132 Perugia, Italy Division of Parasitology, MRC National Institute for Medical Research, London NW7 1AA, England, UK
| | - Anna M Mommaas-Kienhuis
- Leiden Malaria Research Group, Department of Parasitology, Department of Molecular Cell Biology, and Department of Pathology, Leiden University Medical Centre, 2333 ZA Leiden, Netherlands
| | - Tom O'Toole
- Department of Molecular Cell Biology and Immunology, Vrije University Medical Center, 1007 MB Amsterdam, Netherlands
| | - Frans Prins
- Leiden Malaria Research Group, Department of Parasitology, Department of Molecular Cell Biology, and Department of Pathology, Leiden University Medical Centre, 2333 ZA Leiden, Netherlands
| | - Blandine M D Franke-Fayard
- Leiden Malaria Research Group, Department of Parasitology, Department of Molecular Cell Biology, and Department of Pathology, Leiden University Medical Centre, 2333 ZA Leiden, Netherlands
| | - Jai Ramesar
- Leiden Malaria Research Group, Department of Parasitology, Department of Molecular Cell Biology, and Department of Pathology, Leiden University Medical Centre, 2333 ZA Leiden, Netherlands
| | - Séverine Chevalley-Maurel
- Leiden Malaria Research Group, Department of Parasitology, Department of Molecular Cell Biology, and Department of Pathology, Leiden University Medical Centre, 2333 ZA Leiden, Netherlands
| | - Hans Kroeze
- Leiden Malaria Research Group, Department of Parasitology, Department of Molecular Cell Biology, and Department of Pathology, Leiden University Medical Centre, 2333 ZA Leiden, Netherlands
| | - Abraham J Koster
- Leiden Malaria Research Group, Department of Parasitology, Department of Molecular Cell Biology, and Department of Pathology, Leiden University Medical Centre, 2333 ZA Leiden, Netherlands
| | - Hans J Tanke
- Leiden Malaria Research Group, Department of Parasitology, Department of Molecular Cell Biology, and Department of Pathology, Leiden University Medical Centre, 2333 ZA Leiden, Netherlands
| | - Andrea Crisanti
- Department of Experimental Medicine, University of Perugia, Piazzale Gambuli, 06132 Perugia, Italy Department of Biological Sciences, Imperial College London, South Kensington Campus, SAF, London SW7 2AZ, England, UK
| | - Jean Langhorne
- Division of Parasitology, MRC National Institute for Medical Research, London NW7 1AA, England, UK
| | - Paolo Arese
- Department of Oncology, University of Torino, 10124 Torino, Italy
| | - Philippe E Van den Steen
- Laboratory of Immunobiology, Rega Institute for Medical Research, KU Leuven - University of Leuven, 3000 Leuven, Belgium
| | - Chris J Janse
- Leiden Malaria Research Group, Department of Parasitology, Department of Molecular Cell Biology, and Department of Pathology, Leiden University Medical Centre, 2333 ZA Leiden, Netherlands
| | - Shahid M Khan
- Leiden Malaria Research Group, Department of Parasitology, Department of Molecular Cell Biology, and Department of Pathology, Leiden University Medical Centre, 2333 ZA Leiden, Netherlands
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Allosteric regulation of the Plasmodium falciparum cysteine protease falcipain-2 by heme. Arch Biochem Biophys 2015; 573:92-9. [PMID: 25791019 DOI: 10.1016/j.abb.2015.03.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 02/22/2015] [Accepted: 03/09/2015] [Indexed: 11/20/2022]
Abstract
During the erythrocytic cycle of Plasmodium falciparum malaria parasites break down host hemoglobin, resulting in the release of free heme (ferriprotoporphyrin IX). Heme is a generator of free radicals that cause oxidative stress, but it is detoxified by crystallization into hemozoin inside the food vacuole. We evaluated the interaction of heme and heme analogues with falcipain-2, a P. falciparum food vacuole cysteine protease that plays a key role in hemoglobin digestion. Heme bound to falcipain-2 with a 1:1 stoichiometry, and heme inhibited falcipain-2 activity against both human hemoglobin and chromogenic peptide substrates through a noncompetitive-like mechanism. A series of porphyrin analogues was screened for inhibition of falcipain-2, demonstrating a minor contribution of iron to heme-falcipain-2 interaction, and revealing dependence on both propionic and vinyl groups for inhibition of falcipain-2 by heme. Docking and molecular dynamics simulation unveiled a novel, inducible heme-binding moiety in falcipain-2 adjacent to the catalytic site. Kinetic data suggested that the noncompetitive-like inhibition was substrate inhibition induced by heme. Collectively these data suggest that binding of heme to falcipain-2 may limit the accumulation of free heme in the parasite food vacuole, providing a means of heme detoxification in addition to crystallization into hemozoin.
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Gomes MM, Budu A, Ventura PDS, Bagnaresi P, Cotrin SS, Cunha RLOR, Carmona AK, Juliano L, Gazarini ML. Specific calpain activity evaluation in Plasmodium parasites. Anal Biochem 2014; 468:22-7. [PMID: 25281458 DOI: 10.1016/j.ab.2014.09.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 08/13/2014] [Accepted: 09/06/2014] [Indexed: 01/26/2023]
Abstract
In the intraerythrocytic trophozoite stages of Plasmodium falciparum, the calcium-dependent cysteine protease calpain (Pf-calpain) has an important role in the parasite calcium modulation and cell development. We established specific conditions to follow by confocal microscopy and spectrofluorimetry measurements the intracellular activity of Pf-calpain in live cells. The catalytic activity was measured using the fluorogenic Z-Phe-Arg-MCA (where Z is carbobenzoxy and MCA is 4-methylcoumaryl-7-amide). The calmodulin inhibitor calmidazolium and the sarcoplasmic reticulum calcium ATPase inhibitor thapsigargin were used for modifications in the cytosolic calcium concentrations that persisted in the absence of extracellular calcium. The observed calcium-dependent peptidase activity was greatly inhibited by specific cysteine protease inhibitor E-64 and by the selective calpain inhibitor ALLN (N-acetyl-l-leucyl-l-leucyl-l-norleucinal). Taken together, we observed that intracellular Pf-calpain can be selectively detected and is the main calcium-dependent protease in the intraerythrocytic stages of the parasite. The method described here can be helpful in cell metabolism studies and antimalarial drug screening.
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Affiliation(s)
- Mayrim M Gomes
- Departamento de Microbiologia, Imunologia e Parasitologia, Escola Paulista de Medicina, UNIFESP, São Paulo, SP, Brazil; Departamento de Biociências, Universidade Federal de São Paulo, Santos, SP, Brazil
| | - Alexandre Budu
- Departamento de Biofísica, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | | | - Piero Bagnaresi
- Departamento de Biofísica, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Simone S Cotrin
- Departamento de Biofísica, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Rodrigo L O R Cunha
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Santo André, SP, Brazil
| | - Adriana K Carmona
- Departamento de Biofísica, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Luiz Juliano
- Departamento de Biofísica, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Marcos L Gazarini
- Departamento de Biociências, Universidade Federal de São Paulo, Santos, SP, Brazil.
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Clark MA, Goheen MM, Cerami C. Influence of host iron status on Plasmodium falciparum infection. Front Pharmacol 2014; 5:84. [PMID: 24834053 PMCID: PMC4018558 DOI: 10.3389/fphar.2014.00084] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 04/04/2014] [Indexed: 01/25/2023] Open
Abstract
Iron deficiency affects one quarter of the world's population and causes significant morbidity, including detrimental effects on immune function and cognitive development. Accordingly, the World Health Organization (WHO) recommends routine iron supplementation in children and adults in areas with a high prevalence of iron deficiency. However, a large body of clinical and epidemiological evidence has accumulated which clearly demonstrates that host iron deficiency is protective against falciparum malaria and that host iron supplementation may increase the risk of malaria. Although many effective antimalarial treatments and preventive measures are available, malaria remains a significant public health problem, in part because the mechanisms of malaria pathogenesis remain obscured by the complexity of the relationships that exist between parasite virulence factors, host susceptibility traits, and the immune responses that modulate disease. Here we review (i) the clinical and epidemiological data that describes the relationship between host iron status and malaria infection and (ii) the current understanding of the biological basis for these clinical and epidemiological observations.
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Affiliation(s)
- Martha A. Clark
- Microbiology and Immunology, University of North CarolinaChapel Hill, NC, USA
| | - Morgan M. Goheen
- Microbiology and Immunology, University of North CarolinaChapel Hill, NC, USA
| | - Carla Cerami
- Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel HillChapel Hill, NC, USA
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Melo PM, Bagnaresi P, Paschoalin T, Hirata IY, Gazarini ML, Carmona AK. Plasmodium falciparum proteases hydrolyze plasminogen, generating angiostatin-like fragments. Mol Biochem Parasitol 2014; 193:45-54. [DOI: 10.1016/j.molbiopara.2014.01.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Revised: 01/22/2014] [Accepted: 01/25/2014] [Indexed: 12/27/2022]
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Mugumbate G, Newton AS, Rosenthal PJ, Gut J, Moreira R, Chibale K, Guedes RC. Novel anti-plasmodial hits identified by virtual screening of the ZINC database. J Comput Aided Mol Des 2013; 27:859-71. [PMID: 24158745 DOI: 10.1007/s10822-013-9685-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Accepted: 10/12/2013] [Indexed: 01/16/2023]
Abstract
Increased resistance of Plasmodium falciparum to most available drugs challenges the control of malaria. Studies with protease inhibitors have suggested important roles for the falcipain family of cysteine proteases. These enzymes act in concert with other proteases to hydrolyze host erythrocyte hemoglobin in the parasite food vacuole. In order to find potential new antimalarial drugs, we screened in silico the ZINC database using two different protocols involving structure- and ligand-based methodologies. Our search identified 19 novel low micromolar inhibitors of cultured chloroquine resistant P. falciparum. The most active compound presented an IC50 value of 0.5 μM against cultured parasites and it also inhibited the cysteine protease falcipain-2 (IC50 = 25.5 μM). These results identify novel classes of antimalarials that are structurally different from those currently in use and which can be further derivatized to deliver leads suitable for optimisation.
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Affiliation(s)
- Grace Mugumbate
- Department of Chemistry, University of Cape Town, Rondebosch, 7701, South Africa
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Blocking Plasmodium falciparum development via dual inhibition of hemoglobin degradation and the ubiquitin proteasome system by MG132. PLoS One 2013; 8:e73530. [PMID: 24023882 PMCID: PMC3759421 DOI: 10.1371/journal.pone.0073530] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 07/22/2013] [Indexed: 12/31/2022] Open
Abstract
Among key potential drug target proteolytic systems in the malaria parasite Plasmodium falciparum are falcipains, a family of hemoglobin-degrading cysteine proteases, and the ubiquitin proteasomal system (UPS), which has fundamental importance in cellular protein turnover. Inhibition of falcipains blocks parasite development, primarily due to inhibition of hemoglobin degradation that serves as a source of amino acids for parasite growth. Falcipains prefer P2 leucine in substrates and peptides, and their peptidyl inhibitors with leucine at the P2 position show potent antimalarial activity. The peptidyl inhibitor MG132 (Z-Leu-Leu-Leu-CHO) is a widely used proteasome inhibitor, which also has P2 leucine, and has also been shown to inhibit parasite development. However, the antimalarial targets of MG132 are unclear. We investigated whether MG132 blocks malaria parasite development by inhibiting hemoglobin degradation and/or by targeting the UPS. P. falciparum was cultured with inhibitors of the UPS (MG132, epoxomicin, and lactacystin) or falcipains (E64), and parasites were assessed for morphologies, extent of hemoglobin degradation, and accumulation of ubiquitinated proteins. MG132, like E64 and unlike epoxomicin or lactacystin, blocked parasite development, with enlargement of the food vacuole and accumulation of undegraded hemoglobin, indicating inhibition of hemoglobin degradation by MG132, most likely due to inhibition of hemoglobin-degrading falcipain cysteine proteases. Parasites cultured with epoxomicin or MG132 accumulated ubiquitinated proteins to a significantly greater extent than untreated or E64-treated parasites, indicating that MG132 inhibits the parasite UPS as well. Consistent with these findings, MG132 inhibited both cysteine protease and UPS activities present in soluble parasite extracts, and it strongly inhibited recombinant falcipains. MG132 was highly selective for inhibition of P. falciparum (IC50 0.0476 µM) compared to human peripheral blood mononuclear cells (IC50 10.8 µM). Thus, MG132 inhibits two distinct proteolytic systems in P. falciparum, and it may serve as a lead molecule for development of dual-target inhibitors of malaria parasites.
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Marques AF, Esser D, Rosenthal PJ, Kassack MU, Lima LMTR. Falcipain-2 inhibition by suramin and suramin analogues. Bioorg Med Chem 2013; 21:3667-73. [PMID: 23680445 DOI: 10.1016/j.bmc.2013.04.047] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 04/09/2013] [Accepted: 04/17/2013] [Indexed: 10/26/2022]
Abstract
Falcipain-2 is a cysteine protease of the malaria parasite Plasmodium falciparum that plays a key role in the hydrolysis of hemoglobin, a process that is required by intraerythrocytic parasites to obtain amino acids. In this work we show that the polysulfonated napthylurea suramin is capable of binding to falcipain-2, inhibiting its catalytic activity at nanomolar concentrations against both synthetic substrates and the natural substrate hemoglobin. Kinetic measurements suggest that the inhibition occurs through an noncompetitive allosteric mechanism, eliciting substrate inhibition. Smaller suramin analogues and those with substituted methyl groups also showed inhibition within the nanomolar range. Our results identify the suramin family as a potential starting point for the design of falcipain-2 inhibitor antimalarials that act through a novel inhibition mechanism.
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Affiliation(s)
- Adriana Fonseca Marques
- Laboratory for Pharmaceutical Biotechnology, School of Pharmacy, Federal University of Rio de Janeiro, CCS, Bss34, Ilha do Fundão, 21941-590 Rio de Janeiro, RJ, Brazil
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Wasyl K, Zawistowska-Deniziak A, Bąska P, Wędrychowicz H, Wiśniewski M. Molecular cloning and expression of the cDNA sequence encoding a novel aspartic protease from Uncinaria stenocephala. Exp Parasitol 2013; 134:220-7. [PMID: 23541464 DOI: 10.1016/j.exppara.2013.03.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 03/08/2013] [Accepted: 03/17/2013] [Indexed: 11/27/2022]
Abstract
Uncinaria stenocephala belongs to Ancylostomatidae family. Members of this family - hookworms - infect millions of people and animals worldwide. U. stenocephala is most pathogenic in dogs and other Canidae, which are the main hosts, and infection causes anemia or even death. So far no effective hookworm vaccine has been developed that is economically viable. Attempts to identify vaccine antigens have led to a group of aspartic proteases, which play a key role in parasite feeding, migration through host tissues and immune evasion. The cDNA of an aspartic protease from U. stenocephala was cloned using the RACE-PCR method. Computational analysis showed that the cDNA encodes a 447 amino acid protein with a molecular mass of 52kDa that shows high homology to aspartic proteases from related hookworms. Analysis identified 1 potential N-glycosylation site, 3 potential disulfide bonds and no O-glycosylation sites. The recombinant protein was expressed in Escherichia coli followed by purification and mouse immunization. Using raised anti-Us-APR-1(2) (Uncinaria stenocephala Aspartic protease-1) serum the presence of Us-APR-1 in the adult stage of U. stenocephala and the expression of homologous protease in L3 and adult stages of A. ceylanicum was confirmed. This analysis is the first phase of work exploring the biological role of Us-APR-1 in parasite-host interactions and raises hope for successful vaccine development against Uncinaria sp. and possibly Ancylostoma sp.
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Affiliation(s)
- Katarzyna Wasyl
- Division of Parasitology, Department of Preclinical Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences - SGGW, Ciszewskiego 8, 02-786 Warsaw, Poland.
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31
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Pei Y, Miller JL, Lindner SE, Vaughan AM, Torii M, Kappe SHI. Plasmodium yoelii inhibitor of cysteine proteases is exported to exomembrane structures and interacts with yoelipain-2 during asexual blood-stage development. Cell Microbiol 2013; 15:1508-1526. [PMID: 23421981 DOI: 10.1111/cmi.12124] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Revised: 02/06/2013] [Accepted: 02/07/2013] [Indexed: 11/28/2022]
Abstract
Plasmodium falciparum (Pf) blood stages express falstatin, an inhibitor of cysteine proteases (ICP), which is implicated in regulating proteolysis during red blood cell infection. Recent data using the Plasmodium berghei rodent malaria model suggested an additional role for ICP in the infection of hepatocytes by sporozoites and during liver-stage development. Here we further characterize the role of ICP in vivo during infection with Plasmodium yoelii (Py) and Pf. We found that Py-ICP was refractory to targeted gene deletion indicating an essential function during asexual blood-stage replication, but significant downregulation of ICP using a regulated system did not impact blood-stage growth. Py-ICP localized to vesicles within the asexual blood-stage parasite cytoplasm, as well as the parasitophorous vacuole, and was exported to dynamic exomembrane structures in the infected RBC. In sporozoites, expression was observed in rhoptries, in addition to intracellular vesicles distinct from TRAP containing micronemes. During liver-stage development, Py-ICP was confined to the parasite compartment until the final phase of liver-stage development when, after parasitophorous vacuolemembrane breakdown, it was released into the infected hepatocyte. Finally, we identified the cysteine protease yoelipain-2 as a binding partner of Py-ICP during blood-stage infection. These data show that ICP may be important in regulating proteolytic processes during blood-stage development, and is likely playing a role in liver stage-hepatocyte interactions at the time of exoerythrocytic merozoite release.
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Affiliation(s)
- Ying Pei
- Seattle Biomedical Research Institute, 307 Westlake Avenue North, Suite 500, Seattle, WA 98109, USA
| | - Jessica L Miller
- Seattle Biomedical Research Institute, 307 Westlake Avenue North, Suite 500, Seattle, WA 98109, USA
| | - Scott E Lindner
- Seattle Biomedical Research Institute, 307 Westlake Avenue North, Suite 500, Seattle, WA 98109, USA
| | - Ashley M Vaughan
- Seattle Biomedical Research Institute, 307 Westlake Avenue North, Suite 500, Seattle, WA 98109, USA
| | - Motomi Torii
- Department of Molecular Parasitology, Ehime University Graduate School of Medicine, Toon, Ehime 791-0295, Japan
| | - Stefan H I Kappe
- Seattle Biomedical Research Institute, 307 Westlake Avenue North, Suite 500, Seattle, WA 98109, USA.,Department of Global Health, University of Washington, Seattle, WA, 98195, USA
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Substrate specificity studies of the cysteine peptidases falcipain-2 and falcipain-3 from Plasmodium falciparum and demonstration of their kininogenase activity. Mol Biochem Parasitol 2013; 187:111-6. [DOI: 10.1016/j.molbiopara.2013.01.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 10/20/2012] [Accepted: 01/16/2013] [Indexed: 01/19/2023]
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Expression, characterization, and cellular localization of knowpains, papain-like cysteine proteases of the Plasmodium knowlesi malaria parasite. PLoS One 2012; 7:e51619. [PMID: 23251596 PMCID: PMC3520923 DOI: 10.1371/journal.pone.0051619] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 11/02/2012] [Indexed: 01/09/2023] Open
Abstract
Papain-like cysteine proteases of malaria parasites degrade haemoglobin in an acidic food vacuole to provide amino acids for intraerythrocytic parasites. These proteases are potential drug targets because their inhibitors block parasite development, and efforts are underway to develop chemotherapeutic inhibitors of these proteases as the treatments for malaria. Plasmodium knowlesi has recently been shown to be an important human pathogen in parts of Asia. We report expression and characterization of three P. knowlesi papain-like proteases, termed knowpains (KP2-4). Recombinant knowpains were produced using a bacterial expression system, and tested for various biochemical properties. Antibodies against recombinant knowpains were generated and used to determine their cellular localization in parasites. Inhibitory effects of the cysteine protease inhibitor E64 were assessed on P. knowlesi culture to validate drug target potential of knowpains. All three knowpains were present in the food vacuole, active in acidic pH, and capable of degrading haemoglobin at the food vacuolar pH (≈5.5), suggesting roles in haemoglobin degradation. The proteases showed absolute (KP2 and KP3) to moderate (KP4) preference for peptide substrates containing leucine at the P2 position; KP4 preferred arginine at the P2 position. While the three knowpains appear to have redundant roles in haemoglobin degradation, KP4 may also have a role in degradation of erythrocyte cytoskeleton during merozoite egress, as it displayed broad substrate specificity and was primarily localized at the parasite periphery. Importantly, E64 blocked erythrocytic development of P. knowlesi, with enlargement of food vacuoles, indicating inhibition of haemoglobin hydrolysis and supporting the potential for inhibition of knowpains as a strategy for the treatment of malaria. Functional expression and characterization of knowpains should enable simultaneous screening of available cysteine protease inhibitor libraries against knowpains for developing broadly effective compounds active against multiple human malaria parasites.
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Aureggi V, Ehmke V, Wieland J, Schweizer WB, Bernet B, Bur D, Meyer S, Rottmann M, Freymond C, Brun R, Breit B, Diederich F. Potent inhibitors of malarial aspartic proteases, the plasmepsins, by hydroformylation of substituted 7-azanorbornenes. Chemistry 2012; 19:155-64. [PMID: 23161835 DOI: 10.1002/chem.201202941] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Indexed: 12/23/2022]
Abstract
The increasing prevalence of multidrug-resistant strains of the malarial parasite Plasmodium falciparum requires the urgent development of new therapeutic agents with novel modes of action. The vacuolar malarial aspartic proteases plasmepsin (PM) I, II, and IV are involved in hemoglobin degradation and play a central role in the growth and maturation of the parasite in the human host. We report the structure-based design, synthesis, and in vitro evaluation of a new generation of PM inhibitors featuring a highly decorated 7-azabicyclo[2.2.1]heptane core. While this protonated central core addresses the catalytic Asp dyad, three substituents bind to the flap, the S1/S3, and the S1' pockets of the enzymes. A hydroformylation reaction is the key synthetic step for the introduction of the new vector reaching into the S1' pocket. The configuration of the racemic ligands was confirmed by extensive NMR and X-ray crystallographic analysis. In vitro biological assays revealed high potency of the new inhibitors against the three plasmepsins (IC(50) values down to 6 nM) and good selectivity towards the closely related human cathepsins D and E. The occupancy of the S1' pocket makes an essential contribution to the gain in binding affinity and selectivity, which is particularly large in the case of the PM IV enzyme. Designing non-peptidic ligands for PM II is a valid route to generate compounds that inhibit the entire family of vacuolar plasmepsins.
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Affiliation(s)
- Valentina Aureggi
- Laboratorium für Organische Chemie, ETH Zurich, Hönggerberg HCI, 8093 Zurich, Switzerland
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Sundararaj S, Singh D, Saxena AK, Vashisht K, Sijwali PS, Dixit R, Pandey KC. The Ionic and hydrophobic interactions are required for the auto activation of cysteine proteases of Plasmodium falciparum. PLoS One 2012; 7:e47227. [PMID: 23077573 PMCID: PMC3473063 DOI: 10.1371/journal.pone.0047227] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Accepted: 09/11/2012] [Indexed: 02/05/2023] Open
Abstract
The Plasmodium falciparum cysteine proteases falcipain-2 and falcipain-3 are major hemoglobinases and potential antimalarial drug targets. Our previous studies demonstrated that these enzymes are equipped with specific domains for specific functions. Structural and functional analysis of falcipains showed that they have unique domains including a refolding domain and a hemoglobin binding domain. As with many proteases, falcipain-2 and falcipain-3 are synthesized as inactive zymogens. However, it is not known how these enzymes get activated for hemoglobin hydrolysis. In this study, we are presenting the first evidence that salt bridges and hydrophobic interactions are required for the auto activation of cysteine proteases of P.falciparum. To investigate the mechanism of activation of these enzymes, we expressed the wild type protein as well as different mutants in E.coli. Refolding was assessed by circular dichroism. Both CD and trans activation data showed that the wild type enzymes and mutants are rich in secondary structures with similar folds. Our study revealed that prodomain-mature domain of falcipain-2 and falcipain-3 interacts via salt bridges and hydrophobic interactions. We mutated specific residues of falcipain-2 and falcipain-3, and evaluated their ability to undergo auto processing. Mutagenesis result showed that two salt bridges (Arg¹⁸⁵- Glu²²¹, Glu²¹⁰- Lys⁴⁰³) in falcipain-2, and one salt bridge (Arg²⁰²-Glu²³⁸) in falcipain-3, play crucial roles in the activation of these enzymes. Further study revealed that hydrophobic interactions present both in falcipain-2 (Phe²¹⁴ Trp⁴⁴⁹ Trp⁴⁵³) and falcipain-3 (Phe²³¹ Trp⁴⁵⁷ Trp⁴⁶¹) also play important roles in the activation of these enzymes. Our results revealed the interactions involved in auto processing of two major hemoglobinases of malaria parasite.
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Affiliation(s)
- Srinivasan Sundararaj
- Host–Parasite Interaction Biology Group, National Institute of Malaria Research, Indian Council of Medical Research, Dwarka, New Delhi, India
| | - Deepak Singh
- Host–Parasite Interaction Biology Group, National Institute of Malaria Research, Indian Council of Medical Research, Dwarka, New Delhi, India
| | - Ajay K. Saxena
- Structural Biology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Kapil Vashisht
- Host–Parasite Interaction Biology Group, National Institute of Malaria Research, Indian Council of Medical Research, Dwarka, New Delhi, India
| | | | - Rajnikant Dixit
- Host–Parasite Interaction Biology Group, National Institute of Malaria Research, Indian Council of Medical Research, Dwarka, New Delhi, India
| | - Kailash C. Pandey
- Host–Parasite Interaction Biology Group, National Institute of Malaria Research, Indian Council of Medical Research, Dwarka, New Delhi, India
- * E-mail:
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Bagnaresi P, Barros NM, Assis DM, Melo PM, Fonseca RG, Juliano MA, Pesquero JB, Juliano L, Rosenthal PJ, Carmona AK, Gazarini ML. Intracellular proteolysis of kininogen by malaria parasites promotes release of active kinins. Malar J 2012; 11:156. [PMID: 22564457 PMCID: PMC3407703 DOI: 10.1186/1475-2875-11-156] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Accepted: 05/07/2012] [Indexed: 01/22/2023] Open
Abstract
Background The malaria burden remains a major public health concern, especially in sub-Saharan Africa. The complex biology of Plasmodium, the apicomplexan parasite responsible for this disease, challenges efforts to develop new strategies to control the disease. Proteolysis is a fundamental process in the metabolism of malaria parasites, but roles for proteases in generating vasoactive peptides have not previously been explored. Results In the present work, it was demonstrated by mass spectrometry analysis that Plasmodium parasites (Plasmodium chabaudi and Plasmodium falciparum) internalize and process plasma kininogen, thereby releasing vasoactive kinins (Lys-BK, BK and des-Arg9-BK) that may mediate haemodynamic alterations during acute malaria. In addition, it was demonstrated that the P. falciparum cysteine proteases falcipain-2 and falcipain-3 generated kinins after incubation with human kininogen, suggesting that these enzymes have an important role in this process. The biologic activity of peptides released by Plasmodium parasites was observed by measuring ileum contraction and activation of kinin receptors (B1 and B2) in HUVEC cells; the peptides elicited an increase in intracellular calcium, measured by Fluo-3 AM fluorescence. This effect was suppressed by the specific receptor antagonists Des-Arg9[Leu8]-BK and HOE-140. Conclusions In previously undescribed means of modulating host physiology, it was demonstrated that malaria parasites can generate active kinins by proteolysis of plasma kininogen.
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Affiliation(s)
- Piero Bagnaresi
- Departamento de Biofísica, Universidade Federal de São Paulo, Rua Pedro de Toledo, 669 - 7 andar, 04039-032, São Paulo, Brazil
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Shah F, Gut J, Legac J, Shivakumar D, Sherman W, Rosenthal PJ, Avery MA. Computer-aided drug design of falcipain inhibitors: virtual screening, structure-activity relationships, hydration site thermodynamics, and reactivity analysis. J Chem Inf Model 2012; 52:696-710. [PMID: 22332946 DOI: 10.1021/ci2005516] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Falcipains (FPs) are hemoglobinases of Plasmodium falciparum that are validated targets for the development of antimalarial chemotherapy. A combined ligand- and structure-based virtual screening of commercial databases was performed to identify structural analogs of virtual screening hits previously discovered in our laboratory. A total of 28 low micromolar inhibitors of FP-2 and FP-3 were identified and the structure-activity relationship (SAR) in each series was elaborated. The SAR of the compounds was unusually steep in some cases and could not be explained by a traditional analysis of the ligand-protein interactions (van der Waals, electrostatics, and hydrogen bonds). To gain further insights, a statistical thermodynamic analysis of explicit solvent in the ligand binding domains of FP-2 and FP-3 was carried out to understand the roles played by water molecules in binding of these inhibitors. Indeed, the energetics associated with the displacement of water molecules upon ligand binding explained some of the complex trends in the SAR. Furthermore, low potency of a subset of FP-2 inhibitors that could not be understood by the water energetics was explained in the context of poor chemical reactivity of the reactive centers of these compounds. The present study highlights the importance of considering energetic contributors to binding beyond traditional ligand-protein interactions.
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Affiliation(s)
- Falgun Shah
- Department of Medicinal Chemistry, School of Pharmacy, University of Mississippi, University, Mississippi 38677, USA
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Structure-function of falcipains: malarial cysteine proteases. J Trop Med 2012; 2012:345195. [PMID: 22529862 PMCID: PMC3317066 DOI: 10.1155/2012/345195] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 10/12/2011] [Accepted: 10/27/2011] [Indexed: 02/05/2023] Open
Abstract
Evidence indicates that cysteine proteases play essential role in malaria parasites; therefore an obvious area of investigation is the inhibition of these enzymes to treat malaria. Studies with cysteine protease inhibitors and manipulating cysteine proteases genes have suggested a role for cysteine proteases in hemoglobin hydrolysis. The best characterized Plasmodium cysteine proteases are falcipains, which are papain family enzymes. Falcipain-2 and falcipain-3 are major hemoglobinases of P. falciparum. Structural and functional analysis of falcipains showed that they have unique domains including a refolding domain and a hemoglobin binding domain. Overall, the complexes of falcipain-2 and falcipain-3 with small and macromolecular inhibitors provide structural insight to facilitate the design or modification of effective drug treatment against malaria. Drug development targeting falcipains should be aided by a strong foundation of biochemical and structural studies.
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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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Centenary celebrations article: Cysteine proteases of human malaria parasites. J Parasit Dis 2011; 35:94-103. [PMID: 23024488 DOI: 10.1007/s12639-011-0084-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 11/09/2011] [Indexed: 01/07/2023] Open
Abstract
There is an urgent need for new drugs against malaria, which takes millions of lives annually. Cysteine proteases are potential new drug targets, especially when current drugs are showing resistance. Falcipains and vivapains are well characterized cysteine proteases of P. falciparum and P. vivax, respectively. Studies with cysteine protease inhibitors and manipulating cysteine proteases specific genes have suggested their roles in hemoglobin hydrolysis. In P. falciparum, falcipain-2 and falcipain-3 are major hemoglobinases that hydrolyze host erythrocyte hemoglobin in the parasite food vacuole. It is confirmed that disruption of the falcipain-2 gene led to a transient block in hemoglobin hydrolysis, and disruption of falcipain-3 gene was not possible, suggesting that protease is essential for erythrocytic parasites. On the other hand, vivapain-2, vivapain-3 and vivapain-4 are important cysteine proteases of P. vivax, which shared a number of features with falcipain-2 and falcipain-3. A recent study indicates that vivapains and aspartic protease of P. vivax works collaboratively to enhance the parasites' ability to hydrolyze host erythrocyte hemoglobin. Studies also indicate that falcipains and vivapains also hydrolyse the erythrocyte cytoskeleton proteins and involved in rupture of red blood cell. Structural and biochemical analysis of falcipains and vivapains showed that they have unique domains for specific functions. Overall, the complexes of cysteine proteases with small and macromolecular inhibitors provide structural insight to facilitate the drug design. Therefore, giving due importance to the cysteine proteases, this review will briefly focus the recent advancement in the field of cysteine proteases of human malaria parasites.
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Teixeira C, Gomes JRB, Couesnon T, Gomes P. Molecular docking and 3D-quantitative structure activity relationship analyses of peptidyl vinyl sulfones: Plasmodium Falciparum cysteine proteases inhibitors. J Comput Aided Mol Des 2011; 25:763-75. [PMID: 21786172 DOI: 10.1007/s10822-011-9459-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Accepted: 07/11/2011] [Indexed: 10/18/2022]
Abstract
Comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) based on three-dimensional quantitative structure-activity relationship (3D-QSAR) studies were conducted on a series (39 molecules) of peptidyl vinyl sulfone derivatives as potential Plasmodium Falciparum cysteine proteases inhibitors. Two different methods of alignment were employed: (i) a receptor-docked alignment derived from the structure-based docking algorithm GOLD and (ii) a ligand-based alignment using the structure of one of the ligands derived from a crystal structure from the PDB databank. The best predictions were obtained for the receptor-docked alignment with a CoMFA standard model (q (2) = 0.696 and r (2) = 0.980) and with CoMSIA combined electrostatic, and hydrophobic fields (q (2) = 0.711 and r (2) = 0.992). Both models were validated by a test set of nine compounds and gave satisfactory predictive r (2) (pred) values of 0.76 and 0.74, respectively. CoMFA and CoMSIA contour maps were used to identify critical regions where any change in the steric, electrostatic, and hydrophobic fields may affect the inhibitory activity, and to highlight the key structural features required for biological activity. Moreover, the results obtained from 3D-QSAR analyses were superimposed on the Plasmodium Falciparum cysteine proteases active site and the main interactions were studied. The present work provides extremely useful guidelines for future structural modifications of this class of compounds towards the development of superior antimalarials.
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Affiliation(s)
- Cátia Teixeira
- Centro de Investigação em Química da Universidade do Porto, Departamento de Química, Portugal.
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Shah F, Mukherjee P, Gut J, Legac J, Rosenthal PJ, Tekwani BL, Avery MA. Identification of novel malarial cysteine protease inhibitors using structure-based virtual screening of a focused cysteine protease inhibitor library. J Chem Inf Model 2011; 51:852-64. [PMID: 21428453 DOI: 10.1021/ci200029y] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Malaria, in particular that caused by Plasmodium falciparum , is prevalent across the tropics, and its medicinal control is limited by widespread drug resistance. Cysteine proteases of P. falciparum , falcipain-2 (FP-2) and falcipain-3 (FP-3), are major hemoglobinases, validated as potential antimalarial drug targets. Structure-based virtual screening of a focused cysteine protease inhibitor library built with soft rather than hard electrophiles was performed against an X-ray crystal structure of FP-2 using the Glide docking program. An enrichment study was performed to select a suitable scoring function and to retrieve potential candidates against FP-2 from a large chemical database. Biological evaluation of 50 selected compounds identified 21 diverse nonpeptidic inhibitors of FP-2 with a hit rate of 42%. Atomic Fukui indices were used to predict the most electrophilic center and its electrophilicity in the identified hits. Comparison of predicted electrophilicity of electrophiles in identified hits with those in known irreversible inhibitors suggested the soft-nature of electrophiles in the selected target compounds. The present study highlights the importance of focused libraries and enrichment studies in structure-based virtual screening. In addition, few compounds were screened against homologous human cysteine proteases for selectivity analysis. Further evaluation of structure-activity relationships around these nonpeptidic scaffolds could help in the development of selective leads for antimalarial chemotherapy.
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Affiliation(s)
- Falgun Shah
- Department of Medicinal Chemistry, School of Pharmacy, University of Mississippi , University, Mississippi 38677, USA
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Shah F, Wu Y, Gut J, Pedduri Y, Legac J, Rosenthal PJ, Avery MA. Design, synthesis and biological evaluation of novel benzothiazole and triazole analogs as falcipain inhibitors. MEDCHEMCOMM 2011. [DOI: 10.1039/c1md00129a] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Rosenthal PJ. Falcipains and other cysteine proteases of malaria parasites. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 712:30-48. [PMID: 21660657 DOI: 10.1007/978-1-4419-8414-2_3] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A number of cysteine proteases of malaria parasites have been described and many more are suggested by analysis of the Plasmodium falciparum genome sequence. The best characterized of these proteases are the falcipains, a family of four papain-family enzymes. Falcipain-2 and falcipain-3 act in concert with other proteases to hydrolyze host erythrocyte hemoglobin in the parasite food vacuole. Disruption of the falcipain-2 gene led to a transient block in hemoglobin hydrolysis and parasites with increased sensitivity to protease inhibitors. Disruption of the falcipain-3 gene was not possible, strongly suggesting that this protease is essential for erythrocytic parasites. Disruption of the falcipain-1 gene did not alter development in erythrocytes, but led to decreased production of oocysts in mosquitoes. other papain-family proteases predicted by the genome sequence include dipeptidyl peptidases, a calpain homolog and serine-repeat antigens (SERAs). Dipeptidyl aminopeptidase 1 appears to be essential and localized to the food vacuole, suggesting a role in hemoglobin hydrolysis. Dipeptidyl aminopeptidase 3 appears to play a role in the rupture of erythrocytes by mature parasites. the P. falciparum calpain homolog gene could not be disrupted, suggesting that the protein is essential and a role in the parasite cell cycle has been suggested. Nine P. falciparum SERAs have cysteine protease motifs, but in some the active site cys is replaced by a Ser. Gene disruption studies suggested that SERA-5 and SERA-6 are essential. activation of SERA-5 by a serine protease seems to be required for merozoite egress from the erythrocyte. New drugs for malaria are greatly needed and cysteine proteases represent potential drug targets. cysteine protease inhibitors have demonstrated potent antimalarial effects and the optimization and testing of falcipain inhibitor antimalarials is underway.
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Affiliation(s)
- Philip J Rosenthal
- Department of Medicine, San Francisco General Hospital, University of California, San Francisco, California, USA.
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In vivo uptake of a haem analogue Zn protoporphyrin IX by the human malaria parasite P. falciparum-infected red blood cells. Cell Biol Int 2010; 34:859-65. [PMID: 20491653 DOI: 10.1042/cbi20090427] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The cellular traffic of haem during the development of the human malaria parasite Plasmodium falciparum, through the stages R (ring), T (trophozoite) and S (schizonts), was investigated within RBC (red blood cells). When Plasmodium cultures were incubated with a fluorescent haem analogue, ZnPPIX (Zn protoporphyrin IX) the probe was seen at the cytoplasm (R stage), and the vesicle-like structure distribution pattern was more evident at T and S stages. The temporal sequence of ZnPPIX uptake by P. falciparum-infected erythrocytes shows that at R and S stages, a time-increase acquisition of the porphyrin reaches the maximum fluorescence distribution after 60 min; in contrast, at the T stage, the maximum occurs after 120 min of ZnPPIX uptake. The difference in time-increase acquisition of the porphyrin is in agreement with a maximum activity of haem uptake at the T stage. To gain insights into haem metabolism, recombinant PfHO (P. falciparum haem oxygenase) was expressed, and the conversion of haem into BV (biliverdin) was detected. These findings point out that, in addition to haemozoin formation, the malaria parasite P. falciparum has evolved two distinct mechanisms for dealing with haem toxicity, namely, the uptake of haem into a cellular compartment where haemozoin is formed and HO activity. However, the low Plasmodium HO activity detected reveals that the enzyme appears to be a very inefficient way to scavenge the haem compared with the Plasmodium ability to uptake the haem analogue ZnPPIX and delivering it to the food vacuole.
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Na BK, Bae YA, Zo YG, Choe Y, Kim SH, Desai PV, Avery MA, Craik CS, Kim TS, Rosenthal PJ, Kong Y. Biochemical properties of a novel cysteine protease of Plasmodium vivax, vivapain-4. PLoS Negl Trop Dis 2010; 4:e849. [PMID: 20967286 PMCID: PMC2953480 DOI: 10.1371/journal.pntd.0000849] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2010] [Accepted: 09/14/2010] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Multiple cysteine proteases of malaria parasites are required for maintenance of parasite metabolic homeostasis and egress from the host erythrocyte. In Plasmodium falciparum these proteases appear to mediate the processing of hemoglobin and aspartic proteases (plasmepsins) in the acidic food vacuole and the hydrolysis of erythrocyte structural proteins at neutral pH. Two cysteine proteases, vivapain (VX)-2 and VX-3 have been characterized in P. vivax, but comprehensive studies of P. vivax cysteine proteases remain elusive. FINDINGS We characterized a novel cysteine protease of P. vivax, VX-4, of which orthologs appears to have evolved differentially in primate plasmodia with strong cladistic affinity toward those of rodent Plasmodium. Recombinant VX-4 demonstrated dual substrate specificity depending on the surrounding micro-environmental pH. Its hydrolyzing activity against benzyloxycarbonyl-Leu-Arg-4-methyl-coumaryl-7-amide (Z-Leu-Arg-MCA) and Z-Phe-Arg-MCA was highest at acidic pH (5.5), whereas that against Z-Arg-Arg-MCA was maximal at neutral pH (6.5-7.5). VX-4 preferred positively charged amino acids and Gln at the P1 position, with less strict specificity at P3 and P4. P2 preferences depended on pH (Leu at pH 5.5 and Arg at pH 7.5). Three amino acids that delineate the S2 pocket were substituted in VX-4 compared to VX-2 and VX-3 (Ala90, Gly157 and Glu180). Replacement of Glu180 abolished activity against Z-Arg-Arg-MCA at neutral pH, indicating the importance of this amino acid in the pH-dependent substrate preference. VX-4 was localized in the food vacuoles and cytoplasm of the erythrocytic stage of P. vivax. VX-4 showed maximal activity against actin at neutral pH, and that against P. vivax plasmepsin 4 and hemoglobin was detected at neutral/acidic and acidic pH, respectively. CONCLUSION VX-4 demonstrates pH-dependent substrate switching, which might offer an efficient mechanism for the specific cleavage of different substrates in different intracellular environments. VX-4 might function as a hemoglobinase in the acidic parasite food vacuole, a maturase of P. vivax plasmepsin 4 at neutral or acidic pH, and a cytoskeleton-degrading protease in the neutral erythrocyte cytosol.
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Affiliation(s)
- Byoung-Kuk Na
- Department of Molecular Parasitology and Center for Molecular Medicine, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, Korea
- Department of Parasitology and Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, Korea
| | - Young-An Bae
- Department of Molecular Parasitology and Center for Molecular Medicine, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, Korea
| | - Young-Gun Zo
- Department of Molecular Parasitology and Center for Molecular Medicine, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, Korea
| | - Youngchool Choe
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, United States of America
| | - Seon-Hee Kim
- Department of Molecular Parasitology and Center for Molecular Medicine, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, Korea
| | - Prashant V. Desai
- Department of Medicinal Chemistry, National Center for Natural Products Research, University of Mississippi, University, Mississippi, United States of America
| | - Mitchell A. Avery
- Department of Chemistry and Biochemistry, University of Mississippi, University, Mississippi, Unites States of America
| | - Charles S. Craik
- Department of Pharmaceutical Chemistry, University of California San Francisco, San Francisco, California, United States of America
| | - Tong-Soo Kim
- Department of Parasitology, Inha University College of Medicine, Incheon, Korea
| | - Philip J. Rosenthal
- Department of Medicine, University of California San Francisco, San Francisco, California, United States of America
| | - Yoon Kong
- Department of Molecular Parasitology and Center for Molecular Medicine, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon, Korea
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Wang F, Krai P, Deu E, Bibb B, Lauritzen C, Pedersen J, Bogyo M, Klemba M. Biochemical characterization of Plasmodium falciparum dipeptidyl aminopeptidase 1. Mol Biochem Parasitol 2010; 175:10-20. [PMID: 20833209 DOI: 10.1016/j.molbiopara.2010.08.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Revised: 08/17/2010] [Accepted: 08/25/2010] [Indexed: 10/19/2022]
Abstract
Dipeptidyl aminopeptidase 1 (DPAP1) is an essential food vacuole enzyme with a putative role in hemoglobin catabolism by the erythrocytic malaria parasite. Here, the biochemical properties of DPAP1 have been investigated and compared to those of the human ortholog cathepsin C. To facilitate the characterization of DPAP1, we have developed a method for the production of purified recombinant DPAP1 with properties closely resembling those of the native enzyme. Like cathepsin C, DPAP1 is a chloride-activated enzyme that is most efficient in catalyzing amide bond hydrolysis at acidic pH values. The monomeric quaternary structure of DPAP1 differs from the homotetrameric structure of cathepsin C, which suggests that tetramerization is required for a cathepsin C-specific function. The S1 and S2 subsite preferences of DPAP1 and cathepsin C were profiled with a positional scanning synthetic combinatorial library. The S1 preferences bore close similarity to those of other C1-family cysteine peptidases. The S2 subsites of both DPAP1 and cathepsin C accepted aliphatic hydrophobic residues, proline, and some polar residues, yielding a distinct specificity profile. DPAP1 efficiently catalyzed the hydrolysis of several fluorogenic dipeptide substrates; surprisingly, however, a potential substrate with a P2-phenylalanine residue was instead a competitive inhibitor. Together, our biochemical data suggest that DPAP1 accelerates the production of amino acids from hemoglobin by bridging the gap between the endopeptidase and aminopeptidase activities of the food vacuole. Two reversible cathepsin C inhibitors potently inhibited both recombinant and native DPAP1, thereby validating the use of recombinant DPAP1 for future inhibitor discovery and characterization.
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Affiliation(s)
- Flora Wang
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA
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Cruz CE, Fogaça AC, Nakayasu ES, Angeli CB, Belmonte R, Almeida IC, Miranda A, Miranda MTM, Tanaka AS, Braz GR, Craik CS, Schneider E, Caffrey CR, Daffre S. Characterization of proteinases from the midgut of Rhipicephalus (Boophilus) microplus involved in the generation of antimicrobial peptides. Parasit Vectors 2010; 3:63. [PMID: 20663211 PMCID: PMC2921360 DOI: 10.1186/1756-3305-3-63] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Accepted: 07/27/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Hemoglobin is a rich source of biologically active peptides, some of which are potent antimicrobials (hemocidins). A few hemocidins have been purified from the midgut contents of ticks. Nonetheless, how antimicrobials are generated in the tick midgut and their role in immunity is still poorly understood. Here we report, for the first time, the contribution of two midgut proteinases to the generation of hemocidins. RESULTS An aspartic proteinase, designated BmAP, was isolated from the midgut of Rhipicephalus (Boophilus) microplus using three chromatographic steps. Reverse transcription-quantitative polymerase chain reaction revealed that BmAP is restricted to the midgut. The other enzyme is a previously characterized midgut cathepsin L-like cysteine proteinase designated BmCL1. Substrate specificities of native BmAP and recombinant BmCL1 were mapped using a synthetic combinatorial peptide library and bovine hemoglobin. BmCL1 preferred substrates containing non-polar residues at P2 subsite and polar residues at P1, whereas BmAP hydrolysed substrates containing non-polar amino acids at P1 and P1'. CONCLUSIONS BmAP and BmCL1 generate hemocidins from hemoglobin alpha and beta chains in vitro. We postulate that hemocidins may be important for the control of tick pathogens and midgut flora.
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Affiliation(s)
- Carlos E Cruz
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP 05508-900, Brazil.
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Löser R, Gut J, Rosenthal PJ, Frizler M, Gütschow M, Andrews KT. Antimalarial activity of azadipeptide nitriles. Bioorg Med Chem Lett 2009; 20:252-5. [PMID: 19913414 DOI: 10.1016/j.bmcl.2009.10.122] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2009] [Accepted: 10/27/2009] [Indexed: 10/20/2022]
Abstract
Azadipeptide nitriles-novel cysteine protease inhibitors-display structure-dependent antimalarial activity against both chloroquine-sensitive and chloroquine-resistant lines of cultured Plasmodium falciparum malaria parasites. Inhibition of parasite's hemoglobin-degrading cysteine proteases was also investigated, revealing the azadipeptide nitriles as potent inhibitors of falcipain-2 and -3. A correlation between the cysteine protease-inhibiting activity and the antimalarial potential of the compounds was observed. These first generation azadipeptide nitriles represent a promising new class of compounds for antimalarial drug development.
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Affiliation(s)
- Reik Löser
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia.
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Ragheb D, Bompiani K, Dalal S, Klemba M. Evidence for catalytic roles for Plasmodium falciparum aminopeptidase P in the food vacuole and cytosol. J Biol Chem 2009; 284:24806-15. [PMID: 19574214 DOI: 10.1074/jbc.m109.018424] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The metalloenzyme aminopeptidase P catalyzes the hydrolysis of amino acids from the amino termini of peptides with a prolyl residue in the second position. The human malaria parasite Plasmodium falciparum expresses a homolog of aminopeptidase P during its asexual intraerythrocytic cycle. P. falciparum aminopeptidase P (PfAPP) shares with mammalian cytosolic aminopeptidase P a three-domain, homodimeric organization and is most active with Mn(II) as the cofactor. A distinguishing feature of PfAPP is a 120-amino acid amino-terminal extension that appears to be removed from the mature protein. PfAPP is present in the food vacuole and cytosol of the parasite, a distribution that suggests roles in vacuolar hemoglobin catabolism and cytosolic peptide turnover. To evaluate the plausibility of these putative functions, the stability and kinetic properties of recombinant PfAPP were evaluated at the acidic pH of the food vacuole and at the near-neutral pH of the cytosol. PfAPP exhibited high stability at 37 degrees C in the pH range 5.0-7.5. In contrast, recombinant human cytosolic APP1 was unstable and formed a high molecular weight aggregate at acidic pH. At both acidic and slightly basic pH values, PfAPP efficiently hydrolyzed the amino-terminal X-Pro bond of the nonapeptide bradykinin and of two globin pentapeptides that are potential in vivo substrates. These results provide support for roles for PfAPP in peptide catabolism in both the food vacuole and the cytosol and suggest that PfAPP has evolved a dual distribution in response to the metabolic needs of the intraerythrocytic parasite.
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Affiliation(s)
- Daniel Ragheb
- Department of Biochemistry, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061, USA
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