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Chandrasekharan G, Unnikrishnan M. High throughput methods to study protein-protein interactions during host-pathogen interactions. Eur J Cell Biol 2024; 103:151393. [PMID: 38306772 DOI: 10.1016/j.ejcb.2024.151393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 01/18/2024] [Accepted: 01/21/2024] [Indexed: 02/04/2024] Open
Abstract
The ability of a pathogen to survive and cause an infection is often determined by specific interactions between the host and pathogen proteins. Such interactions can be both intra- and extracellular and may define the outcome of an infection. There are a range of innovative biochemical, biophysical and bioinformatic techniques currently available to identify protein-protein interactions (PPI) between the host and the pathogen. However, the complexity and the diversity of host-pathogen PPIs has led to the development of several high throughput (HT) techniques that enable the study of multiple interactions at once and/or screen multiple samples at the same time, in an unbiased manner. We review here the major HT laboratory-based technologies employed for host-bacterial interaction studies.
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Affiliation(s)
| | - Meera Unnikrishnan
- Division of Biomedical Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom.
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2
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Mannuthodikayil J, Sinha S, Singh S, Biswas A, Ali I, Mashurabad PC, Tabassum W, Vydyam P, Bhattacharyya MK, Mandal K. A Chimeric Peptide Inhibits Red Blood Cell Invasion by Plasmodium falciparum with Hundredfold Increased Efficacy. Chembiochem 2022; 24:e202200533. [PMID: 36449557 DOI: 10.1002/cbic.202200533] [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: 09/14/2022] [Revised: 11/29/2022] [Accepted: 11/30/2022] [Indexed: 12/05/2022]
Abstract
Inhibiting the formation of a tight junction between two malaria parasite proteins, apical membrane antigen 1 and rhoptry neck protein 2, crucial for red blood cell invasion, prevents progression of the disease. In this work, we have used a unique approach to design a chimeric peptide, prepared by fusion of the best features of two peptide inhibitors, that has displayed parasite growth inhibition ex vivo with nanomolar IC50 , which is 100 times better than any of its parent peptides. Furthermore, to gain structural insights, we computationally modelled the hybrid peptide on its receptor.
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Affiliation(s)
- Jamsad Mannuthodikayil
- Tata Institute of Fundamental Research Hyderabad, 36/p Gopanpally, Hyderabad, Telangana, 500046, India
| | - Suman Sinha
- Tata Institute of Fundamental Research Hyderabad, 36/p Gopanpally, Hyderabad, Telangana, 500046, India
| | - Sameer Singh
- Tata Institute of Fundamental Research Hyderabad, 36/p Gopanpally, Hyderabad, Telangana, 500046, India
| | - Anamika Biswas
- Tata Institute of Fundamental Research Hyderabad, 36/p Gopanpally, Hyderabad, Telangana, 500046, India
| | - Irshad Ali
- Tata Institute of Fundamental Research Hyderabad, 36/p Gopanpally, Hyderabad, Telangana, 500046, India
| | - Purna Chandra Mashurabad
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, 500046, India
| | - Wahida Tabassum
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, 500046, India
| | - Pratap Vydyam
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, 500046, India
| | - Mrinal Kanti Bhattacharyya
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, 500046, India
| | - Kalyaneswar Mandal
- Tata Institute of Fundamental Research Hyderabad, 36/p Gopanpally, Hyderabad, Telangana, 500046, India
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Rittipornlertrak A, Nambooppha B, Muenthaisong A, Apinda N, Koonyosying P, Srisawat W, Chomjit P, Sangkakam K, Punyapornwithaya V, Tiwananthagorn S, Yokoyama N, Sthitmatee N. Immunization of Cattle With Recombinant Structural Ectodomains I and II of Babesia bovis Apical Membrane Antigen 1 [BbAMA-1(I/II)] Induces Strong Th1 Immune Response. Front Vet Sci 2022; 9:917389. [PMID: 35812841 PMCID: PMC9260583 DOI: 10.3389/fvets.2022.917389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 05/23/2022] [Indexed: 12/04/2022] Open
Abstract
Both strong innate and adaptive immune responses are an important component of protection against intraerythrocytic protozoan parasites. Resistance to bovine babesiosis is associated with interferon (IFN)-γ mediated responses. CD4+ T cells and macrophages have been identified as major effector cells mediating the clearance of pathogens. Previously, the apical membrane antigen 1 (AMA-1) was found to significantly induce the immune response inhibiting B. bovis merozoite growth and invasion. However, a detailed characterization of both humoral and cellular immune responses against the structure of B. bovis AMA-1 (BbAMA-1) has not yet been established. Herein, the present study aimed to express the recombinant BbAMA-1 domain I+II protein [rBbAMA-1(I/II)], which is the most predominant immune response region, and to characterize its immune response. As a result, cattle vaccinated with BbAMA-1(I/II) significantly developed high titters of total immunoglobulin (Ig) G antibodies and a high ratio of IgG2/IgG1 when compared to control groups. Interestingly, the BbAMA-1(I/II)-based formulations produced in our study could elicit CD4+ T cells and CD8+ T cells producing IFN-γ and tumor necrosis factor (TNF)-α. Collectively, the results indicate that immunization of cattle with BbAMA-1(I/II) could induce strong Th1 cell responses. In support of this, we observed the up-regulation of Th1 cytokine mRNA transcripts, including IFN-γ, TNF-α, Interleukin (IL)-2 and IL-12, in contrast to down regulation of IL-4, IL-6 and IL-10, which would be indicative of a Th2 cytokine response. Moreover, the up-regulation of inducible nitric oxide synthase (iNOS) was observed. In conclusion, this is the first report on the in-depth immunological characterization of the response to BbAMA-1. According to our results, BbAMA-1 is recognized as a potential candidate vaccine against B. bovis infection. As evidenced by the Th1 cell response, it could potentially provide protective immunity. However, further challenge-exposure with virulent B. bovis strain in immunized cattle would be needed to determine its protective efficacy.
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Affiliation(s)
- Amarin Rittipornlertrak
- Laboratory of Veterinary Vaccine and Biological Products, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
- Ruminant Clinic, Department of Food Animal Clinics, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Boondarika Nambooppha
- Laboratory of Veterinary Vaccine and Biological Products, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
- Department of Veterinary Bioscience and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Anucha Muenthaisong
- Laboratory of Veterinary Vaccine and Biological Products, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Nisachon Apinda
- Laboratory of Veterinary Vaccine and Biological Products, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Pongpisid Koonyosying
- Laboratory of Veterinary Vaccine and Biological Products, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Wanwisa Srisawat
- Laboratory of Veterinary Vaccine and Biological Products, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Paweena Chomjit
- Laboratory of Veterinary Vaccine and Biological Products, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Kanokwan Sangkakam
- Laboratory of Veterinary Vaccine and Biological Products, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Veerasak Punyapornwithaya
- Ruminant Clinic, Department of Food Animal Clinics, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Saruda Tiwananthagorn
- Department of Veterinary Bioscience and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Naoaki Yokoyama
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan
| | - Nattawooti Sthitmatee
- Laboratory of Veterinary Vaccine and Biological Products, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
- Department of Veterinary Bioscience and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Chiang Mai, Thailand
- Excellent Center in Veterinary Bioscience, Chiang Mai University, Chiang Mai, Thailand
- *Correspondence: Nattawooti Sthitmatee ;
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Fernandes P, Loubens M, Le Borgne R, Marinach C, Ardin B, Briquet S, Vincensini L, Hamada S, Hoareau-Coudert B, Verbavatz JM, Weiner A, Silvie O. The AMA1-RON complex drives Plasmodium sporozoite invasion in the mosquito and mammalian hosts. PLoS Pathog 2022; 18:e1010643. [PMID: 35731833 PMCID: PMC9255738 DOI: 10.1371/journal.ppat.1010643] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 07/05/2022] [Accepted: 06/02/2022] [Indexed: 11/22/2022] Open
Abstract
Plasmodium sporozoites that are transmitted by blood-feeding female Anopheles mosquitoes invade hepatocytes for an initial round of intracellular replication, leading to the release of merozoites that invade and multiply within red blood cells. Sporozoites and merozoites share a number of proteins that are expressed by both stages, including the Apical Membrane Antigen 1 (AMA1) and the Rhoptry Neck Proteins (RONs). Although AMA1 and RONs are essential for merozoite invasion of erythrocytes during asexual blood stage replication of the parasite, their function in sporozoites was still unclear. Here we show that AMA1 interacts with RONs in mature sporozoites. By using DiCre-mediated conditional gene deletion in P. berghei, we demonstrate that loss of AMA1, RON2 or RON4 in sporozoites impairs colonization of the mosquito salivary glands and invasion of mammalian hepatocytes, without affecting transcellular parasite migration. Three-dimensional electron microscopy data showed that sporozoites enter salivary gland cells through a ring-like structure and by forming a transient vacuole. The absence of a functional AMA1-RON complex led to an altered morphology of the entry junction, associated with epithelial cell damage. Our data establish that AMA1 and RONs facilitate host cell invasion across Plasmodium invasive stages, and suggest that sporozoites use the AMA1-RON complex to efficiently and safely enter the mosquito salivary glands to ensure successful parasite transmission. These results open up the possibility of targeting the AMA1-RON complex for transmission-blocking antimalarial strategies. Malaria is caused by Plasmodium parasites, which are transmitted by mosquitoes. Infectious stages of the parasite known as sporozoites colonize the mosquito salivary glands and are injected into the host when the insect probes the skin for blood feeding. Sporozoites rapidly migrate to the host liver, invade hepatocytes and differentiate into the next invasive forms, the merozoites, which invade and replicate inside red blood cells. Merozoites invade cells through a specialized structure, known as the moving junction, formed by proteins called AMA1 and RONs. The role of these proteins in sporozoites remains unclear. Here we used conditional genome editing in a rodent malaria model to generate AMA1- and RON-deficient sporozoites. Phenotypic analysis of the mutants revealed that sporozoites use the AMA1-RON complex twice, first in the mosquito to safely enter the salivary glands and ensure successful parasite transmission, then in the mammalian host liver to establish a replicative niche. Our data establish that AMA1 and RONs facilitate host cell invasion across Plasmodium invasive stages, and might represent potential targets for transmission-blocking antimalarial strategies.
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Affiliation(s)
- Priyanka Fernandes
- Sorbonne Université, INSERM, CNRS, Centre d’Immunologie et des Maladies Infectieuses, Paris, France
| | - Manon Loubens
- Sorbonne Université, INSERM, CNRS, Centre d’Immunologie et des Maladies Infectieuses, Paris, France
| | - Rémi Le Borgne
- Institut Jacques Monod, Université Paris Cité, CNRS, UMR 7592, Paris, France
| | - Carine Marinach
- Sorbonne Université, INSERM, CNRS, Centre d’Immunologie et des Maladies Infectieuses, Paris, France
| | - Béatrice Ardin
- Sorbonne Université, INSERM, CNRS, Centre d’Immunologie et des Maladies Infectieuses, Paris, France
| | - Sylvie Briquet
- Sorbonne Université, INSERM, CNRS, Centre d’Immunologie et des Maladies Infectieuses, Paris, France
| | - Laetitia Vincensini
- Sorbonne Université, INSERM, CNRS, Centre d’Immunologie et des Maladies Infectieuses, Paris, France
| | - Soumia Hamada
- Sorbonne Université, INSERM, CNRS, Centre d’Immunologie et des Maladies Infectieuses, Paris, France
- Sorbonne Université, INSERM, UMS PASS, Plateforme Post-génomique de la Pitié Salpêtrière (P3S), Paris, France
| | - Bénédicte Hoareau-Coudert
- Sorbonne Université, INSERM, UMS PASS, Plateforme de cytométrie de la Pitié-Salpêtrière (CyPS), Paris, France
| | - Jean-Marc Verbavatz
- Institut Jacques Monod, Université Paris Cité, CNRS, UMR 7592, Paris, France
| | - Allon Weiner
- Sorbonne Université, INSERM, CNRS, Centre d’Immunologie et des Maladies Infectieuses, Paris, France
| | - Olivier Silvie
- Sorbonne Université, INSERM, CNRS, Centre d’Immunologie et des Maladies Infectieuses, Paris, France
- * E-mail:
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Global diversity and balancing selection of 23 leading Plasmodium falciparum candidate vaccine antigens. PLoS Comput Biol 2022; 18:e1009801. [PMID: 35108259 PMCID: PMC8843232 DOI: 10.1371/journal.pcbi.1009801] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 02/14/2022] [Accepted: 01/03/2022] [Indexed: 12/30/2022] Open
Abstract
Investigation of the diversity of malaria parasite antigens can help prioritize and validate them as vaccine candidates and identify the most common variants for inclusion in vaccine formulations. Studies of vaccine candidates of the most virulent human malaria parasite, Plasmodium falciparum, have focused on a handful of well-known antigens, while several others have never been studied. Here we examine the global diversity and population structure of leading vaccine candidate antigens of P. falciparum using the MalariaGEN Pf3K (version 5.1) resource, comprising more than 2600 genomes from 15 malaria endemic countries. A stringent variant calling pipeline was used to extract high quality antigen gene 'haplotypes' from the global dataset and a new R-package named VaxPack was used to streamline population genetic analyses. In addition, a newly developed algorithm that enables spatial averaging of selection pressure on 3D protein structures was applied to the dataset. We analysed the genes encoding 23 leading and novel candidate malaria vaccine antigens including csp, trap, eba175, ama1, rh5, and CelTOS. Our analysis shows that current malaria vaccine formulations are based on rare haplotypes and thus may have limited efficacy against natural parasite populations. High levels of diversity with evidence of balancing selection was detected for most of the erythrocytic and pre-erythrocytic antigens. Measures of natural selection were then mapped to 3D protein structures to predict targets of functional antibodies. For some antigens, geographical variation in the intensity and distribution of these signals on the 3D structure suggests adaptation to different human host or mosquito vector populations. This study provides an essential framework for the diversity of P. falciparum antigens to be considered in the design of the next generation of malaria vaccines.
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Ishizaki T, Asada M, Hakimi H, Chaiyawong N, Kegawa Y, Yahata K, Kaneko O. cAMP-dependent protein kinase regulates secretion of apical membrane antigen 1 (AMA1) in Plasmodium yoelii. Parasitol Int 2021; 85:102435. [PMID: 34390881 DOI: 10.1016/j.parint.2021.102435] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 08/06/2021] [Accepted: 08/06/2021] [Indexed: 12/18/2022]
Abstract
Malaria remains a heavy global burden on human health, and it is important to understand the molecular and cellular biology of the parasite to find targets for drug and vaccine development. The mouse malaria model is an essential tool to characterize the function of identified molecules; however, robust technologies for targeted gene deletions are still poorly developed for the widely used rodent malaria parasite, Plasmodium yoelii. To overcome this problem, we established a DiCre-loxP inducible knockout (iKO) system in P. yoelii, which showed more than 80% excision efficacy of the target locus and more than 90% reduction of locus transcripts 24 h (one cell cycle) after RAP administration. Using this developed system, cAMP-dependent protein kinase (PKAc) was inducibly disrupted and the phenotypes of the resulting PKAc-iKO parasites were analyzed. We found that PKAc-iKO parasites showed severe growth and erythrocyte invasion defects. We also found that disruption of PKAc impaired the secretion of AMA1 in P. yoelii, in contrast to a report showing no role of PKAc in AMA1 secretion in P. falciparum. This discrepancy may be related to the difference in the timing of AMA1 distribution to the merozoite surface, which occurs just after egress for P. falciparum, but after several minutes for P. yoelii. Secretions of PyEBL, Py235, and RON2 were not affected by the disruption of PKAc in P. yoelii. PyRON2 was already secreted to the merozoite surface immediately after merozoite egress, which is inconsistent with the current model that RON2 is injected into the erythrocyte cytosol. Further investigations are required to understand the role of RON2 exposed on the merozoite surface.
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Affiliation(s)
- Takahiro Ishizaki
- Program for Nurturing Global Leaders in Tropical and Emerging Communicable Diseases, Graduate school of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan; Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan; Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå University, Umeå 901 87, Sweden
| | - Masahito Asada
- Program for Nurturing Global Leaders in Tropical and Emerging Communicable Diseases, Graduate school of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan; Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan; National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11, Obihiro, Hokkaido 080-0834, Japan.
| | - Hassan Hakimi
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan; Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College station, TX 77843, USA.
| | - Nattawat Chaiyawong
- Program for Nurturing Global Leaders in Tropical and Emerging Communicable Diseases, Graduate school of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan; Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
| | - Yuto Kegawa
- Program for Nurturing Global Leaders in Tropical and Emerging Communicable Diseases, Graduate school of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan; Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan; Section on Integrative Biophysics, Eunice Kennedy Shriver National Institutes of Child Health and Human Development, National Institute of Health, 9000 Rockville Pike, Bethesda, Mary land 20892, USA
| | - Kazuhide Yahata
- Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan.
| | - Osamu Kaneko
- Program for Nurturing Global Leaders in Tropical and Emerging Communicable Diseases, Graduate school of Biomedical Sciences, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan; Department of Protozoology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan.
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Rittipornlertrak A, Nambooppha B, Muenthaisong A, Punyapornwithaya V, Tiwananthagorn S, Chung YT, Tuvshintulga B, Sivakumar T, Yokoyama N, Sthitmatee N. Structural and immunological characterization of an epitope within the PAN motif of ectodomain I in Babesia bovis apical membrane antigen 1 for vaccine development. PeerJ 2021; 9:e11765. [PMID: 34316404 PMCID: PMC8288113 DOI: 10.7717/peerj.11765] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 06/22/2021] [Indexed: 11/25/2022] Open
Abstract
Background Bovine babesiosis caused by Babesia bovis (B. bovis) has had a significant effect on the mobility and mortality rates of the cattle industry worldwide. Live-attenuated vaccines are currently being used in many endemic countries, but their wide use has been limited for a number of reasons. Although recombinant vaccines have been proposed as an alternative to live vaccines, such vaccines are not commercially available to date. Apical membrane antigen-1 (AMA-1) is one of the leading candidates in the development of a vaccine against diseases caused by apicomplexan parasite species. In Plasmodium falciparum (P. falciparum) AMA-1 (PfAMA-1), several antibodies against epitopes in the plasminogen, apple, and nematode (PAN) motif of PfAMA-1 domain I significantly inhibited parasite growth. Therefore, the purpose of this study was to predict an epitope from the PAN motif of domain I in the B. bovis AMA-1 (BbAMA-1) using a combination of linear and conformational B-cell epitope prediction software. The selected epitope was then bioinformatically analyzed, synthesized as a peptide (sBbAMA-1), and then used to immunize a rabbit. Subsequently, in vitro growth- and the invasion-inhibitory effects of the rabbit antiserum were immunologically characterized. Results Our results demonstrated that the predicted BbAMA-1 epitope was located on the surface-exposed α-helix of the PAN motif in domain I at the apex area between residues 181 and 230 with six polymorphic sites. Subsequently, sBbAMA-1 elicited antibodies capable of recognizing the native BbAMA-1 in immunoassays. Furthermore, anti-serum against sBbAMA-1 was immunologically evaluated for its growth- and invasion-inhibitory effects on B. bovis merozoites in vitro. Our results demonstrated that the rabbit anti-sBbAMA-1 serum at a dilution of 1:5 significantly inhibited (p < 0.05) the growth of B. bovis merozoites by approximately 50–70% on days 3 and 4 of cultivation, along with the invasion of merozoites by approximately 60% within 4 h of incubation when compared to the control groups. Conclusion Our results indicate that the epitope predicted from the PAN motif of BbAMA-1 domain I is neutralization-sensitive and may serve as a target antigen for vaccine development against bovine babesiosis caused by B. bovis.
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Affiliation(s)
| | - Boondarika Nambooppha
- Graduate School of Veterinary Sciences, Chiang Mai University, Muang, Chiang Mai, Thailand
| | - Anucha Muenthaisong
- Graduate School of Veterinary Sciences, Chiang Mai University, Muang, Chiang Mai, Thailand
| | - Veerasak Punyapornwithaya
- Department of Food Animal Clinic, Faculty of Veterinary Medicine, Chiang Mai University, Muang, Chiang Mai, Thailand
| | - Saruda Tiwananthagorn
- Department of Veterinary Bioscience and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Muang, Chiang Mai, Thailand
| | - Yang-Tsung Chung
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taichung, Taiwan
| | - Bumduuren Tuvshintulga
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Thillaiampalam Sivakumar
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Naoaki Yokoyama
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan
| | - Nattawooti Sthitmatee
- Department of Veterinary Bioscience and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University, Muang, Chiang Mai, Thailand
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8
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Biswas A, Raran-Kurussi S, Narayan A, Kar A, Chandra Mashurabad P, Bhattacharyya MK, Mandal K. Efficient refolding and functional characterization of PfAMA1(DI+DII) expressed in E. coli. Biochem Biophys Rep 2021; 26:100950. [PMID: 33665380 PMCID: PMC7907217 DOI: 10.1016/j.bbrep.2021.100950] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 01/18/2021] [Accepted: 02/04/2021] [Indexed: 11/30/2022] Open
Abstract
Apical membrane antigen 1 (AMA1) is a surface protein of Plasmodium sp. that plays a crucial role in forming moving junction (MJ) during the invasion of human red blood cells. The obligatory presence of AMA1 in the parasite lifecycle designates this protein as a potential vaccine candidate and an essential target for the development of novel peptide or protein therapeutics. However, due to multiple cysteine residues in the protein sequence, attaining the native fold with correct disulfide linkages during the refolding process after expression in bacteria has remained challenging for years. Although several approaches to obtain the refolded protein from bacterial expression have been reported previously, achieving high yield during refolding and proper functional validation of the expressed protein was lacking. We report here an improved method of refolding to obtain higher quantity of refolded protein. We have also validated the refolded protein's functional activity by evaluating the expressed AMA1 protein binding with a known inhibitory peptide, rhoptry neck protein 2 (RON2), using surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC). A simple yet effective protocol for P. falciparum AMA1 protein expression from E. coli. Highly reproducible and scalable refolding protocol. The modified refolding method uses a step-wise dialysis technique. Functional validation of the refolded protein shown by binding with PfRON2 ectodomain using SPR and ITC.
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Affiliation(s)
- Anamika Biswas
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 36/p Gopanpally, Hyderabad, Telangana 500046, India
| | - Sreejith Raran-Kurussi
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 36/p Gopanpally, Hyderabad, Telangana 500046, India
| | - Akash Narayan
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 36/p Gopanpally, Hyderabad, Telangana 500046, India
| | - Abhisek Kar
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 36/p Gopanpally, Hyderabad, Telangana 500046, India
| | - Purna Chandra Mashurabad
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, Telangana 500046, India
| | - Mrinal Kanti Bhattacharyya
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, Telangana 500046, India
| | - Kalyaneswar Mandal
- TIFR Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research Hyderabad, 36/p Gopanpally, Hyderabad, Telangana 500046, India
- Corresponding author.
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Arredondo SA, Schepis A, Reynolds L, Kappe SHI. Secretory Organelle Function in the Plasmodium Sporozoite. Trends Parasitol 2021; 37:651-663. [PMID: 33589364 DOI: 10.1016/j.pt.2021.01.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/20/2021] [Accepted: 01/20/2021] [Indexed: 12/14/2022]
Abstract
Plasmodium sporozoites exhibit a complex infection biology in the mosquito and mammalian hosts. The sporozoite apical secretory organelles, the micronemes and rhoptries, store protein mediators of parasite/host/vector interactions and must secrete them in a temporally and spatially well orchestrated manner. Micronemal proteins are critical for sporozoite motility throughout its journey from the mosquito midgut oocyst to the mammalian liver, and also for cell traversal (CT) and hepatocyte invasion. Rhoptry proteins, until recently thought to be only important for hepatocyte invasion, appear to also play an unexpected role in motility and in the interaction with mosquito tissue. Therefore, navigating the different microenvironments with secretion likely requires the sporozoite to have a more complex system of secretory organelles than previously appreciated.
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Affiliation(s)
- Silvia A Arredondo
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA 98109, USA
| | - Antonino Schepis
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA 98109, USA
| | - Laura Reynolds
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA 98109, USA
| | - Stefan H I Kappe
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA 98109, USA; Department of Pediatrics, University of Washington, Seattle, WA 98105, USA; Department of Global Health, University of Washington, Seattle, WA 98105, USA.
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10
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Hou N, Jiang N, Ma Y, Zou Y, Piao X, Liu S, Chen Q. Low-Complexity Repetitive Epitopes of Plasmodium falciparum Are Decoys for Humoural Immune Responses. Front Immunol 2020; 11:610. [PMID: 32351503 PMCID: PMC7174639 DOI: 10.3389/fimmu.2020.00610] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 03/17/2020] [Indexed: 01/18/2023] Open
Abstract
Induction of humoural immunity is critical for clinical protection against malaria. More than 100 malaria vaccine candidates have been investigated at different developmental stages, but with limited protection. One of the roadblocks constrains the development of malaria vaccines is the poor immunogenicity of the antigens. The objective of this study was to map the linear B-cell epitopes of the Plasmodium falciparum erythrocyte invasion-associated antigens with a purpose of understanding humoural responses and protection. We conducted a large-scale screen using overlapping peptide microarrays of 37 proteins from the P. falciparum parasite, most of which are invasion-associated antigens which have been tested in clinical settings as vaccine candidates, with sera from individuals with various infection episodes. Analysis of the epitome of the antigens revealed that the most immunogenic epitopes were predominantly located in the low-complexity regions of the proteins containing repetitive and/or glutamate-rich motifs in different sequence contexts. However, in vitro assay showed the antibodies specific for these epitopes did not show invasion inhibitory effect. These discoveries indicated that the low-complexity regions of the parasite proteins might drive immune responses away from functional domains, which may be an instructive finding for the rational design of vaccine candidates.
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Affiliation(s)
- Nan Hou
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Ning Jiang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China.,The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, Shenyang, China
| | - Yu Ma
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Yang Zou
- Beijing Key Laboratory for Research on Prevention and Treatment of Tropical Diseases, Beijing Tropical Medicine Research Institute, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Xianyu Piao
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Shuai Liu
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Qijun Chen
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.,Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China.,The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, Shenyang, China
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11
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Dans MG, Weiss GE, Wilson DW, Sleebs BE, Crabb BS, de Koning-Ward TF, Gilson PR. Screening the Medicines for Malaria Venture Pathogen Box for invasion and egress inhibitors of the blood stage of Plasmodium falciparum reveals several inhibitory compounds. Int J Parasitol 2020; 50:235-252. [PMID: 32135179 DOI: 10.1016/j.ijpara.2020.01.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 12/30/2019] [Accepted: 01/05/2020] [Indexed: 12/14/2022]
Abstract
With emerging resistance to frontline treatments, it is vital that new drugs are identified to target Plasmodium falciparum. One of the most critical processes during parasites asexual lifecycle is the invasion and subsequent egress of red blood cells (RBCs). Many unique parasite ligands, receptors and enzymes are employed during egress and invasion that are essential for parasite proliferation and survival, therefore making these processes druggable targets. To identify potential inhibitors of egress and invasion, we screened the Medicines for Malaria Venture Pathogen Box, a 400 compound library against neglected tropical diseases, including 125 with antimalarial activity. For this screen, we utilised transgenic parasites expressing a bioluminescent reporter, nanoluciferase (Nluc), to measure inhibition of parasite egress and invasion in the presence of the Pathogen Box compounds. At a concentration of 2 µM, we found 15 compounds that inhibited parasite egress by >40% and 24 invasion-specific compounds that inhibited invasion by >90%. We further characterised 11 of these inhibitors through cell-based assays and live cell microscopy, and found two compounds that inhibited merozoite maturation in schizonts, one compound that inhibited merozoite egress, one compound that directly inhibited parasite invasion and one compound that slowed down invasion and arrested ring formation. The remaining compounds were general growth inhibitors that acted during the egress and invasion phase of the cell cycle. We found the sulfonylpiperazine, MMV020291, to be the most invasion-specific inhibitor, blocking successful merozoite internalisation within human RBCs and having no substantial effect on other stages of the cell cycle. This has significant implications for the possible development of an invasion-specific inhibitor as an antimalarial in a combination based therapy, in addition to being a useful tool for studying the biology of the invading parasite.
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Affiliation(s)
- Madeline G Dans
- Burnet Institute, Melbourne, Victoria 3004, Australia; School of Medicine, Deakin University, Waurn Ponds, Victoria 3216, Australia.
| | - Greta E Weiss
- Burnet Institute, Melbourne, Victoria 3004, Australia
| | - Danny W Wilson
- Research Centre for Infectious Diseases, The University of Adelaide, Adelaide, South Australia 5005, Australia; Burnet Institute, Melbourne, Victoria 3004, Australia
| | - Brad E Sleebs
- Walter and Eliza Hall Institute, Parkville, Victoria 3052, Australia; The University of Melbourne, Parkville, Victoria 3010, Australia
| | - Brendan S Crabb
- Burnet Institute, Melbourne, Victoria 3004, Australia; The University of Melbourne, Parkville, Victoria 3010, Australia
| | | | - Paul R Gilson
- Burnet Institute, Melbourne, Victoria 3004, Australia.
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12
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Helton LG, Kennedy EJ. Targeting Plasmodium with constrained peptides and peptidomimetics. IUBMB Life 2020; 72:1103-1114. [PMID: 32037730 DOI: 10.1002/iub.2244] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 01/24/2020] [Indexed: 01/04/2023]
Abstract
Malaria remains a worldwide health concern with an estimated quarter of a billion people infected and nearly half a million deaths annually. Malaria is caused by a parasite infection from Plasmodium strains which are transmitted from mosquitoes into the human host. Although several small molecule inhibitors have been found to target the early stages of transmission and prevent parasite proliferation, multiple drug resistant parasite strains have emerged and drug resistance remains a major hurdle. As an alternative to small molecule inhibition, several peptide-based therapeutics have been explored for their potential as antimalarial compounds. Chemically constrained peptides or peptidomimetics were developed to target large binding interfaces of parasite-based proteins that have historically been difficult to selectively inhibit using small molecules. Here, we review ongoing research aimed at developing constrained peptides targeting protein-protein interactions pertinent to malaria pathogenesis. These targets include Falcipain-2, the J domain of CDPK1, myosin A tail domain interacting protein, the PKA signaling pathway, and an unclear signaling pathway involving angiotensin-derived peptides. Diverse synthetic methods were also used for each target. Merging parasite biology with synthetic strategies may provide new opportunities to develop alternative methods for uncovering novel antimalarials and may offer an alternate source for targeting drug-resistant parasite strains.
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Affiliation(s)
- Leah G Helton
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, Georgia
| | - Eileen J Kennedy
- Department of Pharmaceutical and Biomedical Sciences, College of Pharmacy, University of Georgia, Athens, Georgia
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13
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Burns AL, Dans MG, Balbin JM, de Koning-Ward TF, Gilson PR, Beeson JG, Boyle MJ, Wilson DW. Targeting malaria parasite invasion of red blood cells as an antimalarial strategy. FEMS Microbiol Rev 2019; 43:223-238. [PMID: 30753425 PMCID: PMC6524681 DOI: 10.1093/femsre/fuz005] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2018] [Accepted: 02/11/2019] [Indexed: 12/20/2022] Open
Abstract
Plasmodium spp. parasites that cause malaria disease remain a significant global-health burden. With the spread of parasites resistant to artemisinin combination therapies in Southeast Asia, there is a growing need to develop new antimalarials with novel targets. Invasion of the red blood cell by Plasmodium merozoites is essential for parasite survival and proliferation, thus representing an attractive target for therapeutic development. Red blood cell invasion requires a co-ordinated series of protein/protein interactions, protease cleavage events, intracellular signals, organelle release and engagement of an actin-myosin motor, which provide many potential targets for drug development. As these steps occur in the bloodstream, they are directly susceptible and exposed to drugs. A number of invasion inhibitors against a diverse range of parasite proteins involved in these different processes of invasion have been identified, with several showing potential to be optimised for improved drug-like properties. In this review, we discuss red blood cell invasion as a drug target and highlight a number of approaches for developing antimalarials with invasion inhibitory activity to use in future combination therapies.
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Affiliation(s)
- Amy L Burns
- Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, Adelaide, Australia 5005
| | - Madeline G Dans
- Burnet Institute, Melbourne, Victoria, Australia 3004.,Deakin University, School of Medicine, Waurn Ponds, Victoria, Australia 3216
| | - Juan M Balbin
- Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, Adelaide, Australia 5005
| | | | - Paul R Gilson
- Burnet Institute, Melbourne, Victoria, Australia 3004
| | - James G Beeson
- Burnet Institute, Melbourne, Victoria, Australia 3004.,Central Clinical School and Department of Microbiology, Monash University 3004.,Department of Medicine, University of Melbourne, Australia 3052
| | - Michelle J Boyle
- Burnet Institute, Melbourne, Victoria, Australia 3004.,QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia 4006
| | - Danny W Wilson
- Research Centre for Infectious Diseases, School of Biological Sciences, University of Adelaide, Adelaide, Australia 5005.,Burnet Institute, Melbourne, Victoria, Australia 3004
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14
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Wichers JS, Scholz JAM, Strauss J, Witt S, Lill A, Ehnold LI, Neupert N, Liffner B, Lühken R, Petter M, Lorenzen S, Wilson DW, Löw C, Lavazec C, Bruchhaus I, Tannich E, Gilberger TW, Bachmann A. Dissecting the Gene Expression, Localization, Membrane Topology, and Function of the Plasmodium falciparum STEVOR Protein Family. mBio 2019; 10:e01500-19. [PMID: 31363031 PMCID: PMC6667621 DOI: 10.1128/mbio.01500-19] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 07/02/2019] [Indexed: 01/22/2023] Open
Abstract
During its intraerythrocytic development, the malaria parasite Plasmodium falciparum exposes variant surface antigens (VSAs) on infected erythrocytes to establish and maintain an infection. One family of small VSAs is the polymorphic STEVOR proteins, which are marked for export to the host cell surface through their PEXEL signal peptide. Interestingly, some STEVORs have also been reported to localize to the parasite plasma membrane and apical organelles, pointing toward a putative function in host cell egress or invasion. Using deep RNA sequencing analysis, we characterized P. falciparumstevor gene expression across the intraerythrocytic development cycle, including free merozoites, in detail and used the resulting stevor expression profiles for hierarchical clustering. We found that most stevor genes show biphasic expression oscillation, with maximum expression during trophozoite stages and a second peak in late schizonts. We selected four STEVOR variants, confirmed the expected export of these proteins to the host cell membrane, and tracked them to a secondary location, either to the parasite plasma membrane or the secretory organelles of merozoites in late schizont stages. We investigated the function of a particular STEVOR that showed rhoptry localization and demonstrated its role at the parasite-host interface during host cell invasion by specific antisera and targeted gene disruption. Experimentally determined membrane topology of this STEVOR revealed a single transmembrane domain exposing the semiconserved as well as variable protein regions to the cell surface.IMPORTANCE Malaria claims about half a million lives each year. Plasmodium falciparum, the causative agent of the most severe form of the disease, uses proteins that are translocated to the surface of infected erythrocytes for immune evasion. To circumvent the detection of these gene products by the immune system, the parasite evolved a complex strategy that includes gene duplications and elaborate sequence polymorphism. STEVORs are one family of these variant surface antigens and are encoded by about 40 genes. Using deep RNA sequencing of blood-stage parasites, including free merozoites, we first established stevor expression of the cultured isolate and compared it with published transcriptomes. We reveal a biphasic expression of most stevor genes and confirm this for individual STEVORs at the protein level. The membrane topology of a rhoptry-associated variant was experimentally elucidated and linked to host cell invasion, underlining the importance of this multifunctional protein family for parasite proliferation.
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Affiliation(s)
- J Stephan Wichers
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany
| | | | - Jan Strauss
- Centre for Structural Systems Biology (CSSB), DESY, and European Molecular Biology Laboratory Hamburg, Hamburg, Germany
| | - Susanne Witt
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Andrés Lill
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany
| | | | | | - Benjamin Liffner
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, Australia
| | - Renke Lühken
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Michaela Petter
- Institute of Microbiology, University Hospital Erlangen, Erlangen, Germany
| | - Stephan Lorenzen
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Danny W Wilson
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, Australia
- Burnet Institute, Melbourne, Victoria, Australia
| | - Christian Löw
- Centre for Structural Systems Biology (CSSB), DESY, and European Molecular Biology Laboratory Hamburg, Hamburg, Germany
| | | | - Iris Bruchhaus
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Egbert Tannich
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
| | - Tim W Gilberger
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany
- Biology Department, University of Hamburg, Hamburg, Germany
| | - Anna Bachmann
- Bernhard Nocht Institute for Tropical Medicine, Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany
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15
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A suite of kinetically superior AEP ligases can cyclise an intrinsically disordered protein. Sci Rep 2019; 9:10820. [PMID: 31346249 PMCID: PMC6658665 DOI: 10.1038/s41598-019-47273-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 07/11/2019] [Indexed: 11/29/2022] Open
Abstract
Asparaginyl endopeptidases (AEPs) are a class of enzymes commonly associated with proteolysis in the maturation of seed storage proteins. However, a subset of AEPs work preferentially as peptide ligases, coupling release of a leaving group to formation of a new peptide bond. These “ligase-type” AEPs require only short recognition motifs to ligate a range of targets, making them useful tools in peptide and protein engineering for cyclisation of peptides or ligation of separate peptides into larger products. Here we report the recombinant expression, ligase activity and cyclisation kinetics of three new AEPs from the cyclotide producing plant Oldenlandia affinis with superior kinetics to the prototypical recombinant AEP ligase OaAEP1b. These AEPs work preferentially as ligases at both acidic and neutral pH and we term them “canonical AEP ligases” to distinguish them from other AEPs where activity preferences shift according to pH. We show that these ligases intrinsically favour ligation over hydrolysis, are highly efficient at cyclising two unrelated peptides and are compatible with organic co-solvents. Finally, we demonstrate the broad scope of recombinant AEPs in biotechnology by the backbone cyclisation of an intrinsically disordered protein, the 25 kDa malarial vaccine candidate Plasmodium falciparum merozoite surface protein 2 (MSP2).
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16
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Akter M, Drinkwater N, Devine SM, Drew SC, Krishnarjuna B, Debono CO, Wang G, Scanlon MJ, Scammells PJ, McGowan S, MacRaild CA, Norton RS. Identification of the Binding Site of Apical Membrane Antigen 1 (AMA1) Inhibitors Using a Paramagnetic Probe. ChemMedChem 2019; 14:603-612. [PMID: 30653832 DOI: 10.1002/cmdc.201800802] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Indexed: 11/08/2022]
Abstract
Apical membrane antigen 1 (AMA1) is essential for the invasion of host cells by malaria parasites. Several small-molecule ligands have been shown to bind to a conserved hydrophobic cleft in Plasmodium falciparum AMA1. However, a lack of detailed structural information on the binding pose of these molecules has hindered their further optimisation as inhibitors. We have developed a spin-labelled peptide based on RON2, the native binding partner of AMA1, to probe the binding sites of compounds on PfAMA1. The crystal structure of this peptide bound to PfAMA1 shows that it binds at one end of the hydrophobic groove, leaving much of the binding site unoccupied and allowing fragment hits to bind without interference. In paramagnetic relaxation enhancement (PRE)-based NMR screening, the 1 H relaxation rates of compounds binding close to the probe were enhanced. Compounds experienced different degrees of PRE as a result of their different orientations relative to the spin label while bound to AMA1. Thus, PRE-derived distance constraints can be used to identify binding sites and guide further hit optimisation.
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Affiliation(s)
- Mansura Akter
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia
| | - Nyssa Drinkwater
- Biomedicine Discovery Institute, Department of Microbiology, Monash University, Wellington Road, Clayton, Victoria, 3800, Australia
| | - Shane M Devine
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia
| | - Simon C Drew
- Department of Medicine (Royal Melbourne Hospital), The University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Bankala Krishnarjuna
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia
| | - Cael O Debono
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia
| | - Geqing Wang
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia
| | - Martin J Scanlon
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia
| | - Peter J Scammells
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia
| | - Sheena McGowan
- Biomedicine Discovery Institute, Department of Microbiology, Monash University, Wellington Road, Clayton, Victoria, 3800, Australia
| | - Christopher A MacRaild
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia
| | - Raymond S Norton
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, Victoria, 3052, Australia
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17
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Siau A, Huang X, Loh HP, Zhang N, Meng W, Sze SK, Renia L, Preiser P. Immunomic Identification of Malaria Antigens Associated With Protection in Mice. Mol Cell Proteomics 2019; 18:837-853. [PMID: 30718293 DOI: 10.1074/mcp.ra118.000997] [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: 07/30/2018] [Revised: 01/22/2019] [Indexed: 11/06/2022] Open
Abstract
Efforts to develop vaccines against malaria represent a major research target. The observations that 1) sterile protection can be obtained when the host is exposed to live parasites and 2) the immunity against blood stage parasite is principally mediated by protective antibodies suggest that a protective vaccine is feasible. However, only a small number of proteins have been investigated so far and most of the Plasmodium proteome has yet to be explored. To date, only few immunodominant antigens have emerged for testing in clinical trials but no formulation has led to substantial protection in humans. The nature of parasite molecules associated with protection remains elusive. Here, immunomic screening of mice immune sera with different protection efficiencies against the whole parasite proteome allowed us to identify a large repertoire of antigens validated by screening a library expressing antigens. The calculation of weighted scores reflecting the likelihood of protection of each antigen using five predictive criteria derived from immunomic and proteomic data sets, highlighted a priority list of protective antigens. Altogether, the approach sheds light on conserved antigens across Plasmodium that are amenable to targeting by the host immune system upon merozoite invasion and blood stage development. Most of these antigens have preliminary protection data but have not been widely considered as candidate for vaccine trials, opening new perspectives that overcome the limited choice of immunodominant, poorly protective vaccines currently being the focus of malaria vaccine researches.
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Affiliation(s)
- Anthony Siau
- From the ‡Nanyang Technological University, School of Biological Sciences, Singapore;.
| | - Ximei Huang
- From the ‡Nanyang Technological University, School of Biological Sciences, Singapore;; From the ‡Nanyang Technological University, School of Biological Sciences, Singapore
| | - Han Ping Loh
- From the ‡Nanyang Technological University, School of Biological Sciences, Singapore;; From the ‡Nanyang Technological University, School of Biological Sciences, Singapore
| | - Neng Zhang
- From the ‡Nanyang Technological University, School of Biological Sciences, Singapore
| | - Wei Meng
- From the ‡Nanyang Technological University, School of Biological Sciences, Singapore
| | - Siu Kwan Sze
- From the ‡Nanyang Technological University, School of Biological Sciences, Singapore
| | - Laurent Renia
- §Singapore Immunology Network (SIgN), A*STAR, Biopolis, Singapore
| | - Peter Preiser
- From the ‡Nanyang Technological University, School of Biological Sciences, Singapore;.
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18
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In Vitro and In Planta Cyclization of Target Peptides Using an Asparaginyl Endopeptidase from Oldenlandia affinis. Methods Mol Biol 2019; 2012:211-235. [PMID: 31161511 DOI: 10.1007/978-1-4939-9546-2_12] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cyclization of the peptide backbone by connecting the N- and C-terminus can endow target peptides with favorable properties, such as increased stability or potential oral bioavailability. However, there are few tools available for carrying out this modification. Asparaginyl endopeptidases (AEPs) are a class of enzymes that typically work as proteases, but a subset is highly efficient at cyclization of the peptide backbone. In this chapter we describe how to utilize a cyclizing AEP (OaAEP1b) to produce backbone-cyclized peptides both in planta and in vitro. Using the in planta method, OaAEP1b and the target precursor peptide are coexpressed in the leaves of the model plant Nicotiana benthamiana, and cyclization of the target peptide occurs in planta. Using the in vitro method, purified recombinant OaAEP1b produced in bacteria is used to cyclize the target precursor peptide in vitro.
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19
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Abstract
Humoral immune responses against the malaria parasite are an important component of a protective immune response. Antibodies are often directed towards conformational epitopes, and the native structure of the antigenic region is usually critical for antibody recognition. We examined the structural features of various Plasmodium antigens that may impact on epitope location, by performing a comprehensive analysis of known and modelled structures from P. falciparum. Examining the location of known polymorphisms over all available structures, we observed a strong propensity for polymorphic residues to be exposed on the surface and to occur in particular secondary structure segments such as hydrogen-bonded turns. We also utilised established prediction algorithms for B-cell epitopes and MHC class II binding peptides, examining predicted epitopes in relation to known polymorphic sites within structured regions. Finally, we used the available structures to examine polymorphic hotspots and Tajima's D values using a spatial averaging approach. We identified a region of PfAMA1 involving both domains II and III under a high degree of balancing selection relative to the rest of the protein. In summary, we developed general methods for examining how sequence-based features relate to one another in three-dimensional space and applied these methods to key P. falciparum antigens.
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20
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Vetrivel U, Nagarajan H, Thirumudi I. Design of inhibitory peptide targeting
Toxoplasma gondii
RON4‐human β‐tubulin interactions by implementing structural bioinformatics methods. J Cell Biochem 2017; 119:3236-3246. [DOI: 10.1002/jcb.26480] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 10/31/2017] [Indexed: 12/12/2022]
Affiliation(s)
- Umashankar Vetrivel
- Centre for Bioinformatics, Kamalnayan Bajaj Institute for Research in Vision and OphthalmologyVision Research Foundation, Sankara NethralayaChennaiTamil NaduIndia
| | - Hemavathy Nagarajan
- Centre for Bioinformatics, Kamalnayan Bajaj Institute for Research in Vision and OphthalmologyVision Research Foundation, Sankara NethralayaChennaiTamil NaduIndia
| | - Indhuja Thirumudi
- Centre for Bioinformatics, Kamalnayan Bajaj Institute for Research in Vision and OphthalmologyVision Research Foundation, Sankara NethralayaChennaiTamil NaduIndia
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21
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Chew CH, Lim YAL, Chua KH. Heterologous expression of Plasmodium vivax apical membrane antigen 1 (PvAMA1) for binding peptide selection. PeerJ 2017; 5:e3794. [PMID: 28929019 PMCID: PMC5600724 DOI: 10.7717/peerj.3794] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 08/19/2017] [Indexed: 12/14/2022] Open
Abstract
Background Plasmodium is an obligate intracellular parasite. Apical membrane antigen 1 (AMA1) is the most prominent and well characterized malarial surface antigen that is essential for parasite-host cell invasion, i.e., for sporozoite to invade and replicate within hepatocytes in the liver stage and merozoite to penetrate and replicate within erythrocytes in the blood stage. AMA1 has long served as a potent antimalarial drug target and is a pivotal vaccine candidate. A good understanding of the structure and molecular function of this Plasmodium protein, particularly its involvement in host-cell adhesion and invasion, is of great interest and hence it offers an attractive target for the development of novel therapeutics. The present study aims to heterologous express recombinant Plasmodium AMA1 ectodomain of P. vivax (rPvAMA1) for the selection of binding peptides. Methods The rPvAMA1 protein was heterologous expressed using a tag-free Profinity eXactTM system and codon optimized BL21-Codon Plus (DE3)-RIL Escherichia coli strain and further refolded by dialysis for renaturation. Binding peptides toward refolded rPvAMA1 were panned using a Ph.D.-12 random phage display library. Results The rPvAMA1 was successfully expressed and refolded with three phage-displayed dodecapeptides designated as PdV1 (DLTFTVNPLSKA), PdV2 (WHWSWWNPNQLT), and PdV3 (TSVSYINNRHNL) with affinity towards rPvAMA1 identified. All of them exhibited positive binding signal to rPvAMA1 in both direct phage assays, i.e., phage ELISA binding assay and Western blot binding assay. Discussion Phage display technology enables the mapping of protein-protein interactions based on a simple principle that a library of phage particles displaying peptides is used and the phage clones that bind to the target protein are selected and identified. The binding sites of each selected peptides toward PvAMA1 (Protein Data Bank, PDB ID: 1W8K) were in silico predicted using CABS-dock web server. In this case, the binding peptides provide a valuable starting point for the development of peptidomimetic as antimalarial antagonists directed at PvAMA1.
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Affiliation(s)
- Ching Hoong Chew
- School of Biomedicine, Faculty of Health Sciences, Universiti Sultan Zainal Abidin, Kuala Nerus, Terengganu, Malaysia
| | - Yvonne Ai Lian Lim
- Department of Parasitology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Kek Heng Chua
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
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22
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Vulliez-Le Normand B, Saul FA, Hoos S, Faber BW, Bentley GA. Cross-reactivity between apical membrane antgen 1 and rhoptry neck protein 2 in P. vivax and P. falciparum: A structural and binding study. PLoS One 2017; 12:e0183198. [PMID: 28817634 PMCID: PMC5560645 DOI: 10.1371/journal.pone.0183198] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 07/31/2017] [Indexed: 02/03/2023] Open
Abstract
Malaria, a disease endemic in many tropical and subtropical regions, is caused by infection of the erythrocyte by the apicomplexan parasite Plasmodium. Host-cell invasion is a complex process but two Plasmodium proteins, Apical Membrane Antigen 1 (AMA1) and the Rhoptry Neck protein complex (RON), play a key role. AMA1, present on the surface of the parasite, binds tightly to the RON2 component of the RON protein complex, which is inserted into the erythrocyte membrane during invasion. Blocking the AMA1-RON2 interaction with antibodies or peptides inhibits invasion, underlining its importance in the Plasmodium life cycle and as a target for therapeutic strategies. We describe the crystal structure of the complex formed between AMA1 from P. vivax (PvAMA1) and a peptide derived from the externally exposed region of P. vivax RON2 (PvRON2sp1), and of the heterocomplex formed between P. falciparum AMA1 (PfAMA1) and PvRON2sp1. Binding studies show that the affinity of PvRON2sp1 for PvAMA1 is weaker than that previously reported for the PfRON2sp1-PfAMA1 association. Moreover, while PvRON2sp1 shows strong cross-reactivity with PfAMA1, PfRON2sp1 displays no detectable interaction with PvAMA1. The structures show that the equivalent residues PvRON2-Thr2055 and PfRON2-Arg2041 largely account for this pattern of reactivity.
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Affiliation(s)
- Brigitte Vulliez-Le Normand
- Institut Pasteur, Unité de Microbiologie Structurale, Département de Biologie Structurale et Chimie, Centre National de la Recherche Scientifique, UMR 3528, Université Paris Diderot, Sorbonne Paris Cité, Microbiologie Structurale, Paris, France
| | - Frederick A. Saul
- Institut Pasteur, Plate-forme de Cristallographie, Département de Biologie Structurale et Chimie, Centre National de la Recherche Scientifique UMR 3528, Paris, France
| | - Sylviane Hoos
- Institut Pasteur, Plate-Forme de Biophysique Moléculaire, Département de Biologie Structurale et Chimie, Centre National de la Recherche Scientifique UMR 3528, Paris, France
| | - Bart W. Faber
- Department of Parasitology, Biomedical Primate Research Centre, Rijswijk, The Netherlands
| | - Graham A. Bentley
- Institut Pasteur, Unité d’Immunologie Structurale, Département de Biologie Structurale et Chimie, Centre National de la Recherche Scientifique, URA 2185, Paris, France
- * E-mail:
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23
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Yang ASP, Lopaticki S, O'Neill MT, Erickson SM, Douglas DN, Kneteman NM, Boddey JA. AMA1 and MAEBL are important for Plasmodium falciparum sporozoite infection of the liver. Cell Microbiol 2017; 19. [PMID: 28371168 DOI: 10.1111/cmi.12745] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 03/23/2017] [Accepted: 03/28/2017] [Indexed: 12/20/2022]
Abstract
The malaria sporozoite injected by a mosquito migrates to the liver by traversing host cells. The sporozoite also traverses hepatocytes before invading a terminal hepatocyte and developing into exoerythrocytic forms. Hepatocyte infection is critical for parasite development into merozoites that infect erythrocytes, and the sporozoite is thus an important target for antimalarial intervention. Here, we investigated two abundant sporozoite proteins of the most virulent malaria parasite Plasmodium falciparum and show that they play important roles during cell traversal and invasion of human hepatocytes. Incubation of P. falciparum sporozoites with R1 peptide, an inhibitor of apical merozoite antigen 1 (AMA1) that blocks merozoite invasion of erythrocytes, strongly reduced cell traversal activity. Consistent with its inhibitory effect on merozoites, R1 peptide also reduced sporozoite entry into human hepatocytes. The strong but incomplete inhibition prompted us to study the AMA-like protein, merozoite apical erythrocyte-binding ligand (MAEBL). MAEBL-deficient P. falciparum sporozoites were severely attenuated for cell traversal activity and hepatocyte entry in vitro and for liver infection in humanized chimeric liver mice. This study shows that AMA1 and MAEBL are important for P. falciparum sporozoites to perform typical functions necessary for infection of human hepatocytes. These two proteins therefore have important roles during infection at distinct points in the life cycle, including the blood, mosquito, and liver stages.
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Affiliation(s)
- Annie S P Yang
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Sash Lopaticki
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - Matthew T O'Neill
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - Sara M Erickson
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
| | - Donna N Douglas
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Norman M Kneteman
- Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Justin A Boddey
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Department of Medical Biology, The University of Melbourne, Parkville, Victoria, Australia
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24
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Aniweh Y, Gao X, Hao P, Meng W, Lai SK, Gunalan K, Chu TT, Sinha A, Lescar J, Chandramohanadas R, Li HY, Sze SK, Preiser PR. P. falciparum RH5-Basigin interaction induces changes in the cytoskeleton of the host RBC. Cell Microbiol 2017; 19. [PMID: 28409866 DOI: 10.1111/cmi.12747] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 04/06/2017] [Accepted: 04/07/2017] [Indexed: 11/26/2022]
Abstract
The successful invasion of Plasmodium is an essential step in their life cycle. The parasite reticulocyte-binding protein homologues (RHs) and erythrocyte-binding like proteins are two families involved in the invasion leading to merozoite-red blood cell (RBC) junction formation. Ca2+ signaling has been shown to play a critical role in the invasion. RHs have been linked to Ca2+ signaling, which triggers the erythrocyte-binding like proteins release ahead of junction formation, consistent with RHs performing an initial sensing function in identifying suitable RBCs. RH5, the only essential RHs, is a highly promising vaccine candidate. RH5-basigin interaction is essential for merozoite invasion and also important in determining host tropism. Here, we show that RH5 has a distinct function from the other RHs. We show that RH5-Basigin interaction on its own triggers a Ca2+ signal in the RBC resulting in changes in RBC cytoskeletal proteins phosphorylation and overall alterations in RBC cytoskeleton architecture. Antibodies targeting RH5 that block the signal prevent invasion before junction formation consistent with the Ca2+ signal in the RBC leading to rearrangement of the cytoskeleton required for invasion. This work provides the first time a functional context for the essential role of RH5 and will now open up new avenues to target merozoite invasion.
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Affiliation(s)
- Yaw Aniweh
- Division of Molecular Genetics and Cell biology, Nanyang Technological University, Singapore
| | - Xiaohong Gao
- Division of Molecular Genetics and Cell biology, Nanyang Technological University, Singapore
| | - Piliang Hao
- Division of Structural Biology and Biochemistry, School of Biological Sciences, Nanyang Technological University, Singapore
| | - Wei Meng
- Division of Structural Biology and Biochemistry, School of Biological Sciences, Nanyang Technological University, Singapore
| | - Soak Kuan Lai
- Division of Molecular Genetics and Cell biology, Nanyang Technological University, Singapore
| | - Karthigayan Gunalan
- Division of Molecular Genetics and Cell biology, Nanyang Technological University, Singapore
| | - Trang T Chu
- Pillar of Engineering Product Development, Singapore University of Technology and Design (SUTD), Singapore
| | - Ameya Sinha
- Division of Molecular Genetics and Cell biology, Nanyang Technological University, Singapore.,Pillar of Engineering Product Development, Singapore University of Technology and Design (SUTD), Singapore
| | - Julien Lescar
- Division of Structural Biology and Biochemistry, School of Biological Sciences, Nanyang Technological University, Singapore
| | - Rajesh Chandramohanadas
- Pillar of Engineering Product Development, Singapore University of Technology and Design (SUTD), Singapore
| | - Hoi Yeung Li
- Division of Molecular Genetics and Cell biology, Nanyang Technological University, Singapore
| | - Siu Kwan Sze
- Division of Structural Biology and Biochemistry, School of Biological Sciences, Nanyang Technological University, Singapore
| | - Peter R Preiser
- Division of Molecular Genetics and Cell biology, Nanyang Technological University, Singapore
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25
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Devine SM, MacRaild CA, Norton RS, Scammells PJ. Antimalarial drug discovery targeting apical membrane antigen 1. MEDCHEMCOMM 2017; 8:13-20. [PMID: 30108688 PMCID: PMC6072474 DOI: 10.1039/c6md00495d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 10/27/2016] [Indexed: 01/06/2023]
Abstract
Malaria continues to frustrate humanity's attempts to eradicate this deadly disease. Although gains have been made over the last 15 years, drug resistance to malaria continues to be a major concern. The lack of new antimalarials with novel mechanisms of action continues to challenge the scientific community to find innovative targets to combat this persistent disease. One such target, apical membrane antigen 1 (AMA1), is an essential protein that helps the parasite invade host erythrocytes. Recently, a number of efforts have focused on the druggability of this target, aiming to block the interactions of AMA1 that mediate invasion of host cells. This review covers recent progress in drug discovery targeting this crucial protein-protein interaction in malaria.
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Affiliation(s)
- Shane M Devine
- Medicinal Chemistry , Monash Institute of Pharmaceutical Sciences , Monash University , Parkville , VIC 3052 , Australia . ;
| | - Christopher A MacRaild
- Medicinal Chemistry , Monash Institute of Pharmaceutical Sciences , Monash University , Parkville , VIC 3052 , Australia . ;
| | - Raymond S Norton
- Medicinal Chemistry , Monash Institute of Pharmaceutical Sciences , Monash University , Parkville , VIC 3052 , Australia . ;
| | - Peter J Scammells
- Medicinal Chemistry , Monash Institute of Pharmaceutical Sciences , Monash University , Parkville , VIC 3052 , Australia . ;
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26
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Hierarchical phosphorylation of apical membrane antigen 1 is required for efficient red blood cell invasion by malaria parasites. Sci Rep 2016; 6:34479. [PMID: 27698395 PMCID: PMC5048298 DOI: 10.1038/srep34479] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 09/08/2016] [Indexed: 12/03/2022] Open
Abstract
Central to the pathogenesis of malaria is the proliferation of Plasmodium falciparum parasites within human erythrocytes. Parasites invade erythrocytes via a coordinated sequence of receptor-ligand interactions between the parasite and host cell. One key ligand, Apical Membrane Antigen 1 (AMA1), is a leading blood-stage vaccine and previous work indicates that phosphorylation of its cytoplasmic domain (CPD) is important to its function during invasion. Here we investigate the significance of each of the six available phospho-sites in the CPD. We confirm that the cyclic AMP/protein kinase A (PKA) signalling pathway elicits a phospho-priming step upon serine 610 (S610), which enables subsequent phosphorylation in vitro of a conserved, downstream threonine residue (T613) by glycogen synthase kinase 3 (GSK3). Both phosphorylation steps are required for AMA1 to function efficiently during invasion. This provides the first evidence that the functions of key invasion ligands of the malaria parasite are regulated by sequential phosphorylation steps.
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27
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Wang G, Drinkwater N, Drew DR, MacRaild CA, Chalmers DK, Mohanty B, Lim SS, Anders RF, Beeson JG, Thompson PE, McGowan S, Simpson JS, Norton RS, Scanlon MJ. Structure–Activity Studies of β-Hairpin Peptide Inhibitors of the Plasmodium falciparum AMA1–RON2 Interaction. J Mol Biol 2016; 428:3986-3998. [DOI: 10.1016/j.jmb.2016.07.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2016] [Revised: 06/25/2016] [Accepted: 07/04/2016] [Indexed: 12/01/2022]
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28
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Norton RS, Leung EWW, Chandrashekaran IR, MacRaild CA. Applications of (19)F-NMR in Fragment-Based Drug Discovery. Molecules 2016; 21:molecules21070860. [PMID: 27438818 PMCID: PMC6273323 DOI: 10.3390/molecules21070860] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 06/21/2016] [Accepted: 06/21/2016] [Indexed: 11/16/2022] Open
Abstract
(19)F-NMR has proved to be a valuable tool in fragment-based drug discovery. Its applications include screening libraries of fluorinated fragments, assessing competition among elaborated fragments and identifying the binding poses of promising hits. By observing fluorine in both the ligand and the target protein, useful information can be obtained on not only the binding pose but also the dynamics of ligand-protein interactions. These applications of (19)F-NMR will be illustrated in this review with studies from our fragment-based drug discovery campaigns against protein targets in parasitic and infectious diseases.
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Affiliation(s)
- Raymond S Norton
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Australia.
| | - Eleanor W W Leung
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Australia.
| | - Indu R Chandrashekaran
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Australia.
| | - Christopher A MacRaild
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville 3052, Australia.
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29
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Absalon S, Robbins JA, Dvorin JD. An essential malaria protein defines the architecture of blood-stage and transmission-stage parasites. Nat Commun 2016; 7:11449. [PMID: 27121004 PMCID: PMC4853479 DOI: 10.1038/ncomms11449] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 03/29/2016] [Indexed: 11/30/2022] Open
Abstract
Blood-stage replication of the human malaria parasite Plasmodium falciparum occurs via schizogony, wherein daughter parasites are formed by a specialized cytokinesis known as segmentation. Here we identify a parasite protein, which we name P. falciparum Merozoite Organizing Protein (PfMOP), as essential for cytokinesis of blood-stage parasites. We show that, following PfMOP knockdown, parasites undergo incomplete segmentation resulting in a residual agglomerate of partially divided cells. While organelles develop normally, the structural scaffold of daughter parasites, the inner membrane complex (IMC), fails to form in this agglomerate causing flawed segmentation. In PfMOP-deficient gametocytes, the IMC formation defect causes maturation arrest with aberrant morphology and death. Our results provide insight into the mechanisms of replication and maturation of malaria parasites. Blood-stage malaria parasites replicate through a specialised type of cell division known as schizogony. Here, Absalon et al. identify a parasite protein that is essential during schizogony for cytokinesis and formation of the inner membrane complex, the structural scaffold of daughter parasites.
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Affiliation(s)
- Sabrina Absalon
- Division of Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115, USA
| | - Jonathan A Robbins
- Division of Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Division of Infectious Diseases, Massachusetts General Hospital/Brigham and Women's Hospital, Boston, Massachusetts 02115, USA
| | - Jeffrey D Dvorin
- Division of Infectious Diseases, Boston Children's Hospital, Boston, Massachusetts 02115, USA.,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts 02115, USA
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30
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Weiss GE, Crabb BS, Gilson PR. Overlaying Molecular and Temporal Aspects of Malaria Parasite Invasion. Trends Parasitol 2016; 32:284-295. [DOI: 10.1016/j.pt.2015.12.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 12/02/2015] [Accepted: 12/10/2015] [Indexed: 12/31/2022]
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31
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Lin CS, Uboldi AD, Epp C, Bujard H, Tsuboi T, Czabotar PE, Cowman AF. Multiple Plasmodium falciparum Merozoite Surface Protein 1 Complexes Mediate Merozoite Binding to Human Erythrocytes. J Biol Chem 2016; 291:7703-15. [PMID: 26823464 DOI: 10.1074/jbc.m115.698282] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Indexed: 11/06/2022] Open
Abstract
Successful invasion of human erythrocytes byPlasmodium falciparummerozoites is required for infection of the host and parasite survival. The early stages of invasion are mediated via merozoite surface proteins that interact with human erythrocytes. The nature of these interactions are currently not well understood, but it is known that merozoite surface protein 1 (MSP1) is critical for successful erythrocyte invasion. Here we show that the peripheral merozoite surface proteins MSP3, MSP6, MSPDBL1, MSPDBL2, and MSP7 bind directly to MSP1, but independently of each other, to form multiple forms of the MSP1 complex on the parasite surface. These complexes have overlapping functions that interact directly with human erythrocytes. We also show that targeting the p83 fragment of MSP1 using inhibitory antibodies inhibits all forms of MSP1 complexes and disrupts parasite growthin vitro.
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Affiliation(s)
- Clara S Lin
- From the Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia, the Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Alessandro D Uboldi
- From the Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
| | - Christian Epp
- the Department of Infectious Diseases, Parasitology, Universität Heidelberg, INF 324, 69120 Heidelberg, Germany
| | - Hermann Bujard
- the Zentrum für Molekulare Biologie der Universität Heidelberg, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany, and
| | - Takafumi Tsuboi
- the Proteo-Science Center, Ehime University, Matsuyama, Ehime 790-8577, Japan
| | - Peter E Czabotar
- From the Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia, the Department of Medical Biology, University of Melbourne, Melbourne, Australia
| | - Alan F Cowman
- From the Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia, the Department of Medical Biology, University of Melbourne, Melbourne, Australia,
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32
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Krishnarjuna B, Lim SS, Devine SM, Debono CO, Lam R, Chandrashekaran IR, Jaipuria G, Yagi H, Atreya HS, Scanlon MJ, MacRaild CA, Scammells PJ, Norton RS. Solution NMR characterization of apical membrane antigen 1 and small molecule interactions as a basis for designing new antimalarials. J Mol Recognit 2016; 29:281-91. [DOI: 10.1002/jmr.2529] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Accepted: 11/28/2015] [Indexed: 01/12/2023]
Affiliation(s)
- Bankala Krishnarjuna
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences; Monash University; 381 Royal Parade Parkville Victoria 3052 Australia
| | - San Sui Lim
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences; Monash University; 381 Royal Parade Parkville Victoria 3052 Australia
| | - Shane M. Devine
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences; Monash University; 381 Royal Parade Parkville Victoria 3052 Australia
| | - Cael O. Debono
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences; Monash University; 381 Royal Parade Parkville Victoria 3052 Australia
| | - Raymond Lam
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences; Monash University; 381 Royal Parade Parkville Victoria 3052 Australia
| | - Indu R. Chandrashekaran
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences; Monash University; 381 Royal Parade Parkville Victoria 3052 Australia
| | - Garima Jaipuria
- NMR Research Centre; Indian Institute of Science; Bangalore 560012 India
| | - Hiromasa Yagi
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences; Monash University; 381 Royal Parade Parkville Victoria 3052 Australia
| | | | - Martin J. Scanlon
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences; Monash University; 381 Royal Parade Parkville Victoria 3052 Australia
| | - Christopher A. MacRaild
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences; Monash University; 381 Royal Parade Parkville Victoria 3052 Australia
| | - Peter J. Scammells
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences; Monash University; 381 Royal Parade Parkville Victoria 3052 Australia
| | - Raymond S. Norton
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences; Monash University; 381 Royal Parade Parkville Victoria 3052 Australia
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33
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Alam MS, Rathore S, Tyagi RK, Sharma YD. Host-parasite interaction: multiple sites in the Plasmodium vivax tryptophan-rich antigen PvTRAg38 interact with the erythrocyte receptor band 3. FEBS Lett 2016; 590:232-41. [PMID: 26823170 PMCID: PMC7163959 DOI: 10.1002/1873-3468.12053] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 11/03/2015] [Accepted: 01/01/2016] [Indexed: 12/25/2022]
Abstract
Tryptophan‐rich antigens of malarial parasites interact with host molecules and play an important role in parasite survival. Merozoite expressed Plasmodium vivax tryptophan‐rich antigen PvTRAg38 binds to human erythrocytes and facilitates parasite growth in a heterlologous Plasmodium falciparum culture system. Recently, we identified band 3 in human erythrocytes as one of its receptors, although the receptor‐ligand binding mechanisms remain unknown. In the present study, using synthetic mutated peptides of PvTRAg38, we show that multiple amino acid residues of its 12 amino acid domain (KWVQWKNDKIRS) at position 197–208 interact with three different ectodomains of band 3 receptor on human erythrocytes. Our findings may help in the design of new therapeutic approaches for malaria.
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Affiliation(s)
- Mohd S Alam
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Sumit Rathore
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Rupesh K Tyagi
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Yagya D Sharma
- Department of Biotechnology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
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34
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Efficient backbone cyclization of linear peptides by a recombinant asparaginyl endopeptidase. Nat Commun 2015; 6:10199. [PMID: 26680698 PMCID: PMC4703859 DOI: 10.1038/ncomms10199] [Citation(s) in RCA: 169] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 11/16/2015] [Indexed: 01/05/2023] Open
Abstract
Cyclotides are diverse plant backbone cyclized peptides that have attracted interest as pharmaceutical scaffolds, but fundamentals of their biosynthetic origin remain elusive. Backbone cyclization is a key enzyme-mediated step of cyclotide biosynthesis and confers a measure of stability on the resultant cyclotide. Furthermore, cyclization would be desirable for engineered peptides. Here we report the identification of four asparaginyl endopeptidases (AEPs), proteases implicated in cyclization, from the cyclotide-producing plant Oldenlandia affinis. We recombinantly express OaAEP1b and find it functions preferably as a cyclase by coupling C-terminal cleavage of propeptide substrates with backbone cyclization. Interestingly, OaAEP1b cannot cleave at the N-terminal site of O. affinis cyclotide precursors, implicating additional proteases in cyclotide biosynthesis. Finally, we demonstrate the broad utility of this enzyme by cyclization of peptides unrelated to cyclotides. We propose that recombinant OaAEP1b is a powerful tool for use in peptide engineering applications where increased stability of peptide products is desired. Cyclotides are plant backbone-cyclised peptides with potential as pharmaceutical scaffolds. Here the authors report on the efficient backbone cyclization of cyclotides and unrelated peptides by a newly identified asparaginyl endopeptidase from Oldenlandia affinis.
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35
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Mutungi JK, Yahata K, Sakaguchi M, Kaneko O. Isolation of invasive Plasmodium yoelii merozoites with a long half-life to evaluate invasion dynamics and potential invasion inhibitors. Mol Biochem Parasitol 2015; 204:26-33. [DOI: 10.1016/j.molbiopara.2015.12.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Revised: 10/28/2015] [Accepted: 12/05/2015] [Indexed: 11/28/2022]
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36
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Wilson DW, Goodman CD, Sleebs BE, Weiss GE, de Jong NW, Angrisano F, Langer C, Baum J, Crabb BS, Gilson PR, McFadden GI, Beeson JG. Macrolides rapidly inhibit red blood cell invasion by the human malaria parasite, Plasmodium falciparum. BMC Biol 2015; 13:52. [PMID: 26187647 PMCID: PMC4506589 DOI: 10.1186/s12915-015-0162-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2015] [Accepted: 06/30/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Malaria invasion of red blood cells involves multiple parasite-specific targets that are easily accessible to inhibitory compounds, making it an attractive target for antimalarial development. However, no current antimalarial agents act against host cell invasion. RESULTS Here, we demonstrate that the clinically used macrolide antibiotic azithromycin, which is known to kill human malaria asexual blood-stage parasites by blocking protein synthesis in their apicoplast, is also a rapid inhibitor of red blood cell invasion in human (Plasmodium falciparum) and rodent (P. berghei) malarias. Multiple lines of evidence demonstrate that the action of azithromycin in inhibiting parasite invasion of red blood cells is independent of its inhibition of protein synthesis in the parasite apicoplast, opening up a new strategy to develop a single drug with multiple parasite targets. We identified derivatives of azithromycin and erythromycin that are better invasion inhibitors than parent compounds, offering promise for development of this novel antimalarial strategy. CONCLUSIONS Safe and effective macrolide antibiotics with dual modalities could be developed to combat malaria and reduce the parasite's options for resistance.
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Affiliation(s)
- Danny W Wilson
- Research Centre for Infectious Diseases, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia. .,Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3050, Australia. .,Department of Medical Biology, University of Melbourne, Parkville, Victoria, 3050, Australia. .,Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, 3004, Australia.
| | - Christopher D Goodman
- Plant Cell Biology Research Centre, School of Biosciences, University of Melbourne, Parkville, Victoria, 3010, Australia.
| | - Brad E Sleebs
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3050, Australia. .,Department of Medical Biology, University of Melbourne, Parkville, Victoria, 3050, Australia.
| | - Greta E Weiss
- Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, 3004, Australia.
| | - Nienke Wm de Jong
- Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, 3004, Australia.
| | - Fiona Angrisano
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3050, Australia. .,Department of Medical Biology, University of Melbourne, Parkville, Victoria, 3050, Australia. .,Department of Life Sciences, Imperial College London, South Kensington, London, SW7 2AZ, UK.
| | - Christine Langer
- Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, 3004, Australia.
| | - Jake Baum
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3050, Australia. .,Department of Medical Biology, University of Melbourne, Parkville, Victoria, 3050, Australia. .,Department of Life Sciences, Imperial College London, South Kensington, London, SW7 2AZ, UK.
| | - Brendan S Crabb
- Department of Medical Biology, University of Melbourne, Parkville, Victoria, 3050, Australia. .,Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, 3004, Australia. .,Department of Immunology, Monash University, Clayton, Victoria, 3800, Australia.
| | - Paul R Gilson
- Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, 3004, Australia. .,Department of Immunology, Monash University, Clayton, Victoria, 3800, Australia.
| | - Geoffrey I McFadden
- Plant Cell Biology Research Centre, School of Biosciences, University of Melbourne, Parkville, Victoria, 3010, Australia.
| | - James G Beeson
- Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3050, Australia. .,Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, 3004, Australia. .,Department of Microbiology, Monash University, Clayton, Victoria, 3168, Australia.
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Reddy SB, Anders RF, Cross N, Mueller I, Senn N, Stanisic DI, Siba PM, Wahlgren M, Kironde F, Beeson JG, Persson KEM. Differences in affinity of monoclonal and naturally acquired polyclonal antibodies against Plasmodium falciparum merozoite antigens. BMC Microbiol 2015; 15:133. [PMID: 26149471 PMCID: PMC4491891 DOI: 10.1186/s12866-015-0461-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 06/03/2015] [Indexed: 11/10/2022] Open
Abstract
Background Malaria is a major global cause of deaths and a vaccine is urgently needed. Results We have employed the P. falciparum merozoite antigens MSP2-3D7/FC27 and AMA1, used them in ELISA, and coupled them in different ways using surface plasmon resonance (SPR) and estimated affinity (measured as kd) of monoclonal as well as naturally-acquired polyclonal antibodies in human plasma. There were major differences in kd depending on how the antigens were immobilized and where the His-tag was placed. For AMA1 we could see correlations with invasion inhibition. Using different immobilizations of proteins in SPR, we could see only moderate correlations with levels of antibodies in ELISA, indicating that in ELISA the proteins were not uniformly bound and that antibodies with many specificities exist in natural immunisation. The correlations between ELISA and SPR were enhanced when only parasite positive samples were included, which may indicate that high affinity antibodies are difficult to maintain over long periods of time. We found higher kd values for MSP2 (indicating lower affinity) compared to AMA1, which might be partly explained by MSP2 being an intrinsically disordered protein, while AMA1 is globular. Conclusions For future vaccine studies and for understanding immunity, it is important to consider how to present proteins to the immune system to achieve highest antibody affinities. Electronic supplementary material The online version of this article (doi:10.1186/s12866-015-0461-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sreenivasulu B Reddy
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, 171 77, Stockholm, Sweden
| | - Robin F Anders
- Department of Biochemistry, La Trobe University, Vic, 3086, Australia
| | - Nadia Cross
- The Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia
| | - Ivo Mueller
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia.,Papua New Guinea Institute of Medical Research, Goroka, 441, Papua New Guinea
| | - Nicolas Senn
- Papua New Guinea Institute of Medical Research, Goroka, 441, Papua New Guinea.,Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Danielle I Stanisic
- Papua New Guinea Institute of Medical Research, Goroka, 441, Papua New Guinea.,Institute for Glycomics, Griffith University, Queensland, Australia
| | - Peter M Siba
- Papua New Guinea Institute of Medical Research, Goroka, 441, Papua New Guinea
| | - Mats Wahlgren
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, 171 77, Stockholm, Sweden
| | - Fred Kironde
- Department of Biochemistry, Makerere University, Kampala, Uganda.,Habib Medical School, IUIU, Kampala, Uganda
| | - James G Beeson
- The Macfarlane Burnet Institute for Medical Research and Public Health, Melbourne, Victoria, Australia.,The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - Kristina E M Persson
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, 171 77, Stockholm, Sweden. .,Department of Laboratory Medicine, Lund University, 22185, Lund, Sweden.
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38
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Bianchin A, Bell A, Chubb AJ, Doolan N, Leneghan D, Stavropoulos I, Shields DC, Mooney C. Design and evaluation of antimalarial peptides derived from prediction of short linear motifs in proteins related to erythrocyte invasion. PLoS One 2015; 10:e0127383. [PMID: 26039561 PMCID: PMC4454681 DOI: 10.1371/journal.pone.0127383] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 04/15/2015] [Indexed: 11/19/2022] Open
Abstract
The purpose of this study was to investigate the blood stage of the malaria causing parasite, Plasmodium falciparum, to predict potential protein interactions between the parasite merozoite and the host erythrocyte and design peptides that could interrupt these predicted interactions. We screened the P. falciparum and human proteomes for computationally predicted short linear motifs (SLiMs) in cytoplasmic portions of transmembrane proteins that could play roles in the invasion of the erythrocyte by the merozoite, an essential step in malarial pathogenesis. We tested thirteen peptides predicted to contain SLiMs, twelve of them palmitoylated to enhance membrane targeting, and found three that blocked parasite growth in culture by inhibiting the initiation of new infections in erythrocytes. Scrambled peptides for two of the most promising peptides suggested that their activity may be reflective of amino acid properties, in particular, positive charge. However, one peptide showed effects which were stronger than those of scrambled peptides. This was derived from human red blood cell glycophorin-B. We concluded that proteome-wide computational screening of the intracellular regions of both host and pathogen adhesion proteins provides potential lead peptides for the development of anti-malarial compounds.
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Affiliation(s)
- Alessandra Bianchin
- Conway Institute of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
- Complex and Adaptive Systems Laboratory, University College Dublin, Dublin, Ireland
- School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
- Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, Trinity College, Dublin, Ireland
| | - Angus Bell
- Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, Trinity College, Dublin, Ireland
| | - Anthony J. Chubb
- Conway Institute of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
- Complex and Adaptive Systems Laboratory, University College Dublin, Dublin, Ireland
- School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Nathalie Doolan
- School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Darren Leneghan
- Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, Trinity College, Dublin, Ireland
| | - Ilias Stavropoulos
- Conway Institute of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
- Complex and Adaptive Systems Laboratory, University College Dublin, Dublin, Ireland
- School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Denis C. Shields
- Conway Institute of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
- Complex and Adaptive Systems Laboratory, University College Dublin, Dublin, Ireland
- School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Catherine Mooney
- Conway Institute of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
- Complex and Adaptive Systems Laboratory, University College Dublin, Dublin, Ireland
- School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
- * E-mail:
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39
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Josling G, Petter M, Oehring S, Gupta A, Dietz O, Wilson D, Schubert T, Längst G, Gilson P, Crabb B, Moes S, Jenoe P, Lim S, Brown G, Bozdech Z, Voss T, Duffy M. A Plasmodium Falciparum Bromodomain Protein Regulates Invasion Gene Expression. Cell Host Microbe 2015; 17:741-51. [DOI: 10.1016/j.chom.2015.05.009] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 03/30/2015] [Accepted: 05/14/2015] [Indexed: 11/27/2022]
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40
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Pihan E, Delgadillo RF, Tonkin ML, Pugnière M, Lebrun M, Boulanger MJ, Douguet D. Computational and biophysical approaches to protein-protein interaction inhibition of Plasmodium falciparum AMA1/RON2 complex. J Comput Aided Mol Des 2015; 29:525-39. [PMID: 25822046 DOI: 10.1007/s10822-015-9842-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 03/25/2015] [Indexed: 11/30/2022]
Abstract
Invasion of the red blood cell by Plasmodium falciparum parasites requires formation of an electron dense circumferential ring called the Moving Junction (MJ). The MJ is anchored by a high affinity complex of two parasite proteins: Apical Membrane Antigen 1 (PfAMA1) displayed on the surface of the parasite and Rhoptry Neck Protein 2 that is discharged from the parasite and imbedded in the membrane of the host cell. Structural studies of PfAMA1 revealed a conserved hydrophobic groove localized to the apical surface that coordinates RON2 and invasion inhibitory peptides. In the present work, we employed computational and biophysical methods to identify competitive P. falciparum AMA1-RON2 inhibitors with the goal of exploring the 'druggability' of this attractive antimalarial target. A virtual screen followed by molecular docking with the PfAMA1 crystal structure was performed using an eight million compound collection that included commercial molecules, the ChEMBL malaria library and approved drugs. The consensus approach resulted in the selection of inhibitor candidates. We also developed a fluorescence anisotropy assay using a modified inhibitory peptide to experimentally validate the ability of the selected compounds to inhibit the AMA1-RON2 interaction. Among those, we identified one compound that displayed significant inhibition. This study offers interesting clues to improve the throughput and reliability of screening for new drug leads.
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Affiliation(s)
- Emilie Pihan
- Institut de Pharmacologie Moléculaire et Cellulaire, Université de Nice Sophia-Antipolis, CNRS, UMR 7275, 660, Route des Lucioles, Sophia Antipolis, 06560, Valbonne, France
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41
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Arévalo-Pinzón G, Bermúdez M, Curtidor H, Patarroyo MA. The Plasmodium vivax rhoptry neck protein 5 is expressed in the apical pole of Plasmodium vivax VCG-1 strain schizonts and binds to human reticulocytes. Malar J 2015; 14:106. [PMID: 25888962 PMCID: PMC4359499 DOI: 10.1186/s12936-015-0619-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 02/22/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Different proteins derived from the membrane or the apical organelles become involved in malarial parasite invasion of host cells. Among these, the rhoptry neck proteins (RONs) interact with a protein component of the micronemes to enable the formation of a strong bond which is crucial for the parasite's successful invasion. The present study was aimed at identifying and characterizing the RON5 protein in Plasmodium vivax and evaluating its ability to bind to reticulocytes. METHODS Taking the Plasmodium falciparum and Plasmodium knowlesi RON5 amino acid sequences as template, an in-silico search was made in the P. vivax genome for identifying the orthologous gene. Different molecular tools were used for experimentally ascertaining pvron5 gene presence and transcription in P. vivax VCG-1 strain schizonts. Polyclonal antibodies against PvRON5 peptides were used for evaluating protein expression (by Western blot) and sub-cellular localization (by immunofluorescence). A 33 kDa PvRON5 fragment was expressed in Escherichia coli and used for evaluating the reactivity of sera from patients infected by P. vivax. Two assays were made for determining the RON5 recombinant fragment's ability to bind to reticulocyte-enriched human umbilical cord samples. RESULTS The pvron5 gene (3,477 bp) was transcribed in VCG-1 strain schizonts and encoded a ~133 kDa protein which was expressed in the rhoptry neck of VCG-1 strain late schizonts, together with PvRON2 and PvRON4. Polyclonal sera against PvRON5 peptides specifically detected ~85 and ~30 kDa fragments in parasite lysate, thereby suggesting proteolytic processing in this protein. Comparative analysis of VCG-1 strain PvRON5 with other P. vivax strains having different geographic localizations suggested its low polymorphism regarding other malarial antigens. A recombinant fragment of the PvRON5 protein (rPvRON5) was recognized by sera from P. vivax-infected patients and bound to red blood cells, having a marked preference for human reticulocytes. CONCLUSIONS The pvron5 gene is transcribed in the VCG-1 strain, the encoded protein is expressed at the parasite's apical pole and might be participating in merozoite invasion of host cells, taking into account its marked binding preference for human reticulocytes.
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Affiliation(s)
- Gabriela Arévalo-Pinzón
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 # 26-20, Bogotá, Colombia. .,Universidad del Rosario, Carrera 24 # 63C-69, Bogotá, Colombia.
| | - Maritza Bermúdez
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 # 26-20, Bogotá, Colombia. .,Universidad del Rosario, Carrera 24 # 63C-69, Bogotá, Colombia.
| | - Hernando Curtidor
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 # 26-20, Bogotá, Colombia. .,Universidad del Rosario, Carrera 24 # 63C-69, Bogotá, Colombia.
| | - Manuel A Patarroyo
- Fundación Instituto de Inmunología de Colombia (FIDIC), Carrera 50 # 26-20, Bogotá, Colombia. .,Universidad del Rosario, Carrera 24 # 63C-69, Bogotá, Colombia.
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42
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Weiss GE, Gilson PR, Taechalertpaisarn T, Tham WH, de Jong NWM, Harvey KL, Fowkes FJI, Barlow PN, Rayner JC, Wright GJ, Cowman AF, Crabb BS. Revealing the sequence and resulting cellular morphology of receptor-ligand interactions during Plasmodium falciparum invasion of erythrocytes. PLoS Pathog 2015; 11:e1004670. [PMID: 25723550 PMCID: PMC4344246 DOI: 10.1371/journal.ppat.1004670] [Citation(s) in RCA: 193] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 01/08/2015] [Indexed: 11/18/2022] Open
Abstract
During blood stage Plasmodium falciparum infection, merozoites invade uninfected erythrocytes via a complex, multistep process involving a series of distinct receptor-ligand binding events. Understanding each element in this process increases the potential to block the parasite’s life cycle via drugs or vaccines. To investigate specific receptor-ligand interactions, they were systematically blocked using a combination of genetic deletion, enzymatic receptor cleavage and inhibition of binding via antibodies, peptides and small molecules, and the resulting temporal changes in invasion and morphological effects on erythrocytes were filmed using live cell imaging. Analysis of the videos have shown receptor-ligand interactions occur in the following sequence with the following cellular morphologies; 1) an early heparin-blockable interaction which weakly deforms the erythrocyte, 2) EBA and PfRh ligands which strongly deform the erythrocyte, a process dependant on the merozoite’s actin-myosin motor, 3) a PfRh5-basigin binding step which results in a pore or opening between parasite and host through which it appears small molecules and possibly invasion components can flow and 4) an AMA1–RON2 interaction that mediates tight junction formation, which acts as an anchor point for internalization. In addition to enhancing general knowledge of apicomplexan biology, this work provides a rational basis to combine sequentially acting merozoite vaccine candidates in a single multi-receptor-blocking vaccine. The development of an effective malaria vaccine is a world health priority and would be a critical step toward the control and eventual elimination of this disease. In addition, new pharmacological solutions are necessary as Plasmodium falciparum, the deadliest of the malaria-causing parasites, has developed resistance to every drug currently approved for treatment. Understanding the interactions required for the parasite to invade its erythrocyte host, as well as being valuable to our basic knowledge of parasite biology, is important for the development of drug-based therapies and vaccines. In this study we have, for the first time, filmed P. falciparum parasites invading erythrocytes while systematically blocking several specific interactions between the parasite and the erythrocyte. We have shown there is a sequential progression of specific interactions that occur in at least four distinct steps leading up to invasion. Previous vaccine attempts have targeted one or two of these steps, however, if a single vaccine were designed to block interactions at all four steps, the combined effect might so reduce invasion that parasite growth and disease progression would be arrested. A better understanding of each interaction during invasion, their role and order, can also inform the development of new anti-malarial drugs.
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Affiliation(s)
| | - Paul R. Gilson
- Burnet Institute, Melbourne, Australia
- Department of Immunology, Monash University, Melbourne, Australia
- * E-mail: (PRG); (BSC)
| | - Tana Taechalertpaisarn
- Burnet Institute, Melbourne, Australia
- Department of Medical Biology, University of Melbourne, Australia
| | - Wai-Hong Tham
- Department of Medical Biology, University of Melbourne, Australia
- The Walter & Eliza Hall Institute of Medical Research, Parkville, Australia
| | | | - Katherine L. Harvey
- Burnet Institute, Melbourne, Australia
- Department of Microbiology & Immunology, University of Melbourne, Australia
| | - Freya J. I. Fowkes
- Burnet Institute, Melbourne, Australia
- Centre for Molecular, Environmental, Genetic and Analytic Epidemiology, University of Melbourne, Australia
- Department of Epidemiology and Preventive Medicine and Department of Infectious Diseases, Monash University, Melbourne, Australia
| | - Paul N. Barlow
- Schools of Chemistry and Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Julian C. Rayner
- Malaria Programme, Wellcome Trust Sanger Institute, Cambridge, United Kingdom
| | - Gavin J. Wright
- Cell Surface Signalling Laboratory, Wellcome Trust Sanger Institute, Cambridge, United Kingdom
| | - Alan F. Cowman
- Department of Medical Biology, University of Melbourne, Australia
- The Walter & Eliza Hall Institute of Medical Research, Parkville, Australia
| | - Brendan S. Crabb
- Burnet Institute, Melbourne, Australia
- Department of Immunology, Monash University, Melbourne, Australia
- Department of Microbiology & Immunology, University of Melbourne, Australia
- * E-mail: (PRG); (BSC)
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43
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Devine SM, Mulcair MD, Debono CO, Leung EWW, Nissink JWM, Lim SS, Chandrashekaran IR, Vazirani M, Mohanty B, Simpson JS, Baell JB, Scammells PJ, Norton RS, Scanlon MJ. Promiscuous 2-aminothiazoles (PrATs): a frequent hitting scaffold. J Med Chem 2015; 58:1205-14. [PMID: 25559643 DOI: 10.1021/jm501402x] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We have identified a class of molecules, known as 2-aminothiazoles (2-ATs), as frequent-hitting fragments in biophysical binding assays. This was exemplified by 4-phenylthiazol-2-amine being identified as a hit in 14/14 screens against a diverse range of protein targets, suggesting that this scaffold is a poor starting point for fragment-based drug discovery. This prompted us to analyze this scaffold in the context of an academic fragment library used for fragment-based drug discovery (FBDD) and two larger compound libraries used for high-throughput screening (HTS). This analysis revealed that such "promiscuous 2-aminothiazoles" (PrATs) behaved as frequent hitters under both FBDD and HTS settings, although the problem was more pronounced in the fragment-based studies. As 2-ATs are present in known drugs, they cannot necessarily be deemed undesirable, but the combination of their promiscuity and difficulties associated with optimizing them into a lead compound makes them, in our opinion, poor scaffolds for fragment libraries.
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Affiliation(s)
- Shane M Devine
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, Victoria 3052, Australia
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44
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Douse CH, Vrielink N, Wenlin Z, Cota E, Tate EW. Targeting a dynamic protein-protein interaction: fragment screening against the malaria myosin A motor complex. ChemMedChem 2015; 10:134-43. [PMID: 25367834 PMCID: PMC4506568 DOI: 10.1002/cmdc.201402357] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Indexed: 01/13/2023]
Abstract
Motility is a vital feature of the complex life cycle of Plasmodium falciparum, the apicomplexan parasite that causes human malaria. Processes such as host cell invasion are thought to be powered by a conserved actomyosin motor (containing myosin A or myoA), correct localization of which is dependent on a tight interaction with myosin A tail domain interacting protein (MTIP) at the inner membrane of the parasite. Although disruption of this protein-protein interaction represents an attractive means to investigate the putative roles of myoA-based motility and to inhibit the parasitic life cycle, no small molecules have been identified that bind to MTIP. Furthermore, it has not been possible to obtain a crystal structure of the free protein, which is highly dynamic and unstable in the absence of its natural myoA tail partner. Herein we report the de novo identification of the first molecules that bind to and stabilize MTIP via a fragment-based, integrated biophysical approach and structural investigations to examine the binding modes of hit compounds. The challenges of targeting such a dynamic system with traditional fragment screening workflows are addressed throughout.
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Affiliation(s)
- Christopher H Douse
- Department of Chemistry, Imperial College London, South KensingtonLondon SW7 2AZ (UK) E-mail:
- Centre for Structural Biology, Department of Life Sciences, Imperial College LondonSouth Kensington, London SW7 2AZ (UK)
- Institute of Chemical Biology, Imperial College LondonSouth Kensington, London SW7 2AZ (UK)
| | - Nina Vrielink
- Department of Chemistry, Imperial College London, South KensingtonLondon SW7 2AZ (UK) E-mail:
| | - Zhang Wenlin
- Department of Chemistry, Imperial College London, South KensingtonLondon SW7 2AZ (UK) E-mail:
| | - Ernesto Cota
- Centre for Structural Biology, Department of Life Sciences, Imperial College LondonSouth Kensington, London SW7 2AZ (UK)
- Institute of Chemical Biology, Imperial College LondonSouth Kensington, London SW7 2AZ (UK)
| | - Edward W Tate
- Department of Chemistry, Imperial College London, South KensingtonLondon SW7 2AZ (UK) E-mail:
- Institute of Chemical Biology, Imperial College LondonSouth Kensington, London SW7 2AZ (UK)
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45
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Bioinformatic Identification of Peptidomimetic-Based Inhibitors against Plasmodium falciparum Antigen AMA1. Malar Res Treat 2014; 2014:642391. [PMID: 25580351 PMCID: PMC4281401 DOI: 10.1155/2014/642391] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 11/18/2014] [Indexed: 11/17/2022] Open
Abstract
Plasmodium falciparum apical membrane antigen 1 (PfAMA1) is a valuable vaccine candidate and exported on the merozoite surface at the time of erythrocyte invasion. PfAMA1 interacts with rhoptry neck protein PfRON2, a component of the rhoptry protein complex, which forms the tight junction at the time of invasion. Phage display studies have identified a 15-residue (F1) and a 20-residue (R1) peptide that bind to PfAMA1 and block the invasion of erythrocytes. Cocrystal structures of central region of PfAMA1 containing disulfide-linked clusters (domains I and II) with R1 peptide and a peptide derived from PfRON2 showed strong structural similarity in binding. The peptides bound to a hydrophobic groove surrounded by domain I and II loops. In this study, peptidomimetics based on the crucial PfAMA1-binding residues of PfRON2 peptide have been identified. Top 5 peptidomimetics when checked for their docking on the region of PfAMA1 encompassing the hydrophobic groove were found to dock on the groove. Drug-like molecules having structural similarity to the top 5 peptidomimetics were identified based on their binding ability to PfAMA1 hydrophobic groove in blind docking. These inhibitors provide potential lead compounds, which could be used in the development of antimalarials targeting PfAMA1.
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46
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Lim SS, Yang W, Krishnarjuna B, Kannan Sivaraman K, Chandrashekaran IR, Kass I, MacRaild CA, Devine SM, Debono CO, Anders RF, Scanlon MJ, Scammells PJ, Norton RS, McGowan S. Structure and dynamics of apical membrane antigen 1 from Plasmodium falciparum FVO. Biochemistry 2014; 53:7310-20. [PMID: 25360546 DOI: 10.1021/bi5012089] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Apical membrane antigen 1 (AMA1) interacts with RON2 to form a protein complex that plays a key role in the invasion of host cells by malaria parasites. Blocking this protein-protein interaction represents a potential route to controlling malaria and related parasitic diseases, but the polymorphic nature of AMA1 has proven to be a major challenge to vaccine-induced antibodies and peptide inhibitors exerting strain-transcending inhibitory effects. Here we present the X-ray crystal structure of AMA1 domains I and II from Plasmodium falciparum strain FVO. We compare our new structure to those of AMA1 from P. falciparum 3D7 and Plasmodium vivax. A combination of normalized B factor analysis and computational methods has been used to investigate the flexibility of the domain I loops and how this correlates with their roles in determining the strain specificity of human antibody responses and inhibitory peptides. We also investigated the domain II loop, a key region involved in inhibitor binding, by comparison of multiple AMA1 crystal structures. Collectively, these results provide valuable insights that should contribute to the design of strain-transcending agents targeting P. falciparum AMA1.
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Affiliation(s)
- San Sui Lim
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University , Parkville, Victoria 3052, Australia
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47
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Molecular insights into the interaction between Plasmodium falciparum apical membrane antigen 1 and an invasion-inhibitory peptide. PLoS One 2014; 9:e109674. [PMID: 25343578 PMCID: PMC4208761 DOI: 10.1371/journal.pone.0109674] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2014] [Accepted: 09/03/2014] [Indexed: 11/28/2022] Open
Abstract
Apical membrane antigen 1 (AMA1) of the human malaria parasite Plasmodium falciparum has been implicated in invasion of the host erythrocyte. It interacts with malarial rhoptry neck (RON) proteins in the moving junction that forms between the host cell and the invading parasite. Agents that block this interaction inhibit invasion and may serve as promising leads for anti-malarial drug development. The invasion-inhibitory peptide R1 binds to a hydrophobic cleft on AMA1, which is an attractive target site for small molecules that block parasite invasion. In this work, truncation and mutational analyses show that Phe5-Phe9, Phe12 and Arg15 in R1 are the most important residues for high affinity binding to AMA1. These residues interact with two well-defined binding hot spots on AMA1. Computational solvent mapping reveals that one of these hot spots is suitable for small molecule targeting. We also confirm that R1 in solution binds to AMA1 with 1∶1 stoichiometry and adopts a secondary structure consistent with the major form of R1 observed in the crystal structure of the complex. Our results provide a basis for designing high affinity inhibitors of the AMA1-RON2 interaction.
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Tonkin ML, Crawford J, Lebrun ML, Boulanger MJ. Babesia divergens and Neospora caninum apical membrane antigen 1 structures reveal selectivity and plasticity in apicomplexan parasite host cell invasion. Protein Sci 2014; 22:114-27. [PMID: 23169033 DOI: 10.1002/pro.2193] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 10/02/2012] [Accepted: 10/05/2012] [Indexed: 11/09/2022]
Abstract
Host cell invasion by the obligate intracellular apicomplexan parasites, including Plasmodium (malaria) and Toxoplasma (toxoplasmosis), requires a step-wise mechanism unique among known host-pathogen interactions. A key step is the formation of the moving junction (MJ) complex, a circumferential constriction between the apical tip of the parasite and the host cell membrane that traverses in a posterior direction to enclose the parasite in a protective vacuole essential for intracellular survival. The leading model of MJ assembly proposes that Rhoptry Neck Protein 2 (RON2) is secreted into the host cell and integrated into the membrane where it serves as the receptor for apical membrane antigen 1 (AMA1) on the parasite surface. We have previously demonstrated that the AMA1-RON2 interaction is an effective target for inhibiting apicomplexan invasion. To better understand the AMA1-dependant molecular recognition events that promote invasion, including the significant AMA1-RON2 interaction, we present the structural characterization of AMA1 from the apicomplexan parasites Babesia divergens (BdAMA1) and Neospora caninum (NcAMA1) by X-ray crystallography. These studies offer intriguing structural insight into the RON2-binding surface groove in the AMA1 apical domain, which shows clear evidence for receptor-ligand co-evolution, and the hyper variability of the membrane proximal domain, which in Plasmodium is responsible for direct binding to erythrocytes. By incorporating the structural analysis of BdAMA1 and NcAMA1 with existing AMA1 structures and complexes we were able to define conserved pockets in the AMA1 apical groove that could be targeted for the design of broadly reactive therapeutics.
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Affiliation(s)
- Michelle L Tonkin
- Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia, V8W 3P6, Canada
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49
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Ge X, MacRaild CA, Devine SM, Debono CO, Wang G, Scammells PJ, Scanlon MJ, Anders RF, Foley M, Norton RS. Ligand-Induced Conformational Change of Plasmodium falciparum AMA1 Detected Using 19F NMR. J Med Chem 2014; 57:6419-27. [DOI: 10.1021/jm500390g] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Xiaopeng Ge
- Department
of Biochemistry, La Trobe University, Melbourne 3086, Victoria, Australia
| | - Christopher A. MacRaild
- Medicinal
Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria, Australia
| | - Shane M. Devine
- Medicinal
Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria, Australia
| | - Cael O. Debono
- Medicinal
Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria, Australia
| | - Geqing Wang
- Medicinal
Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria, Australia
| | - Peter J. Scammells
- Medicinal
Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria, Australia
| | - Martin J. Scanlon
- Medicinal
Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria, Australia
| | - Robin F. Anders
- Department
of Biochemistry, La Trobe University, Melbourne 3086, Victoria, Australia
| | - Michael Foley
- Department
of Biochemistry, La Trobe University, Melbourne 3086, Victoria, Australia
| | - Raymond S. Norton
- Medicinal
Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville 3052, Victoria, Australia
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50
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Yap A, Azevedo MF, Gilson PR, Weiss GE, O'Neill MT, Wilson DW, Crabb BS, Cowman AF. Conditional expression of apical membrane antigen 1 in Plasmodium falciparum shows it is required for erythrocyte invasion by merozoites. Cell Microbiol 2014; 16:642-56. [PMID: 24571085 PMCID: PMC4231980 DOI: 10.1111/cmi.12287] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 02/23/2014] [Accepted: 02/24/2014] [Indexed: 11/30/2022]
Abstract
Malaria is caused by obligate intracellular parasites, of which Plasmodium falciparum is the most lethal species. In humans, P. falciparum merozoites (invasive forms of the parasite) employ a host of parasite proteins to rapidly invade erythrocytes. One of these is the P. falciparum apical membrane antigen 1 (PfAMA1) which forms a complex with rhoptry neck proteins at the tight junction. Here, we have placed the Pfama1 gene under conditional control using dimerizable Cre recombinase (DiCre) in P. falciparum. DiCre-mediated excision of the loxP-flanked Pfama1 gene results in approximately 80% decreased expression of the protein within one intraerythrocytic growth cycle. This reduces growth by 40%, due to decreased invasion efficiency characterized by a post-invasion defect in sealing of the parasitophorous vacuole. These results show that PfAMA1 is an essential protein for merozoite invasion in P. falciparum and either directly or indirectly plays a role in resealing of the red blood cell at the posterior end of the invasion event.
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Affiliation(s)
- Alan Yap
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Vic., 3052, Australia
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