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Salman AA, Goldring JPD. Expression and copper binding studies of a Plasmodium falciparum protein with Cox19 copper binding motifs. Exp Parasitol 2023:108572. [PMID: 37348640 DOI: 10.1016/j.exppara.2023.108572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 05/25/2023] [Accepted: 06/19/2023] [Indexed: 06/24/2023]
Abstract
Copper can exist in an oxidized and a reduced form, which enables the metal to play essential roles as a catalytic co-factor in redox reactions in many organisms. Copper confers redox activity to the terminal electron transport chain cytochrome c oxidase protein. Cytochrome c oxidase in yeast obtains copper for the CuB site in the Cox1 subunit from Cox11 in association with Cox19. When copper is chelated in growth medium, Plasmodium falciparum parasite development in infected red blood cells is inhibited and excess copper is toxic for the parasite. The gene of a 26 kDa Plasmodium falciparum PfCox19 protein with two Cx9C Cox19 copper binding motifs, was cloned and expressed as a 66 kDa fusion protein with maltose binding protein and affinity purified (rMBP-PfCox19). rMBP-PfCox19 bound copper measured by: a bicinchoninic acid release assay; an in vivo bacterial host growth inhibition assay; ascorbate oxidation inhibition and differential scanning fluorimetry. The native protein was detected by antibodies raised against rMBP-PfCox19. PfCox19 binds copper and is predicted to associate with PfCox11 in the insertion of copper into the CuB site of Plasmodium cytochrome c oxidase. Characterisation of the proteins involved in Plasmodium spp. copper metabolism will help us understand the role of cytochrome c oxidase and this essential metal in Plasmodium homeostasis.
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Affiliation(s)
| | - J P Dean Goldring
- Biochemistry, University of KwaZulu-Natal, Pietermaritzburg, 3201, South Africa.
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Jang IK, Jiménez A, Rashid A, Barney R, Golden A, Ding XC, Domingo GJ, Mayor A. Comparison of two malaria multiplex immunoassays that enable quantification of malaria antigens. Malar J 2022; 21:176. [PMID: 35672772 PMCID: PMC9171962 DOI: 10.1186/s12936-022-04203-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 05/25/2022] [Indexed: 11/10/2022] Open
Abstract
Background Immunoassay platforms that simultaneously detect malaria antigens including histidine-rich protein 2 (HRP2)/HRP3 and Plasmodium lactate dehydrogenase (pLDH), are useful epidemiological tools for rapid diagnostic test evaluation. This study presents the comparative evaluation of two multiplex platforms in identifying Plasmodium falciparum with presence or absence of HRP2/HRP3 expression as being indicative of hrp2/hrp3 deletions and other Plasmodium species. Moreover, correlation between the malaria antigen measurements performed at these platforms is assessed after calibrating with either assay standards or international standards and the cross-reactivity among Plasmodium species is examined. Methods A 77-member panel of specimens composed of the World Health Organization (WHO) international Plasmodium antigen standards, cultured parasites for P. falciparum and Plasmodium knowlesi, and clinical specimens with mono-infections for P. falciparum, Plasmodium vivax, and Plasmodium malariae was generated as both whole blood and dried blood spot (DBS) specimens. Assays for HRP2, P. falciparum–specific pLDH (PfLDH), P. vivax–specific pLDH (PvLDH), and all human Plasmodium species Pan malaria pLDH (PanLDH) on the Human Malaria Array Q-Plex and the xMAP platforms were evaluated with these panels. Results The xMAP showed a higher percent positive agreement for identification of hrp2-deleted P. falciparum and Plasmodium species in whole blood and DBS than the Q-Plex. For whole blood samples, there was a highly positive correlation between the two platforms for PfLDH (Pearson r = 0.9926) and PvLDH (r = 0. 9792), moderate positive correlation for HRP2 (r = 0.7432), and poor correlation for PanLDH (r = 0.6139). In Pearson correlation analysis between the two platforms on the DBS, the same assays were r = 0.9828, r = 0.7679, r = 0.6432, and r = 0.8957, respectively. The xMAP HRP2 assay appeared to cross-react with HRP3, while the Q-Plex did not. The Q-Plex PfLDH assay cross-reacted with P. malariae, while the xMAP did not. For both platforms, P. knowlesi was detected on the PvLDH assay. The WHO international standards allowed normalization across both platforms on their HRP2, PfLDH, and PvLDH assays in whole blood and DBS. Conclusions Q-Plex and xMAP show good agreement for identification of P. falciparum mutants with hrp2/hrp3 deletions, and other Plasmodium species. Quantitative results from both platforms, normalized into international units for HRP2, PfLDH, and PvLDH, showed good agreement and should allow comparison and analysis of results generated by either platform. Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04203-9.
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Ogunmolasuyi AM, Fogel R, Hoppe H, Goldring D, Limson J. A microfluidic paper analytical device using capture aptamers for the detection of PfLDH in blood matrices. Malar J 2022; 21:174. [PMID: 35672848 PMCID: PMC9172074 DOI: 10.1186/s12936-022-04187-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 05/19/2022] [Indexed: 11/26/2022] Open
Abstract
Background The prevalence and death rate arising from malaria infection, and emergence of other diseases showing similar symptoms to malaria require the development of malaria-specific and sensitive devices for its diagnosis. To address this, the design and fabrication of low-cost, rapid, paper-based analytical devices (µPAD) using surface-immobilized aptamers to detect the presence of a recombinant malarial biomarker—Plasmodium falciparum lactate dehydrogenase (rPfLDH)—is reported in this study. Methods Test zones on paper surfaces were created by covalently immobilizing streptavidin to the paper, subsequently attaching biotinylated aptamers to streptavidin. Aptamers selectively bound rPfLDH. The measurement of captured rPfLDH enzyme activity served as the means of detecting this biomarker. Enzyme activity across three replicate sensors was digitally quantified using the colorimetric Malstat assay. Results Screening of several different aptamers reported in the literature showed that aptamers rLDH7 and 2008s immobilized in this manner specifically recognised and captured PfLDH. Using rLDH7, the sensitivity of the µPAD sensor was evaluated and the µPAD sensor was applied for preferential detection of rPfLDH, both in buffered solutions of the protein and in spiked serum and red blood cell lysate samples. In buffered solutions, the test zone of the µPAD sensor exhibited a KD of 24 ± 11 nM and an empirical limit of detection of 17 nM, respectively, a limit similar to commercial antibody-based sensors exposed to rPfLDH. The specific recognition of 133 nM rPfLDH in undiluted serum and blood samples was demonstrated by the µPAD. Conclusion The reported µPAD demonstrates the potential of integrating aptamers into paper-based malarial rapid diagnostic tests. Graphical Abstract The assembly of µPAD sensors using APTEC assay principles for the detection the malarial biomarker, lactate dehydrogenase enzymes from Plasmodium falciparum (PfLDH). The aptamers immobilized at the test zones capture the PfLDH in samples. After washing the unbound sample components from the zones, Malstat assay reagents are added for colour development, proportional to the amount of captured PfLDH. ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s12936-022-04187-6.
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Laboratory Detection of Malaria Antigens: a Strong Tool for Malaria Research, Diagnosis, and Epidemiology. Clin Microbiol Rev 2021; 34:e0025020. [PMID: 34043447 DOI: 10.1128/cmr.00250-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The identification and characterization of proteins produced during human infection with Plasmodium spp. have guided the malaria community in research, diagnosis, epidemiology, and other efforts. Recently developed methods for the detection of these proteins (antigens) in the laboratory have provided new types of data that can inform the evaluation of malaria diagnostics, epidemiological investigations, and overall malaria control strategies. Here, the focus is primarily on antigens that are currently known to be detectable in human specimens and on their impact on the understanding of malaria in human populations. We highlight historical and contemporary laboratory assays for malaria antigen detection, the concept of an antigen profile for a biospecimen, and ways in which binary results for a panel of antigens could be interpreted and utilized for different analyses. Particular emphasis is given to the direct comparison of field-level malaria diagnostics and laboratory antigen detection for the development of an external evaluation scheme. The current limitations of laboratory antigen detection are considered, and the future of this developing field is discussed.
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Jang IK, Aranda S, Barney R, Rashid A, Helwany M, Rek JC, Arinaitwe E, Adrama H, Murphy M, Imwong M, Proux S, Haohankhunnatham W, Ding XC, Nosten F, Greenhouse B, Gamboa D, Domingo GJ. Assessment of Plasmodium antigens and CRP in dried blood spots with multiplex malaria array. J Parasit Dis 2021; 45:479-489. [PMID: 34290484 PMCID: PMC8254675 DOI: 10.1007/s12639-020-01325-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 11/21/2020] [Indexed: 11/24/2022] Open
Abstract
Dried blood spots (DBS) typically prepared on filter papers are an ideal sample type for malaria surveillance by offering easy and cost-effective methods in terms of sample collection, storage, and transport. The objective of this study was to evaluate the applicability of DBS with a commercial multiplex malaria assay, developed to concurrently measure Plasmodium antigens, histidine-rich protein 2 (HRP2), Plasmodium lactate dehydrogenase (pLDH), and a host inflammatory biomarker, C-reactive protein (CRP), in whole blood. The assay conditions were optimized for DBS, and thermal stability for measurement of Plasmodium antigens and CRP in dried blood were determined. Performance of the multiplex assay on matched DBS and whole blood pellet samples was also evaluated using the clinical samples. The results indicate the acceptable performance in multiplex antigen detection using DBS samples. At cutoff levels for DBS, with a diagnostic specificity with a lower 95% confidence bound > 92%, diagnostic sensitivities against polymerase chain reaction (PCR)–confirmed malaria for HRP2, Pf LDH, Pv LDH, and Pan LDH were 93.5%, 80.4%, 21.3%, and 55.6%, respectively. The half-life of pLDH was significantly less than that of HRP2 in thermal stability studies. Results with DBS samples collected from Peru indicate that the uncontrolled storage conditions of DBS can result in inaccurate reporting for infection with P. falciparum parasites with hrp2/3 deletions. With careful consideration that minimizing the unfavorable DBS storage environment is essential for ensuring integrity of heat-labile Plasmodium antigens, DBS samples can be used as an alternative to liquid whole blood to detect P. falciparum with hrp2/3 deletions in malaria surveillance.
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Affiliation(s)
| | | | | | | | | | - John C Rek
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | - Harriet Adrama
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Maxwell Murphy
- Department of Medicine, University of California at San Francisco, San Francisco, CA USA
| | - Mallika Imwong
- Faculty of Tropical Medicine, Department of Molecular Tropical Medicine and Genetics, Mahidol University, Bangkok, Thailand
| | - Stephane Proux
- Faculty of Tropical Medicine, Mahidol-Oxford Tropical Medicine Research Unit, Shoklo Malaria Research Unit, Mahidol University, Mae Sot, Thailand
| | - Warat Haohankhunnatham
- Faculty of Tropical Medicine, Mahidol-Oxford Tropical Medicine Research Unit, Shoklo Malaria Research Unit, Mahidol University, Mae Sot, Thailand
| | - Xavier C Ding
- The Foundation for Innovative New Diagnostics, Geneva, Switzerland
| | - François Nosten
- Faculty of Tropical Medicine, Mahidol-Oxford Tropical Medicine Research Unit, Shoklo Malaria Research Unit, Mahidol University, Mae Sot, Thailand.,Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Bryan Greenhouse
- Department of Medicine, University of California at San Francisco, San Francisco, CA USA
| | - Dionicia Gamboa
- Departamento de Ciencias Celulares y Moleculares, Facultad de Ciencias y Filosofía, Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
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Jang IK, Tyler A, Lyman C, Rek JC, Arinaitwe E, Adrama H, Murphy M, Imwong M, Proux S, Haohankhunnatham W, Barney R, Rashid A, Kalnoky M, Kahn M, Golden A, Nosten F, Greenhouse B, Gamboa D, Domingo GJ. Multiplex Human Malaria Array: Quantifying Antigens for Malaria Rapid Diagnostics. Am J Trop Med Hyg 2020; 102:1366-1369. [PMID: 32189616 PMCID: PMC7253106 DOI: 10.4269/ajtmh.19-0763] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Malaria antigen detection through rapid diagnostic tests (RDTs) is widely used to diagnose malaria and estimate prevalence. To support more sensitive next-generation RDT development and screen asymptomatic malaria, we developed and evaluated the Q-Plex™ Human Malaria Array (Quansys Biosciences, Logan, UT), which quantifies the antigens commonly used in RDTs—Plasmodium falciparum–specific histidine-rich protein 2 (HRP2), P. falciparum-specific lactate dehydrogenase (Pf LDH), Plasmodium vivax–specific LDH (Pv LDH), and Pan malaria lactate dehydrogenase (Pan LDH), and human C-reactive protein (CRP), a biomarker of severity in malaria. At threshold levels yielding 99.5% or more diagnostic specificity, diagnostic sensitivities against polymerase chain reaction–confirmed malaria for HRP2, Pf LDH, Pv LDH, and Pan LDH were 92.7%, 71.5%, 46.1%, and 83.8%, respectively. P. falciparum culture strains and samples from Peru indicated that HRP2 and Pf LDH combined improves detection of P. falciparum parasites with hrp2 and hrp3 deletions. This array can be used for antigen-based malaria screening and detecting hrp2/3 deletion mutants of P. falciparum.
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Affiliation(s)
| | | | | | - John C Rek
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | | | - Harriet Adrama
- Infectious Diseases Research Collaboration, Kampala, Uganda
| | - Maxwell Murphy
- Department of Medicine, University of California at San Francisco, San Francisco, California
| | - Mallika Imwong
- Faculty of Tropical Medicine, Department of Molecular Tropical Medicine and Genetics, Mahidol University, Bangkok, Thailand
| | - Stephane Proux
- Faculty of Tropical Medicine, Mahidol-Oxford Tropical Medicine Research Unit, Shoklo Malaria Research Unit, Mahidol University, Mae Sot, Thailand
| | - Warat Haohankhunnatham
- Faculty of Tropical Medicine, Mahidol-Oxford Tropical Medicine Research Unit, Shoklo Malaria Research Unit, Mahidol University, Mae Sot, Thailand
| | | | | | | | | | | | - François Nosten
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, United Kingdom.,Faculty of Tropical Medicine, Mahidol-Oxford Tropical Medicine Research Unit, Shoklo Malaria Research Unit, Mahidol University, Mae Sot, Thailand
| | - Bryan Greenhouse
- Department of Medicine, University of California at San Francisco, San Francisco, California
| | - Dionicia Gamboa
- Department of Cellular and Molecular Sciences, Institute of Tropical Medicine Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
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Shaik Abdool F, Coetzer THT, Goldring JPD. Isolation of Nile crocodile (Crocodylus niloticus) serum immunoglobulin M and Y (IgM and IgY). J Immunol Methods 2019; 478:112724. [PMID: 31837304 DOI: 10.1016/j.jim.2019.112724] [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] [Received: 08/09/2019] [Revised: 11/18/2019] [Accepted: 12/09/2019] [Indexed: 11/27/2022]
Abstract
Crocodile immunity has not been fully characterised with more studies on crocodile innate immunity than cell-mediated or humoral immunity. Crocodile immunoglobulin genes have been described but immunoglobulin proteins have not been isolated or studied biochemically. Two large proteins proposed to be crocodile IgM and IgY were isolated and purified from Crocodylus niloticus sera using two different protocols. A 50% (w/v) ammonium sulfate and a 15% (w/v) polyethylene glycol precipitation step was followed by Cibacron blue F3GA affinity- and Sephacryl-S300 gel filtration chromatography. An alternate purification protocol, with only two steps, involved thiophilic affinity- and Sephacryl-S300 gel filtration chromatography. The purified crocodile IgM resolved on reducing SDS-PAGE with an apparent mass of 180 kDa. Purified crocodile IgY resolved at 180 kDa alongside chicken IgY on a non-reducing SDS-PAGE gel, and is deduced to consist of two 66 kDa heavy and two 23 kDa light chains under reducing conditions. The thiophilic/gel filtration two-step protocol gave three-fold higher yields of isolated protein than the four-step precipitation/chromatography protocol. Antibodies against the isolated crocodile IgM and IgY were raised in chickens and affinity purified. The chicken antibodies differentiated between crocodile IgM and IgY and have the potential for use in the diagnosis of crocodile infections. The purified crocodile antibodies can be biochemically characterised and compared to mammalian and avian antibodies to give a better understanding of crocodile humoral immunity.
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Affiliation(s)
- Faiaz Shaik Abdool
- Biochemistry, School of Life Sciences, University of KwaZulu-Natal (Pietermaritzburg campus), Private Bag X01, Scottsville 3209, South Africa
| | - Theresa H T Coetzer
- Biochemistry, School of Life Sciences, University of KwaZulu-Natal (Pietermaritzburg campus), Private Bag X01, Scottsville 3209, South Africa
| | - J P Dean Goldring
- Biochemistry, School of Life Sciences, University of KwaZulu-Natal (Pietermaritzburg campus), Private Bag X01, Scottsville 3209, South Africa.
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Peptides, Antibodies, Peptide Antibodies and More. Int J Mol Sci 2019; 20:ijms20246289. [PMID: 31847088 PMCID: PMC6941022 DOI: 10.3390/ijms20246289] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 12/02/2019] [Accepted: 12/05/2019] [Indexed: 02/07/2023] Open
Abstract
The applications of peptides and antibodies to multiple targets have emerged as powerful tools in research, diagnostics, vaccine development, and therapeutics. Antibodies are unique since they, in theory, can be directed to any desired target, which illustrates their versatile nature and broad spectrum of use as illustrated by numerous applications of peptide antibodies. In recent years, due to the inherent limitations such as size and physical properties of antibodies, it has been attempted to generate new molecular compounds with equally high specificity and affinity, albeit with relatively low success. Based on this, peptides, antibodies, and peptide antibodies have established their importance and remain crucial reagents in molecular biology.
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Ahmad A, Verma AK, Krishna S, Sharma A, Singh N, Bharti PK. Plasmodium falciparum glutamate dehydrogenase is genetically conserved across eight malaria endemic states of India: Exploring new avenues of malaria elimination. PLoS One 2019; 14:e0218210. [PMID: 31199842 PMCID: PMC6568416 DOI: 10.1371/journal.pone.0218210] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 05/28/2019] [Indexed: 02/04/2023] Open
Abstract
Accurate and timely diagnosis is very critical for management, control and elimination of the malaria. Malaria rapid diagnostic tests (RDTs) have improved the diagnosis and management of malaria in remote areas, community and places where microscopy is not available for diagnosis. According to WHO report 2018, Plasmodium falciparum malaria constitutes more than 50% of malaria cases in India. Most of the RDTs used for diagnosis of falciparum malaria today employ HRP2 as a target antigen. However, low density parasitemia and deletion of hrp-2 gene in P. falciparum leads to false negative results and necessitates the development of alternative/ new or improved RDT for malaria diagnosis. We have analysed the genetic diversity and homology modelling of Pfgdh (glutamate dehydrogenase), ldh (lactate dehydrogenase) and aldolase genes in P. falciparum isolates from the eight endemic states of India to assess their potential as antigen for RDT development. We observed negligible sequence diversity in Pfgdh in comparison to the low level of diversity in ldh and aldolase gene. No structural or functional changes were observed in modelling studies and all three genes were under negative purifying selection pressure. The highly conserved nature of pfgdh gene suggests that GDH could be a potential target molecule for Pan/Pf diagnostic test for malaria.
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Affiliation(s)
- Amreen Ahmad
- ICMR-National Institute of Research in Tribal Health (NIRTH), Garha, Jabalpur, India
| | - Anil Kumar Verma
- ICMR-National Institute of Research in Tribal Health (NIRTH), Garha, Jabalpur, India
| | - Sri Krishna
- ICMR-National Institute of Research in Tribal Health (NIRTH), Garha, Jabalpur, India
| | - Anjana Sharma
- Department of P. G. Studies and Research in Biological Science, Rani Durgavati University, Pachpedi, Jabalpur, Madhya Pradesh, India
| | - Neeru Singh
- ICMR-National Institute of Research in Tribal Health (NIRTH), Garha, Jabalpur, India
| | - Praveen Kumar Bharti
- ICMR-National Institute of Research in Tribal Health (NIRTH), Garha, Jabalpur, India
- * E-mail:
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Frith KA, Fogel R, Goldring JPD, Krause RGE, Khati M, Hoppe H, Cromhout ME, Jiwaji M, Limson JL. Towards development of aptamers that specifically bind to lactate dehydrogenase of Plasmodium falciparum through epitopic targeting. Malar J 2018; 17:191. [PMID: 29724225 PMCID: PMC5934816 DOI: 10.1186/s12936-018-2336-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 04/26/2018] [Indexed: 11/19/2022] Open
Abstract
Background Early detection is crucial for the effective treatment of malaria, particularly in those cases infected with Plasmodium falciparum. There is a need for diagnostic devices with the capacity to distinguish P. falciparum from other strains of malaria. Here, aptamers generated against targeted species-specific epitopes of P. falciparum lactate dehydrogenase (rPfLDH) are described. Results Two classes of aptamers bearing high binding affinity and specificity for recombinant P. falciparum lactate dehydrogenase (rPfLDH) and P. falciparum-specific lactate dehydrogenase epitopic oligopeptide (LDHp) were separately generated. Structurally-relevant moieties with particular consensus sequences (GGTAG and GGCG) were found in aptamers reported here and previously published, confirming their importance in recognition of the target, while novel moieties particular to this work (ATTAT and poly-A stretches) were identified. Aptamers with diagnostically-supportive functions were synthesized, prime examples of which are the aptamers designated as LDHp 1, LDHp 11 and rLDH 4 and rLDH 15 in work presented herein. Of the sampled aptamers raised against the recombinant protein, rLDH 4 showed the highest binding to the target rPfLDH in the ELONA assay, with both rLDH 4 and rLDH 15 indicating an ability to discriminate between rPfLDH and rPvLDH. LDHp 11 was generated against a peptide selected as a unique P. falciparum LDH peptide. The aptamer, LDHp 11, like antibodies against the same peptide, only detected rPfLDH and discriminated between rPfLDH and rPvLDH. This was supported by affinity binding experiments where only aptamers generated against a unique species-specific epitope showed an ability to preferentially bind to rPfLDH relative to rPvLDH rather than those generated against the whole recombinant protein. In addition, rLDH 4 and LDHp 11 demonstrated in situ binding to P. falciparum cells during confocal microscopy. Conclusions The utilization and application of LDHp 11, an aptamer generated against a unique species-specific epitope of P. falciparum LDH indicated the ability to discriminate between recombinant P. falciparum and Plasmodium vivax LDH. This aptamer holds promise as a biorecognition element in malaria diagnostic devices for the detection, and differentiation, of P. falciparum and P. vivax malaria infections. This study paves the way to explore aptamer generation against targeted species-specific epitopes of other Plasmodium species.
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Affiliation(s)
- Kelly-Anne Frith
- Biotechnology Innovation Centre, Rhodes University, P.O. Box 94, Grahamstown, 6140, Eastern Cape, South Africa
| | - Ronen Fogel
- Biotechnology Innovation Centre, Rhodes University, P.O. Box 94, Grahamstown, 6140, Eastern Cape, South Africa
| | - J P Dean Goldring
- Department of Biochemistry, Genetics and Microbiology, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, KwaZulu-Natal, South Africa
| | - Robert G E Krause
- Department of Biochemistry, Genetics and Microbiology, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, KwaZulu-Natal, South Africa
| | - Makobetsa Khati
- Emerging Health Technologies Platform, Biosciences Division, Council for Scientific and Industrial Research, PO Box 395, Pretoria, 0001, Gauteng, South Africa
| | - Heinrich Hoppe
- Department of Biochemistry and Microbiology, Rhodes University, P.O. Box 94, Grahamstown, 6140, Eastern Cape, South Africa
| | - Mary E Cromhout
- Biotechnology Innovation Centre, Rhodes University, P.O. Box 94, Grahamstown, 6140, Eastern Cape, South Africa
| | - Meesbah Jiwaji
- Department of Biochemistry and Microbiology, Rhodes University, P.O. Box 94, Grahamstown, 6140, Eastern Cape, South Africa
| | - Janice L Limson
- Biotechnology Innovation Centre, Rhodes University, P.O. Box 94, Grahamstown, 6140, Eastern Cape, South Africa.
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Krause RGE, Goldring JPD. Phosphoethanolamine-N-methyltransferase is a potential biomarker for the diagnosis of P. knowlesi and P. falciparum malaria. PLoS One 2018; 13:e0193833. [PMID: 29505599 PMCID: PMC5837800 DOI: 10.1371/journal.pone.0193833] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 02/20/2018] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Plasmodium knowlesi is recognised as the main cause of human malaria in Southeast Asia. The disease is often misdiagnosed as P. falciparum or P. malariae infections by microscopy, and the disease is difficult to eliminate due to its presence in both humans and monkeys. P. knowlesi infections can rapidly cause severe disease and require prompt diagnosis and treatment. No protein biomarker exists for the rapid diagnostic test (RDT) detection of P. knowlesi infections. Plasmodium knowlesi infections can be diagnosed by PCR. METHODS AND PRINCIPAL FINDINGS Phosphoethanolamine-N-methyltransferase (PMT) is involved in malaria lipid biosynthesis and is not found in the human host. The P. falciparum, P. vivax and P. knowlesi PMT proteins were recombinantly expressed in BL21(DE3) Escherichia coli host cells, affinity purified and used to raise antibodies in chickens. Antibodies against each recombinant PMT protein all detected all three recombinant proteins and the native 29 kDa P. falciparum PMT protein on western blots and in ELISA. Antibodies against a PMT epitope (PLENNQYTDEGVKC) common to all three PMT orthologues detected all three proteins. Antibodies against unique peptides from each orthologue of PMT, PfCEVEHKYLHENKE, PvVYSIKEYNSLKDC, PkLYPTDEYNSLKDC detected only the parent protein in western blots and P. falciparum infected red blood cell lysates or blood lysates spiked with the respective proteins. Similar concentrations of PfPMT and the control, PfLDH, were detected in the same parasite lysate. The recombinant PfPMT protein was detected by a human anti-malaria antibody pool. CONCLUSION PMT, like the pan-specific LDH biomarker used in RDT tests, is both soluble, present at comparable concentrations in the parasite and constitutes a promising antimalarial drug target. PMT is absent from the human proteome. PMT has the potential as a biomarker for human malaria and in particular as the first P. knowlesi specific protein with diagnostic potential for the identification of a P. knowlesi infection.
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Simpalipan P, Pattaradilokrat S, Harnyuttanakorn P. Global sequence diversity of the lactate dehydrogenase gene in Plasmodium falciparum. Malar J 2018; 17:16. [PMID: 29316927 PMCID: PMC5761093 DOI: 10.1186/s12936-017-2157-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 12/23/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Antigen-detecting rapid diagnostic tests (RDTs) have been recommended by the World Health Organization for use in remote areas to improve malaria case management. Lactate dehydrogenase (LDH) of Plasmodium falciparum is one of the main parasite antigens employed by various commercial RDTs. It has been hypothesized that the poor detection of LDH-based RDTs is attributed in part to the sequence diversity of the gene. To test this, the present study aimed to investigate the genetic diversity of the P. falciparum ldh gene in Thailand and to construct the map of LDH sequence diversity in P. falciparum populations worldwide. METHODS The ldh gene was sequenced for 50 P. falciparum isolates in Thailand and compared with hundreds of sequences from P. falciparum populations worldwide. Several indices of molecular variation were calculated, including the proportion of polymorphic sites, the average nucleotide diversity index (π), and the haplotype diversity index (H). Tests of positive selection and neutrality tests were performed to determine signatures of natural selection on the gene. Mean genetic distance within and between species of Plasmodium ldh was analysed to infer evolutionary relationships. RESULTS Nucleotide sequences of P. falciparum ldh could be classified into 9 alleles, encoding 5 isoforms of LDH. L1a was the most common allelic type and was distributed in P. falciparum populations worldwide. Plasmodium falciparum ldh sequences were highly conserved, with haplotype and nucleotide diversity values of 0.203 and 0.0004, respectively. The extremely low genetic diversity was maintained by purifying selection, likely due to functional constraints. Phylogenetic analysis inferred the close genetic relationship of P. falciparum to malaria parasites of great apes, rather than to other human malaria parasites. CONCLUSIONS This study revealed the global genetic variation of the ldh gene in P. falciparum, providing knowledge for improving detection of LDH-based RDTs and supporting the candidacy of LDH as a therapeutic drug target.
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Affiliation(s)
- Phumin Simpalipan
- Zoology Ph.D. Programme, Faculty of Science, Chulalongkorn University, Bangkok, 10330 Thailand
| | - Sittiporn Pattaradilokrat
- Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok, 10330 Thailand
- Veterinary Parasitology Research Group, Department of Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330 Thailand
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Iwuafor AA, Ita OI, Ogban GI, Udoh UA, Amajor CA. Evaluation of Diagnostic Accuracy of Rapid Diagnostic Test for Malaria Diagnosis among Febrile Children in Calabar, Nigeria. Niger Med J 2018; 59:64-69. [PMID: 31423044 PMCID: PMC6668302 DOI: 10.4103/nmj.nmj_165_18] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Background The WHO recommends that all cases of suspected malaria should undergo parasitological test. Currently, the parasitological test comprises the rapid diagnostic test (RDT) or the microscopy. The performance of RDT in relation to microscopy is yet to be fully comprehended. Objectives This study evaluated the diagnostic accuracy of RDT as against the diagnosis provided by microscopy in detecting malaria parasites among febrile under-5 children. Design The study was a cross-sectional hospital-based design. Materials and Methods Capillary blood samples were collected from 167 children who came to the hospital with a history of fever over a period of 6 months. The Paracheck-Pf RDT kit was used and its performance was compared with the gold standard, microscopy using thick film. Results The prevalence of malaria infection was 41.9%. On comparing RDT with microscopy (microscopy assumed to be 100% sensitive and specific), RDT had a sensitivity of 51.4% and a specificity of 73.2%. The false-positive rate was 26.8% whereas the false-negative rate was 48.6%. The positive predictive value was 58.1% whereas the negative predictive value (NPV) was 67.6%. The RDT also had a positive likelihood ratio (LR) of 1.92 and a negative LR of 0.67. The RDT test accuracy was 64.1%. Conclusion Malaria prevalence among febrile children was found to be high. The findings also suggest that inconsistencies in the performance of RDT kits may arise from many extraneous factors, and as such, they should not be used as a stand-alone test kit except a prior batch/lot validation test was carried on them.
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Affiliation(s)
- Anthony Achizie Iwuafor
- Department of Medical Microbiology and Parasitology, Faculty of Medicine, College of Medical Sciences, University of Calabar, Calabar, Cross River State, Nigeria
| | - Okokon Ita Ita
- Department of Medical Microbiology and Parasitology, Faculty of Medicine, College of Medical Sciences, University of Calabar, Calabar, Cross River State, Nigeria
| | - Godwin Ibitham Ogban
- Department of Medical Microbiology and Parasitology, Faculty of Medicine, College of Medical Sciences, University of Calabar, Calabar, Cross River State, Nigeria
| | - Ubong A Udoh
- Department of Medical Microbiology and Parasitology, Faculty of Medicine, College of Medical Sciences, University of Calabar, Calabar, Cross River State, Nigeria
| | - Chimereze Anthony Amajor
- Department of Paediatrics, Faculty of Medicine, College of Medical Sciences, University of Calabar, Calabar, Cross River State, Nigeria
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Plasmodium glyceraldehyde-3-phosphate dehydrogenase: A potential malaria diagnostic target. Exp Parasitol 2017; 179:7-19. [DOI: 10.1016/j.exppara.2017.05.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 05/18/2017] [Indexed: 01/09/2023]
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Jain P, Chakma B, Singh N, Patra S, Goswami P. Metal-DNA Interactions Improve signal in High-Resolution Melting of DNA for Species Differentiation of Plasmodium Parasite. Mol Biotechnol 2017; 59:179-191. [PMID: 28421327 DOI: 10.1007/s12033-017-0004-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The success of high-resolution melting (HRM) analysis for distinguishing similar DNAs with minor base mismatch differences is limited. Here, metal-mediated structural change in DNA has been exploited to amplify HRM signals leading to differentiation of target DNAs in an orthologous gene corresponding to four Plasmodium species. Conserved 26-mer ssDNAs from ldh gene of the four Plasmodium species were employed as targets. A capture probe (CP) that is fully complementary to the Plasmodium falciparum target (FT) and has two base mismatches each, with the targets of Plasmodium vivax (VT), Plasmodium malariae, (MT), and Plasmodium ovale (OT), was considered. The DNA duplexes were treated with metal ions for structural perturbation and analyzed by HRM. Distinct resolution of melting fluorescence signal in otherwise identical HRM profiles for each of the DNA duplexes was achieved by using Ca+2 or Mg+2 ions, where, Ca+2 conferred higher resolution. The increase in resolution for CP-FT versus CP-OT, CP-FT versus CP-VT, CP-FT versus CP-MT, CP-VT versus CP-OT, and CP-MT versus CP-OT with Ca-DNA as compared to control was 67.3-, 20.4-, 22.0-, 10.9-, and 8.3-fold, respectively. The signal resolution was the highest at pH 8. The method could detect 0.25 pmol/µl of the target DNA. Structural analysis showed that Ca+2 and Mg+2 ions perturbed the structure of DNA. This perturbation helped to improve HRM signal resolution among DNA targets corresponding to the orthologous gene of four Plasmodium species. This novel approach has potential application not only for Plasmodium species-specific diagnosis but also for differentiation of DNAs with minor sequence variation.
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Affiliation(s)
- Priyamvada Jain
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, India
| | - Babina Chakma
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, India
| | - Naveen Singh
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, India
| | - Sanjukta Patra
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, India
| | - Pranab Goswami
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, India.
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Abstract
Peptide antibodies, with their high specificities and affinities, are invaluable reagents for peptide and protein recognition in biological specimens. Depending on the application and the assay, in which the peptide antibody is to used, several factors influence successful antibody production, including peptide selection and antibody screening. Peptide antibodies have been used in clinical laboratory diagnostics with great success for decades, primarily because they can be produced to multiple targets, recognizing native wildtype proteins, denatured proteins, and newly generated epitopes. Especially mutation-specific peptide antibodies have become important as diagnostic tools in the detection of various cancers. In addition to their use as diagnostic tools in malignant and premalignant conditions, peptide antibodies are applied in all other areas of clinical laboratory diagnostics, including endocrinology, hematology, neurodegenerative diseases, cardiovascular diseases, infectious diseases, and amyloidoses.
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Krause RGE, Grobler AF, Goldring JPD. Comparing Antibody Responses in Chickens Against Plasmodium falciparum Lactate Dehydrogenase and Glyceraldehyde-3-phosphate Dehydrogenase with Freund's and Pheroid® Adjuvants. Immunol Invest 2016; 44:627-42. [PMID: 26436851 DOI: 10.3109/08820139.2015.1070268] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Pheroid® technology was assessed as an alternative to Freund's adjuvant to raise antibodies in experimental animals. Chickens were immunized with two recombinantly expressed Plasmodium falciparum proteins, lactate dehydrogenase (PfLDH) and glyceraldehyde-3-phosphate dehydrogenase (PfGAPDH), alone or in combination with Freund's adjuvant or Pheroid®. Chicken egg yolk antibodies (IgY) were isolated and compared for specificity, sensitivity and yield. Freund's adjuvant and Pheroid® stimulated prolonged antibody responses in chickens against both antigens. Affinity purified antibodies had specificity for the recombinant and the native proteins on Western blots. Antibodies generated in the presence of Freund's adjuvant had high sensitivity for both antigens. Pheroid® generated antibodies that detected the lowest concentration of recombinant PfLDH. Freund's adjuvant and Pheroid® both improved chicken IgY yields, with Pheroid® showing a 2-fold increase relative to controls. Pheroid® was well-tolerated in chickens and has potential for development as a safe adjuvant for testing alternative stimulatory factors to improve adjuvant formulations.
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Affiliation(s)
- Robert G E Krause
- a Department of Biochemistry , University of KwaZulu-Natal , Scottsville , South Africa and
| | - Anne F Grobler
- b DST/NWU Preclinical Drug Development Platform, Faculty of Health Sciences, North-West University , Potchefstroom , South Africa
| | - J P Dean Goldring
- a Department of Biochemistry , University of KwaZulu-Natal , Scottsville , South Africa and
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De SL, Stanisic DI, Rivera F, Batzloff MR, Engwerda C, Good MF. Plasmodium berghei bio-burden correlates with parasite lactate dehydrogenase: application to murine Plasmodium diagnostics. Malar J 2016; 15:3. [PMID: 26729268 PMCID: PMC4700574 DOI: 10.1186/s12936-015-1027-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 12/02/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The spectrum of techniques to detect malaria parasites in whole blood is limited to measuring parasites in circulation. One approach that is currently used to enumerate total parasite bio-burden involves the use of bio-luminescent parasites. As an alternative approach, this study describes the use of a commercial ELISA human parasite lactate dehydrogenase (pLDH) detection kit to estimate total parasite bio-burden in murine malaria models. METHODS The cross reactivity of pLDH in a commercial human malaria pLDH diagnostic kit was established in different components of blood for different murine malaria models. The use of pLDH as a measure of parasite bio-burden was evaluated by examining pLDH in relation to peripheral blood parasitaemia as determined by microscopy and calculating total parasite bio-burden using a bio-luminescent Plasmodium berghei ANKA luciferase parasite. RESULTS The pLDH antigen was detected in all four murine Plasmodium species and in all components of Plasmodium-infected blood. A significant correlation (r = 0.6922, P value <0.0001) was observed between total parasite bio-burden, measured as log average radiance, and concentration of pLDH units. CONCLUSIONS This high throughput assay is a suitable measure of total parasite bio-burden in murine malaria infections. Unlike existing methods, it permits the estimation of both circulating and sequestered parasites, allowing a more accurate assessment of parasite bio-burden.
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Affiliation(s)
- Sai Lata De
- Institute for Glycomics, Griffith University, Gold Coast, QLD, Australia.
| | | | - Fabian Rivera
- QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.
| | - Michael R Batzloff
- Institute for Glycomics, Griffith University, Gold Coast, QLD, Australia.
| | | | - Michael F Good
- Institute for Glycomics, Griffith University, Gold Coast, QLD, Australia.
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Das S, Nag A, Liang J, Bunck DN, Umeda A, Farrow B, Coppock MB, Sarkes DA, Finch AS, Agnew HD, Pitram S, Lai B, Yu MB, Museth AK, Deyle KM, Lepe B, Rodriguez‐Rivera FP, McCarthy A, Alvarez‐Villalonga B, Chen A, Heath J, Stratis‐Cullum DN, Heath JR. A General Synthetic Approach for Designing Epitope Targeted Macrocyclic Peptide Ligands. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201505243] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Samir Das
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Arundhati Nag
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - JingXin Liang
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - David N. Bunck
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Aiko Umeda
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Blake Farrow
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Matthew B. Coppock
- Biotechnology Branch, Sensors & Electronic Devices Directorate, U.S. Army Research Laboratory, 2800 Powder Mill Road, Adelphi, MD 20783 (USA)
| | - Deborah A. Sarkes
- Biotechnology Branch, Sensors & Electronic Devices Directorate, U.S. Army Research Laboratory, 2800 Powder Mill Road, Adelphi, MD 20783 (USA)
| | - Amethist S. Finch
- Biotechnology Branch, Sensors & Electronic Devices Directorate, U.S. Army Research Laboratory, 2800 Powder Mill Road, Adelphi, MD 20783 (USA)
| | - Heather D. Agnew
- Indi Molecular, 6162 Bristol Parkway, Culver City, CA 90230 (USA)
| | - Suresh Pitram
- Indi Molecular, 6162 Bristol Parkway, Culver City, CA 90230 (USA)
| | - Bert Lai
- Indi Molecular, 6162 Bristol Parkway, Culver City, CA 90230 (USA)
| | - Mary Beth Yu
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - A. Katrine Museth
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Kaycie M. Deyle
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Bianca Lepe
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Frances P. Rodriguez‐Rivera
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Amy McCarthy
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Belen Alvarez‐Villalonga
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Ann Chen
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - John Heath
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Dimitra N. Stratis‐Cullum
- Biotechnology Branch, Sensors & Electronic Devices Directorate, U.S. Army Research Laboratory, 2800 Powder Mill Road, Adelphi, MD 20783 (USA)
| | - James R. Heath
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
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20
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Das S, Nag A, Liang J, Bunck DN, Umeda A, Farrow B, Coppock MB, Sarkes DA, Finch AS, Agnew HD, Pitram S, Lai B, Yu MB, Museth AK, Deyle KM, Lepe B, Rodriguez-Rivera FP, McCarthy A, Alvarez-Villalonga B, Chen A, Heath J, Stratis-Cullum DN, Heath JR. A General Synthetic Approach for Designing Epitope Targeted Macrocyclic Peptide Ligands. Angew Chem Int Ed Engl 2015; 54:13219-24. [PMID: 26377818 DOI: 10.1002/anie.201505243] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 08/12/2015] [Indexed: 12/20/2022]
Abstract
We describe a general synthetic strategy for developing high-affinity peptide binders against specific epitopes of challenging protein biomarkers. The epitope of interest is synthesized as a polypeptide, with a detection biotin tag and a strategically placed azide (or alkyne) presenting amino acid. This synthetic epitope (SynEp) is incubated with a library of complementary alkyne or azide presenting peptides. Library elements that bind the SynEp in the correct orientation undergo the Huisgen cycloaddition, and are covalently linked to the SynEp. Hit peptides are tested against the full-length protein to identify the best binder. We describe development of epitope-targeted linear or macrocycle peptide ligands against 12 different diagnostic or therapeutic analytes. The general epitope targeting capability for these low molecular weight synthetic ligands enables a range of therapeutic and diagnostic applications, similar to those of monoclonal antibodies.
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Affiliation(s)
- Samir Das
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Arundhati Nag
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - JingXin Liang
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - David N Bunck
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Aiko Umeda
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Blake Farrow
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Matthew B Coppock
- Biotechnology Branch, Sensors & Electronic Devices Directorate, U.S. Army Research Laboratory, 2800 Powder Mill Road, Adelphi, MD 20783 (USA)
| | - Deborah A Sarkes
- Biotechnology Branch, Sensors & Electronic Devices Directorate, U.S. Army Research Laboratory, 2800 Powder Mill Road, Adelphi, MD 20783 (USA)
| | - Amethist S Finch
- Biotechnology Branch, Sensors & Electronic Devices Directorate, U.S. Army Research Laboratory, 2800 Powder Mill Road, Adelphi, MD 20783 (USA)
| | - Heather D Agnew
- Indi Molecular, 6162 Bristol Parkway, Culver City, CA 90230 (USA)
| | - Suresh Pitram
- Indi Molecular, 6162 Bristol Parkway, Culver City, CA 90230 (USA)
| | - Bert Lai
- Indi Molecular, 6162 Bristol Parkway, Culver City, CA 90230 (USA)
| | - Mary Beth Yu
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - A Katrine Museth
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Kaycie M Deyle
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Bianca Lepe
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Frances P Rodriguez-Rivera
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Amy McCarthy
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Belen Alvarez-Villalonga
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Ann Chen
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - John Heath
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA)
| | - Dimitra N Stratis-Cullum
- Biotechnology Branch, Sensors & Electronic Devices Directorate, U.S. Army Research Laboratory, 2800 Powder Mill Road, Adelphi, MD 20783 (USA)
| | - James R Heath
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd, Pasadena, CA 91125 (USA).
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Mathema VB, Na-Bangchang K. A brief review on biomarkers and proteomic approach for malaria research. ASIAN PAC J TROP MED 2015; 8:253-62. [DOI: 10.1016/s1995-7645(14)60327-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Choveaux DL, Krause RG, Przyborski JM, Goldring JD. Identification and initial characterisation of a Plasmodium falciparum Cox17 copper metallochaperone. Exp Parasitol 2015; 148:30-9. [DOI: 10.1016/j.exppara.2014.11.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Accepted: 11/06/2014] [Indexed: 12/15/2022]
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Kaushal NA, Kaushal DC. Production and characterization of monoclonal antibodies against substrate specific loop region ofPlasmodium falciparumlactate dehydrogenase. Immunol Invest 2014; 43:556-71. [DOI: 10.3109/08820139.2014.892962] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Jain P, Chakma B, Patra S, Goswami P. Potential biomarkers and their applications for rapid and reliable detection of malaria. BIOMED RESEARCH INTERNATIONAL 2014; 2014:852645. [PMID: 24804253 PMCID: PMC3996934 DOI: 10.1155/2014/852645] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 02/11/2014] [Indexed: 12/21/2022]
Abstract
Malaria has been responsible for the highest mortality in most malaria endemic countries. Even after decades of malaria control campaigns, it still persists as a disease of high mortality due to improper diagnosis and rapidly evolving drug resistant malarial parasites. For efficient and economical malaria management, WHO recommends that all malaria suspected patients should receive proper diagnosis before administering drugs. It is thus imperative to develop fast, economical, and accurate techniques for diagnosis of malaria. In this regard an in-depth knowledge on malaria biomarkers is important to identify an appropriate biorecognition element and utilize it prudently to develop a reliable detection technique for diagnosis of the disease. Among the various biomarkers, plasmodial lactate dehydrogenase and histidine-rich protein II (HRP II) have received increasing attention for developing rapid and reliable detection techniques for malaria. The widely used rapid detection tests (RDTs) for malaria succumb to many drawbacks which promotes exploration of more efficient economical detection techniques. This paper provides an overview on the current status of malaria biomarkers, along with their potential utilization for developing different malaria diagnostic techniques and advanced biosensors.
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Affiliation(s)
- Priyamvada Jain
- Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
| | - Babina Chakma
- Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
| | - Sanjukta Patra
- Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
| | - Pranab Goswami
- Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati, Assam 781039, India
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25
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Mouatcho JC, Goldring JPD. Malaria rapid diagnostic tests: challenges and prospects. J Med Microbiol 2013; 62:1491-1505. [PMID: 24048274 DOI: 10.1099/jmm.0.052506-0] [Citation(s) in RCA: 157] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In the last decade, there has been an upsurge of interest in developing malaria rapid diagnostic test (RDT) kits for the detection of Plasmodium species. Three antigens - Plasmodium falciparum histidine-rich protein 2 (PfHRP2), plasmodial aldolase and plasmodial lactate dehydrogenase (pLDH) - are currently used for RDTs. Tests targeting HRP2 contribute to more than 90% of the malaria RDTs in current use. However, the specificities, sensitivities, numbers of false positives, numbers of false negatives and temperature tolerances of these tests vary considerably, illustrating the difficulties and challenges facing current RDTs. This paper describes recent developments in malaria RDTs, reviewing RDTs detecting PfHRP2, pLDH and plasmodial aldolase. The difficulties associated with RDTs, such as genetic variability in the Pfhrp2 gene and the persistence of antigens in the bloodstream following the elimination of parasites, are discussed. The prospect of overcoming the problems associated with current RDTs with a new generation of alternative malaria antigen targets is also described.
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Affiliation(s)
- Joel C Mouatcho
- Department of Biochemistry, School of Life Science, University of Kwazulu-Natal, Pietermaritzburg, Private Bag X01 Scottsville 3209, South Africa
| | - J P Dean Goldring
- Department of Biochemistry, School of Life Science, University of Kwazulu-Natal, Pietermaritzburg, Private Bag X01 Scottsville 3209, South Africa
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26
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Choveaux DL, Przyborski JM, Goldring JPD. A Plasmodium falciparum copper-binding membrane protein with copper transport motifs. Malar J 2012. [PMID: 23190769 PMCID: PMC3528452 DOI: 10.1186/1475-2875-11-397] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Background Copper is an essential catalytic co-factor for metabolically important cellular enzymes, such as cytochrome-c oxidase. Eukaryotic cells acquire copper through a copper transport protein and distribute intracellular copper using molecular chaperones. The copper chelator, neocuproine, inhibits Plasmodium falciparum ring-to-trophozoite transition in vitro, indicating a copper requirement for malaria parasite development. How the malaria parasite acquires or secretes copper still remains to be fully elucidated. Methods PlasmoDB was searched for sequences corresponding to candidate P. falciparum copper-requiring proteins. The amino terminal domain of a putative P. falciparum copper transport protein was cloned and expressed as a maltose binding fusion protein. The copper binding ability of this protein was examined. Copper transport protein-specific anti-peptide antibodies were generated in chickens and used to establish native protein localization in P. falciparum parasites by immunofluorescence microscopy. Results Six P. falciparum copper-requiring protein orthologs and a candidate P. falciparum copper transport protein (PF14_0369), containing characteristic copper transport protein features, were identified in PlasmoDB. The recombinant amino terminal domain of the transport protein bound reduced copper in vitro and within Escherichia coli cells during recombinant expression. Immunolocalization studies tracked the copper binding protein translocating from the erythrocyte plasma membrane in early ring stage to a parasite membrane as the parasites developed to schizonts. The protein appears to be a PEXEL-negative membrane protein. Conclusion Plasmodium falciparum parasites express a native protein with copper transporter characteristics that binds copper in vitro. Localization of the protein to the erythrocyte and parasite plasma membranes could provide a mechanism for the delivery of novel anti-malarial compounds.
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Affiliation(s)
- David L Choveaux
- Biochemistry, University of KwaZulu-Natal, Carbis Road, Scottsville, 3209, South Africa
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Piper RC, Buchanan I, Choi YH, Makler MT. Opportunities for improving pLDH-based malaria diagnostic tests. Malar J 2011; 10:213. [PMID: 21806821 PMCID: PMC3163226 DOI: 10.1186/1475-2875-10-213] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Accepted: 08/01/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Monoclonal antibodies to Plasmodium lactate dehydrogenase (pLDH) have been previously used to format immunochromatographic tests for the diagnosis of malaria. Using pLDH as an antigen has several advantages as a sensitive measure of the presence of parasites within patient blood samples. However, variable results in terms of specificity and sensitivity among different commercially available diagnostic kits have been reported and it has not been clear from these studies whether the performance of an individual test is due simply to how it is engineered or whether it is due to the biochemical nature of the pLDH-antibody reaction itself. METHODS A series of systematic studies to determine how various pLDH monoclonal antibodies work in combination was undertaken. Different combinations of anti-pLDH monoclonal antibodies were used in a rapid-test immunochromatographic assay format to determine parameters of sensitivity and specificity with regard to individual Plasmodium species. RESULTS Dramatic differences were found in both species specificity and overall sensitivity depending on which antibody is used on the immunochromatographic strip and which is used on the colorimetric colloidal-gold used for visual detection. DISCUSSION The results demonstrate the feasibility of different test formats for the detection and speciation of malarial infections. In addition, the data will enable the development of a universal rapid test algorithm that may potentially provide a cost-effective strategy to diagnose and manage patients in a wide range of clinical settings. CONCLUSION These data emphasize that using different anti-pLDH antibody combinations offers a tractable way to optimize immunochromatographic pLDH tests.
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Affiliation(s)
- Robert C Piper
- Flow Incorporated, 6127 SW Corbett, Portland, OR 97239-3601, USA.
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