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Igwe CL, Pauk JN, Müller DF, Jaeger M, Deuschitz D, Hartmann T, Spadiut O. Comprehensive evaluation of recombinant lactate dehydrogenase production from inclusion bodies. J Biotechnol 2024; 379:65-77. [PMID: 38036002 DOI: 10.1016/j.jbiotec.2023.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 11/22/2023] [Accepted: 11/23/2023] [Indexed: 12/02/2023]
Abstract
A broad application spectrum ranging from clinical diagnostics to biosensors in a variety of sectors, makes the enzyme Lactate dehydrogenase (LDH) highly interesting for recombinant protein production. Expression of recombinant LDH is currently mainly carried out in uncontrolled shake-flask cultivations leading to protein that is mostly produced in its soluble form, however in rather low yields. Inclusion body (IB) processes have gathered a lot of attention due to several benefits like increased space-time yields and high purity of the target product. Thus, to investigate the suitability of this processing strategy for ldhL1 production, a fed-batch fermentation steering the production of IBs rather than soluble product formation was developed. It was shown that the space-time-yield of the fermentation could be increased almost 3-fold by increasing qs to 0.25 g g-1 h-1 which corresponds to 21% of qs,max, and keeping the temperature at 37°C after induction. Solubilization and refolding unit operations were developed to regain full bioactivity of the ldhL1. The systematic approach in screening for solubilization and refolding conditions revealed buffer compositions and processing strategies that ultimately resulted in 50% product recovery in the refolding step, revealing major optimization potential in the downstream processing chain. The recovered ldhL1 showed an optimal activity at pH 5.5 and 30∘C with a high catalytic activity and KM values of 0.46 mM and 0.18 mM for pyruvate and NADH, respectively. These features, show that the here produced LDH is a valuable source for various commercial applications, especially considering low pH-environments.
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Affiliation(s)
- Chika Linda Igwe
- Competence Center CHASE GmbH, Hafenstraße 47-51, Linz 4020, Austria; Institute of Chemical, Getreidemarkt 9, Vienna 1060, Austria
| | - Jan Niklas Pauk
- Competence Center CHASE GmbH, Hafenstraße 47-51, Linz 4020, Austria; Institute of Chemical, Getreidemarkt 9, Vienna 1060, Austria
| | | | - Mira Jaeger
- Institute of Chemical, Getreidemarkt 9, Vienna 1060, Austria
| | | | - Thomas Hartmann
- Institute of Chemical, Getreidemarkt 9, Vienna 1060, Austria
| | - Oliver Spadiut
- Institute of Chemical, Getreidemarkt 9, Vienna 1060, Austria.
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2
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Kim YJ, Shin JS, Lee KW, Eom HJ, Jo BG, Lee JW, Kim JH, Kim SY, Kang JH, Choi JW. Expression, Purification, and Characterization of Plasmodium vivax Lactate Dehydrogenase from Bacteria without Codon Optimization. Int J Mol Sci 2023; 24:11083. [PMID: 37446261 DOI: 10.3390/ijms241311083] [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: 05/30/2023] [Revised: 06/30/2023] [Accepted: 06/30/2023] [Indexed: 07/15/2023] Open
Abstract
Plasmodium vivax is the most widespread cause of malaria, especially in subtropical and temperate regions such as Asia-Pacific and America. P. vivax lactate dehydrogenase (PvLDH), an essential enzyme in the glycolytic pathway, is required for the development and reproduction of the parasite. Thus, LDH from these parasites has garnered attention as a diagnostic biomarker for malaria and as a potential molecular target for developing antimalarial drugs. In this study, we prepared a transformed Escherichia coli strain for the overexpression of PvLDH without codon optimization. We introduced this recombinant plasmid DNA prepared by insertion of the PvLDH gene in the pET-21a(+) expression vector, into the Rosetta(DE3), an E. coli strain suitable for eukaryotic protein expression. The time, temperature, and inducer concentration for PvLDH expression from this E. coli Rosetta(DE3), containing the original PvLDH gene, were optimized. We obtained PvLDH with a 31.0 mg/L yield and high purity (>95%) from this Rosetta(DE3) strain. The purified protein was characterized structurally and functionally. The PvLDH expressed and purified from transformed bacteria without codon optimization was successfully demonstrated to exhibit its potential tetramer structure and enzyme activity. These findings are expected to provide valuable insights for research on infectious diseases, metabolism, diagnostics, and therapeutics for malaria caused by P. vivax.
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Affiliation(s)
- Yeon-Jun Kim
- Department of Biomedical Science, Cheongju University, Cheongju 28160, Republic of Korea
| | - Jun-Seop Shin
- Department of Biomedical Science, Cheongju University, Cheongju 28160, Republic of Korea
| | - Kang Woo Lee
- Department of Biomedical Science, Cheongju University, Cheongju 28160, Republic of Korea
| | - Hyo-Ji Eom
- Department of Biomedical Science, Cheongju University, Cheongju 28160, Republic of Korea
| | - Byung Gwan Jo
- Department of Biomedical Science, Cheongju University, Cheongju 28160, Republic of Korea
| | - Jin Woo Lee
- College of Pharmacy, Duksung Women's University, Seoul 01369, Republic of Korea
| | - Jun Hyoung Kim
- Division of Infectious Diseases, Department of Internal Medicine, Chungbuk National University Hospital, Cheongju 28644, Republic of Korea
| | - So Yeon Kim
- Department of Dental Hygiene, Cheongju University, Cheongju 28503, Republic of Korea
| | - Jung Hoon Kang
- Department of Biomedical Science, Cheongju University, Cheongju 28160, Republic of Korea
- Department of Biopharmaceutical Sciences, Cheongju University, Cheongju 28160, Republic of Korea
| | - Jae-Won Choi
- Department of Biomedical Science, Cheongju University, Cheongju 28160, Republic of Korea
- Department of Biopharmaceutical Sciences, Cheongju University, Cheongju 28160, Republic of Korea
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Salim NO, Fuad FAA, Khairuddin F, Seman WMKW, Jonet MA. Purifying and Characterizing Bacterially Expressed Soluble Lactate Dehydrogenase from Plasmodium knowlesi for the Development of Anti-Malarial Drugs. Molecules 2021; 26:molecules26216625. [PMID: 34771034 PMCID: PMC8588329 DOI: 10.3390/molecules26216625] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 10/11/2021] [Accepted: 10/19/2021] [Indexed: 11/30/2022] Open
Abstract
Plasmodium lactate dehydrogenase (pLH) is one of the enzymes in glycolysis with potential target for chemotherapy. This study aimed to clone, overexpress and characterize soluble recombinant lactate dehydrogenase from Plasmodium knowlesi in a bacterial system. Synthetic P. knowlesi lactate dehydrogenase (Pk-LDH) gene was cloned into pET21a expression vector, transformed into Escherichia coli strain BL21 (DE3) expression system and then incubated for 18 h, 20 °C with the presence of 0.5 mM isopropyl β-d-thiogalactoside in Terrific broth supplemented with Magnesium sulfate, followed by protein purifications using Immobilized Metal Ion Affinity Chromatography and size exclusion chromatography (SEC). Enzymatic assay was conducted to determine the activity of the enzyme. SDS-PAGE analysis revealed that protein of 34 kDa size was present in the soluble fraction. In SEC, a single peak corresponding to the size of Pk-LDH protein was observed, indicating that the protein has been successfully purified. From MALDI-TOF analysis findings, a peptide score of 282 was established, which is significant for lactate dehydrogenase from P. knowlesi revealed via MASCOT analysis. Secondary structure analysis of CD spectra indicated 79.4% α helix and 1.37% β strand structure. Specific activity of recombinant Pk-LDH was found to be 475.6 U/mg, confirming the presence of active protein. Soluble Pk-LDH that is biologically active was produced, which can be used further in other malaria studies.
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Affiliation(s)
- Nurhainis Ogu Salim
- Department of Biotechnology Engineering, Faculty of Engineering, International Islamic University Malaysia, P.O. Box 10, Kuala Lumpur 50728, W.P. Kuala Lumpur, Malaysia;
- Parasitology Unit, Institute for Medical Research, National Institutes of Health (NIH), Ministry of Health Malaysia NIH Complex, Bandar Setia Alam, Shah Alam 40170, Selangor, Malaysia
| | - Fazia Adyani Ahmad Fuad
- Department of Biotechnology Engineering, Faculty of Engineering, International Islamic University Malaysia, P.O. Box 10, Kuala Lumpur 50728, W.P. Kuala Lumpur, Malaysia;
- Correspondence: ; Tel.: +603-6421-4577
| | - Farahayu Khairuddin
- Malaysia Genome Institute, National Institutes of Biotechnology Malaysia, Jalan Bangi, Kajang 43000, Selangor, Malaysia; (F.K.); (W.M.K.W.S.); (M.A.J.)
| | - Wan Mohd Khairulikhsan Wan Seman
- Malaysia Genome Institute, National Institutes of Biotechnology Malaysia, Jalan Bangi, Kajang 43000, Selangor, Malaysia; (F.K.); (W.M.K.W.S.); (M.A.J.)
| | - Mohd Anuar Jonet
- Malaysia Genome Institute, National Institutes of Biotechnology Malaysia, Jalan Bangi, Kajang 43000, Selangor, Malaysia; (F.K.); (W.M.K.W.S.); (M.A.J.)
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4
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Tian L, Zhou J, Lv Q, Liu F, Yang T, Zhang X, Xu M, Rao Z. Rational engineering of the Plasmodium falciparuml-lactate dehydrogenase loop involved in catalytic proton transfer to improve chiral 2-hydroxybutyric acid production. Int J Biol Macromol 2021; 179:71-79. [PMID: 33631263 DOI: 10.1016/j.ijbiomac.2021.02.144] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/13/2021] [Accepted: 02/19/2021] [Indexed: 12/29/2022]
Abstract
l-lactate dehydrogenases (LDHs) has been widely studied for their ability to reduce 2-keto acids for the production of 2-hydroxy acids, whereby 2-hydroxybutyric acids (2-HBA) is among the most important fundamental building blocks for synthesizing pharmaceuticals and biodegradable materials. However, LDHs usually show low activity towards 2-keto acids with longer side chain such as 2-oxobutyric acid (2-OBA). Here rational engineering of the Plasmodium falciparum LDH loop with residue involved in the catalytic proton transfer was initially studied. By combining homology alignment and structure-based design approach, we found that changing the charge characteristics or hydrogen bond network interactions of this loop could improve enzymatic catalytic activities and stabilities towards 2-OBA. Compared with wild type, variant N197Dldh showed 1.15 times higher activity and 2.73 times higher Kcat/Km. The half-life of variant N197Dldh at 40 °C increased to 77.9 h compared with 50.4 h of wild type. Furthermore, asymmetric synthesis of (S)-2-HBA with coenzyme regeneration revealed 95.8 g/L production titer within 12 h for variant N197Dldh, 2.05 times higher than using wild type. Our study indicated the importance of loop with residues involved in the catalytic proton transfer process, and the engineered LDH would be more suitable for (S)-2-HBA production.
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Affiliation(s)
- Lingzhi Tian
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province 214122, China
| | - Junping Zhou
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province 214122, China
| | - Qinglan Lv
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province 214122, China
| | - Fei Liu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province 214122, China
| | - Taowei Yang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province 214122, China
| | - Xian Zhang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province 214122, China
| | - Meijuan Xu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province 214122, China.
| | - Zhiming Rao
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu Province 214122, China.
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5
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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: 2.1] [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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Novy V, Brunner B, Müller G, Nidetzky B. Toward "homolactic" fermentation of glucose and xylose by engineered Saccharomyces cerevisiae harboring a kinetically efficient l-lactate dehydrogenase within pdc1-pdc5 deletion background. Biotechnol Bioeng 2016; 114:163-171. [PMID: 27426989 DOI: 10.1002/bit.26048] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 06/20/2016] [Accepted: 07/14/2016] [Indexed: 10/21/2022]
Abstract
l-Lactic acid is an important platform chemical and its production from the lignocellulosic sugars glucose and xylose is, therefore, of high interest. Tolerance to low pH and a generally high robustness make Saccharomyces cerevisiae a promising host for l-lactic acid fermentation but strain development for effective utilization of both sugars is an unsolved problem. The herein used S. cerevisiae strain IBB10B05 incorporates a NADH-dependent pathway for oxidoreductive xylose assimilation within CEN.PK113-7D background and was additionally evolved for accelerated xylose-to-ethanol fermentation. Selecting the Plasmodium falciparum l-lactate dehydrogenase (pfLDH) for its high kinetic efficiency, strain IBB14LA1 was derived from IBB10B05 by placing the pfldh gene at the pdc1 locus under control of the pdc1 promotor. Strain IBB14LA1_5 additionally had the pdc5 gene disrupted. With both strains, continued l-lactic acid formation from glucose or xylose, each at 50 g/L, necessitated stabilization of pH. Using calcium carbonate (11 g/L), anaerobic shaken bottle fermentations at pH ≥ 5 resulted in l-lactic acid yields (YLA ) of 0.67 g/g glucose and 0.80 g/g xylose for strain IBB14LA1_5. Only little xylitol was formed (≤0.08 g/g) and no ethanol. In pH stabilized aerobic conversions of glucose, strain IBB14LA1_5 further showed excellent l-lactic acid productivities (1.8 g/L/h) without losses in YLA (0.69 g/g glucose). In strain IBB14LA1, the YLA was lower (≤0.18 g/g glucose; ≤0.27 g/g xylose) due to ethanol as well as xylitol formation. Therefore, this study shows that a S. cerevisiae strain originally optimized for xylose-to-ethanol fermentation was useful to implement l-lactic acid production from glucose and xylose; and with the metabolic engineering strategy applied, advance toward homolactic fermentation of both sugars was made. Biotechnol. Bioeng. 2017;114: 163-171. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Vera Novy
- Graz University of Technology, Institute of Biotechnology and Biochemical Engineering, NAWI Graz, Petersgasse 12/I, 8010 Graz, Austria
| | - Bernd Brunner
- Graz University of Technology, Institute of Biotechnology and Biochemical Engineering, NAWI Graz, Petersgasse 12/I, 8010 Graz, Austria
| | - Gerdt Müller
- Graz University of Technology, Institute of Biotechnology and Biochemical Engineering, NAWI Graz, Petersgasse 12/I, 8010 Graz, Austria
| | - Bernd Nidetzky
- Graz University of Technology, Institute of Biotechnology and Biochemical Engineering, NAWI Graz, Petersgasse 12/I, 8010 Graz, Austria.,Austrian Centre of Industrial Biotechnology, Graz, Austria
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7
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Vasuvat J, Montree A, Moonsom S, Leartsakulpanich U, Petmitr S, Focher F, Wright GE, Chavalitshewinkoon-Petmitr P. Biochemical and functional characterization of Plasmodium falciparum DNA polymerase δ. Malar J 2016; 15:116. [PMID: 26911594 PMCID: PMC4766629 DOI: 10.1186/s12936-016-1166-0] [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: 10/14/2015] [Accepted: 02/11/2016] [Indexed: 12/05/2022] Open
Abstract
Background Emergence of drug-resistant Plasmodium falciparum has created an urgent need for new drug targets. DNA polymerase δ is an essential enzyme required for chromosomal DNA replication and repair, and therefore may be a potential target for anti-malarial drug development. However, little is known of the characteristics and function of this P. falciparum enzyme. Methods The coding sequences of DNA polymerase δ catalytic subunit (PfPolδ-cat), DNA polymerase δ small subunit (PfPolδS) and proliferating cell nuclear antigen (PfPCNA) from chloroquine- and pyrimethamine-resistant P. falciparum strain K1 were amplified, cloned into an expression vector and expressed in Escherichia coli. The recombinant proteins were analysed by SDS-PAGE and identified by LC–MS/MS. PfPolδ-cat was biochemically characterized. The roles of PfPolδS and PfPCNA in PfPolδ-cat function were investigated. In addition, inhibitory effects of 11 compounds were tested on PfPolδ-cat activity and on in vitro parasite growth using SYBR Green I assay. Results The purified recombinant protein PfPolδ-cat, PfPolδS and PfPCNA showed on SDS-PAGE the expected size of 143, 57 and 34 kDa, respectively. Predicted amino acid sequence of the PfPolδ-cat and PfPolδS had 59.2 and 24.7 % similarity respectively to that of the human counterpart. The PfPolδ-cat possessed both DNA polymerase and 3′–5′ exonuclease activities. It used both Mg2+ and Mn2+ as cofactors and was inhibited by high KCl salt (>200 mM). PfPolδS stimulated PfPolδ-cat activity threefolds and up to fourfolds when PfPCNA was included in the assay. Only two compounds were potent inhibitors of PfPolδ-cat, namely, butylphenyl-dGTP (BuPdGTP; IC50 of 38 µM) and 7-acetoxypentyl-(3, 4 dichlorobenzyl) guanine (7-acetoxypentyl-DCBG; IC50 of 55 µM). The latter compound showed higher inhibition on parasite growth (IC50 of 4.1 µM). Conclusions Recombinant PfPolδ-cat, PfPolδS and PfPCNA were successfully expressed and purified. PfPolS and PfPCNA increased DNA polymerase activity of PfPolδ-cat. The high sensitivity of PfPolδ to BuPdGTP can be used to differentiate parasite enzyme from mammalian and human counterparts. Interestingly, 7-acetoxypentyl-DCBG showed inhibitory effects on both enzyme activity and parasite growth. Thus, 7-acetoxypentyl-DCBG is a potential candidate for future development of a new class of anti-malarial agents targeting parasite replicative DNA polymerase.
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Affiliation(s)
- Jitlada Vasuvat
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand.
| | - Atcha Montree
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand.
| | - Sangduen Moonsom
- Department of Protozoology, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand.
| | - Ubolsree Leartsakulpanich
- National Centre for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Thailand Science Park, Pahonyothin Rd, Pathumthani, 12120, Thailand.
| | - Songsak Petmitr
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand.
| | | | - George E Wright
- GLSynthesis Inc., One Innovation Drive, Worcester, MA, 01605, USA.
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Cheung YW, Kwok J, Law AWL, Watt RM, Kotaka M, Tanner JA. Structural basis for discriminatory recognition of Plasmodium lactate dehydrogenase by a DNA aptamer. Proc Natl Acad Sci U S A 2013; 110:15967-72. [PMID: 24043813 PMCID: PMC3791781 DOI: 10.1073/pnas.1309538110] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
DNA aptamers have significant potential as diagnostic and therapeutic agents, but the paucity of DNA aptamer-target structures limits understanding of their molecular binding mechanisms. Here, we report a distorted hairpin structure of a DNA aptamer in complex with an important diagnostic target for malaria: Plasmodium falciparum lactate dehydrogenase (PfLDH). Aptamers selected from a DNA library were highly specific and discriminatory for Plasmodium as opposed to human lactate dehydrogenase because of a counterselection strategy used during selection. Isothermal titration calorimetry revealed aptamer binding to PfLDH with a dissociation constant of 42 nM and 2:1 protein:aptamer molar stoichiometry. Dissociation constants derived from electrophoretic mobility shift assays and surface plasmon resonance experiments were consistent. The aptamer:protein complex crystal structure was solved at 2.1-Å resolution, revealing two aptamers bind per PfLDH tetramer. The aptamers showed a unique distorted hairpin structure in complex with PfLDH, displaying a Watson-Crick base-paired stem together with two distinct loops each with one base flipped out by specific interactions with PfLDH. Aptamer binding specificity is dictated by extensive interactions of one of the aptamer loops with a PfLDH loop that is absent in human lactate dehydrogenase. We conjugated the aptamer to gold nanoparticles and demonstrated specificity of colorimetric detection of PfLDH over human lactate dehydrogenase. This unique distorted hairpin aptamer complex provides a perspective on aptamer-mediated molecular recognition and may guide rational design of better aptamers for malaria diagnostics.
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Affiliation(s)
| | - Jane Kwok
- Physiology, Li Ka Shing Faculty of Medicine, and
| | | | - Rory M. Watt
- Faculty of Dentistry, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, People's Republic of China
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Mutlu Ö, Balık DT. Kinetic analysis of the amino terminal end of active site loop of lactate deyhdrogenase from Plasmodium vivax. Balkan Med J 2012; 29:364-9. [PMID: 25207035 PMCID: PMC4115892 DOI: 10.5152/balkanmedj.2012.047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2012] [Accepted: 06/05/2012] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE In this study, kinetic analysis was performed to understand the functional importance of the amino terminal of the active site of previously mutated Plasmodium vivax Lactate Dehydrogenase enzyme by mimicking Toxoplasma gondii I, II, Eimeria acervulina and Eimeria tenella LDH's. MATERIAL AND METHODS Mutant LDH genes were amplified by PCR and 6xHistag was added to the C-terminal of the enzymes. Then LDH enzymes are overproduced as recombinant in E. coli cells, purified by Ni-NTA agarose matrix and kinetic properties were analysed. RESULTS Observing increase of Km values of mutant enzymes showed that mutations in this place caused decreasing affinity of enzyme for its substrate. However kcat values were about the same throughout all mutant proteins. CONCLUSION Sensitivity of the studied region emphasizes the significance of this site for drug design studies for both Plasmodium and some other Apicomplexans.
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Affiliation(s)
- Özal Mutlu
- Department of Biology, Faculty of Arts and Sciences, Marmara University, İstanbul, Turkey
| | - Dilek Turgut Balık
- Department of Bioengineering, Faculty of Chemical and Metallurgical Engineering, Yıldız Technical University, İstanbul, Turkey
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Plata G, Hsiao TL, Olszewski KL, Llinás M, Vitkup D. Reconstruction and flux-balance analysis of the Plasmodium falciparum metabolic network. Mol Syst Biol 2010; 6:408. [PMID: 20823846 PMCID: PMC2964117 DOI: 10.1038/msb.2010.60] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2010] [Accepted: 07/09/2010] [Indexed: 12/18/2022] Open
Abstract
Genome-scale metabolic reconstructions can serve as important tools for hypothesis generation and high-throughput data integration. Here, we present a metabolic network reconstruction and flux-balance analysis (FBA) of Plasmodium falciparum, the primary agent of malaria. The compartmentalized metabolic network accounts for 1001 reactions and 616 metabolites. Enzyme-gene associations were established for 366 genes and 75% of all enzymatic reactions. Compared with other microbes, the P. falciparum metabolic network contains a relatively high number of essential genes, suggesting little redundancy of the parasite metabolism. The model was able to reproduce phenotypes of experimental gene knockout and drug inhibition assays with up to 90% accuracy. Moreover, using constraints based on gene-expression data, the model was able to predict the direction of concentration changes for external metabolites with 70% accuracy. Using FBA of the reconstructed network, we identified 40 enzymatic drug targets (i.e. in silico essential genes), with no or very low sequence identity to human proteins. To demonstrate that the model can be used to make clinically relevant predictions, we experimentally tested one of the identified drug targets, nicotinate mononucleotide adenylyltransferase, using a recently discovered small-molecule inhibitor.
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Affiliation(s)
- Germán Plata
- Center for Computational Biology and Bioinformatics, Columbia University, New York City, NY 10032, USA
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11
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Selective expression of the soluble product fraction in Escherichia coli cultures employed in recombinant protein production processes. Appl Microbiol Biotechnol 2010; 87:2047-58. [DOI: 10.1007/s00253-010-2608-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Revised: 03/31/2010] [Accepted: 04/09/2010] [Indexed: 10/19/2022]
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12
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Hurdayal R, Achilonu I, Choveaux D, Coetzer THT, Dean Goldring JP. Anti-peptide antibodies differentiate between plasmodial lactate dehydrogenases. Peptides 2010; 31:525-32. [PMID: 20093160 DOI: 10.1016/j.peptides.2010.01.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2009] [Revised: 01/08/2010] [Accepted: 01/08/2010] [Indexed: 11/27/2022]
Abstract
Malaria lactate dehydrogenase, a glycolytic enzyme, is a malaria diagnostic target in lateral flow immunochromatographic rapid diagnostic tests. Recombinant Plasmodium yoelii LDH was cloned into the pET-28a vector, expressed and the expressed protein purified from a Ni-NTA affinity matrix. A pan-malarial LDH antibody directed against a common malaria LDH peptide (APGKSDKEWNRDDLL) and two anti-peptide antibodies, each targeting a unique Plasmodium falciparum (LISDAELEAIFDC) and Plasmodium vivax (KITDEEVEGIFDC) LDH peptide were raised in chickens. The antibodies were affinity purified with the appropriate peptide affinity matrix. The affinity purified anti-peptide antibodies detected recombinant P. falciparum, P. vivax and P. yoelii LDH and native P. falciparum and P. yoelii LDH in western blots and immunofluorescence studies. The pan-malarial antibody detected LDH from the three malaria species in western blots. The species-specific anti-peptide antibodies differentiated between P. falciparum and P. vivax LDH. Affinity purified chicken antibodies against recombinant PfLDH, PvLDH and PyLDH proteins each detected the parent and orthologous proteins with similar titers in an ELISA. The study supports an anti-peptide antibody approach to the development of diagnostic reagents.
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Affiliation(s)
- Ramona Hurdayal
- Biochemistry, University of KwaZulu-Natal, PB X01, Carbis Road, Scottsville 3209, South Africa
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Heterologous expression of plasmodial proteins for structural studies and functional annotation. Malar J 2008; 7:197. [PMID: 18828893 PMCID: PMC2567985 DOI: 10.1186/1475-2875-7-197] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Accepted: 10/01/2008] [Indexed: 11/10/2022] Open
Abstract
Malaria remains the world's most devastating tropical infectious disease with as many as 40% of the world population living in risk areas. The widespread resistance of Plasmodium parasites to the cost-effective chloroquine and antifolates has forced the introduction of more costly drug combinations, such as Coartem®. In the absence of a vaccine in the foreseeable future, one strategy to address the growing malaria problem is to identify and characterize new and durable antimalarial drug targets, the majority of which are parasite proteins. Biochemical and structure-activity analysis of these proteins is ultimately essential in the characterization of such targets but requires large amounts of functional protein. Even though heterologous protein production has now become a relatively routine endeavour for most proteins of diverse origins, the functional expression of soluble plasmodial proteins is highly problematic and slows the progress of antimalarial drug target discovery. Here the status quo of heterologous production of plasmodial proteins is presented, constraints are highlighted and alternative strategies and hosts for functional expression and annotation of plasmodial proteins are reviewed.
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