1
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Liu JL, Shriver-Lake LC, Zabetakis D, Goldman ER, Anderson GP. Selection of Single-Domain Antibodies towards Western Equine Encephalitis Virus. Antibodies (Basel) 2018; 7:E44. [PMID: 31544894 PMCID: PMC6698954 DOI: 10.3390/antib7040044] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 12/12/2018] [Accepted: 12/12/2018] [Indexed: 12/21/2022] Open
Abstract
In this work, we describe the selection and characterization of single-domain antibodies (sdAb) towards the E2/E3E2 envelope protein of the Western equine encephalitis virus (WEEV). Our purpose was to identify novel recognition elements which could be used for the detection, diagnosis, and perhaps treatment of western equine encephalitis (WEE). To achieve this goal, we prepared an immune phage display library derived from the peripheral blood lymphocytes of a llama that had been immunized with an equine vaccine that includes killed WEEV (West Nile Innovator + VEWT). This library was panned against recombinant envelope (E2/E3E2) protein from WEEV, and seven representative sdAb from the five identified sequence families were characterized. The specificity, affinity, and melting point of each sdAb was determined, and their ability to detect the recombinant protein in a MagPlex sandwich immunoassay was confirmed. Thus, these new binders represent novel recognition elements for the E2/E3E2 proteins of WEEV that are available to the research community for further investigation into their applicability for use in the diagnosis or treatment of WEE.
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Affiliation(s)
- Jinny L Liu
- Naval Research Laboratory, Center for Biomolecular Science and Engineering, Washington, DC 20375, USA.
| | - Lisa C Shriver-Lake
- Naval Research Laboratory, Center for Biomolecular Science and Engineering, Washington, DC 20375, USA.
| | - Dan Zabetakis
- Naval Research Laboratory, Center for Biomolecular Science and Engineering, Washington, DC 20375, USA.
| | - Ellen R Goldman
- Naval Research Laboratory, Center for Biomolecular Science and Engineering, Washington, DC 20375, USA.
| | - George P Anderson
- Naval Research Laboratory, Center for Biomolecular Science and Engineering, Washington, DC 20375, USA.
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2
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Rajan R, Matsumura K. A zwitterionic polymer as a novel inhibitor of protein aggregation. J Mater Chem B 2015; 3:5683-5689. [DOI: 10.1039/c5tb01021g] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A zwitterionic polymer was synthesized via RAFT polymerization. This polymer prevented heat induced protein aggregation, by preventing hydrophobic interactions between protein chains in solution, thus acting as a molecular shield.
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Affiliation(s)
- Robin Rajan
- School of Materials Science
- Japan Advanced Institute of Science and
- Technology
- Nomi
- Japan
| | - Kazuaki Matsumura
- School of Materials Science
- Japan Advanced Institute of Science and
- Technology
- Nomi
- Japan
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3
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Hülseweh B, Rülker T, Pelat T, Langermann C, Frenzel A, Schirrmann T, Dübel S, Thullier P, Hust M. Human-like antibodies neutralizing Western equine encephalitis virus. MAbs 2014; 6:718-27. [PMID: 24518197 PMCID: PMC4011916 DOI: 10.4161/mabs.28170] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
This study describes the development of the first neutralizing antibodies against Western equine encephalitis virus (WEEV), a member of the genus Alphavirus. WEEV is transmitted by mosquitoes and can spread to the human central nervous system, causing symptoms ranging from mild febrile reactions to life-threatening encephalitis. WEEV has been classified as a biological warfare agent by the US Centers for Disease Control and Prevention. No anti-WEEV drugs are currently commercially available. Neutralizing antibodies are useful for the pre- and post-exposure treatment of WEEV infections. In this study, two immune antibody gene libraries were constructed from two macaques immunized with inactivated WEEV. Four antibodies were selected from these libraries and recloned as scFv-Fc, with a human Fc part. These antibodies bound WEEV specifically in ELISA with little or no cross-reaction with other alphaviruses. They were further analyzed by immunohistochemistry. All binders were suitable for the intracellular detection of WEEV particles. Neutralizing activity was determined in vitro. Three of the four antibodies were found to be neutralizing; about 1 ng/mL of the best antibody (ToR69–3A2) neutralized 50% of 5x104 TCID50/mL. Due to its human-like nature with a germinality index of 89% (VH) and 91% (VL), the ToR69–3A2 antibody is a promising candidate for future passive vaccine development.
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Affiliation(s)
- Birgit Hülseweh
- Wehrwissenschaftliches Institut für Schutztechnologien (WIS); ABC-Schutz; Munster, Germany
| | - Torsten Rülker
- Technische Universität Braunschweig; Institut für Biochemie, Biotechnologie und Bioinformatik; Braunschweig, Germany
| | - Thibaut Pelat
- Institut de Recherche Biomédicale des Armées (IRBA-CRSSA); Département de Microbiologie; Unité de biotechnologie des anticorps et des toxines; La Tronche, France
| | - Claudia Langermann
- Wehrwissenschaftliches Institut für Schutztechnologien (WIS); ABC-Schutz; Munster, Germany
| | - Andrè Frenzel
- Technische Universität Braunschweig; Institut für Biochemie, Biotechnologie und Bioinformatik; Braunschweig, Germany
| | - Thomas Schirrmann
- Technische Universität Braunschweig; Institut für Biochemie, Biotechnologie und Bioinformatik; Braunschweig, Germany
| | - Stefan Dübel
- Technische Universität Braunschweig; Institut für Biochemie, Biotechnologie und Bioinformatik; Braunschweig, Germany
| | - Philippe Thullier
- Institut de Recherche Biomédicale des Armées (IRBA-CRSSA); Département de Microbiologie; Unité de biotechnologie des anticorps et des toxines; La Tronche, France
| | - Michael Hust
- Technische Universität Braunschweig; Institut für Biochemie, Biotechnologie und Bioinformatik; Braunschweig, Germany
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4
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Huber G, Bánki Z, Kunert R, Stoiber H. Novel bifunctional single-chain variable antibody fragments to enhance virolysis by complement: generation and proof-of-concept. BIOMED RESEARCH INTERNATIONAL 2014; 2014:971345. [PMID: 24524088 PMCID: PMC3913500 DOI: 10.1155/2014/971345] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Accepted: 10/03/2013] [Indexed: 12/20/2022]
Abstract
When bound to the envelope of viruses, factor H (FH), a soluble regulator of complement activation, contributes to the protection against a potent immune defense mechanism, the complement-mediated lysis (CML). Thus, removing FH from the surface renders viruses, such as HIV, susceptible to CML. For a proof of concept, we developed a construct consisting of recombinant bifunctional single-chain variable fragment (scFv) based on a monoclonal antibody against Friend murine leukemia virus (F-MuLV) envelope protein gp70, which was coupled to specific binding domains (short consensus repeats 19-20; SCR1920) of FH. We used Pichia pastoris as expression system in common shake flasks and optimized expression in high density bench top fermentation. Specific binding of recombinant scFv was proven by flow cytometry. The recombinant scFv-SCR significantly enhanced CML of F-MuLV in vitro implying that FH binding to the viral surface was impaired by the scFv-SCR. This novel concept to enhance virolysis may provide a new approach for antiviral treatment.
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Affiliation(s)
- Georg Huber
- Division of Virology, Innsbruck Medical University, Peter-Mayr-Straße 4b, 6020 Innsbruck, Austria
| | - Zoltán Bánki
- Division of Virology, Innsbruck Medical University, Peter-Mayr-Straße 4b, 6020 Innsbruck, Austria
| | - Renate Kunert
- Department of Biotechnology, VIBT, BOKU-University of Natural Resources and Life Sciences, Muthgasse 11, 1190 Vienna, Austria
| | - Heribert Stoiber
- Division of Virology, Innsbruck Medical University, Peter-Mayr-Straße 4b, 6020 Innsbruck, Austria
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5
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Erdag B, Balcioglu BK, Bahadir AO, Serhatli M, Kacar O, Bahar A, Seker UOS, Akgun E, Ozkan A, Kilic T, Tamerler C, Baysal K. Identification of novel neutralizing single-chain antibodies against vascular endothelial growth factor receptor 2. Biotechnol Appl Biochem 2011; 58:412-22. [PMID: 22172104 DOI: 10.1002/bab.61] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Accepted: 09/23/2011] [Indexed: 01/05/2023]
Abstract
Human vascular endothelial growth factor (VEGF) and its receptor (VEGFR-2/kinase domain receptor [KDR]) play a crucial role in angiogenesis, which makes the VEGFR-2 signaling pathway a major target for therapeutic applications. In this study, a single-chain antibody phage display library was constructed from spleen cells of mice immunized with recombinant human soluble extracellular VEGFR-2/KDR consisting of all seven extracellular domains (sKDR D1-7) to obtain antibodies that block VEGF binding to VEGFR-2. Two specific single-chain antibodies (KDR1.3 and KDR2.6) that recognized human VEGFR-2 were selected; diversity analysis of the clones was performed by BstNI fingerprinting and nucleotide sequencing. The single-chain variable fragments (scFvs) were expressed in soluble form and specificity of interactions between affinity purified scFvs and VEGFR-2 was confirmed by ELISA. Binding of the recombinant antibodies for VEGFR-2 receptors was investigated by surface plasmon resonance spectroscopy. In vitro cell culture assays showed that KDR1.3 and KDR2.6 scFvs significantly suppressed the mitogenic response of human umbilical vein endothelial cells to recombinant human VEGF(165) in a dose-dependent manner, and reduced VEGF-dependent cell proliferation by 60% and 40%, respectively. In vivo analysis of these recombinant antibodies in a rat cornea angiogenesis model revealed that both antibodies suppressed the development of new corneal vessels (p < 0.05). Overall, in vitro and in vivo results disclose strong interactions of KDR1.3 and KDR2.6 scFvs with VEGFR-2. These findings indicate that KDR1.3 and KDR2.6 scFvs are promising antiangiogenic therapeutic agents.
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Affiliation(s)
- Berrin Erdag
- TUBITAK Marmara Research Center, Genetic Engineering and Biotechnology Institute, Gebze, Kocaeli, Turkey.
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6
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Yang H, Wang H, Xue T, Xue XP, Huyan T, Wang W, Song K. Single-chain variable fragment antibody against human aspartyl/asparaginyl beta-hydroxylase expressed in recombinant Escherichia coli. Hybridoma (Larchmt) 2011; 30:69-79. [PMID: 21466288 DOI: 10.1089/hyb.2010.0070] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The human aspartyl beta-hydroxylase (HAAH) is a highly conserved enzyme that hydroxylates epidermal growth factor-like domains in transformation-associated proteins. Previous studies showed that the gene of HAAH was overexpressed in many human malignancies. In the present study, the HAAH-specific single-chain variable fragment (ScFv) antibody was produced in recombinant Escherichia coli. The variable regions of the genes of the heavy chain (VH) and light chain (VL) cloned from the hybridoma cells G3/F11 were connected with a flexible linker using an overlap extension polymerase chain reaction. Nucleotide sequence analysis revealed that the anti-HAAH VH was a member of the VH V gene family and the VL gene belonged to the Vκ gene family VI subgroup. Extensive efforts to express the functional ScFv antibody in E. coli have been made by using two different prokaryotic expression vectors-pHEN1 and pET-16b-to compare the expression level and solubility of the antibody. The recombinant pHEN1/E1-anti-HAAH vector could express soluble ScFv, although the yield was only 7.8% of the total cellular protein. However, the pET-16b/E2-anti-HAAH vector produced the ScFv as inclusion bodies inside the host cytoplasm, although the expression level of the antibody was quite high (28.5% of the total cellular protein). Soluble ScFv antibody produced by pHEN1/E1-anti-HAAH was characterized for its antigen-binding characteristics. Its antigen affinity as antibody was measured by indirect enzyme linked immunosorbent assay analysis and proved to have high binding activity to the antigen HAAH.
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Affiliation(s)
- Hui Yang
- Faculty of Life Sciences, Northwestern Polytechnical University, 127 Youyi West Road, Xi'an, China
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7
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Zhan K, Xie H, Gall J, Ma M, Griesbeck O, Salehi A, Rao J. Real-time imaging of Rab5 activity using a prequenched biosensor. ACS Chem Biol 2011; 6:692-9. [PMID: 21506516 DOI: 10.1021/cb100377m] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
A key regulator of receptor-mediated endocytosis, Rab5, plays a pivotal role in cargo receptor internalization, endosomal maturation, and transduction and degradation of internalized signaling molecules and recycling cargo receptor. Stressful conditions within cells lead to increased Rab5 activation, and increasing evidence correlates Rab5 activity abnormalities with certain diseases. Current antibody-based imaging methods cannot distinguish active Rab5 from total Rab5 population and provide dynamic information on magnitude and duration of Rab5 activation in cellular events and pathogenesis. We report here novel molecular imaging probes that specifically target GTP-bound Rab5 associated with the early endosome membrane in live cells and fixed mouse brain tissues. Our Rab5 activity fluorescent biosensor (RAFB) contains the Rab5 binding domain of the Rab5 effector Rabaptin 5, a fluorophore (a quantum dot or fluorescent dye) and a cell-penetrating peptide for live-cell delivery. The quantum dot conjugated RAFB was able to image the elevated Rab5 activity in both the cortex and hippocampi tissues of a Ts65Dn mouse. A prequenched RAFB based on fluorescence resonance energy transfer (FRET) can image cytosolic active Rab5 in single live cells. This novel method should enable imaging of the biological process in which Rab5 activity is regulated in various cellular systems.
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Affiliation(s)
| | | | | | | | - Oliver Griesbeck
- Max-Planck-Institute of Neurobiology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Ahmad Salehi
- Palo Alto VA Health Care System, 3801 Miranda Avenue, Palo Alto, California 94304, United States
| | - Jianghong Rao
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
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8
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Huang Z, Ni C, Zhou X, Liu Y, Tan Y, Xiao J, Feng W, Li X, Yang S. Mechanism of pH-sensitive polymer-assisted protein refolding and its application in TGF-β1 and KGF-2. Biotechnol Prog 2009; 25:1387-95. [DOI: 10.1002/btpr.218] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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9
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Molecular-assisted refolding: Study of two different ionic forms of recombinant human fibroblast growth factors. J Biotechnol 2009; 142:157-63. [DOI: 10.1016/j.jbiotec.2009.04.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2008] [Revised: 04/01/2009] [Accepted: 04/15/2009] [Indexed: 10/20/2022]
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10
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Yang B, Yajima W, Das D, Suresh MR, Kav NN. Isolation, expression and characterization of two single-chain variable fragment antibodies against an endo-polygalacturonase secreted by Sclerotinia sclerotiorum. Protein Expr Purif 2009; 64:237-43. [DOI: 10.1016/j.pep.2008.12.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2008] [Revised: 12/03/2008] [Accepted: 12/04/2008] [Indexed: 10/21/2022]
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11
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Huang ZF, Wang SS, Ni CY, Yang SL, Li XK, Leong SS. pH-sensitive polymer-assisted refolding of urea-denatured fibroblast growth factor. CHINESE CHEM LETT 2009. [DOI: 10.1016/j.cclet.2008.12.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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12
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Das D, Mongkolaungkoon S, Suresh MR. Super induction of dengue virus NS1 protein in E. coli. Protein Expr Purif 2009; 66:66-72. [PMID: 19232392 PMCID: PMC7129434 DOI: 10.1016/j.pep.2009.02.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2009] [Revised: 01/30/2009] [Accepted: 02/05/2009] [Indexed: 12/28/2022]
Abstract
The non-structural protein 1 (NS1) of dengue virus is a useful target for diagnostics of dengue infection since the protein is abundantly circulating in blood during the acute phase of the disease. Prior work has established that secreted NS1 levels in plasma correlates with viremia levels and hence can also be used to diagnose patients at the risk for developing dengue hemorrhagic fever. Thus detection of non-structural dengue antigens may be of benefit for an early rapid diagnosis of dengue infection due to its long half life in the blood. Here we describe a simple and efficient method for the expression of NS1 in Escherichia coli, which could potentially be used to develop monoclonal and bispecific antibodies for point of care diagnostics. E. coli codon optimized synthetic full-length NS1 gene of dengue serotype 1 (DEN-1) was successfully cloned and expressed in very high-level as inclusion bodies. The NS1 protein was successfully affinity purified and refolded as a recombinant NS1 (rNS1) protein in E. coli and yield was 230–250 mg/L of bacterial culture. The rNS1 protein was used to immunize mice for hybridoma development. The polyclonal antiserum from animals immunized with this rNS1 protein was found to specifically recognize the rNS1, thus demonstrating the immunogenic nature of the protein. The rNS1 protein purified from E. coli could be useful for developing a sensitive serum diagnostic assay to monitor dengue outbreaks.
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Affiliation(s)
- Dipankar Das
- Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, 11304-89 Avenue, Edmonton, Alberta, Canada
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13
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von zur Muhlen C, Peter K, Ali ZA, Schneider JE, McAteer MA, Neubauer S, Channon KM, Bode C, Choudhury RP. Visualization of activated platelets by targeted magnetic resonance imaging utilizing conformation-specific antibodies against glycoprotein IIb/IIIa. J Vasc Res 2008; 46:6-14. [PMID: 18515970 PMCID: PMC2914450 DOI: 10.1159/000135660] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2007] [Accepted: 01/19/2008] [Indexed: 12/18/2022] Open
Abstract
Ruptured atherosclerotic plaques, lined with activated platelets, constitute an attractive target for magnetic resonance imaging (MRI). This study evaluated whether microparticles of iron oxide (MPIO) targeting ligand-induced binding sites (LIBS) on the activated conformation of glycoprotein IIb/IIIa could be used to image platelets. MPIO (size: 1 μm) were conjugated to anti-LIBS or control single-chain antibody. Following guidewire injury to mouse femoral artery, platelet adhesion was present after 24 h. Mice were perfused with anti-LIBS-MPIO (or control MPIO) via the left ventricle and 11.7-tesla MRI was performed on femoral arteries ex vivo. A 3D gradient echo sequence attained an isotropic resolution of 25 μm. MPIO binding, quantified by MRI, was 4-fold higher with anti-LIBS-MPIO in comparison to control MPIO (p < 0.01). In histological sections, low signal zones on MRI and MPIO correlated strongly (R2 = 0.72; p < 0.001), indicating accurate MR quantification. In conclusion, anti-LIBS-MPIO bind to activated platelets in mouse arteries, providing a basis for the use of function-specific single-chain antibody-MPIO conjugates for molecular MRI, and represent the first molecular imaging of a conformational change in a surface receptor. This presents an opportunity to specifically image activated platelets involved in acute atherothrombosis with MRI.
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14
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Das D, Jacobs F, Feldmann H, Jones SM, Suresh MR. Differential expression of the Ebola virus GP(1,2) protein and its fragments in E. coli. Protein Expr Purif 2007; 54:117-25. [PMID: 17383893 DOI: 10.1016/j.pep.2007.02.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2007] [Revised: 02/07/2007] [Accepted: 02/08/2007] [Indexed: 12/20/2022]
Abstract
Bacterial expression platforms are frequently used for the expression and production of different recombinant proteins. The full length Ebola virus (EBOV) GP(1,2) gene and subfragments of the GP(1) gene were cloned in a bacterial expression vector as a C-terminal His(6) fusion protein. Surprisingly, the full length EBOV GP(1,2) gene could not be expressed in Escherichia coli. The subfragments of GP(1) were only expressed in small amounts with the exception of one small fragment (subfragment D) which was expressed at very high levels as inclusion bodies. This was seen even in the in vitro translation system with no expression of full length GP(1,2), GP(1) subfragments A and C and low level expression of subfragment B. Only the subfragment D showed high level of expression. In E. coli (Top10), the recombinant GP(1) subfragment D protein was expressed exclusively as an insoluble approximately 25 kDa His(6) fusion protein, which is the expected size for a non-glycosylated recombinant protein. The IMAC purified and refolded non-glycosylated protein was used to immunize mice for the development of monoclonal anti-EBOV antibodies which successfully yielded several monoclonal antibodies with different specificities. The monoclonal and polyclonal antiserum derived from the animals immunized with this recombinant GP(1) subfragment D protein was found to specifically recognize the full length glycosylated EBOV GP(1,2) protein expressed in mammalian 293T cells, thus, demonstrating the immunogenicity of the recombinant subfragment.
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Affiliation(s)
- Dipankar Das
- University of Alberta, Edmonton, Alta., Canada T6G 2N8
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15
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Das D, Suresh MR. Copious production of SARS-CoV nucleocapsid protein employing codon optimized synthetic gene. J Virol Methods 2006; 137:343-6. [PMID: 16904198 PMCID: PMC7112773 DOI: 10.1016/j.jviromet.2006.06.029] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2006] [Revised: 04/04/2006] [Accepted: 06/29/2006] [Indexed: 12/15/2022]
Abstract
The severe acute respiratory syndrome coronavirus (SARS-CoV) nucleocapsid protein (NP) is one of the predominant antigenic protein and the most abundant shed antigen throughout the SARS-CoV infection. This feature makes it a suitable molecular target for diagnostic applications. In this study the full length codon optimized NP gene and its subfragment gene segment was cloned in a bacterial expression vector. The full length NP could be expressed in E. coli at very high level within inclusion bodies. The inclusion bodies were successfully solubilized, purified under denaturing conditions employing IMAC column and refolded. The non-glycosylated NP was used to immunize mice for hybridoma development. The polyclonal antiserum from animals immunized with this recombinant NP protein was found to specifically recognize the NP and its subfragments, thus demonstrating the immunogenic nature of the recombinant protein. The NP antigen or a subfragment could be useful for developing a sensitive serum diagnostic assay to monitor SARS-CoV outbreaks by detecting the early human anti-SARS antibodies. In addition, the availability of the NP fragments could facilitate epitope mapping of anti-NP monoclonals for identifying suitable sandwich pairs.
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MESH Headings
- Animals
- Antibodies, Monoclonal/biosynthesis
- Antibodies, Viral/biosynthesis
- Antibodies, Viral/immunology
- Antigens, Viral/biosynthesis
- Antigens, Viral/genetics
- Antigens, Viral/immunology
- Antigens, Viral/isolation & purification
- Cloning, Molecular
- Codon/genetics
- Coronavirus Nucleocapsid Proteins
- Electrophoresis, Polyacrylamide Gel
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Gene Expression
- Genes, Synthetic
- Inclusion Bodies
- Mice
- Nucleocapsid Proteins/biosynthesis
- Nucleocapsid Proteins/genetics
- Nucleocapsid Proteins/immunology
- Nucleocapsid Proteins/isolation & purification
- Recombinant Proteins/biosynthesis
- Severe acute respiratory syndrome-related coronavirus/genetics
- Severe acute respiratory syndrome-related coronavirus/immunology
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16
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Liu YD, Li JJ, Wang FW, Chen J, Li P, Su ZG. A newly proposed mechanism for arginine-assisted protein refolding--not inhibiting soluble oligomers although promoting a correct structure. Protein Expr Purif 2006; 51:235-42. [PMID: 16931044 DOI: 10.1016/j.pep.2006.07.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2006] [Revised: 06/27/2006] [Accepted: 07/03/2006] [Indexed: 11/27/2022]
Abstract
Arginine has been demonstrated to be capable of suppressing aggregation during protein refolding. However, the pathway and the mechanism for arginine to participate in and to assist refolding process still remains unclear. In this study, arginine-assisted refolding of recombinant consensus interferon (rIFN-con1) was investigated. It was found that although arginine minimized the formation of protein precipitate, it failed to prevent the formation of the soluble oligomeric species. The amount of the oligomers increased with the increase in arginine concentration. This phenomenon has not been reported. On the other hand, arginine was able to promote the yield of correctly refolded rIFN-con1, which was more than 2 times higher than that in the absence of arginine. A proposed mechanism is the stabilization of different soluble species by arginine, which slowed down the conformational movement. The stabilization effect on native-like structure formation overwhelmed the oligomeric promotion effect, which resulted in a composite effect of increased refolding yield for rIFN-con1 when arginine concentration was below 0.5M.
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Affiliation(s)
- Yong-Dong Liu
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100080, PR China
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17
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Das D, Allen TM, Suresh MR. Comparative evaluation of two purification methods of anti-CD19-c-myc-His6-Cys scFv. Protein Expr Purif 2005; 39:199-208. [PMID: 15642471 DOI: 10.1016/j.pep.2004.10.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2004] [Revised: 10/06/2004] [Indexed: 11/27/2022]
Abstract
Different chromatographic methods have been used to purify bacterially expressed single chain antibodies in soluble or insoluble form. Here, we compared two methods for purification of anti-CD19-c-myc-His6-Cys scFv expressed in Escherichia coli as soluble protein. The protein-L-agarose purification method is a one step purification method that yielded significant amounts of pure protein compared to the two-step Ni-NTA-agarose plus Resource 15S purification method. However, the protein-L purification method exhibited an additional lower molecular weight protein contaminant. Based on results from in vitro gel digestion, mass spectrometry and database search results, we confirmed that the lower molecular weight protein contaminant, which could not be purified by Ni-NTA-agarose and 15S column method, is a degraded product of the full length scFv construct.
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Affiliation(s)
- Dipankar Das
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada T6G 2H7
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