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Borges B, Gallo G, Coelho C, Negri N, Maiello F, Hardy L, Würtele M. Dynamic cross correlation analysis of Thermus thermophilus alkaline phosphatase and determinants of thermostability. Biochim Biophys Acta Gen Subj 2021; 1865:129895. [PMID: 33781823 DOI: 10.1016/j.bbagen.2021.129895] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 02/18/2021] [Accepted: 03/22/2021] [Indexed: 10/21/2022]
Abstract
BACKGROUND Understanding the determinants of protein thermostability is very important both from the theoretical and applied perspective. One emerging view in thermostable enzymes seems to indicate that a salt bridge/charged residue network plays a fundamental role in their thermostability. METHODS The structure of alkaline phosphatase (AP) from Thermus thermophilus HB8 was solved by X-ray crystallography at 2.1 Å resolution. The obtained structure was further analyzed by molecular dynamics studies at different temperatures (303 K, 333 K and 363 K) and compared to homologous proteins from the cold-adapted organisms Shewanella sp. and Vibrio strain G15-21. To analyze differences in measures of dynamic variation, several data reduction techniques like principal component analysis (PCA), residue interaction network (RIN) analysis and rotamer analysis were used. Using hierarchical clustering, the obtained results were combined to determine residues showing high degree dynamical variations due to temperature jumps. Furthermore, dynamic cross correlation (DCC) analysis was carried out to characterize networks of charged residues. RESULTS Top clustered residues showed a higher propensity for thermostabilizing mutations, indicating evolutionary pressure acting on thermophilic organisms. The description of rotamer distributions by Gini coefficients and Kullback-Leibler (KL) divergence both revealed significant correlations with temperature. DCC analysis revealed a significant trend to de-correlation of the movement of charged residues at higher temperatures. SIGNIFICANCE The de-correlation of charged residues detected in Thermus thermophilus AP, highlights the importance of dynamic electrostatic network interactions for the thermostability of this enzyme.
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Affiliation(s)
- Bruno Borges
- Department of Science and Technology, Federal University of São Paulo, São José dos Campos, Brazil
| | - Gloria Gallo
- Department of Science and Technology, Federal University of São Paulo, São José dos Campos, Brazil
| | - Camila Coelho
- Department of Science and Technology, Federal University of São Paulo, São José dos Campos, Brazil
| | - Naiane Negri
- Department of Science and Technology, Federal University of São Paulo, São José dos Campos, Brazil; Alberto Luiz Coimbra Institute for Graduate Studies and Research in Engineering (COPPE), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fernando Maiello
- Department of Science and Technology, Federal University of São Paulo, São José dos Campos, Brazil
| | - Leon Hardy
- Department of Physics, University of South Florida, Tampa, United States
| | - Martin Würtele
- Department of Science and Technology, Federal University of São Paulo, São José dos Campos, Brazil.
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Hannachi E, Bouratbine A, Mousli M. Enhancing the detection of Toxoplasma gondii via an anti-SAG1 scFv-alkaline phosphatase immunoconjugate. BIOTECHNOLOGY REPORTS (AMSTERDAM, NETHERLANDS) 2019; 23:e00360. [PMID: 31341791 PMCID: PMC6630058 DOI: 10.1016/j.btre.2019.e00360] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 06/29/2019] [Accepted: 06/30/2019] [Indexed: 12/11/2022]
Abstract
The purpose of this study was to implement a fluorometric method for enhancing the detection sensitivity of Toxoplasma gondii in biological fluids. To address this challenge, we designed and produced a recombinant immunoconjugate tool based on a single-chain antibody fragment anti-T. gondii SAG1 antigen (scFvSG15) genetically fused to the bacterial alkaline phosphatase (AP) using 4-methyl-umbelliferyl-phosphate as fluorogenic substrate. The anti-SAG1 scFv-AP conjugate was fully bifunctional and was used successfully in different assays including immunoblot, fluorometric ELISA and direct immunofluorescence. The fluorometric immunoassay afforded an extremely low detection limit (1 tachyzoite/well), which was in agreement with the real-time PCR control test. The immunofluorescence imaging has provided captivating visual evidence of T. gondii detection. These results strongly suggest that the recombinant anti-SAG1-AP conjugate generated here might serve as useful and highly sensitive immunoassay probe to direct detect T. gondii in a one-step procedure, opening up new perspectives for diagnosis of toxoplasmosis.
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Affiliation(s)
| | | | - Mohamed Mousli
- Laboratoire de Parasitologie Médicale, Biotechnologies et Biomolécules, LR11-IPT06, Institut Pasteur de Tunis, Université Tunis El-Manar, 13 Place Pasteur -BP74, 1002 Tunis-Belvédère, Tunisia
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3
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SKIK-zipbody-alkaline phosphatase, a novel antibody fusion protein expressed in Escherichia coli cytoplasm. J Biosci Bioeng 2018; 126:705-709. [DOI: 10.1016/j.jbiosc.2018.06.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Revised: 06/05/2018] [Accepted: 06/11/2018] [Indexed: 12/24/2022]
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4
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A time-resolved fluoroimmunoassay to assay the rabies virus glycoprotein: application for estimation of human rabies vaccine potency. Sci Rep 2017; 7:7288. [PMID: 28779162 PMCID: PMC5544697 DOI: 10.1038/s41598-017-07687-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 06/29/2017] [Indexed: 02/06/2023] Open
Abstract
Replacement of the in vivo rabies vaccine potency test (NIH test) by in vitro methods had been discussed by several researcher including WHO expert working groups. In this paper, a time-resolved fluoroimmunoassay (TRFIA) for the assay of rabies virus glycoprotein in rabies vaccine was first established to estimate the rabies vaccine potency by using specific monoclonal antibody that only recognized the native, trimeric and immunogenic form of rabies virus glycoprotein. Potency of the rabies virus glycoprotein was assayed with satisfactory performance under optimal conditions, and the method demonstrated satisfactory results when applied in practical samples. The correlation coefficient of potency values obtained from the present TRFIA and ELISA was 0.912, and 0.903 for those from the present TRFIA and NIH test. These preliminary results confirmed that this TRFIA can replace ELISA with higher performance, and could be a promising replacement of the NIH test. Based upon these results, the present TRFIA seemed to be a convenient tool for evaluating rabies vaccine potency and its products at different stages accordingly.
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Du XJ, Zhou XN, Li P, Sheng W, Ducancel F, Wang S. Development of an Immunoassay for Chloramphenicol Based on the Preparation of a Specific Single-Chain Variable Fragment Antibody. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2016; 64:2971-2979. [PMID: 27003441 DOI: 10.1021/acs.jafc.6b00639] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Specific antibodies are essential for the immune detection of small molecule contaminants. In the present study, the heavy and light variable regions (V(H )and V(L)) of the immunoglobulin genes from a hybridoma secreting a chloramphenicol (CAP)-specific monoclonal antibody (mAb) were cloned and sequenced. In addition, the light and heavy chains obtained from the monoclonal antibody were separated using SDS-PAGE and analyzed using Orbitrap mass spectrometry. The results of DNA sequencing and mass spectrometry analysis were compared, and the V(H) and V(L) chains specific for CAP were determined and used to construct a single-chain variable fragment (scFv). This fragment was recombinantly expressed as a soluble scFv-alkaline phosphatase fusion protein and used to develop a direct competitive ELISA. Compared with the parent mAb, scFv exhibits lower sensitivity but better food matrix resistance. This work highlights the application of engineered antibodies for CAP detection.
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Affiliation(s)
- Xin-jun Du
- Key Laboratory of Food Nutrition and Safety, Ministry of Education of China, Tianjin University of Science and Technology , Tianjin 300457, China
| | - Xiao-nan Zhou
- Key Laboratory of Food Nutrition and Safety, Ministry of Education of China, Tianjin University of Science and Technology , Tianjin 300457, China
| | - Ping Li
- Key Laboratory of Food Nutrition and Safety, Ministry of Education of China, Tianjin University of Science and Technology , Tianjin 300457, China
| | - Wei Sheng
- Key Laboratory of Food Nutrition and Safety, Ministry of Education of China, Tianjin University of Science and Technology , Tianjin 300457, China
| | - Frédéric Ducancel
- Pharmacology and Immune Analysis Department, CEA/Saclay , F-91191 Gif-sur-Yvette, France
| | - Shuo Wang
- Key Laboratory of Food Nutrition and Safety, Ministry of Education of China, Tianjin University of Science and Technology , Tianjin 300457, China
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6
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Immunodetection of the "brown" spider (Loxosceles intermedia) dermonecrotoxin with an scFv-alkaline phosphatase fusion protein. Immunol Lett 2016; 173:1-6. [PMID: 26970375 DOI: 10.1016/j.imlet.2016.03.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 02/16/2016] [Accepted: 03/02/2016] [Indexed: 12/23/2022]
Abstract
Bites by spiders from Loxosceles genus often lead to a wide variance in envenomation profile of patients and diagnosis is difficult due to the number of diseases that mimic loxoscelism. In such a context, it is of interest to consider the design of standardized recombinant colorimetric antibodies for diagnosis and specific detection of individual circulating toxins in biological fluids of envenomed patients. We have previously prepared a monoclonal murine IgG (LiMab7) that reacts with Loxosceles intermedia venom components of 32-35kDa and neutralizes the dermonecrotic activity of the venom. Here, we re-engineered LiMab7 into a colorimetric bifunctional protein consisting in the corresponding single-chain antibody fragment (scFv) fused to alkaline phosphatase (AP) of Escherichia coli. The immune tracer was tested in two different types of immunoassays and it proved to be efficient in both. Thus, this recombinant fusion protein (scFv-LiMab7/AP) can be used for rapid and specific immunotitration of L. intermedia venom with a linear range of 39-20000ng/mL and a detection limit of 39ng/mL without any cross-reaction.
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Ozaki CY, Silveira CRF, Andrade FB, Nepomuceno R, Silva A, Munhoz DD, Yamamoto BB, Luz D, Abreu PAE, Horton DSPQ, Elias WP, Ramos OHP, Piazza RMF. Single Chain Variable Fragments Produced in Escherichia coli against Heat-Labile and Heat-Stable Toxins from Enterotoxigenic E. coli. PLoS One 2015; 10:e0131484. [PMID: 26154103 PMCID: PMC4496030 DOI: 10.1371/journal.pone.0131484] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 06/01/2015] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Diarrhea is a prevalent pathological condition frequently associated to the colonization of the small intestine by enterotoxigenic Escherichia coli (ETEC) strains, known to be endemic in developing countries. These strains can produce two enterotoxins associated with the manifestation of clinical symptoms that can be used to detect these pathogens. Although several detection tests have been developed, minimally equipped laboratories are still in need of simple and cost-effective methods. With the aim to contribute to the development of such diagnostic approaches, we describe here two mouse hybridoma-derived single chain fragment variable (scFv) that were produced in E. coli against enterotoxins of ETEC strains. METHODS AND FINDINGS Recombinant scFv were developed against ETEC heat-labile toxin (LT) and heat-stable toxin (ST), from previously isolated hybridoma clones. This work reports their design, construction, molecular and functional characterization against LT and ST toxins. Both antibody fragments were able to recognize the cell-interacting toxins by immunofluorescence, the purified toxins by ELISA and also LT-, ST- and LT/ST-producing ETEC strains. CONCLUSION The developed recombinant scFvs against LT and ST constitute promising starting point for simple and cost-effective ETEC diagnosis.
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Affiliation(s)
| | | | | | | | - Anderson Silva
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brasil
| | | | - Bruno B. Yamamoto
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brasil
| | - Daniela Luz
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brasil
| | | | | | - Waldir P. Elias
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brasil
| | | | - Roxane M. F. Piazza
- Laboratório de Bacteriologia, Instituto Butantan, São Paulo, SP, Brasil
- * E-mail:
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Grigorenko VG, Andreeva IP, Rubtsova MY, Egorov AM. Recombinant horseradish peroxidase: Production and analytical applications. BIOCHEMISTRY (MOSCOW) 2015; 80:408-16. [DOI: 10.1134/s0006297915040033] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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9
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Turki I, Hammami A, Kharmachi H, Mousli M. Engineering of a recombinant trivalent single-chain variable fragment antibody directed against rabies virus glycoprotein G with improved neutralizing potency. Mol Immunol 2013; 57:66-73. [PMID: 24091293 DOI: 10.1016/j.molimm.2013.08.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 08/14/2013] [Accepted: 08/18/2013] [Indexed: 10/26/2022]
Abstract
Human and equine rabies immunoglobulins are currently available for passive immunization against rabies. However, these are hampered by the limited supply and some drawbacks. Advances in antibody engineering have led to overcome issues of clinical applications and to improve the protective efficacy. In the present study, we report the generation of a trivalent single-chain Fv (scFv50AD1-Fd), that recognizes the rabies virus glycoprotein, genetically fused to the trimerization domain of the bacteriophage T4 fibritin, termed 'foldon' (Fd). scFv50AD1-Fd was expressed as soluble recombinant protein in bacterial periplasmic space and purified through affinity chromatography. The molecular integrity and stability were analyzed by polyacrylamide gradient-gel electrophoresis, size-exclusion chromatography and incubation in human sera. The antigen-binding properties of the trimeric scFv were analyzed by direct and competitive-ELISA. Its apparent affinity constant was estimated at 1.4 ± 0.25 × 10(9)M(-1) and was 75-fold higher than its monovalent scFv (1.9 ± 0.68 × 10(7)M(-1)). The scFv50AD1-Fd neutralized rabies virus in a standard in vitro and in vivo neutralization assay. We showed a high neutralization activity up to 75-fold compared with monovalent format and the WHO standard serum. The gain in avidity resulting from multivalency along with an improved biological activity makes the trivalent scFv50AD1-Fd construct an important reagent for rabies protection. The antibody engineering approach presented here may serve as a strategy for designing a new generation of anti-rabies for passive immunotherapy.
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Affiliation(s)
- Imène Turki
- Laboratoire de Parasitologie Médicale, Biotechnologies et Biomolécules, Institut Pasteur de Tunis, LR11-IPT06, 13 Place Pasteur - BP74, 1002 Tunis-Belvédère, Tunisia
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10
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Chahed Bel-Ochi N, Bouratbine A, Mousli M. Design and characterization of a recombinant colorimetric SAG1–alkaline phosphatase conjugate to detect specific antibody responses against Toxoplasma gondii. J Immunol Methods 2013; 394:107-14. [DOI: 10.1016/j.jim.2013.05.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Revised: 04/25/2013] [Accepted: 05/22/2013] [Indexed: 10/26/2022]
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11
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Smith TG, Ellison JA, Ma X, Kuzmina N, Carson WC, Rupprecht CE. An electrochemiluminescence assay for analysis of rabies virus glycoprotein content in rabies vaccines. Vaccine 2013; 31:3333-8. [PMID: 23742991 PMCID: PMC4568986 DOI: 10.1016/j.vaccine.2013.05.081] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 05/12/2013] [Accepted: 05/20/2013] [Indexed: 12/15/2022]
Abstract
Vaccine potency testing is necessary to evaluate the immunogenicity of inactivated rabies virus (RABV) vaccine preparations before human or veterinary application. Currently, the NIH test is recommended by the WHO expert committee to evaluate RABV vaccine potency. However, numerous disadvantages are inherent concerning cost, number of animals and biosafety requirements. As such, several in vitro methods have been proposed for the evaluation of vaccines based on RABV glycoprotein (G) quality and quantity, which is expected to correlate with vaccine potency. In this study an antigen-capture electrochemiluminescent (ECL) assay was developed utilizing anti-RABV G monoclonal antibodies (MAb) to quantify RABV G. One MAb 2-21-14 was specific for a conformational epitope so that only immunogenic, natively folded G was captured in the assay. MAb 2-21-14 or a second MAb (62-80-6) that binds a linear epitope was used for detection of RABV G. Vaccine efficacy was also assessed in vivo using pre-exposure vaccination of mice. Purified native RABV G induced a RABV neutralizing antibody (rVNA) response with a geometric mean titer of 4.2IU/ml and protected 100% of immunized mice against RABV challenge, while an experimental vaccine with a lower quality and quantity of G induced a rVNA titer<0.05IU/ml and protected <50% of immunized mice. These preliminary results support the hypothesis that in vivo immunogenicity may be predicted from the in vitro measurement of RABV G using an ECL assay. Based upon these results, the ECL assay may have utility in replacement of the NIH test.
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Affiliation(s)
- Todd G Smith
- Poxvirus and Rabies Branch, Division of High-Consequence Pathogens and Pathology, Centers for Disease Control and Prevention, 1600 Clifton Road NE, Atlanta, GA 30329, USA.
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Liu Y, Zhang S, Zhang F, Hu R. A semi-quantitative serological method to assess the potency of inactivated rabies vaccine for veterinary use. Virol Sin 2012; 27:259-64. [PMID: 22899435 PMCID: PMC8218049 DOI: 10.1007/s12250-012-3260-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2012] [Accepted: 07/04/2012] [Indexed: 11/30/2022] Open
Abstract
Potency is one of the most important indexes of inactivated vaccines. A number of methods have been established to assay the potency, of which the NIH test and single-dose mouse protection test are the "prescribed methods". Here, we report a method to semi-quantitatively assay the potency of an inactivated rabies vaccine, which uses fewer animals and takes less time to complete. Depending on the quality requirements of a vaccine (e.g. minimum potency), a rabies reference vaccine is, for example, diluted to the minimum potency, and 50 μL of the dilution is taken to inoculate 10 mice. The same amount of the test rabies vaccine is inoculated into another 10 mice. After two weeks, all mice are bled and serum samples are assayed for viral neutralizing antibody by the fluorescent antibody virus neutralization (FAVN) test. By comparing the median and interquartile range of antibody titers of the reference vaccine with those of the test vaccine, the test vaccine potency can be semi-quantitatively judged as to whether it is in accord with the required quality. The reliability of this method was also confirmed in dogs. The procedure can be recommended for batch potency testing during inactivated rabies vaccine production.
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Affiliation(s)
- Ye Liu
- Laboratory of Epidemiology, Military Veterinary Research Institute, Academy of Military Medical Sciences, Changchun, 130122 China
| | - Shoufeng Zhang
- Laboratory of Epidemiology, Military Veterinary Research Institute, Academy of Military Medical Sciences, Changchun, 130122 China
| | - Fei Zhang
- Laboratory of Epidemiology, Military Veterinary Research Institute, Academy of Military Medical Sciences, Changchun, 130122 China
| | - Rongliang Hu
- Laboratory of Epidemiology, Military Veterinary Research Institute, Academy of Military Medical Sciences, Changchun, 130122 China
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Development of a single-chain variable fragment-alkaline phosphatase fusion protein and a sensitive direct competitive chemiluminescent enzyme immunoassay for detection of ractopamine in pork. Anal Chim Acta 2012; 736:85-91. [DOI: 10.1016/j.aca.2012.05.033] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Revised: 04/08/2012] [Accepted: 05/17/2012] [Indexed: 11/24/2022]
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Xu ZL, Dong JX, Wang H, Li ZF, Beier RC, Jiang YM, Lei HT, Shen YD, Yang JY, Sun YM. Production and characterization of a single-chain variable fragment linked alkaline phosphatase fusion protein for detection of O,O-diethyl organophosphorus pesticides in a one-step enzyme-linked immunosorbent assay. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2012; 60:5076-83. [PMID: 22533788 DOI: 10.1021/jf300570q] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
A single-chain variable fragment (scFv) linked alkaline phosphatase (AP) fusion protein for detection of O,O-diethyl organophosphorus pesticides (O,O-diethyl OPs) was produced and characterized. The scFv gene was prepared by cloning V(L) and V(H) genes from hybridoma cells secreting monoclonal antibody with broad specificity for O,O-diethyl OPs. The amplified V(L) and V(H) regions were assembled using a linker (Gly(4)Ser)(3) by means of splicing overlap extension polymerase chain reaction to obtain the scFv gene, which was cloned into the expression vector pLIP6/GN containing an AP gene to produce the scFv-AP fusion protein in Escherichia coli strain BL21. The protein was purified by antigen-conjugated immunoaffinity chromatography and characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western blotting, and competitive direct enzyme-linked immunosorbent assay (cdELISA). The fusion protein is bifunctional, retaining both antigen binding specificity and AP enzymatic activity. Analysis of spiked and blind river water and Chinese cabbage samples demonstrated that the fusion protein based cdELISA(FP) exhibited good sensitivity and reproducibility.
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Affiliation(s)
- Zhen-Lin Xu
- Guangdong Provincial Key Laboratory of Food Quality and Safety, South China Agricultural University , Guangzhou 510642, China
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Recombinant diabody-based immunocapture enzyme-linked immunosorbent assay for quantification of rabies virus glycoprotein. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2010; 17:1261-8. [PMID: 20573881 DOI: 10.1128/cvi.00204-10] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The potency of rabies vaccines, determined using the NIH mouse protection test, can be directly correlated to the amount of rabies virus glycoprotein (RV GP) present in the vaccine. In an effort to develop a simple and sensitive enzyme-linked immunosorbent assay (ELISA) using recombinant diabody for quantification of RV GP, the variable heavy (V(H)) and light chain (V(L)) domains of an RV GP-specific human monoclonal antibody (MAb) secreted by a human x mouse heterohybridoma (human MAb R16E5) was amplified, linked using splicing by overlap extension PCR (SOE PCR), and expressed as a recombinant diabody (D06) in the pET28a bacterial expression system. The diabody D06 was purified by immobilized metal affinity chromatography on a nickel-nitrilotriacetic acid (NTA) agarose column and characterized. The purified diabody was used in combination with a well-characterized RV GP-specific mouse MAb, M5B4, to develop an immunocapture ELISA (IC-ELISA) for the quantification of RV GP in human rabies vaccine preparations. The maximum detection limit of the IC-ELISA using the M5B4-D06 combination was up to 31.25 ng/ml of RV GP. The specificity of the diabody was established by its nonreactivity toward other human viral antigens as determined by ELISA and toward RV GP as determined by immunoblot transfer assay and competitive ELISA with the parent human MAb R16E5 and MAb M5B4. The adjusted r(2) value obtained by the regression through the origin model was 0.902, and the equation for predicted potency values for M5B4-D06-based IC-ELISA and MAb M5B4 IC-ELISA were 0.5651x and 0.8044x, respectively, where x is the estimate of RV GP from the IC-ELISA in micrograms. Analysis of variance (ANOVA) results showed the estimates of the two methods differed significantly (P < 0.001), while the predicted potencies by the two tests did not differ significantly (P > 0.05). The IC-ELISA can be readily adapted to measure the RV GP content in purified antigen, and a vaccine can be formulated based on the estimated GP.
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Liu X, Wang H, Liang Y, Yang J, Zhang H, Lei H, Shen Y, Sun Y. Production and Characterization of a Single-Chain Fv Antibody–Alkaline Phosphatase Fusion Protein Specific for Clenbuterol. Mol Biotechnol 2010; 45:56-64. [DOI: 10.1007/s12033-010-9240-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Conroy PJ, Hearty S, Leonard P, O’Kennedy RJ. Antibody production, design and use for biosensor-based applications. Semin Cell Dev Biol 2009; 20:10-26. [DOI: 10.1016/j.semcdb.2009.01.010] [Citation(s) in RCA: 172] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Accepted: 01/23/2009] [Indexed: 01/29/2023]
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