1
|
Mohsin AZ, Sukor R, Selamat J, Meor Hussin AS, Ismail IH, Jambari NN, Mustaffa-Kamal F. Generation of High Affinity Anti-Peptide Polyclonal Antibodies Recognizing Goat α s1-Casein. Molecules 2020; 25:E2622. [PMID: 32516919 PMCID: PMC7321099 DOI: 10.3390/molecules25112622] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 05/03/2020] [Accepted: 05/05/2020] [Indexed: 12/02/2022] Open
Abstract
The chemical, technological and allergy properties of goat's milk are significantly affected by the level of αs1-casein. Detection and quantification of αs1-casein requires high-specificity methods to overcome high-sequence similarity between this protein and others in the casein family. Unavailability of antibodies with high affinity and specificity towards goat αs1-casein hinders the development of immuno-based analytical methods such as enzyme-linked immunosorbent assay (ELISA) and biosensors. Here, we report the generation of polyclonal antibodies (or immunoglobulins, IgGs) raised towards goat αs1-casein N- (Nter) and C-terminal (Cter) peptide sequences. The Nter and Cter peptides of goat αs1-casein were immunized in rabbits for the generation of antisera, which were purified using protein G affinity chromatography. The binding affinity of the antisera and purified IgGs were tested and compared using indirect ELISA, where peptide-BSA conjugates and goat αs1-casein were used as the coating antigens. The Nter antiserum displayed higher titer than Cter antiserum, at 1/64,000 and 1/32,000 dilutions, respectively. The purification step further yielded 0.5 mg/mL of purified IgGs from 3 mL of antisera. The purified Nter IgG showed a significantly (p < 0.05) higher binding affinity towards peptide-BSA and goat αs1-casein, with lower Kd value at 5.063 × 10-3 μM compared to 9.046 × 10-3 μM for the Cter IgG. A cross-reactivity test showed that there was no binding in neither Nter nor Cter IgGs towards protein extracts from the milk of cow, buffalo, horse and camel. High-quality antibodies generated will allow further development of immuno-based analytical methods and future in vitro studies to be conducted on goat αs1-casein.
Collapse
Affiliation(s)
- Aliah Zannierah Mohsin
- Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia, Serdang 43400, Malaysia; (A.Z.M.); (J.S.); (N.N.J.)
| | - Rashidah Sukor
- Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia, Serdang 43400, Malaysia; (A.Z.M.); (J.S.); (N.N.J.)
- Faculty of Food Science and Technology, Universiti Putra Malaysia, Serdang 43400, Malaysia;
| | - Jinap Selamat
- Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia, Serdang 43400, Malaysia; (A.Z.M.); (J.S.); (N.N.J.)
- Faculty of Food Science and Technology, Universiti Putra Malaysia, Serdang 43400, Malaysia;
| | | | | | - Nuzul Noorahya Jambari
- Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia, Serdang 43400, Malaysia; (A.Z.M.); (J.S.); (N.N.J.)
- Faculty of Food Science and Technology, Universiti Putra Malaysia, Serdang 43400, Malaysia;
| | | |
Collapse
|
2
|
Cui N, Cao L, Sui J, Lin H, Han X, Chen X, Xie H, Sun X. Quick and convenient construction of lambda-cyhalothrin antigen for the generation of specific antibody. Anal Biochem 2020; 597:113669. [PMID: 32126209 DOI: 10.1016/j.ab.2020.113669] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2019] [Revised: 01/28/2020] [Accepted: 02/27/2020] [Indexed: 10/24/2022]
Abstract
Lambda-cyhalothrin is a pyrethroid widely used in crop, fruit and vegetable production, but has potential health threats to human. Immunoassay is a cheap, rapid and facile method to detect lambda-cyhalothrin, yet wide application of this method still requires improvement in the construction of antigen. In this study, we developed a one-step lambda-cyhalothrin hapten synthesis that transformed the cyanide group in lambda-cyhalothrin to amide. Complete antigen was assembled by coupling the amide with succinic-anhydride-activated carrier proteins, and corresponding polyclonal antibodies were generated using Balb/c mice. Using antibody generated by the method in this paper, the competitive ELISA demonstrated the lowest detection limit of 3.772 μg/L for lambda-cyhalothrin, and no significant cross-reactivity for other pyrethroid pesticides was observed. All the results suggested we have established a more efficient technique of generating lambda-cyhalothrin antibody. Furthermore, since the activated proteins used in this study are highly controllable, we believe these proteins could potentially be the prototype of a series of standardized carrier proteins for the synthesis of complete antigens.
Collapse
Affiliation(s)
- Nan Cui
- Food Safety Laboratory, College of Food Science and Engineering, Ocean University of China, 5 Yushan Rd., Qingdao, China
| | - Limin Cao
- Food Safety Laboratory, College of Food Science and Engineering, Ocean University of China, 5 Yushan Rd., Qingdao, China
| | - Jianxin Sui
- Food Safety Laboratory, College of Food Science and Engineering, Ocean University of China, 5 Yushan Rd., Qingdao, China
| | - Hong Lin
- Food Safety Laboratory, College of Food Science and Engineering, Ocean University of China, 5 Yushan Rd., Qingdao, China
| | - Xiangning Han
- Food Safety Laboratory, College of Food Science and Engineering, Ocean University of China, 5 Yushan Rd., Qingdao, China
| | - Xiangfeng Chen
- Shandong Analysis and Test Centre, Qilu University of Technology (Shandong Academy of Sciences), 19 Keyuan Rd, Jinan, China
| | - Hanyi Xie
- Shandong Analysis and Test Centre, Qilu University of Technology (Shandong Academy of Sciences), 19 Keyuan Rd, Jinan, China
| | - Xun Sun
- Food Safety Laboratory, College of Food Science and Engineering, Ocean University of China, 5 Yushan Rd., Qingdao, China.
| |
Collapse
|
3
|
Isa HI, Ferreira GCH, Crafford JE, Botha CJ. Raising antibodies against epoxyscillirosidine, the toxic principle contained in Moraea pallida Bak. (Iridaceae), in rabbits. J Immunol Methods 2019; 474:112670. [PMID: 31525365 DOI: 10.1016/j.jim.2019.112670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 08/16/2019] [Accepted: 09/12/2019] [Indexed: 11/19/2022]
Abstract
Moraea pallida Bak. (yellow tulp) poisoning is the most important plant cardiac glycoside toxicosis in South Africa. The toxic principle, a bufadienolide, is 1α, 2α-epoxyscillirosidine. The aim was to investigate the potential to develop a vaccine against epoxyscillirosidine. Epoxyscillirosidine, proscillaridin and bufalin, were successfully conjugated to hen ovalbumin (OVA), bovine serum albumin (BSA) and keyhole limpet haemocyanin (KLH). There was a low immune response following vaccination of adult male New Zealand White rabbits with epoxyscillirosidine-OVA (n = 3) and OVA (n = 3) using Freund's adjuvant in Trial (T) 1. The immune response improved significantly in T2 following doubling of the dose to 0.8 mg/rabbit and changing the adjuvant to Montanide. In T3, the rabbits (n = 15), allocated into 5 equal groups, vaccinated with proscillaridin-BSA, bufalin-BSA, epoxyscillirosidine-KLH, epoxyscillirosidine-BSA and BSA respectively, using Montanide adjuvant, developed antibodies against the administered immunogens, with epoxyscillirosidine-KLH inducing the highest immune response. Proscillaridin and bufalin antibodies cross-reacted with epoxyscillirosidine in an enzyme linked immunosorbent assay. The conjugation methodology will be adjusted in the future to target optimal conjugation efficiency. Additional vaccination will be conducted in search of neutralizing antibodies against the yellow tulp toxin. The cross-reactivity of proscillaridin and bufalin antibodies with epoxyscillirosidine could be studied in future to explore the potential to prevent yellow tulp poisoning.
Collapse
Affiliation(s)
- Hamza Ibrahim Isa
- Department of Paraclinical Sciences, University of Pretoria, Onderstepoort 0110, Gauteng, South Africa; Department of Veterinary Pharmacology and Toxicology, Ahmadu Bello University, Zaria, Nigeria.
| | | | - Jan Ernst Crafford
- Department of Veterinary Tropical Diseases, University of Pretoria, Onderstepoort 0110, Gauteng, South Africa
| | - Christoffel Jacobus Botha
- Department of Paraclinical Sciences, University of Pretoria, Onderstepoort 0110, Gauteng, South Africa
| |
Collapse
|
4
|
Zeng R, Bao L, Sheng H, Sun L, Chen M, Feng Y, Zhu M. Heterobimetallic dinuclear lanthanide alkoxide complexes as acid–base bifunctional catalysts for synthesis of carbamates under solvent-free conditions. RSC Adv 2016. [DOI: 10.1039/c6ra15160d] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Heterobimetallic dinuclear lanthanide alkoxide complexes Ln2Na8(OCH2CH2NMe2)12(OH)2 [Ln: I (Nd), II (Sm), III (Yb) and IV (Y)] were used as efficient acid–base bifunctional catalysts for the synthesis of carbamates and the N-Boc protection of amines.
Collapse
Affiliation(s)
- Ruijie Zeng
- School of Chemistry and Chemical Engineering
- Center for Atomic Engineering of Advanced Materials
- Anhui University
- Hefei 230039
- P. R. China
| | - Linquan Bao
- School of Chemistry and Chemical Engineering
- Center for Atomic Engineering of Advanced Materials
- Anhui University
- Hefei 230039
- P. R. China
| | - Hongting Sheng
- School of Chemistry and Chemical Engineering
- Center for Atomic Engineering of Advanced Materials
- Anhui University
- Hefei 230039
- P. R. China
| | - Lili Sun
- School of Chemistry and Chemical Engineering
- Center for Atomic Engineering of Advanced Materials
- Anhui University
- Hefei 230039
- P. R. China
| | - Man Chen
- School of Chemistry and Chemical Engineering
- Center for Atomic Engineering of Advanced Materials
- Anhui University
- Hefei 230039
- P. R. China
| | - Yan Feng
- School of Chemistry and Chemical Engineering
- Center for Atomic Engineering of Advanced Materials
- Anhui University
- Hefei 230039
- P. R. China
| | - Manzhou Zhu
- School of Chemistry and Chemical Engineering
- Center for Atomic Engineering of Advanced Materials
- Anhui University
- Hefei 230039
- P. R. China
| |
Collapse
|
5
|
Bolarinwa IF. Synthesis and Characterization of Hapten-Protein Conjugates for Antibody Production against Cyanogenic Glycosides. J Food Prot 2015; 78:1408-13. [PMID: 26197297 DOI: 10.4315/0362-028x.jfp-15-033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Consumption of cyanogenic plants can cause serious health problems for humans. The ability to detect and quantify cyanogenic glycosides, capable of generating cyanide, could contribute to prevention of cyanide poisoning from the consumption of improperly processed cyanogenic plants. Hapten-protein conjugates were synthesized with amygdalin and linamarin by using a novel approach. Polyclonal antibodies were generated by immunizing four New Zealand White rabbits with synthesized amygdalin-bovine serum albumin and linamarin-bovine serum albumin immunogen. This is the first time an antibody was produced against linamarin. Antibody titer curves were obtained from all the four rabbits by using a noncompetitive enzyme-linked immunosorbent assay. High antibody titer was obtained at dilutions greater than 1:50,000 from both immunogens. This new method is an important step forward in preventing ingestion of toxic cyanogenic glycosides.
Collapse
Affiliation(s)
- Islamiyat Folashade Bolarinwa
- Department of Food Science and Engineering, Ladoke Akintola University of Technology, PMB 4000, Ogbomoso, Oyo State, Nigeria.
| |
Collapse
|
6
|
Characterization of Hapten-Protein Conjugates: Antibody Generation and Immunoassay Development for Pesticides Monitoring. BIONANOSCIENCE 2013; 3:137-144. [PMID: 23705103 PMCID: PMC3657092 DOI: 10.1007/s12668-013-0083-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The generation of specific and sensitive antibodies against small molecules is greatly dependent upon the characteristics of the hapten–protein conjugates. In the present study, we report a new fluorescence-based method for the characterization of hapten–protein conjugates. The method is based on an effect promoted by hapten–protein conjugation density upon the fluorescence intensity of the intrinsic tryptophan chromophore molecules of the protein. The proposed methodology is applied to quantify the hapten–protein conjugation density of two different class of pesticides (atrazine and 2,4-dichlorophenoxyacetic acid in this study) coupled to carrier protein. The study proved useful for monitoring the course of hapten–protein conjugation for the production of specific antibodies against small molecules. Well-characterized hapten–protein conjugates enabled obtaining highly sensitive anti-atrazine and anti-2,4-D antibodies with IC50 values equal to 12 and 70 ng mL−1 for atrazine and 2,4-D respectively. These antibodies were used for developing a fluorescence-based immunoassays format demonstrating a detection limit of atrazine and 2,4-D in standard water samples 2 and 7 ng mL−1, respectively. The developed immunoassay format could be used as convenient quantitative tools for sensitive and specific screening of pesticides in samples.
Collapse
|
7
|
Zhang M, Wang Y, Yu X, Hu Y, Liu S. Rapid monitoring of dicyclohexyl phthalate in foods using the direct competitive ELISA. FOOD AGR IMMUNOL 2013. [DOI: 10.1080/09540105.2013.768964] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
|
8
|
Jones MW, Mantovani G, Blindauer CA, Ryan SM, Wang X, Brayden DJ, Haddleton DM. Direct peptide bioconjugation/PEGylation at tyrosine with linear and branched polymeric diazonium salts. J Am Chem Soc 2012; 134:7406-13. [PMID: 22494012 DOI: 10.1021/ja211855q] [Citation(s) in RCA: 114] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Direct polymer conjugation at peptide tyrosine residues is described. In this study Tyr residues of both leucine enkephalin and salmon calcitonin (sCT) were targeted using appropriate diazonium salt-terminated linear monomethoxy poly(ethylene glycol)s (mPEGs) and poly(mPEG) methacrylate prepared by atom transfer radical polymerization. Judicious choice of the reaction conditions-pH, stoichiometry, and chemical structure of diazonium salt-led to a high degree of site-specificity in the conjugation reaction, even in the presence of competitive peptide amino acid targets such as histidine, lysines, and N-terminal amine. In vitro studies showed that conjugation of mPEG(2000) to sCT did not affect the peptide's ability to increase intracellular cAMP induced in T47D human breast cancer cells bearing sCT receptors. Preliminary in vivo investigation showed preserved ability to reduce [Ca(2+)] plasma levels by mPEG(2000)-sCT conjugate in rat animal models.
Collapse
Affiliation(s)
- Mathew W Jones
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
| | | | | | | | | | | | | |
Collapse
|
9
|
Wang Y, He CH, Zheng H, Zhang HB. Characterization and comparison of Fumonisin B(1)-protein conjugates by six methods. Int J Mol Sci 2011; 13:84-96. [PMID: 22312240 PMCID: PMC3269674 DOI: 10.3390/ijms13010084] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Revised: 11/08/2011] [Accepted: 11/28/2011] [Indexed: 12/04/2022] Open
Abstract
In order to generate an antibody against a small hapten molecule, the hapten is cross-linked with carrier protein to make it immunogenic. In this study, the hapten (Fumonisin B(1), FB(1)) was coupled to ovalbumin (OVA) and bovine serum albumin (BSA), respectively by a short cross-linker reagent (glutaraldehyde, GA). To develop a technique for detecting the conjugation, the hapten-protein conjugates (FB(1)-OVA and FB(1)-BSA) were characterized thoroughly by ultraviolet (UV) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, gel electrophoresis and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS), respectively. The molecular weights of FB(1)-BSA and FB(1)-OVA were 74,355.301 Da and 48,009.212 Da, respectively determined by the method of MALDI-TOF-MS. The molecular coupling ratios were 11 and 5 in FB(1)-BSA and FB(1)-OVA, respectively. In this experiment, MALDI-TOF-MS was selected as the most efficient method to evaluate the cross-linking effect and calculate the molecular coupling ratio.
Collapse
Affiliation(s)
- Ying Wang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China; E-Mails: (Y.W.); (C.-H.H.); (H.Z.)
| | - Cheng-Hua He
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China; E-Mails: (Y.W.); (C.-H.H.); (H.Z.)
| | - Hao Zheng
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China; E-Mails: (Y.W.); (C.-H.H.); (H.Z.)
| | - Hai-Bin Zhang
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China; E-Mails: (Y.W.); (C.-H.H.); (H.Z.)
| |
Collapse
|
10
|
Sharma P, Suri CR. Biotransformation and biomonitoring of phenylurea herbicide diuron. BIORESOURCE TECHNOLOGY 2011; 102:3119-3125. [PMID: 21075624 DOI: 10.1016/j.biortech.2010.10.076] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Revised: 10/16/2010] [Accepted: 10/18/2010] [Indexed: 05/30/2023]
Abstract
A Gram-positive, Micrococcus sp. strain PS-1 isolated from diuron storage site was studied for its capability of biotransformation of phenylurea herbicide diuron to a secondary metabolite, 1-(3,4-dichlorophenyl)urea (DCPU) for bioconjugation and antibody development applications. The metabolite formed associated with profound changes in bacterial cell morphology demonstrated increase in the degradation kinetics of diuron in presence of small quantity of a surfactant. The synthesized metabolite identified by chromatographic and mass spectrometry techniques was conjugated with carrier protein, and used as an immunogen for antibodies production. The generated antibody was highly specific, demonstrating excellent sensitivity against diuron. The antibody was used as receptor molecules in standard fluorescence immunoassay (FIA) format showing detection limit of 0.01 ng/mL in the optimum working concentration range of diuron with good signal precision (∼2%). The study presented first time the degradation pathway of herbicide by specific microorganism to synthesize hapten for bioconjugation and immunoassay development.
Collapse
|
11
|
Sang G, Luo S, Lin J, Qiu L, Chen C, Yang H, Xia Y. Syntheses of haptens and hapten-protein conjugates for insecticide propoxur and cyhalothrin. Sci China Chem 2010. [DOI: 10.1007/s11426-010-0141-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
12
|
Park S, Lee DH, Park JG, Lee YT, Chung J. A sensitive enzyme immunoassay for measuring cotinine in passive smokers. Clin Chim Acta 2010; 411:1238-42. [PMID: 20438723 DOI: 10.1016/j.cca.2010.04.027] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Revised: 04/24/2010] [Accepted: 04/26/2010] [Indexed: 11/30/2022]
Abstract
BACKGROUND Both active smoking and passive exposure to tobacco smoke are major risk factors for cardiovascular, pulmonary, and oncological diseases. The serum level of cotinine, a major proximate metabolite of nicotine, reflects active or passive exposure to tobacco smoke. However, currently available enzyme-linked immunosorbent assays (ELISAs) for cotinine have limited sensitivity, and a high-throughput quantification of the severity of passive exposure to tobacco smoke has not been possible thus far. METHODS We generated a phage display of combinatorial antibody library, from which we selected a recombinant antibody against cotinine, developed a sensitive ELISA using this antibody, and evaluated the method in a clinical setting and an animal model. RESULTS The limits of detection and the lower limit of quantification were 31pg/mL and 1ng/mL cotinine, respectively. The intra- and inter-assay precisions based on three quality control samples were 3.8-13.5% and 14.0-15.0%, respectively. No significant interference from nicotine, trans-3'-hydroxy cotinine, tobacco alkaloids, or other serum components was found. When we applied our ELISA to serum samples from 36 volunteers, the serum cotinine levels were clustered into two groups, which exactly corresponded to their smoking behavior and this ELISA yielded reproducible and accurate results, which were comparable to those of LC/MS in a split assay. In animal studies, we were able to distinguish between rats injected with a nicotine dose equivalent to that of passive exposure to tobacco and rats without exposure. CONCLUSION The competitive ELISA described here is useful for the detection and quantification of the severity of risk of passive smoking.
Collapse
Affiliation(s)
- Sunyoung Park
- Department of Biochemistry and Molecular Biology, Seoul National University School of Medicine, Republic of Korea
| | | | | | | | | |
Collapse
|
13
|
Development and validation of two new sensitive ELISAs for Hesperetin and Naringenin in biological fluids. Food Chem 2010. [DOI: 10.1016/j.foodchem.2009.05.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
14
|
Zhang Y, Lu S, Liu W, Zhao C, Xi R. Preparation of anti-tetracycline antibodies and development of an indirect heterologous competitive enzyme-linked immunosorbent assay to detect residues of tetracycline in milk. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2007; 55:211-8. [PMID: 17227044 DOI: 10.1021/jf062627s] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Tetracycline (TC) is a broad-spectrum antibiotic used increasingly in animal husbandry to treat diseases or to promote growth as feed additives. To avoid using labor-intensive instrumental methods to detect residues of TC in food and food products, a simple and convenient indirect heterologous competitive enzyme-linked immunosorbent assay (ELISA) method for TC was developed using polyclonal antibody prepared in this study. Three new immunogens, TC-o-tolidine-bovine serum albumin (BSA), TC- 4-aminobenzoic acid-cationized BSA (cBSA), and TC-1,1'-carbonyldiimidazole-cBSA, were synthesized in this research to develop anti-TC antibodies. All antibodies raised in rabbits and coating antigens synthesized were screened and characterized using homologous and heterologous ELISA formats to select the best combination. An optimized ELISA gave an IC50 value of 3.92 mug/mL toward TC in PBS buffer. The specificity of the assay was studied by measuring cross-reactivity of the antibody with the structurally closely related compounds of chlortetracycline (112%) and oxytetracycline (<2%). The recovery rates from the TC-fortified raw milk samples were in the range of 74-116%, while the intra- and interassay coefficients of variation were <14.5 and <25.0, respectively.
Collapse
Affiliation(s)
- Yulan Zhang
- The School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, People's Republic of China
| | | | | | | | | |
Collapse
|
15
|
Xu C, Chu X, Peng C, Liu L, Wang L, Jin Z. Comparison of enzyme-linked immunosorbent assay with liquid chromatography-tandem mass spectrometry for the determination of diethylstilbesterol residues in chicken and liver tissues. Biomed Chromatogr 2007; 20:1056-64. [PMID: 16583459 DOI: 10.1002/bmc.638] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A competitive enzyme-linked immunosorbent assay (ELISA) was developed for the quantitative detection of the diethylstilbesterol (DES). Polyclonal rabbit antisera, raised against protein conjugate diethylstilbesterol-mono-caroxyl-propyl-ethyl-bovine-serum-albumin (DES-MCPE-BSA), were utilized in immobilized antibody-based and competitive immunoassays. Assay conditions, including concentrations of antisera and horseradish peroxidase, (HRP)-DES, were optimized. The effects of incubation time, surfactant concentration, ionic strength and pH of the medium were also investigated. The typical calibration curve gave an average IC(50) value of 2.4 ng/mL, calibration range from 0.2 to 30.5 ng/mL and a detection limit of 0.07 ng/mL. The specificity of the assay was tested against DES structurally related compounds, and the assay proved highly selective for DES. Assay performance was validated using spiked chicken meat and liver tissue samples. Moreover, it was compared with liquid chromatography-tandem mass spectrometry. The ion pair for quantification of DES was m/z 267.4/251.4, and the linear equation of DES was y = 0.1033x + 0.0126 (r = 0.9960). The two analytical methods can be applied to monitor DES and other steroid residues in foods.
Collapse
Affiliation(s)
- Chuanlai Xu
- School of Food Science and Technology, Southern Yangtze University, 214036, WuXi, JiangSu Province, People's Republic of China.
| | | | | | | | | | | |
Collapse
|
16
|
Xu C, Peng C, Liu L, Wang L, Jin Z, Chu X. Determination of hexoestrol residues in animal tissues based on enzyme-linked immunosorbent assay and comparison with liquid chromatography–tandem mass spectrometry. J Pharm Biomed Anal 2006; 41:1029-36. [PMID: 16497468 DOI: 10.1016/j.jpba.2006.01.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2005] [Revised: 01/11/2006] [Accepted: 01/12/2006] [Indexed: 11/15/2022]
Abstract
A competitive enzyme-linked immunosorbent assay (ELISA) was developed for the quantitative detection of the hexoestrol (HES). Polyclonal rabbit antisera, raised against protein conjugate hexoestrol-mono-carboxyl-propyl-ethyl-bovine-serum-albumin (HES-MCPE-BSA), were utilized in immobilized antibody-based and competitive immunoassays. Assay conditions, including concentrations of antisera and Horseradish peroxidase (HRP)-HES were optimized. The effect of incubation time, surfactant concentration, ionic strength and pH of the medium were also investigated. The typical calibration curve gave an average IC50 value of 2.4 ng/ml, calibration range from 0.2 ng/ml to 30.5 ng/ml and a detection limit of 0.07 ng/ml. The specificity of the assay was tested against HES structurally related compounds, and the assay proved highly selective for HES. Assay performance was validated by using spiked pork and liver tissues samples. Moreover, it was compared with liquid chromatography-tandem mass spectrometry. The ion pair for quantification of HES was 269.4/134, and linear equation of HES was Y=0.2148X-0.0374 (r=0.9993). The two analytical methods can be applied to monitor HES and other steroid residues in edible foods.
Collapse
Affiliation(s)
- ChuanLai Xu
- School of Food Science and Technology, Southern Yangtze University, 214036, WuXi, JiangSu Province, PR China.
| | | | | | | | | | | |
Collapse
|
17
|
Selective displacement of aryl fluorides with hydroquinone: synthesis of 4-phenoxyphenols. Tetrahedron Lett 2005. [DOI: 10.1016/j.tetlet.2005.09.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
18
|
Cardozo S, González-Techera A, Last JA, Hammock BD, Kramer K, González-Sapienza GG. Analyte peptidomimetics selected from phage display peptide libraries: a systematic strategy for the development of environmental immunoassays. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2005; 39:4234-41. [PMID: 15984805 DOI: 10.1021/es047931l] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Due to their simplicity, speed, low cost, and specificity, immunoassays have become a useful tool for the analysis of environmental pollutants. Once the anti-hapten antibodies are produced, the same hapten or a related molecule is conjugated to a tracer enzyme or coating protein to set up the assay. Here we report the use of peptides that mimic the analyte as advantageous substitutes of competing haptens. These peptides, which open opportunities for innovation in the development of tracer reagents, can be selected from phage display libraries in a straightforward systematic manner. The concept was proven using assays for the herbicides molinate and atrazine as model systems. Several characteristics of the selection process that may affect the final assay were analyzed, such as the phage coat proteins fused to the peptide, the use of linear or constrained peptide libraries, the effect of the concentration of analyte used during the selection process, and the use of monoclonal or polyclonal antibodies as selector molecules. In all cases we found that the selected peptides performed with improved sensitivity as compared with the chemical hapten conventional assays, showing an analogous cross-reactivity pattern. Interestingly, the phage particles perform as robust and highly standardized assay reagents, and due to their filamentous repetitive structure, they function as sensitive multienzymatic reporters.
Collapse
Affiliation(s)
- Soledad Cardozo
- Facultad de Química, Instituto de Higiene, UDELAR, Av. A. Navarro 3051, piso 2, Montevideo 11600, Uruguay
| | | | | | | | | | | |
Collapse
|
19
|
Comparative study of three immunoassays based on monoclonal antibodies for detection of the pesticide parathion-methyl in real samples. Anal Chim Acta 2004. [DOI: 10.1016/j.aca.2004.01.047] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
20
|
Singh KV, Kaur J, Varshney GC, Raje M, Suri CR. Synthesis and Characterization of Hapten−Protein Conjugates for Antibody Production against Small Molecules. Bioconjug Chem 2003; 15:168-73. [PMID: 14733597 DOI: 10.1021/bc034158v] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
For the generation of antibodies against small hapten molecules, the hapten is cross-linked with some carrier protein to make it immunogenic. However, the formation of such conjugates is not always reproducible. This may lead to inconsistent hapten-protein stoichiometries, resulting in large variations in the generation of the desired antibodies. In the study described here the hapten (mercaptopropionic acid derivative of atrazine) was coupled to carrier protein at five different molar ratios. The hapten-protein conjugates prepared were characterized thoroughly by spectrophotometric absorption, fluorescence, matrix-assisted laser desorption ionization (MALDI), and gel electrophoresis methods, before being used for the immunization and assay purposes. Electrophoresis and fluorescence methods were very useful in detecting hapten-protein cross-linking while MALDI-MS and spectrophotometric detection provided qualitatively comparable hapten density. The production of specific antibodies was sought following the generation of appropriate hapten-protein conjugates. A high antibody titer with moderate antibody specificity was obtained with hapten density around 15 molecules per carrier protein. The study proved useful for monitoring the course of hapten-protein conjugation for the production of specific antibodies against small molecules.
Collapse
Affiliation(s)
- K V Singh
- Institute of Microbial Technology, Sector 39-A, Chandigarh 160 036, India
| | | | | | | | | |
Collapse
|
21
|
Optimization and validation of an enzyme immunoassay for the insect growth regulator fenoxycarb. Anal Chim Acta 2003. [DOI: 10.1016/s0003-2670(03)00299-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
22
|
|
23
|
Le HTM, Szurdoki F, Székács A. Evaluation of an enzyme immunoassay for the detection of the insect growth regulator fenoxycarb in environmental and biological samples. PEST MANAGEMENT SCIENCE 2003; 59:410-416. [PMID: 12701701 DOI: 10.1002/ps.656] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A competitive enzyme-linked immunosorbent assay (ELISA) for fenoxycarb was adapted for quantitative detection of this insect growth regulator in various environmental, agricultural, food and biological matrices. Environmental samples were taken from soil and surface waters in Hungary. The ELISA enabled fenoxycarb detection in surface waters in the 1.1-125 ng ml(-1) concentration range without sample cleanup. In contrast, soil produced a strong matrix effect due to humic acids and other soil components. Several fruit homogenates and commercial fruit juices (eg apple, pear, grape) were analyzed by the ELISA. The assay was found to be suitable for analysis of fenoxycarb in fruit juices diluted 1:40. Biological samples included insect, fish and bovine tissues. The ELISA was applied to detect fenoxycarb in various biological matrices from larvae of the silkworm, Bombyx mori L. The assay proved useful for the analysis of haemolymph diluted 1:10 or at higher dilutions. Fat body and whole body homogenates, however, caused severe matrix effects. Fenoxycarb was detected in liver homogenates (diluted 1:40) from fish treated with various doses of fenoxycarb, and the concentrations determined correlated with the applied doses. The method was used to analyze spiked bovine urine samples diluted 1:10 or at greater dilutions. Fenoxycarb content determined by the ELISA in water and fruit juice samples was validated using GC-MS with solid-phase microextraction (SPME) sample preparation. The results of these studies demonstrated both the value and limitations of the assay when used for monitoring fenoxycarb in environmental, food and biological samples.
Collapse
Affiliation(s)
- Hong T M Le
- Plant Protection Institute, Hungarian Academy of Sciences, PO Box 102, H-1525 Budapest, Hungary
| | | | | |
Collapse
|
24
|
Determination of the insecticide fenoxycarb in apple leaf samples by an enzyme-linked immunosorbent assay. Anal Chim Acta 2003. [DOI: 10.1016/s0003-2670(02)01510-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
25
|
Dedos SG, Szurdoki F, Székács A, Mizoguchi A, Fugo H. Induction of dauer pupae by fenoxycarb in the silkworm, Bombyx mori. JOURNAL OF INSECT PHYSIOLOGY 2002; 48:857-865. [PMID: 12770048 DOI: 10.1016/s0022-1910(02)00155-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Topical application of fenoxycarb (1 &mgr;g per animal) at 129 or 132 h of the fifth instar larvae of the silkworm, Bombyx mori, did not induce morphological abnormalities in the pupal stage, but these animals became dauer (permanent) pupae. This condition of B. mori and the endocrine events leading to permanent pupae are discussed in this work. Application of fenoxycarb at 132 h of the fifth instar elicited a high ecdysteroid titre in the pharate pupal stage and a steadily high ecdysteroid titre in the pupal stage. The fenoxycarb-induced permanent pupae had non-degenerating prothoracic glands that secreted low amounts of ecdysteroid and did not respond to recombinant prothoracicotropic hormone (rPTTH) late in the pupal stage. The Bombyx PTTH titre in the haemolymph, determined by a time-resolved fluoroimmunoassay, was lower than that of controls at the time of pupal ecdysis, but higher than controls later in the pupal stage in fenoxycarb-treated animals. After application of fenoxycarb, its haemolymph level, measured by ELISA, reached a peak at pupal ecdysis, then remained low. These results suggest that the fenoxycarb-mediated induction of permanent pupae is only partially a brain-centred phenomenon. It also involves alterations in the hormonal interplay that govern both the initiation of pupal-adult differentiation and changes in the steroidogenic pathway of the prothoracic glands of B. mori.
Collapse
Affiliation(s)
- S G. Dedos
- Department of Biological Production, Tokyo University of Agriculture and Technology, Fuchu-shi, 183, Tokyo, Japan
| | | | | | | | | |
Collapse
|