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Shen C, Li YH, Lin MM, Zhang JZ, Wang J, Gao MJ, Zhang X, Hu XD, Liu Y, Liu XJ. Identifying the Epitopes of Bacillus thuringiensis Cry2Aa Toxin Involved in Cadherin Interaction by a Monoclonal Antibody. Appl Biochem Biotechnol 2022; 195:2709-2718. [PMID: 36074237 DOI: 10.1007/s12010-022-04162-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/28/2022] [Indexed: 11/26/2022]
Abstract
Antibodies are a useful tool for assistance to map the binding epitopes in Bacillus thuringiensis Cry toxins and their receptors, and even determine how receptors promote toxicity. In this work, a monoclonal antibody (mAb-1D2) was produced by the hybridoma cell line raised against Cry2Aa toxins, with a half inhibition concentration (IC50) of 9.16 μg/mL. The affinity constant of two recombinant toxin-binding fragments derived from Helicoverpa armigera and Plutella xylostella cadherin-like protein (HaCad-TBR or PxCad-TBR) to Cry2Aa toxin was measured to be 1.21 μM and 1.24 μM, respectively. Competitive ELISA showed that mAb-1D2 competed with HaCad-TBR or PxCad-TBR binding to Cry2Aa. Meanwhile, the toxicity of the Cry2Aa toxin to the H. armigera and P. xylostella larvae were greatly reduced when the toxin was mixed with mAb-1D2, which indicated that cadherin may play an important functional role in the toxicity of Cry2Aa. After transforming mAb-1D2 to a single-chain variable fragment (scFv), the hot spot residues of Cry2Aa with 1D2-scFv, PxCad-TBR, and HaCad-TBR were analyzed by molecular docking. It was demonstrated that the hot spot residues of Cry2Aa involving with 1D2-scFv interaction were mainly in Domain II, and some residues in Domain I. Moreover, mAb-1D2 and the two cadherin fragments shared the common hot spot residues on Cry2Aa, which could explain mAb-1D2 inhibited Cry2Aa binding with cadherin fragments. This monoclonal antibody could be a useful tool for identifying the binding epitopes between Cry2Aa and cadherin, and even assist to analyze the roles of cadherin in Cry2Aa toxicity.
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Affiliation(s)
- Cheng Shen
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Food Quality and Safety of Jiangsu Province, Nanjing, 210014, China
| | - Yi-Hang Li
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Food Quality and Safety of Jiangsu Province, Nanjing, 210014, China
| | - Man-Man Lin
- Key Laboratory of Food Quality and Safety of Jiangsu Province, Nanjing, 210014, China
| | - Jiang-Zhao Zhang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Food Quality and Safety of Jiangsu Province, Nanjing, 210014, China
| | - Jing Wang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
- Key Laboratory of Food Quality and Safety of Jiangsu Province, Nanjing, 210014, China
| | - Mei-Jing Gao
- Key Laboratory of Food Quality and Safety of Jiangsu Province, Nanjing, 210014, China
| | - Xiao Zhang
- Key Laboratory of Food Quality and Safety of Jiangsu Province, Nanjing, 210014, China
| | - Xiao-Dan Hu
- Key Laboratory of Food Quality and Safety of Jiangsu Province, Nanjing, 210014, China
| | - Yuan Liu
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.
- Key Laboratory of Food Quality and Safety of Jiangsu Province, Nanjing, 210014, China.
| | - Xian-Jin Liu
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China.
- Key Laboratory of Food Quality and Safety of Jiangsu Province, Nanjing, 210014, China.
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Petrick JS, Bell E, Koch MS. Weight of the evidence: independent research projects confirm industry conclusions on the safety of insect-protected maize MON 810. GM CROPS & FOOD 2019; 11:30-46. [PMID: 31651217 PMCID: PMC7064210 DOI: 10.1080/21645698.2019.1680242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 10/10/2019] [Accepted: 10/11/2019] [Indexed: 01/16/2023]
Abstract
The cumulative weight of the evidence demonstrates the safety and equivalence of genetically engineered (GE) crops compared to the conventional varieties from which they have been derived. Confirmatory toxicology and animal nutrition studies have nevertheless become an expected/mandated component of GE crop safety assessments, despite the lack of additional value these studies provide for product safety assessment. Characterization and safety data (e.g. trait protein safety; molecular, compositional, and agronomic/phenotypic assessments), and animal feeding studies form a weight of the evidence supporting the safety of insect-protected maize MON 810. Independent animal testing has recently confirmed the lack of MON 810 toxicity in subchronic and chronic toxicity studies. These results could have been predicted from the available safety data. Animal testing of GE crops should be supported by testable scientific hypotheses and testing should be consistent with ethical obligations to reduce, refine, and replace (3Rs) animal testing when possible.
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Affiliation(s)
- Jay S. Petrick
- Product Safety Center, Bayer Crop Science, Chesterfield, Missouri, USA
| | - Erin Bell
- Product Safety Center, Monsanto Company, Chesterfield, Missouri, USA
| | - Michael S. Koch
- Product Safety Center, Bayer Crop Science, Chesterfield, Missouri, USA
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Liu M, Huang R, Weisman A, Yu X, Lee SH, Chen Y, Huang C, Hu S, Chen X, Tan W, Liu F, Chen H, Shea KJ. Synthetic Polymer Affinity Ligand for Bacillus thuringiensis (Bt) Cry1Ab/Ac Protein: The Use of Biomimicry Based on the Bt Protein–Insect Receptor Binding Mechanism. J Am Chem Soc 2018; 140:6853-6864. [DOI: 10.1021/jacs.8b01710] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Mingming Liu
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
- Department of Chemistry, University of California−Irvine, Irvine, California 92697, United States
| | - Rong Huang
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Adam Weisman
- Department of Chemistry, University of California−Irvine, Irvine, California 92697, United States
| | - Xiaoyang Yu
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Shih-Hui Lee
- Department of Chemistry, University of California−Irvine, Irvine, California 92697, United States
| | - Yalu Chen
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Chao Huang
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Senhua Hu
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Xiuhua Chen
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Wenfeng Tan
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Fan Liu
- Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China
| | - Hao Chen
- College of Science, Huazhong Agricultural University, Wuhan 430070, China
| | - Kenneth J. Shea
- Department of Chemistry, University of California−Irvine, Irvine, California 92697, United States
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Evaluation of seed extracts from plants found in the Caatinga biome for the control of Aedes aegypti. Parasitol Res 2014; 113:3565-80. [DOI: 10.1007/s00436-014-4022-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Accepted: 07/04/2014] [Indexed: 11/27/2022]
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Endo H, Kobayashi Y, Hoshino Y, Tanaka S, Kikuta S, Tabunoki H, Sato R. Affinity maturation of Cry1Aa toxin to the Bombyx mori cadherin-like receptor by directed evolution based on phage display and biopanning selections of domain II loop 2 mutant toxins. Microbiologyopen 2014; 3:568-77. [PMID: 25044375 PMCID: PMC4287183 DOI: 10.1002/mbo3.188] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 05/12/2014] [Accepted: 05/26/2014] [Indexed: 01/14/2023] Open
Abstract
Directed evolution of a Cry1Aa toxin using phage display and biopanning was performed to generate an increased binding affinity to the Bombyx mori cadherin-like receptor (BtR175). Three mutant toxins (371WGLA374, 371WPHH374, 371WRPQ37425) with 16-, 16-, and 50-fold higher binding affinities, respectively, for BtR175 were selected from a phage library containing toxins with mutations in domain II loop 2. However, the observed toxicities of the three mutants against B. mori larvae and cultured cells expressing the BtR175 toxin-binding region did not increase, suggesting that increased binding affinity to cadherins does not contribute to the insecticidal activity. Affinity maturation of a Cry toxin to a receptor via directed evolution was relatively simple to achieve, and seems to have potential for generating a toxin with increased insecticidal activity.
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Affiliation(s)
- Haruka Endo
- Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo, 184-8588, Japan
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Zhang X, Xu C, Zhang C, Liu Y, Xie Y, Liu X. Established a new double antibodies sandwich enzyme-linked immunosorbent assay for detecting Bacillus thuringiensis (Bt) Cry1Ab toxin based single-chain variable fragments from a naïve mouse phage displayed library. Toxicon 2014; 81:13-22. [DOI: 10.1016/j.toxicon.2014.01.010] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 12/17/2013] [Accepted: 01/16/2014] [Indexed: 10/25/2022]
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Wang Y, Zhang X, Zhang C, Liu Y, Liu X. Isolation of single chain variable fragment (scFv) specific for Cry1C toxin from human single fold scFv libraries. Toxicon 2012; 60:1290-7. [DOI: 10.1016/j.toxicon.2012.08.014] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 08/27/2012] [Accepted: 08/29/2012] [Indexed: 10/27/2022]
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Oliveira GR, Silva MCM, Lucena WA, Nakasu EYT, Firmino AAP, Beneventi MA, Souza DSL, Gomes JE, de Souza JDA, Rigden DJ, Ramos HB, Soccol CR, Grossi-de-Sa MF. Improving Cry8Ka toxin activity towards the cotton boll weevil (Anthonomus grandis). BMC Biotechnol 2011; 11:85. [PMID: 21906288 PMCID: PMC3179717 DOI: 10.1186/1472-6750-11-85] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Accepted: 09/09/2011] [Indexed: 11/13/2022] Open
Abstract
Background The cotton boll weevil (Anthonomus grandis) is a serious insect-pest in the Americas, particularly in Brazil. The use of chemical or biological insect control is not effective against the cotton boll weevil because of its endophytic life style. Therefore, the use of biotechnological tools to produce insect-resistant transgenic plants represents an important strategy to reduce the damage to cotton plants caused by the boll weevil. The present study focuses on the identification of novel molecules that show improved toxicity against the cotton boll weevil. In vitro directed molecular evolution through DNA shuffling and phage display screening was applied to enhance the insecticidal activity of variants of the Cry8Ka1 protein of Bacillus thuringiensis. Results Bioassays carried out with A. grandis larvae revealed that the LC50 of the screened mutant Cry8Ka5 toxin was 3.15-fold higher than the wild-type Cry8Ka1 toxin. Homology modelling of Cry8Ka1 and the Cry8Ka5 mutant suggested that both proteins retained the typical three-domain Cry family structure. The mutated residues were located mostly in loops and appeared unlikely to interfere with molecular stability. Conclusions The improved toxicity of the Cry8Ka5 mutant obtained in this study will allow the generation of a transgenic cotton event with improved potential to control A. grandis.
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Affiliation(s)
- Gustavo R Oliveira
- Embrapa Recursos Genéticos e Biotecnologia, PqEB- Final W5 Norte -Brasília, DF, Brasil
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Functional analysis of active site residues of Bacillus thuringiensis WB7 chitinase by site-directed mutagenesis. World J Microbiol Biotechnol 2009. [DOI: 10.1007/s11274-009-0119-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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