1
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Huan F, Gao S, Ni LN, Wu MX, Gu Y, Yun X, Liu M, Lai D, Xiao AF, Liu GM. Development of Hypoallergenic Derivatives of Cra a 1 with B Cell Epitope Deletion and T Cell Epitope Retention. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:19494-19504. [PMID: 39168117 DOI: 10.1021/acs.jafc.4c04475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/23/2024]
Abstract
Tropomyosin was reported as an important allergen in Crassostrea angulata and designated as Cra a 1. The localization of the T cell epitopes and the reduction of the immunoreactivity of Cra a 1 are still lacking. In this study, four T cell epitopes were identified by using wild-type Cra a 1 (wtCra a 1)-immunized mouse splenocytes cultured with synthetic peptides. The immunoreactivity was maintained after chemical denaturation treatment, indicating that the linear epitope is an immunodominant epitope of wtCra a 1. Furthermore, the hypoallergenic derivative (mCra a 1) was developed by the deletion of linear B cell epitopes and retention of T cell epitopes. mCra a 1 could stimulate CD4+T cell proliferation and upregulate interleukin-10 secretion. Overall, basophil activation by mCra a 1 was low, but its ability to induce T cell proliferation was retained, suggesting that mCra a 1 may serve as a viable candidate for treating oyster allergy.
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Affiliation(s)
- Fei Huan
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Jimei University, Xiamen, Fujian 361021, China
| | - Shuai Gao
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Jimei University, Xiamen, Fujian 361021, China
| | - Ling-Na Ni
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Jimei University, Xiamen, Fujian 361021, China
| | - Ming-Xuan Wu
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Jimei University, Xiamen, Fujian 361021, China
| | - Yi Gu
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Jimei University, Xiamen, Fujian 361021, China
| | - Xiao Yun
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Jimei University, Xiamen, Fujian 361021, China
| | - Meng Liu
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Jimei University, Xiamen, Fujian 361021, China
- College of Marine Biology, Xiamen Ocean Vocational College, Xiamen, Fujian 361100, China
| | - Dong Lai
- The Second Affiliated Hospital of Xiamen Medical College, Xiamen, Fujian 361021, China
| | - An-Feng Xiao
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Jimei University, Xiamen, Fujian 361021, China
| | - Guang-Ming Liu
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Jimei University, Xiamen, Fujian 361021, China
- College of Marine Biology, Xiamen Ocean Vocational College, Xiamen, Fujian 361100, China
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Han X, He X, Wang X, Luo L, Li Y, Lai D, Liu H, Liu J, Rao S, Liu G. Comparative analysis of tropomyosin allergenicity in three different species of molluscs: insights into the role of amino acid composition in IgE epitopes. Food Funct 2024; 15:5397-5413. [PMID: 38639426 DOI: 10.1039/d4fo00958d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2024]
Abstract
Limited research has been conducted on the differences in allergenicity among Alectryonella plicatula tropomyosin (ATM), Haliotis discus hannai tropomyosin (HTM), and Mimachlamys nobilis tropomyosin (MTM) in molluscs. Our study aimed to comprehensively analyze and compare their immunoreactivity, sensitization, and allergenicity while simultaneously elucidating the underlying molecular mechanisms involved. We assessed the immune binding activity of TM utilizing 86 sera from allergic patients and evaluated sensitization and allergenicity through two different types of mouse models. The dot-blot and basophil activation test assays revealed strong immunoreactivity for HTM, ATM, and MTM, with HTM exhibiting significantly lower levels compared to ATM. In the BALB/c mouse sensitization model, all TM groups stimulated the production of specific antibodies, elicited IgE-mediated immediate hypersensitivity responses, and caused an imbalance in the IL-4/IFN-γ ratio. Similarly, in the BALB/c mouse model of food allergy, all TM variants induced IgE-mediated type I hypersensitivity responses, leading to the development of food allergies characterized by clinical symptoms and an imbalance in the IL-4/IFN-γ ratio. The stimulation ability of sensitization and the severity of food allergies consistently ranked as ATM > MTM > HTM. Through an in-depth analysis of non-polar amino acid frequency and polar hydrogen bonds, HTM exhibited higher frequencies of non-polar amino acids in its amino acid sequence and IgE epitopes, in comparison with ATM and MTM. Furthermore, HTM demonstrated a lower number of polar hydrogen bonds in IgE epitopes. Overall, HTM exhibited the lowest allergenic potential in both allergic patients and mouse models, likely due to its lower polarity in the amino acid sequence and IgE epitopes.
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Affiliation(s)
- Xinyu Han
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Jimei University, Xiamen, Fujian 361021, China.
| | - Xinrong He
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Jimei University, Xiamen, Fujian 361021, China.
| | - Xinya Wang
- Department of Bioinformatics, Fujian Key Laboratory of Medical Bioinformatics, Institute of Precision Medicine, School of Medical Technology and Engineering, Fujian Medical University, Fuzhou, Fujian 350122, China
| | - Lianzhong Luo
- Engineering Research Center of Marine Biopharmaceutical Resources, Fujian Province University, Xiamen Medical College, Xiamen, Fujian 361023, China
| | - Yubao Li
- Medical Center of Jimei University, Xiamen, Fujian 361021, China
| | - Dong Lai
- Xiamen Medical College Affiliated Second Hospital, Xiamen, Fujian 361021, China
| | - Hong Liu
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Jimei University, Xiamen, Fujian 361021, China.
| | - Jingwen Liu
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Jimei University, Xiamen, Fujian 361021, China.
| | - Shitao Rao
- Department of Bioinformatics, Fujian Key Laboratory of Medical Bioinformatics, Institute of Precision Medicine, School of Medical Technology and Engineering, Fujian Medical University, Fuzhou, Fujian 350122, China
- School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong SAR, China.
| | - Guangming Liu
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Jimei University, Xiamen, Fujian 361021, China.
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3
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Liu Y, Lin S, Liu K, Wang S, Liu Q, Sun N. Exploration of digestion-resistant immunodominant epitopes in shrimp (Penaeus vannamei) allergens. Food Chem 2024; 438:137920. [PMID: 38000156 DOI: 10.1016/j.foodchem.2023.137920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 10/23/2023] [Accepted: 10/30/2023] [Indexed: 11/26/2023]
Abstract
The digestion products of Penaeus vannamei still had sensitizing and eliciting capacity; however, the underlying mechanism has not been identified. This study analyzed the structural changes of shrimp proteins during digestion, predicted the linearmimotopepeptides and first validated the allergenicity of immunodominantepitopes with binding ability. The results showed that the shrimp proteins were gradually degraded into small peptides during digestion, which might lead to the destruction of linear epitopes. However, these peptides carried IgE epitopes that still trigger allergic reactions. Eighteen digestion-resistant epitopes were predicted by multiple immunoinformatics tools and digestomics. Five epitopes contained more critical amino acids and had strong molecular docking (P1: DSGVGIYAPDAEA, P2: EGELKGTYYPLTGM, P3: GRQGDPHGKFDLPPGV, P4: IFAWPHKDNNGIE, P5: KSTESSVTVPDVPSIHD), and these epitopes were identified as novel IgE binding immunodominantepitopes in Penaeus vannamei. These findings provide novel insight into allergenic epitopes, which might serve as key targets for reducing the allergenicity in shrimp.
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Affiliation(s)
- Yao Liu
- SKL of Marine Food Processing & Safety Control, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, PR China; National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, PR China
| | - Songyi Lin
- SKL of Marine Food Processing & Safety Control, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, PR China; National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, PR China; Engineering Research Center of Special Dietary Food, the Education Department of Liaoning Province, Dalian 116034, PR China
| | - Kexin Liu
- SKL of Marine Food Processing & Safety Control, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, PR China; National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, PR China
| | - Shan Wang
- SKL of Marine Food Processing & Safety Control, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, PR China; National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, PR China
| | - Qiaozhen Liu
- SKL of Marine Food Processing & Safety Control, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, PR China; National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, PR China
| | - Na Sun
- SKL of Marine Food Processing & Safety Control, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, PR China; National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, PR China; Engineering Research Center of Food, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, PR China.
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Gao S, Huan F, Wu MX, Ni LN, Gu Y, Liu YX, Han TJ, Liu M, Lai D, Liu GM. Mutation of Disulfide Bond Sites Reduces the Immunoreactivity of Cra a 4 by Changing the Structural Characteristics. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024. [PMID: 38598840 DOI: 10.1021/acs.jafc.4c01120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2024]
Abstract
Sarcoplasmic calcium-binding protein (Cra a 4) from Crassostrea angulata belongs to the EF-hand superfamily, and understanding of its structure-allergenicity relationship is still insufficient. In this study, chemical denaturants were used to destroy the structure of Cra a 4, showing that disruption of the structure reduced its IgG-/IgE-binding activity. To explore which critical amino acid site affects the allergenicity of Cra a 4, the mutants were obtained by site-directed mutations in the disulfide bonds site (C97), conformational epitopes (I105, D114), or Ca2+-binding region (D106, D110) and their IgG-/IgE-binding activity was reduced significantly using serological tests. Notably, C97A had the lowest immunoreactivity. In addition, two conformational epitopes of Cra 4 were verified. Meanwhile, the increase of the α-helical content, surface hydrophobicity, and surface electrostatic potential of C97A affected its allergenicity. Overall, the understanding of the structure-allergenicity relationship of Cra a 4 allowed the development of a hypoallergenic mutant.
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Affiliation(s)
- Shuai Gao
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Jimei University, Xiamen 361021, Fujian, China
| | - Fei Huan
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Jimei University, Xiamen 361021, Fujian, China
| | - Ming-Xuan Wu
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Jimei University, Xiamen 361021, Fujian, China
| | - Ling-Na Ni
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Jimei University, Xiamen 361021, Fujian, China
| | - Yi Gu
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Jimei University, Xiamen 361021, Fujian, China
| | - Ya-Xin Liu
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Jimei University, Xiamen 361021, Fujian, China
| | - Tian-Jiao Han
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Jimei University, Xiamen 361021, Fujian, China
| | - Meng Liu
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Jimei University, Xiamen 361021, Fujian, China
| | - Dong Lai
- The Second Affiliated Hospital of Xiamen Medical College, Xiamen 361021, Fujian, China
| | - Guang-Ming Liu
- College of Ocean Food and Biological Engineering, Xiamen Key Laboratory of Marine Functional Food, Fujian Provincial Engineering Technology Research Center of Marine Functional Food, Jimei University, Xiamen 361021, Fujian, China
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5
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Koppelman SJ, de Jong GAH, Marsh J, Johnson P, Dowell E, Perusko M, Westphal A, van Hage M, Baumert J, Apostolovic D. Novel post-translationally cleaved Ara h 2 proteoforms: Purification, characterization and IgE-binding properties. Int J Biol Macromol 2024; 264:130613. [PMID: 38447836 DOI: 10.1016/j.ijbiomac.2024.130613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 03/01/2024] [Accepted: 03/02/2024] [Indexed: 03/08/2024]
Abstract
The 2S albumins Ara h 2 and Ara h 6 have been shown to be the most important source of allergenicity in peanut. Several isoforms of these allergens have been described. Using extraction and liquid chromatography we isolated proteins with homology to Ara h 2 and characterized hitherto unknown Ara h 2 proteoforms with additional post-translational cleavage. High-resolution mass spectrometry located the cleavage site on the non-structured loop of Ara h 2 while far UV CD spectroscopy showed a comparable structure to Ara h 2. The cleaved forms of Ara h 2 were present in genotypes of peanut commonly consumed. Importantly, we revealed that newly identified Ara h 2 cleaved proteoforms showed comparable IgE-binding using sera from 28 peanut-sensitized individuals, possessed almost the same IgE binding potency and are likely similarly allergenic as intact Ara h 2. This makes these newly identified forms relevant proteoforms of peanut allergen Ara h 2.
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Affiliation(s)
- Stef J Koppelman
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA
| | | | - Justin Marsh
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA
| | - Phil Johnson
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA
| | - Emily Dowell
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA
| | - Marija Perusko
- Division of Immunology and Allergy, Department of Medicine Solna, Karolinska Institutet, and Karolinska University Hospital, Stockholm, Sweden; Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Adrie Westphal
- Wageningen University and Research (WUR), Wageningen, the Netherlands
| | - Marianne van Hage
- Division of Immunology and Allergy, Department of Medicine Solna, Karolinska Institutet, and Karolinska University Hospital, Stockholm, Sweden; Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Joseph Baumert
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA
| | - Danijela Apostolovic
- Division of Immunology and Allergy, Department of Medicine Solna, Karolinska Institutet, and Karolinska University Hospital, Stockholm, Sweden; Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.
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Zhang Y, Geng Q, Song M, Li X, Yang A, Tong P, Wu Z, Chen H. The structure and potential allergenicity of peanut allergen monomers after roasting. Food Funct 2024; 15:2577-2586. [PMID: 38353700 DOI: 10.1039/d3fo05351b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2024]
Abstract
Given that roasted peanut (Ro) products are commonly used in daily life, peanut allergenicity is a foremost concern. Analyzing the changes in the structure and potential allergenicity of individual allergens can promote the exploration of the structural basis of the alterations in the potential allergenicity of Ro. This work focused on four major allergens in raw peanut (Ra) and Ro. Structural changes were analyzed on the basis of circular dichroism, ultraviolet and fluorescence spectroscopy, and molecular dynamic simulation. The IgE recognition capability of allergens was assessed via western blot analysis. The IgE binding capacity of allergens was detected by conducting enzyme-linked immunosorbent assay. The potential allergenicity of allergens was evaluated using the KU812 cell degranulation model. The results showed that roasting induced different changes in the overall structures of allergens and altered the structures and electrostatic potential of IgE epitopes, especially Ara h 1 and Ara h 6. These alterations affected the potential allergenicity of allergens. Ara h 1 and Ara h 6 in Ro showed significantly enhanced IgE binding capacities and abilities to elicit KU812 cell degranulation, while Ara h 2 and Ara h 3 did not change significantly. For total protein, the roasted peanut protein showed decreased abilities to elicit KU812 cell degranulation. The results indicated that different allergens in Ro showed different changes of structures and potential allergenicity and that the conformational structure plays a crucial role in potential allergenicity of allergens.
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Affiliation(s)
- Ying Zhang
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330047, China.
- College of Food Science and Technology, Nanchang University, Nanchang, 330031, China
| | - Qin Geng
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330047, China.
- College of Food Science and Technology, Nanchang University, Nanchang, 330031, China
| | - Min Song
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330047, China.
- College of Food Science and Technology, Nanchang University, Nanchang, 330031, China
| | - Xin Li
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330047, China.
- College of Food Science and Technology, Nanchang University, Nanchang, 330031, China
| | - Anshu Yang
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330047, China.
- Sino-German Joint Research Institute, Nanchang University, Nanchang 330047, China
| | - Ping Tong
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330047, China.
- College of Food Science and Technology, Nanchang University, Nanchang, 330031, China
| | - Zhihua Wu
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330047, China.
- Sino-German Joint Research Institute, Nanchang University, Nanchang 330047, China
| | - Hongbing Chen
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330047, China.
- Sino-German Joint Research Institute, Nanchang University, Nanchang 330047, China
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7
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Yan Y, Li L, Long C, Dong Y, Li J, Shen C, Zhao Y, Zhao J, Wang J, Xiong A, Li X, Chen H, He S. A novel IgE epitope-specific antibodies-based sandwich ELISA for sensitive measurement of immunoreactivity changes of peanut allergen Ara h 2 in processed foods. Front Nutr 2024; 11:1323553. [PMID: 38439921 PMCID: PMC10910080 DOI: 10.3389/fnut.2024.1323553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 02/05/2024] [Indexed: 03/06/2024] Open
Abstract
Background Peanut is an important source of dietary protein for human beings, but it is also recognized as one of the eight major food allergens. Binding of IgE antibodies to specific epitopes in peanut allergens plays important roles in initiating peanut-allergic reactions, and Ara h 2 is widely considered as the most potent peanut allergen and the best predictor of peanut allergy. Therefore, Ara h 2 IgE epitopes can serve as useful biomarkers for prediction of IgE-binding variations of Ara h 2 and peanut in foods. This study aimed to develop and validate an IgE epitope-specific antibodies (IgE-EsAbs)-based sandwich ELISA (sELISA) for detection of Ara h 2 and measurement of Ara h 2 IgE-immunoreactivity changes in foods. Methods DEAE-Sepharose Fast Flow anion-exchange chromatography combining with SDS-PAGE gel extraction were applied to purify Ara h 2 from raw peanut. Hybridoma and epitope vaccine techniques were employed to generate a monoclonal antibody against a major IgE epitope of Ara h 2 and a polyclonal antibody against 12 IgE epitopes of Ara h 2, respectively. ELISA was carried out to evaluate the target binding and specificity of the generated IgE-EsAbs. Subsequently, IgE-EsAbs-based sELISA was developed to detect Ara h 2 and its allergenic residues in food samples. The IgE-binding capacity of Ara h 2 and peanut in foods was determined by competitive ELISA. The dose-effect relationship between the Ara h 2 IgE epitope content and Ara h 2 (or peanut) IgE-binding ability was further established to validate the reliability of the developed sELISA in measuring IgE-binding variations of Ara h 2 and peanut in foods. Results The obtained Ara h 2 had a purity of 94.44%. Antibody characterization revealed that the IgE-EsAbs recognized the target IgE epitope(s) of Ara h 2 and exhibited high specificity. Accordingly, an IgE-EsAbs-based sELISA using these antibodies was able to detect Ara h 2 and its allergenic residues in food samples, with high sensitivity (a limit of detection of 0.98 ng/mL), accuracy (a mean bias of 0.88%), precision (relative standard deviation < 16.50%), specificity, and recovery (an average recovery of 98.28%). Moreover, the developed sELISA could predict IgE-binding variations of Ara h 2 and peanut in foods, as verified by using sera IgE derived from peanut-allergic individuals. Conclusion This novel immunoassay could be a user-friendly method to monitor low level of Ara h 2 and to preliminary predict in vitro potential allergenicity of Ara h 2 and peanut in processed foods.
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Affiliation(s)
- Yan Yan
- School of Public Health and Health Management, Gannan Medical University, Ganzhou, China
| | - Liming Li
- Department of Dermatology, First Affiliated Hospital of Gannan Medical University, Ganzhou, China
| | - Caiyun Long
- Department of Laboratory, Ganzhou Center for Disease Control and Prevention, Ganzhou, China
| | - Yaping Dong
- School of Public Health and Health Management, Gannan Medical University, Ganzhou, China
| | - Jinyu Li
- Department of Dermatology, First Affiliated Hospital of Gannan Medical University, Ganzhou, China
| | - Caiyi Shen
- School of Public Health and Health Management, Gannan Medical University, Ganzhou, China
| | - Yiqian Zhao
- School of Public Health and Health Management, Gannan Medical University, Ganzhou, China
| | - Jiangqiang Zhao
- School of Public Health and Health Management, Gannan Medical University, Ganzhou, China
| | - Jianbin Wang
- School of Public Health and Health Management, Gannan Medical University, Ganzhou, China
| | - Anqi Xiong
- School of Public Health and Health Management, Gannan Medical University, Ganzhou, China
| | - Xin Li
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang, China
| | - Hongbing Chen
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang, China
| | - Shengfa He
- School of Public Health and Health Management, Gannan Medical University, Ganzhou, China
- Key Laboratory of Environment and Health of Ganzhou, Gannan Medical University, Ganzhou, China
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8
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Song M, Zhang Y, Zhu W, Zhou W, Li X, Yang A, Tong P, Wu Z, Chen H. Mass Spectrometry Analysis on the Breakage of Allergens in High-Molecular-Mass Polymer of Roasted Peanuts. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:3142-3149. [PMID: 38299554 DOI: 10.1021/acs.jafc.3c07007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2024]
Abstract
Peanut allergy is a prevalent and concerning food allergy. Roasting can introduce structural changes to peanut allergens, affecting their allergenicity, but the structure on the primary structure is unclear. Here, the breakage sites were identified by mass spectrometry and software tools, and structural changes were simulated by molecular dynamics and displayed by PyMOL software. Results revealed that the appearance frequencies of L, Q, F, and E were high at the N-terminal of the breakage site, while S and E were dominant at the C-terminal. In the conformational structure, breakage sites were found close to disulfide bonds and the Cupin domains of Ara h 1 and Ara h 3. The breakage of allergens destroyed linear epitopes and might change the conformation of epitopes, which could influence peanuts' potential allergenicity.
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Affiliation(s)
- Min Song
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330031, China
- College of Food Science and Technology, Nanchang University, Nanchang 330047, China
| | - Ying Zhang
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330031, China
- College of Food Science and Technology, Nanchang University, Nanchang 330047, China
| | - Weichao Zhu
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330031, China
- College of Food Science and Technology, Nanchang University, Nanchang 330047, China
| | - Wenlong Zhou
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330031, China
- College of Food Science and Technology, Nanchang University, Nanchang 330047, China
| | - Xin Li
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330031, China
- College of Food Science and Technology, Nanchang University, Nanchang 330047, China
| | - Anshu Yang
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330031, China
- Sino-German Joint Research Institute, Nanchang University, Nanchang 330047, China
| | - Ping Tong
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330031, China
- College of Food Science and Technology, Nanchang University, Nanchang 330047, China
| | - Zhihua Wu
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330031, China
- Sino-German Joint Research Institute, Nanchang University, Nanchang 330047, China
| | - Hongbing Chen
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330031, China
- Sino-German Joint Research Institute, Nanchang University, Nanchang 330047, China
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9
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Geng Q, Zhang Y, McClements DJ, Zhou W, Dai T, Wu Z, Chen H. Investigation of peanut allergen-procyanidin non-covalent interactions: Impact on protein structure and in vitro allergenicity. Int J Biol Macromol 2024; 258:128340. [PMID: 38000575 DOI: 10.1016/j.ijbiomac.2023.128340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 11/19/2023] [Accepted: 11/20/2023] [Indexed: 11/26/2023]
Abstract
Interactions between plant polyphenols and food allergens may be a new way to alleviate food allergies. The non-covalent interactions between the major allergen from peanut (Ara h 2) with procyanidin dimer (PA2) were therefore characterized using spectroscopic, thermodynamic, and molecular simulation analyses. The main interaction between the Ara h 2 and PA2 was hydrogen bonding. PA2 statically quenched the intrinsic fluorescence intensity and altered the conformation of the Ara h 2, leading to a more disordered polypeptide structure with a lower surface hydrophobicity. In addition, the in vitro allergenicity of the Ara h 2-PA2 complex was investigated using enzyme-linked immunosorbent assay (ELISA) kits. The immunoglobulin E (IgE) binding capacity of Ara h 2, as well as the release of allergenic cytokines, decreased after interacting with PA2. When the ratio of Ara h 2-to-PA2 was 1:50, the IgE binding capacity was reduced by around 43 %. This study provides valuable insights into the non-covalent interactions between Ara h 2 and PA2, as well as the potential mechanism of action of the anti-allergic reaction caused by binding of the polyphenols to the allergens.
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Affiliation(s)
- Qin Geng
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang, China
| | - Ying Zhang
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang, China
| | | | - Wenlong Zhou
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang, China
| | - Taotao Dai
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang, China
| | - Zhihua Wu
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang, China; Sino-German Joint Research Institute, Nanchang University, Nanchang, China.
| | - Hongbing Chen
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang, China; Sino-German Joint Research Institute, Nanchang University, Nanchang, China
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Zhang Y, Song M, Xu J, Li X, Yang A, Tong P, Wu Z, Chen H. IgE Recognition and Structural Analysis of Disulfide Bond Rearrangement and Chemical Modifications in Allergen Aggregations in Roasted Peanuts. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023. [PMID: 37256970 DOI: 10.1021/acs.jafc.3c01482] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Given that roasting changes the structure and allergenicity of peanut allergens, the structural information of peanut allergens must be expounded to explain the alteration in their allergenicity. This work focused on allergen aggregations (AAs) in roasted peanuts. IgE recognition capability was assessed via western blot analysis. The disulfide bond (DB) rearrangement and chemical modification in AAs were identified by combining mass spectroscopy and software tools, and structural changes induced by cross-links were displayed by molecular dynamics and PyMOL software. Results showed that AAs were strongly recognized by IgE and cross-linked mainly by DBs. The types of DB rearrangement in AAs included interprotein (98 peptide pairs), intraprotein (22 peptide pairs), and loop-linked (6 peptides) DBs. Among allergens, Ara h 2 and Ara h 6 presented the most cysteine residues to cross-linkf with others or themselves. DB rearrangement involved IgE epitopes and induced structural changes. Ara h 1 and Ara h 3 were predominantly chemically modified. Moreover, chemical modification altered the local structures of proteins, which may change the allergenic potential of allergens.
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Affiliation(s)
- Ying Zhang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China
- College of Food Science and Technology, Nanchang University, Nanchang 330031, China
| | - Min Song
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China
- College of Food Science and Technology, Nanchang University, Nanchang 330031, China
| | - Jiyuan Xu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China
- College of Food Science and Technology, Nanchang University, Nanchang 330031, China
| | - Xin Li
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China
- College of Food Science and Technology, Nanchang University, Nanchang 330031, China
| | - Anshu Yang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China
- Sino-German Joint Research Institute, Nanchang University, Nanchang 330047, China
| | - Ping Tong
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China
- College of Food Science and Technology, Nanchang University, Nanchang 330031, China
| | - Zhihua Wu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China
- Sino-German Joint Research Institute, Nanchang University, Nanchang 330047, China
| | - Hongbing Chen
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China
- Sino-German Joint Research Institute, Nanchang University, Nanchang 330047, China
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