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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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2
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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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3
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Xu Y, Ahmed I, Zhao Z, Lv L. A comprehensive review on glycation and its potential application to reduce food allergenicity. Crit Rev Food Sci Nutr 2023:1-23. [PMID: 37683268 DOI: 10.1080/10408398.2023.2248510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/10/2023]
Abstract
Food allergens are a major concern for individuals who are susceptible to food allergies and may experience various health issues due to allergens in their food. Most allergenic foods are subjected to heat treatment before being consumed. However, thermal processing and prolonged storage can cause glycation reactions to occur in food. The glycation reaction is a common processing method requiring no special chemicals or equipment. It may affect the allergenicity of proteins by altering the structure of the epitope, revealing hidden epitopes, concealing linear epitopes, or creating new ones. Changes in food allergenicity following glycation processing depend on several factors, including the allergen's characteristics, processing parameters, and matrix, and are therefore hard to predict. This review examines how glycation reactions affect the allergenicity of different allergen groups in allergenic foods.
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Affiliation(s)
- Yue Xu
- College of Food Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Ishfaq Ahmed
- Haide College, Ocean University of China, Qingdao, China
| | - Zhengxi Zhao
- College of Food Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Liangtao Lv
- College of Food Science and Engineering, Qingdao Agricultural University, Qingdao, China
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4
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Okada T, Monshi FI, Kudo S, Katsube-Tanaka T. Insertion of ten amino acids into 13S globulin zero-repeat subunit improves trypsin digestibility in common buckwheat ( Fagopyrum esculentum Moench) seeds. FOOD CHEMISTRY. MOLECULAR SCIENCES 2023; 6:100159. [PMID: 36619894 PMCID: PMC9811207 DOI: 10.1016/j.fochms.2022.100159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 12/12/2022] [Accepted: 12/24/2022] [Indexed: 06/17/2023]
Abstract
The 13S globulin zero-repeat subunit is resistant to trypsin and may have higher allergenicity than the 1-6 tandem repeat subunits in common buckwheat (Fagopyrum esculentum Moench). To explore alleles useful for lowering allergenicity, amplicon deep sequencing targeting the zero-repeat subunit gene was conducted in bulked genomic DNA from eight cultivars and landraces. The analysis identified a unique allele encoding a zero-repeat subunit with 10 amino acid insertion (10aa) at a position equivalent to the tandem repeat insertion. Prediction of its 3-D structure suggested that 10aa changes the β-hairpin structure in the non-10aa (native) subunit to a random coil, which is also found in 1- and 3- repeat subunits. Homozygotes of the 10aa allele were developed and showed that the 10aa subunit was more digestible than the native subunit. However, the 10aa subunit was still less digestible than the 1-6 repeat subunits, suggesting needs to explore unfunctional alleles.
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Affiliation(s)
- Takeyuki Okada
- Graduate School of Agriculture, Kyoto University, Kitashirakawa, Kyoto 606-8502, Japan
| | - Fakhrul Islam Monshi
- Graduate School of Agriculture, Kyoto University, Kitashirakawa, Kyoto 606-8502, Japan
- Department of Genetics and Plant Breeding, Sylhet Agricultural University, Sylhet 3100, Bangladesh
| | - Syuto Kudo
- Graduate School of Agriculture, Kyoto University, Kitashirakawa, Kyoto 606-8502, Japan
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5
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INFOGEST Digestion Assay of Raw and Roasted Hazelnuts and Its Impact on Allergens and Their IgE Binding Activity. Foods 2022; 11:foods11182914. [PMID: 36141044 PMCID: PMC9498782 DOI: 10.3390/foods11182914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 09/08/2022] [Accepted: 09/09/2022] [Indexed: 11/21/2022] Open
Abstract
Most of the food allergens sensitized via the gastrointestinal tract resist thermal treatments and digestion, particularly digestion by pepsin. Roasted hazelnuts are more commonly consumed than raw ones. Since no studies have characterized gastric digestion protein fragments of raw and roasted hazelnuts nor their IgE binding properties, we compared these aspects of raw and roasted hazelnuts’ gastric digesta obtained by INFOGEST protocol. Their electrophoretically resolved profiles were probed with hazelnut allergic patients’ sera in 1D and 2D immunoblots. Electrophoretic profiles demonstrated pepsin digestion of all hazelnut allergens to varying extents. While 2D immunoblots indicated that roasting slightly reduced allergenicity, IgE ELISA with the pool of sera showed a slight significant (10%) increase in IgE binding in both gastric digesta. Cor a 9 isolated from the raw and roasted hazelnuts, characterized by far and near CD, remained stable after roasting, with preserved IgE reactivity. Its immunoreactivity contribution by inhibitory ELISA was noticeable in raw and roasted hazelnut digesta; its activity was slightly stronger in the roasted preparations. Roasting has a visible impact on proteins; however, it did not affect overall IgE reactivity. Gastric digestion slightly increases the overall IgE reactivity in raw and roasted hazelnuts, and may therefore impact the profiles of allergens and their fragments available to interact with the immune system in the small intestine.
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6
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Marsh JT, Palmer LK, Koppelman SJ, Johnson PE. Determination of Allergen Levels, Isoforms, and Their Hydroxyproline Modifications Among Peanut Genotypes by Mass Spectrometry. FRONTIERS IN ALLERGY 2022; 3:872714. [PMID: 35769555 PMCID: PMC9234871 DOI: 10.3389/falgy.2022.872714] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 04/12/2022] [Indexed: 11/13/2022] Open
Abstract
The recently published reference genome of peanuts enables a detailed molecular description of the allergenic proteins of the seed. We used LC-MS/MS to investigate peanuts of different genotypes to assess variability and to better describe naturally occurring allergens and isoforms. Using relative quantification by mass spectrometry, minor variation of some allergenic proteins was observed, but total levels of Ara h 1, 2, 3, and 6 were relatively consistent among 20 genotypes. Previously published RP-HPLC methodology was used for comparison. The abundance of three Ara h 3 isoforms were variable among the genotypes and contributed to a large proportion of total Ara h 3 where present. Previously unpublished hydroxyproline sites were identified in Ara h 1 and 3. Hydroxylation did not vary significantly where sites were present. Peanut allergen composition was largely stable, with only some isoforms displaying differences between genotypes. The resulting differences in allergenicity are of unknown clinical significance but are likely to be minor. The data presented herein allow for the design of targeted MS methodology to allow the quantitation and therefore control of peanut allergens of clinical relevance and observed variability.
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7
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Afzaal M, Saeed F, Hussain M, Shahid F, Siddeeg A, Al‐Farga A. Proteomics as a promising biomarker in food authentication, quality and safety: A review. Food Sci Nutr 2022; 10:2333-2346. [PMID: 35844910 PMCID: PMC9281926 DOI: 10.1002/fsn3.2842] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 02/07/2022] [Accepted: 03/12/2022] [Indexed: 12/18/2022] Open
Abstract
Adulteration and mislabeling have become a very common global malpractice in food industry. Especially foods of animal origin are prepared from plant sources and intentionally mislabeled. This type of mislabeling is an important concern in food safety as the replaced ingredients may cause a food allergy or toxicity to vulnerable consumers. Moreover, foodborne pathogens also pose a major threat to food safety. There is a dire need to develop strong analytical tools to deal with related issues. In this context, proteomics stands out as a promising tool used to report the aforementioned issues. The development in the field of omics has inimitable advantages in enabling the understanding of various biological fields especially in the discipline of food science. In this review, current applications and the role of proteomics in food authenticity, safety, and quality and food traceability are highlighted comprehensively. Additionally, the other components of proteomics have also been comprehensively described. Furthermore, this review will be helpful in the provision of new intuition into the use of proteomics in food analysis. Moreover, the pathogens in food can also be identified based on differences in their protein profiling. Conclusively, proteomics, an indicator of food properties, its origin, the processes applied to food, and its composition are also the limelight of this article.
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Affiliation(s)
- Muhammad Afzaal
- Department of Food Science Government College University Faisalabad Faisalabad Pakistan
| | - Farhan Saeed
- Department of Food Science Government College University Faisalabad Faisalabad Pakistan
| | - Muzzamal Hussain
- Department of Food Science Government College University Faisalabad Faisalabad Pakistan
| | - Farheen Shahid
- Department of Food Science Government College University Faisalabad Faisalabad Pakistan
| | - Azhari Siddeeg
- Department of Food Engineering and Technology Faculty of Engineering and Technology University of Gezira Wad Medani Sudan
| | - Ammar Al‐Farga
- Department of Biochemistry College of Sciences University of Jeddah Jeddah Saudi Arabia
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8
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Ramadan S, Marsh J, El-Sherbeny GA, El-Halawany ESF, Luan F, Baumert JL, Johnson P, Osman Y, Goodman RE. Purification of soybean cupins and comparison of IgE binding with peanut allergens in a population of allergic subjects. Food Chem Toxicol 2021; 147:111866. [PMID: 33217527 DOI: 10.1016/j.fct.2020.111866] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 11/09/2020] [Accepted: 11/12/2020] [Indexed: 10/23/2022]
Abstract
Identification, purification and characterization of allergens is crucial to the understanding of IgE-mediated disease. Immunologic and structural studies with purified allergens is essential for understanding relative immunogenicity and cross-reactivity. In this work, the complex soybean 7S vicilins (Gly m 5) with three subunits and 11S legumins (Gly m 6) with five subunits were purified and characterized along with purified peanut allergens (Ara h 1, 2, 3, and 6) by label-free liquid chromatography-tandem mass spectrometry (LC-MS/MS). Individual subjects plasma IgE binding was tested from subjects allergic to soybeans and or peanuts by immunoblotting, ImmunoCAP™ and ISAC™ ImmunoCAP chip, comparing these soybean proteins with those of purified peanut allergens; vicilin (Ara h 1), 2S albumin (Ara h 2 and Ara h 6) and 11S globulin (Ara h 3). Results show differences between methods and subjects demonstrating the complexity of finding answers to questions of cross-reactivity.
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Affiliation(s)
- Samah Ramadan
- Department of Botany, Faculty of Science, Mansoura University, 35516, Egypt
| | - Justin Marsh
- Food Allergy Research and Resource Program, Food Science & Technology, University of Nebraska, Lincoln, 68588-6207, USA
| | | | | | - Fulei Luan
- Hisense Home Appliances Group Co. Ltd., Qingdao, Shandong, 266104, China
| | - Joseph L Baumert
- Food Allergy Research and Resource Program, Food Science & Technology, University of Nebraska, Lincoln, 68588-6207, USA
| | - Philip Johnson
- Food Allergy Research and Resource Program, Food Science & Technology, University of Nebraska, Lincoln, 68588-6207, USA
| | - Yehia Osman
- Department of Botany, Faculty of Science, Mansoura University, 35516, Egypt
| | - Richard E Goodman
- Food Allergy Research and Resource Program, Food Science & Technology, University of Nebraska, Lincoln, 68588-6207, USA.
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9
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Pitre M, L’Hocine L, Achouri A, Blaquière M, Des Roches A. Immunoglobulin E-Binding Pattern of Canadian Peanut Allergic Children and Cross-Reactivity with Almond, Hazelnut and Pistachio. Biomolecules 2020; 10:E1091. [PMID: 32707944 PMCID: PMC7464554 DOI: 10.3390/biom10081091] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 07/17/2020] [Accepted: 07/20/2020] [Indexed: 12/24/2022] Open
Abstract
Peanut allergic individuals can be both co-sensitized and co-allergic to peanut and tree nuts. At the moment, standard diagnostic approaches do not always allow differentiation between clinically relevant sensitization and nonsignificant cross-reactions, and the responsibility of each allergen remains unclear. The objective of this study was therefore to determine a peanut sensitization profile in a cohort of Canadian peanut allergic children and assess the immunoglobulin E (IgE) molecular cross-reactivity between peanut, almond, hazelnut and pistachio. The specific IgE (sIgE) levels of each patient serum were determined by ImmunoCAP, indirect ELISA and immunoblot to examine their sIgE-binding levels and profiles to peanut proteins. Reciprocal inhibition ELISA and immunoblotting were used to study sIgE cross-reactions between peanut and the selected tree nuts using an adjusted and representative serum pool of the nine allergic patients. The results showed that the prepared peanut and tree nut protein extracts allowed for the detection of the majority of peanut and selected tree nut known allergens. The reciprocal inhibition ELISA experiments showed limited sIgE cross-reactivities between peanut and the studied tree nuts, with peanut being most likely the sensitizing allergen and tree nuts the cross-reactive ones. In the case of hazelnut and pistachio, a coexisting primary sensitization to hazelnut and pistachio was also demonstrated in the serum pool. Reciprocal inhibition immunoblotting further revealed that storage proteins (2S albumin, 7S vicilin and 11S legumin) could possibly account for the observed IgE-cross-reactions between peanut and the studied tree nuts in this cohort of allergic individuals. It also demonstrated the importance of conformational epitopes in the exhibited cross-reactions.
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Affiliation(s)
- Mélanie Pitre
- Saint-Hyacinthe Research and Development Centre, Agriculture and Agri-Food Canada, 3600 Casavant Blvd. W. Saint-Hyacinthe, QC J2S 8E3, Canada; (M.P.); (A.A.)
| | - Lamia L’Hocine
- Saint-Hyacinthe Research and Development Centre, Agriculture and Agri-Food Canada, 3600 Casavant Blvd. W. Saint-Hyacinthe, QC J2S 8E3, Canada; (M.P.); (A.A.)
| | - Allaoua Achouri
- Saint-Hyacinthe Research and Development Centre, Agriculture and Agri-Food Canada, 3600 Casavant Blvd. W. Saint-Hyacinthe, QC J2S 8E3, Canada; (M.P.); (A.A.)
| | - Martin Blaquière
- Sherbrooke University Hospital Center, Hôtel-Dieu de Sherbrooke, Department of Pediatrics, 580 Bowen south, Sherbrooke, QC J1G 2E3, Canada;
| | - Anne Des Roches
- Immunoallergy and Rheumatology Service Department of Pediatrics Medical School CHU Sainte-Justine Institution, 3175 Côte Sainte-Catherine, Montreal, QC H3T 1C5, Canada;
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10
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de Jongh HHJ, de Jong GAH, Apostolovic D, Taylor SL, Baumert JL, Koppelman SJ. Effect of heat treatment on the conformational stability of intact and cleaved forms ofthe peanut allergen Ara h 6 in relation to its IgE-binding potency. Food Chem 2020; 326:127027. [PMID: 32438232 DOI: 10.1016/j.foodchem.2020.127027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 04/16/2020] [Accepted: 05/08/2020] [Indexed: 01/14/2023]
Abstract
This work reports on theeffect of heat treatment on the protein conformational stabilityof intact and post-translationallycleaved peanut allergen Ara h 6 in relation to IgE-binding. Intact and post-translationallycleaved Ara h 6 are structurally similar and theirstrong resistance to denaturant-inducedunfolding is comparable. Only upon exposure toautoclave conditions the twoforms of Ara h 6 demonstrated susceptibility toirreversible denaturationresulting in a significant decrease in IgE-binding potency. Thisreduction isfor the intact protein more pronounced than for than for the cleaved form. This isattributed to less conformational constrains of the cleaved form comparedtointact, as suggested by the 2-fold lower activation energy for unfoldingfound for the cleavedform. Overall, harsh conditionsare required to denature Ara h 6 and to significantly reduce its IgE-bindingpotency. The cleavedform possesses more resistance to such denaturation than the intactform.
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Affiliation(s)
| | | | - Danijela Apostolovic
- Clinical Immunology and Allergy Unit, Department of Medicine Solna, Karolinska Institutet, Solnavägen 1, 171 77 Solna, Sweden
| | - Steve L Taylor
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA
| | - Joseph L Baumert
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA
| | - 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.
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11
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Prodić I, Smiljanić K, Simović A, Radosavljević J, Ćirković Veličković T. Thermal Processing of Peanut Grains Impairs Their Mimicked Gastrointestinal Digestion While Downstream Defatting Treatments Affect Digestomic Profiles. Foods 2019; 8:foods8100463. [PMID: 31658590 PMCID: PMC6836028 DOI: 10.3390/foods8100463] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 09/29/2019] [Accepted: 10/02/2019] [Indexed: 11/16/2022] Open
Abstract
Resistance to digestion by digestive proteases represents a critical property of many food allergens. Recently, a harmonized INFOGEST protocol was proposed for solid food digestion. The protocol proposes digestion conditions suitable for all kinds of solid and liquid foods. However, peanuts, as a lipid-rich food, represent a challenge for downstream analyses of the digestome. This is particularly reflected in the methodological difficulties in analyzing proteins and peptides in the presence of lipids. Therefore, the removal of the lipids seems to be a prerequisite for the downstream analysis of digestomes of lipid-rich foods. Here, we aimed to compare the digestomes of raw and thermally treated (boiled and roasted) peanuts, resulting from the INFOGEST digestion protocol for solid food, upon defatting the digests in two different manners. The most reproducible results of peanut digests were obtained in downstream analyses on TCA/acetone defatting. Unfortunately, defatting, even with an optimized TCA/acetone procedure, leads to the loss of proteins and peptides. The results of our study reveal that different thermal treatments of peanuts affect protein extraction and gastric/gastrointestinal digestion. Roasting of peanuts seems to enhance the extraction of proteins during intestinal digestion to a notable extent. The increased intestinal digestion is a consequence of the delayed extraction of thermally treated peanut proteins, which are poorly soluble in acidic gastric digestion juice but are easily extracted when the pH of the media is raised as in the subsequent intestinal phase of the digestion. Thermal processing of peanuts impaired the gastrointestinal digestion of the peanut proteins, especially in the case of roasted samples.
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Affiliation(s)
- Ivana Prodić
- University of Belgrade-Faculty of Chemistry, Innovation Center Ltd, 11000 Belgrade, Serbia.
| | - Katarina Smiljanić
- University of Belgrade-Faculty of Chemistry, Center of Excellence for Molecular Food Sciences & Department of Biochemistry, 11000 Belgrade, Serbia.
| | - Ana Simović
- University of Belgrade-Faculty of Chemistry, Center of Excellence for Molecular Food Sciences & Department of Biochemistry, 11000 Belgrade, Serbia.
| | - Jelena Radosavljević
- University of Belgrade-Faculty of Chemistry, Center of Excellence for Molecular Food Sciences & Department of Biochemistry, 11000 Belgrade, Serbia.
| | - Tanja Ćirković Veličković
- University of Belgrade-Faculty of Chemistry, Center of Excellence for Molecular Food Sciences & Department of Biochemistry, 11000 Belgrade, Serbia.
- Ghent University Global Campus, Incheon 406-840, Korea.
- Ghent University, Faculty of Bioscience Engineering, 9000 Ghent, Belgium.
- Serbian Academy of Sciences and Arts, 11000 Belgrade, Serbia.
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12
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Kleij HPM, Warmenhoven HJM, Ree R, Versteeg SA, Pieters RHH, Dreskin SC, Knulst AC, Hoffen E, Opstelten DJE, Koppelman SJ, Smit JJ. Chemically modified peanut extract shows increased safety while maintaining immunogenicity. Allergy 2019; 74:986-995. [PMID: 30506686 DOI: 10.1111/all.13687] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 10/28/2018] [Accepted: 11/16/2018] [Indexed: 01/14/2023]
Abstract
BACKGROUND Peanuts are most responsible for food-induced anaphylaxis in adults in developed countries. An effective and safe immunotherapy is urgently needed. The aim of this study was to investigate the immunogenicity, allergenicity, and immunotherapeutic efficacy of a well-characterized chemically modified peanut extract (MPE) adsorbed to Al(OH)3 . METHODS Peanut extract (PE) was modified by reduction and alkylation. Using sera of peanut-allergic patients, competitive IgE-binding assays and mediator release assays were performed. The immunogenicity of MPE was evaluated by measuring activation of human PE-specific T-cell lines and the induction of PE-specific IgG in mice. The safety and efficacy of MPE adsorbed to Al(OH)3 was tested in two mouse models by measuring allergic manifestations upon peanut challenge in peanut-allergic mice. RESULTS Compared to PE, the IgE-binding and capacity to induce allergic symptoms of MPE were lower in all patients. PE and MPE displayed similar immunogenicity in vivo and in vitro. In mice sensitized to PE, the threshold for anaphylaxis (drop in BT) upon subcutaneous challenge with PE was 0.01 mg, while at 0.3 mg MPE no allergic reaction occurred. Anaphylaxis was not observed when PE and MPE were fully adsorbed to Al(OH)3 . Both PE and MPE + Al(OH)3 showed to be efficacious in a model for immunotherapy. CONCLUSION In our studies, an Al(OH)3 adsorbed MPE showed reduced allergenicity compared to unmodified PE, while the efficacy of immunotherapy is maintained. The preclinical data presented in this study supports further development of modified peanut allergens for IT.
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Affiliation(s)
| | | | - Ronald Ree
- Department of Experimental Immunology Academic Medical Center University of Amsterdam Amsterdam The Netherlands
- Department of Otorhinolaryngology Academic Medical Center University of Amsterdam AmsterdamThe Netherlands
| | - Serge A. Versteeg
- Department of Experimental Immunology Academic Medical Center University of Amsterdam Amsterdam The Netherlands
| | - Raymond H. H. Pieters
- Institute for Risk Assessment Sciences Immunotoxicology Utrecht University Utrecht The Netherlands
| | - Stephen C. Dreskin
- Division of Allergy and Clinical Immunology Department of Medicine Denver School of Medicine University of Colorado Aurora Colorado
| | - André C. Knulst
- Department Dermatology/Allergology University Medical Center Utrecht Utrecht University Utrecht The Netherlands
| | - Els Hoffen
- Department Dermatology/Allergology University Medical Center Utrecht Utrecht University Utrecht The Netherlands
| | | | | | - Joost J. Smit
- Institute for Risk Assessment Sciences Immunotoxicology Utrecht University Utrecht The Netherlands
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14
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Mamone G, Di Stasio L, De Caro S, Picariello G, Nicolai MA, Ferranti P. Comprehensive analysis of the peanut allergome combining 2-DE gel-based and gel-free proteomics. Food Res Int 2019; 116:1059-1065. [DOI: 10.1016/j.foodres.2018.09.045] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 09/03/2018] [Accepted: 09/17/2018] [Indexed: 02/04/2023]
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15
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de Jong GAH, Jayasena S, Johnson P, Marsh J, Apostolovic D, van Hage M, Nordlee J, Baumert J, Taylor SL, Roucairol C, de Jongh H, Koppelman SJ. Purification and Characterization of Naturally Occurring Post-Translationally Cleaved Ara h 6, an Allergen That Contributes Substantially to the Allergenic Potency of Peanut. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:10855-10863. [PMID: 30284821 DOI: 10.1021/acs.jafc.8b03140] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The 2S albumin Ara h 6 is one of the most important peanut allergens. A post-translationally cleaved Ara h 6 (pAra h 6) was purified from Virginia type peanuts, and the cleavage site was mapped using high-resolution mass spectrometry. Compared to intact Ara h 6, pAra h 6 lacks a 5-amino acid stretch, resembling amino acids 43-47 (UniProt accession number Q647G9) in the nonstructured loop. Consequently, pAra h 6 consists of two chains: an N-terminal chain of approximately 5 kDa and a C-terminal chain of approximately 9 kDa, held together by disulfide bonds. Intermediate post-translationally cleaved products, in which this stretch is cleaved yet still attached to one of the subunits, are also present. The secondary structure and immunoglobulin E (IgE) binding of pAra h 6 resembles that of intact Ara h 6, indicating that the loss of the nonstructured loop is not critical for maintaining the protein structure. Commercially available monoclonal and polyclonal immunoglobulin G (IgG) antibodies directed to Ara h 6 react with both intact Ara h 6 and pAra h 6, suggesting that the involved epitopes are not located in the area that is post-translationally cleaved. No differences between intact Ara h 6 and pAra h 6 in terms of IgE binding were found, suggesting that the area that is post-translationally cleaved is not involved in IgE epitopes either. For all main cultivars Runner, Virginia, Valencia, and Spanish, intact Ara h 6 and pAra h 6 occur in peanut at similar levels, indicating that pAra h 6 is a consistent and important contributor to the allergenic potency of peanut.
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Affiliation(s)
| | - Shyamali Jayasena
- Food Allergy Research and Resource Program, Department of Food Science & Technology , University of Nebraska , 279 Food Innovation Center , Lincoln , Nebraska 68588-6207 , United States
| | - Phil Johnson
- Food Allergy Research and Resource Program, Department of Food Science & Technology , University of Nebraska , 279 Food Innovation Center , Lincoln , Nebraska 68588-6207 , United States
| | - Justin Marsh
- Food Allergy Research and Resource Program, Department of Food Science & Technology , University of Nebraska , 279 Food Innovation Center , Lincoln , Nebraska 68588-6207 , United States
| | - Danijela Apostolovic
- Immunology and Allergy Unit, Department of Medicine Solna , Karolinska Institutet , 171 77 Stockholm , Sweden
| | - Marianne van Hage
- Immunology and Allergy Unit, Department of Medicine Solna , Karolinska Institutet , 171 77 Stockholm , Sweden
| | - Julie Nordlee
- TNO , Utrechtseweg 48 , 3704 HE , Zeist , The Netherlands
| | - Joe Baumert
- TNO , Utrechtseweg 48 , 3704 HE , Zeist , The Netherlands
| | - Steve L Taylor
- TNO , Utrechtseweg 48 , 3704 HE , Zeist , The Netherlands
| | - Camille Roucairol
- DBV Technologies , Development Department , 92120 Montrouge , France
| | | | - Stef J Koppelman
- Food Allergy Research and Resource Program, Department of Food Science & Technology , University of Nebraska , 279 Food Innovation Center , Lincoln , Nebraska 68588-6207 , United States
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Koppelman SJ, Smits M, Tomassen M, de Jong GAH, Baumert J, Taylor SL, Witkamp R, Veldman RJ, Pieters R, Wichers H. Release of Major Peanut Allergens from Their Matrix under Various pH and Simulated Saliva Conditions-Ara h2 and Ara h6 Are Readily Bio-Accessible. Nutrients 2018; 10:E1281. [PMID: 30208580 PMCID: PMC6165493 DOI: 10.3390/nu10091281] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 08/28/2018] [Accepted: 08/31/2018] [Indexed: 01/24/2023] Open
Abstract
The oral mucosa is the first immune tissue that encounters allergens upon ingestion of food. We hypothesized that the bio-accessibility of allergens at this stage may be a key determinant for sensitization. Light roasted peanut flour was suspended at various pH in buffers mimicking saliva. Protein concentrations and allergens profiles were determined in the supernatants. Peanut protein solubility was poor in the pH range between 3 and 6, while at a low pH (1.5) and at moderately high pHs (>8), it increased. In the pH range of saliva, between 6.5 and 8.5, the allergens Ara h2 and Ara h6 were readily released, whereas Ara h1 and Ara h3 were poorly released. Increasing the pH from 6.5 to 8.5 slightly increased the release of Ara h1 and Ara h3, but the recovery remained low (approximately 20%) compared to that of Ara h2 and Ara h6 (approximately 100% and 65%, respectively). This remarkable difference in the extraction kinetics suggests that Ara h2 and Ara h6 are the first allergens an individual is exposed to upon ingestion of peanut-containing food. We conclude that the peanut allergens Ara h2 and Ara h6 are quickly bio-accessible in the mouth, potentially explaining their extraordinary allergenicity.
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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.
| | - Mieke Smits
- Research Group Innovative Testing in Life Sciences and Chemistry, University of Applied Sciences, Heidelberglaan 7, 3584 CS Utrecht, The Netherlands.
| | - Monic Tomassen
- Food & Biobased Research, Wageningen University and Research, Bornse Weilanden 9, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
| | | | - Joe Baumert
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA.
| | - Steve L Taylor
- Food Allergy Research and Resource Program, Department of Food Science & Technology, University of Nebraska, 279 Food Innovation Center, Lincoln, NE 68588-6207, USA.
| | - Renger Witkamp
- Department of Human Nutrition, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
| | - Robert Jan Veldman
- Research Group Innovative Testing in Life Sciences and Chemistry, University of Applied Sciences, Heidelberglaan 7, 3584 CS Utrecht, The Netherlands.
| | - Raymond Pieters
- Research Group Innovative Testing in Life Sciences and Chemistry, University of Applied Sciences, Heidelberglaan 7, 3584 CS Utrecht, The Netherlands.
- Institute for Risk Assessment Sciences, Faculty of Veterinary Medicines, Utrecht University, Yalelaan 1, 3584 CL, Utrecht, The Netherlands.
| | - Harry Wichers
- Food & Biobased Research, Wageningen University and Research, Bornse Weilanden 9, P.O. Box 17, 6700 AA Wageningen, The Netherlands.
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17
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Effect of thermal/pressure processing and simulated human digestion on the immunoreactivity of extractable peanut allergens. Food Res Int 2018; 109:126-137. [PMID: 29803434 DOI: 10.1016/j.foodres.2018.04.021] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 04/06/2018] [Accepted: 04/12/2018] [Indexed: 11/24/2022]
Abstract
Peanut allergy is one of the most widespread types of food allergies especially affecting developed countries. To reduce the risk of triggering allergic reactions, several technological strategies have been devised to modify or remove allergens from foods. Herein we investigated the combination of high temperature and pressure on the modulation of peanuts immunoreactivity after simulated gastro-duodenal digestion. Extractable proteins of raw and autoclaved peanuts were separated on SDS-PAGE and immunogenicity was assessed by ELISA and Western Blot analyses. Proteins surviving the heat treatment and reacting towards allergic patients' sera were analysed and attributed to Ara h 3 and Ara h 1 proteins by untargeted LC-high resolution-MS/MS. A progressive reduction in the intensity of the major allergen proteins was also highlighted in the protein fraction extracted from autoclaved peanuts, with a total disappearance of the high molecular allergens when samples were preliminary exposed to 2 h hydration although the lower molecular weight fraction was not investigated in the present work. Furthermore, raw and processed peanuts underwent simulated digestion experiments and the IgE binding was assessed by using allergic patients' sera. The persistence of an immunoreactive band was displayed around 20 kDa. In conclusion, the synergistic effects of heat and pressure played a pivotal role in the disappearance of the major peanut allergens also contributing to the significant alteration of the final immunoreactivity. In addition, the surviving of allergenic determinants in peanuts after gastrointestinal breakdown provides more insights on the fate of allergenic proteins after autoclaving treatments.
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Kamalakannan M, Chang LM, Grishina G, Sampson HA, Masilamani M. Identification and characterization of DC-SIGN-binding glycoproteins in allergenic foods. Allergy 2016; 71:1145-55. [PMID: 26948687 DOI: 10.1111/all.12873] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/03/2016] [Indexed: 12/17/2022]
Abstract
BACKGROUND DC-SIGN (dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin) is a C-type lectin receptor expressed on macrophages and dendritic cells. DC-SIGN has high affinity for fucosylated glycans in several plant glycoproteins and pathogens. DC-SIGN is thought to be crucial for the development of allergic sensitization. However, the precise role of DC-SIGN in food allergy pathogenesis is not yet understood. OBJECTIVE We sought to characterize DC-SIGN-binding glycoproteins in a panel of allergenic and non-allergenic foods. METHODS Fluorescent-labeled peanut and soy extracts were used to test protein binding to human monocyte-derived dendritic cells (DCs) by flow cytometry. DC-SIGN-blocking assays were performed by incubating DCs with food extracts followed by staining with anti-DC-SIGN antibody. Using a DC-SIGN-Fc chimera, food extracts were tested for binding by ELISA and autoradiography. IgE immunoblotting was performed with pooled sera from food-allergic subjects. DC activation and maturation were assessed by flow cytometry. RESULTS AND CONCLUSIONS We demonstrate that peanut agglutinin, a minor peanut allergen, is a novel ligand for DC-SIGN. Peanut agglutinin activates DCs to induce the expression of costimulatory molecules in vitro. We present a comprehensive report on the characterization of DC-SIGN-binding proteins in common allergenic foods such as peanut, soy, tree nuts, egg, and milk. Foods that rarely induce allergy, such as pine nuts, chickpea, and corn, showed no binding to DC-SIGN. Several DC-SIGN-binding proteins show reactivity in serum IgE immunoblots. We have also identified novel non-IgE-binding proteins that interact with DC-SIGN; these proteins may be important for regulating immune responses to these foods.
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Affiliation(s)
- M. Kamalakannan
- Division of Allergy and Immunology; Department of Pediatrics; The Jaffe Food Allergy Institute; Icahn School of Medicine at Mount Sinai; New York NY USA
| | - L. M. Chang
- Division of Allergy and Immunology; Department of Pediatrics; The Jaffe Food Allergy Institute; Icahn School of Medicine at Mount Sinai; New York NY USA
| | - G. Grishina
- Division of Allergy and Immunology; Department of Pediatrics; The Jaffe Food Allergy Institute; Icahn School of Medicine at Mount Sinai; New York NY USA
| | - H. A. Sampson
- Division of Allergy and Immunology; Department of Pediatrics; The Jaffe Food Allergy Institute; Icahn School of Medicine at Mount Sinai; New York NY USA
- Immunology Institute and The Mindich Child Health and Development Institute; Icahn School of Medicine at Mount Sinai; New York NY USA
| | - M. Masilamani
- Division of Allergy and Immunology; Department of Pediatrics; The Jaffe Food Allergy Institute; Icahn School of Medicine at Mount Sinai; New York NY USA
- Immunology Institute and The Mindich Child Health and Development Institute; Icahn School of Medicine at Mount Sinai; New York NY USA
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20
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Allergenicity attributes of different peanut market types. Food Chem Toxicol 2016; 91:82-90. [DOI: 10.1016/j.fct.2016.02.016] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Revised: 01/28/2016] [Accepted: 02/19/2016] [Indexed: 11/20/2022]
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21
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L’Hocine L, Pitre M. Quantitative and qualitative optimization of allergen extraction from peanut and selected tree nuts. Part 2. Optimization of buffer and ionic strength using a full factorial experimental design. Food Chem 2016; 194:820-7. [DOI: 10.1016/j.foodchem.2015.08.032] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 07/03/2015] [Accepted: 08/10/2015] [Indexed: 10/23/2022]
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22
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Singh H, Cantoria MJ, Malave P, Saputra D, Maleki S. Standardization of RP-HPLC methods for the detection of the major peanut allergens Ara h 1, Ara h 2 and Ara h 3. Food Chem 2016; 194:383-90. [DOI: 10.1016/j.foodchem.2015.08.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 08/06/2015] [Accepted: 08/08/2015] [Indexed: 11/30/2022]
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23
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Iqbal A, Shah F, Hamayun M, Ahmad A, Hussain A, Waqas M, Kang SM, Lee IJ. Allergens of Arachis hypogaea and the effect of processing on their detection by ELISA. Food Nutr Res 2016; 60:28945. [PMID: 26931300 PMCID: PMC4773821 DOI: 10.3402/fnr.v60.28945] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 02/02/2016] [Accepted: 02/06/2016] [Indexed: 11/14/2022] Open
Abstract
Food allergies are an emerging public health problem in industrialized areas of the world. They represent a considerable health problem in these areas because of the relatively high number of reported cases. Usually, food allergens are proteins or glycoproteins with a molecular mass ranging from 10 to 70 kDa. Among the food allergies, peanut is accounted to be responsible for more than 50% of the food allergy fatalities. Threshold doses for peanut allergenic reactions have been found to range from as low as 100 µg to 1 g of peanut protein, which equal to 400 µg to 4 g peanut meal. Allergens from peanut are mainly seed storage proteins that are composed of conglutin, vicilin, and glycinin families. Several peanut proteins have been identified to induce allergic reactions, particularly Ara h 1-11. This review is mainly focused on different classes of peanut allergens, the effect of thermal and chemical treatment of peanut allergens on the IgY binding and detectability of these allergens by enzyme linked immunosorbent assay (ELISA) to provide knowledge for food industry.
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Affiliation(s)
- Amjad Iqbal
- Department of Food Safety and Food Quality, University of Gent, Gent, Belgium
- Department of Agriculture, Abdul Wali Khan University Mardan, Mardan, Pakistan
| | - Farooq Shah
- Department of Agriculture, Abdul Wali Khan University Mardan, Mardan, Pakistan
| | - Muhammad Hamayun
- Department of Botany, Abdul Wali Khan University Mardan, Mardan, Pakistan
| | - Ayaz Ahmad
- Department of Biotechnology, Abdul Wali Khan University Mardan, Mardan, Pakistan
| | - Anwar Hussain
- Department of Botany, Abdul Wali Khan University Mardan, Mardan, Pakistan
| | - Muhammad Waqas
- School of Applied Biosciences, College of Agriculture and Life Science, Kyungpook National University, Daegu, South Korea
| | - Sang-Mo Kang
- School of Applied Biosciences, College of Agriculture and Life Science, Kyungpook National University, Daegu, South Korea
| | - In-Jung Lee
- School of Applied Biosciences, College of Agriculture and Life Science, Kyungpook National University, Daegu, South Korea;
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Sayers RL, Johnson PE, Marsh JT, Barran P, Brown H, Mills ENC. The effect of thermal processing on the behaviour of peanut allergen peptide targets used in multiple reaction monitoring mass spectrometry experiments. Analyst 2016; 141:4130-41. [DOI: 10.1039/c6an00359a] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Identification of processing-stable targets provides important validation when developing targeted mass spectrometry methods for quantifying peanut allergens.
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Affiliation(s)
- R. L. Sayers
- Institute of Inflammation and Repair
- Manchester Academic Health Science Centre
- Manchester Institute of Biotechnology
- The University of Manchester
- UK
| | - P. E. Johnson
- Institute of Inflammation and Repair
- Manchester Academic Health Science Centre
- Manchester Institute of Biotechnology
- The University of Manchester
- UK
| | - J. T. Marsh
- Institute of Inflammation and Repair
- Manchester Academic Health Science Centre
- Manchester Institute of Biotechnology
- The University of Manchester
- UK
| | - P. Barran
- School of Chemistry
- Michael Barber Centre
- Manchester Institute of Biotechnology
- The University of Manchester
- UK
| | - H. Brown
- Campden BRI (Chipping Campden) Limited - part of the Campden BRI group
- Gloucestershire
- UK
| | - E. N. C. Mills
- Institute of Inflammation and Repair
- Manchester Academic Health Science Centre
- Manchester Institute of Biotechnology
- The University of Manchester
- UK
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25
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Wilson KA, Tan-Wilson A. Proteolysis of the peanut allergen Ara h 1 by an endogenous aspartic protease. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2015; 96:301-310. [PMID: 26322854 DOI: 10.1016/j.plaphy.2015.08.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 08/11/2015] [Accepted: 08/12/2015] [Indexed: 06/04/2023]
Abstract
The 7S and 11S globulins of peanuts are subjected to proteolysis two days after seed imbibition, with Ara h 1 and the arachin acidic chains being among the first storage proteins to be mobilized. Proteolytic activity was greatest at pH 2.6-3 and is inhibited by pepstatin A, characteristic of an aspartic protease. This activity persists in seedling cotyledons up to at least 8 days after imbibition. In vitro proteolysis of Ara h 1 at pH 2.6 by extracts of cotyledons from seedlings harvested 24 h after seed imbibition generates newly appearing bands on SDS-PAGE. Partial sequences of Ara h 1 that were obtained through LC-MS/MS analysis of in-gel trypsin digests of those bands, combined with information on fragment size, suggest that proteolysis begins in the region that links the two cupin domains to produce two 33/34 kD fragments, each one encompassing an intact cupin domain. The later appearance of two 18 and 10/11 kD fragments can be explained by proteolysis within an exposed site in the cupin domains of each of the 33/34 kD fragments. The same or similar proteolytic activity was observed in developing seeds, but Ara h 1 remains intact through seed maturation. This is partly explained by the observation that acidification of the protein storage vacuoles, demonstrated by vacuolar accumulation of acridine orange that was dissipated by a membrane-permeable base, occurs only after germination. These findings suggest a method for use of the seed aspartic protease in reducing peanut allergy due to Ara h 1.
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Affiliation(s)
- Karl A Wilson
- Department of Biological Sciences, State University of New York at Binghamton, Binghamton, NY 13902-6000, USA
| | - Anna Tan-Wilson
- Department of Biological Sciences, State University of New York at Binghamton, Binghamton, NY 13902-6000, USA.
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Chandran M, Chu Y, Maleki SJ, Ozias-Akins P. Stability of transgene expression in reduced allergen peanut (Arachis hypogaea L.) across multiple generations and at different soil sulfur levels. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:1788-1797. [PMID: 25616282 DOI: 10.1021/jf504892f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Transgenic peanut (Arachis hypogaea L.) containing a gene designed for RNA interference (RNAi) showed stable complete silencing of Ara h 2 and partial silencing of Ara h 6, two potent peanut allergens/proteins, along with minimal collateral changes to other allergens, Ara h 1 and Ara h 3, across three generations (T3, T4, and T5) under field conditions. Different soil sulfur levels (0.012, 0.3, and 3.0 mM) differentially impacted sulfur-rich (Ara h 2, Ara h 3, and Ara h 6) versus sulfur-poor (Ara h 1) proteins in non-transgenic versus transgenic peanut. The sulfur level had no effect on Ara h 1, whereas low sulfur led to a significant reduction of Ara h 3 in transgenic and non-transgenic seeds and Ara h 2 and Ara h 6 in non-transgenic but not in transgenic peanuts because these proteins already were reduced by gene silencing. These results demonstrate stability of transgene expression and the potential utility of RNAi in allergen manipulation.
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Affiliation(s)
- Manju Chandran
- Department of Horticulture, University of Georgia , Tifton, Georgia 31793-5766, United States
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Aalberse RC, Knol EF. Historic overview of allergy research in the Netherlands. Immunol Lett 2014; 162:163-72. [PMID: 25455604 DOI: 10.1016/j.imlet.2014.10.015] [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] [Indexed: 11/18/2022]
Abstract
Research in allergy has a long history in the Netherlands, although the relation with immunology has not always been appreciated. In many aspects Dutch researchers have made major contribution in allergy research. This ranges from the first characterization of house dust mite as an important allergen, the first characterization of human Th2 and Th1 T cell clones, to the development of diagnostic test systems. In this overview Aalberse and Knol have made an overview of the major contributions of Dutch immunologists in allergy.
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Affiliation(s)
- Rob C Aalberse
- Department of Immunopathology, Sanquin Blood Supply Foundation and Academic Medical Centre, Amsterdam, The Netherlands
| | - Edward F Knol
- Department of Immunology, University Medical Center Utrecht, The Netherlands; Department of Dermatology and Allergology, University Medical Center Utrecht, The Netherlands.
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28
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Zhang Q, Noble KA, Mao Y, Young NL, Sathe SK, Roux KH, Marshall AG. Rapid screening for potential epitopes reactive with a polycolonal antibody by solution-phase H/D exchange monitored by FT-ICR mass spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2013; 24:1016-1025. [PMID: 23681851 DOI: 10.1007/s13361-013-0644-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2013] [Revised: 04/03/2013] [Accepted: 04/03/2013] [Indexed: 06/02/2023]
Abstract
The potential epitopes of a recombinant food allergen protein, cashew Ana o 2, reactive to polyclonal antibodies, were mapped by solution-phase amide backbone H/D exchange (HDX) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Ana o 2 polyclonal antibodies were purified in the serum from a goat immunized with cashew nut extract. Antibodies were incubated with recombinant Ana o 2 (rAna o 2) to form antigen:polyclonal antibody (Ag:pAb) complexes. Complexed and uncomplexed (free) rAna o 2 were then subjected to HDX-MS analysis. Four regions protected from H/D exchange upon pAb binding are identified as potential epitopes and mapped onto a homologous model.
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Affiliation(s)
- Qian Zhang
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, FL 32306, USA
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29
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Aalberse JA, Meijer Y, Derksen N, van der Palen-Merkus T, Knol E, Aalberse RC. Moving from peanut extract to peanut components: towards validation of component-resolved IgE tests. Allergy 2013; 68:748-56. [PMID: 23621551 DOI: 10.1111/all.12160] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/28/2013] [Indexed: 11/28/2022]
Abstract
BACKGROUND Replacement of peanut extracts by recombinant peanut components is an important step in allergy serologic testing. Criteria are needed for the unbiased inclusion of patients into a study to validate such a replacement. METHODS Plasma samples from 64 peanut-positive children (42 reactors, 22 nonreactors in a double-blind, placebo-controlled food challenge) were used to compare IgE reactivity to six recombinant peanut allergens with reactivity to natural peanut proteins extracted at neutral or low pH. We tested the hypothesis that poor extractability of Ara h 9 and other basic allergens at neutral pH leads to under-representation of patients with such sensitization. RESULTS IgE reactivity to the components did not fully explain IgE reactivity to peanut extract in 5 of 32 reactors with IgE to peanut extract ≤100 kUA /l. IgE reactivity to components was stronger than to the extract in 11 plasma samples, which was largely due to a low Ara h 8 reactivity of the extract. IgE reactivity to Ara h 9 was much lower than reactivity to other basic proteins, some of which bound IgE well in the RAST, but lost IgE reactivity upon immunoblotting. CONCLUSIONS Conventional peanut extracts are deficient in significant IgE-binding components. The inclusion of patients for a validation study should be based on serology performed with improved peanut reagents to avoid a bias against these under-represented, potentially important allergens. To judge clinical relevance of an allergen, the reagent used for inclusion of patients needs to be efficient in detecting IgE to this component.
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Affiliation(s)
| | - Y. Meijer
- Wilhelmina Children's Hospital; University Medical Center; Utrecht; The Netherlands
| | - N. Derksen
- Sanquin Blood Supply Foundation and Academic Medical Center; Amsterdam; The Netherlands
| | | | - E. Knol
- Department of Dermatology; University Medical Center; Utrecht; The Netherlands
| | - R. C. Aalberse
- Sanquin Blood Supply Foundation and Academic Medical Center; Amsterdam; The Netherlands
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30
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Kim J, Lee JY, Han Y, Ahn K. Significance of Ara h 2 in clinical reactivity and effect of cooking methods on allergenicity. Ann Allergy Asthma Immunol 2012; 110:34-8. [PMID: 23244656 DOI: 10.1016/j.anai.2012.10.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Revised: 09/19/2012] [Accepted: 10/14/2012] [Indexed: 11/16/2022]
Abstract
BACKGROUND The prevalence and clinical severity of peanut allergy vary between Western countries and Asia. It has been suggested that cooking methods are responsible for this discrepancy. OBJECTIVES To evaluate the specific IgE responses to major peanut allergens in peanut allergic Korean children and to examine the influence of different cooking methods on peanut proteins. METHODS Raw peanut protein extracts were immunolabeled with serum samples from 42 children with a level of peanut specific IgE of 15 kUA/L or higher to detect specific binding to Ara h 1, Ara h 2, and Ara h 3. Clinical severity scores were assessed on a scale of 0 to 5. Protein extracts from boiled, roasted, fried, and pickled peanuts were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting with pooled serum samples from 7 patients. RESULTS Most patients' serum samples reacted with Ara h 1 (76.2%) and Ara h 3 (78.6%) from raw peanuts, whereas only 53.0% of patients had specific IgE against Ara h 2. IgE binding to Ara h 2 was more prevalent in patients with more severe reaction than in those with mild reactions. IgE binding to Ara h 2 was increased by roasting, but there was significantly less IgE binding after vinegar treatment. CONCLUSION Our results suggest that Ara h 2 is an important allergen to predict clinical symptoms but less prevalent in Korean children than in Western children. This finding may be attributed in part to different cooking methods and dietary habits among regions.
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Affiliation(s)
- Jihyun Kim
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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Hebling CM, Ross MM, Callahan JH, McFarland MA. Size-selective fractionation and visual mapping of allergen protein chemistry in Arachis hypogaea. J Proteome Res 2012; 11:5384-95. [PMID: 23020697 DOI: 10.1021/pr300617a] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Peanuts (Arachis hypogaea) in addition to milk, eggs, fish, crustaceans, wheat, tree nuts, and soybean are commonly referred to as the "big eight" foods that contribute to the majority of food allergies worldwide. Despite the severity of allergic reactions and growing prevalence in children and adults, there is no cure for peanut allergy, leaving avoidance as the primary mode of treatment. To improve analytical methods for peanut allergen detection, researchers must overcome obstacles involved in handling complex food matrices while attempting to decipher the chemistry that underlies allergen protein interactions. To address such challenges, we conducted a global proteome characterization of raw peanuts using a sophisticated GELFrEE-PAGE-LC-MS/MS platform consisting of gel-based protein fractionation followed by mass spectrometric identification. The in-solution mass-selective protein fractionation: (1) enhances the number of unique peptide identifications, (2) provides a visual map of protein isoforms, and (3) aids in the identification of disulfide-linked protein complexes. GELFrEE-PAGE-LC-MS/MS not only overcomes many of the challenges involved in the study of plant proteomics, but enriches the understanding of peanut protein chemistry, which is typically unattainable in a traditional bottom-up proteomic analysis. A global understanding of protein chemistry in Arachis hypogaea ultimately will aid the development of improved methods for allergen detection in food.
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Affiliation(s)
- Christine M Hebling
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, 5100 Paint Branch Parkway, College Park, Maryland 20740, USA.
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Yusnawan E, Marquis CP, Lee NA. Purification and characterization of Ara h1 and Ara h3 from four peanut market types revealed higher order oligomeric structures. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2012; 60:10352-10358. [PMID: 22998620 DOI: 10.1021/jf302800e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
This study aimed to purify and characterize the peanut allergens Ara h1 and Ara h3 from four cultivars that represent the four major market types to provide better understanding of the molecular organization of oligomers in different market types. The chromatographic profiles of Ara h1 and Ara h3 from the four cultivars obtained from anion exchange chromatography were similar. However, they differed in the distribution of trimeric and hexameric structures of Ara h3 isolated by size exclusion chromatography. The Menzies (Runner market type) and Walter (Spanish market type) cultivars, wherein Ara h3 proteins consist of two acidic subunits, exhibited trimeric and hexameric conformations proportionally. However, the Middleton (Virginia market type) and Kelinci (Valencia market type) cultivars, wherein Ara h3 proteins consist of three acidic subunits, showed predominantly a hexameric structure. The oligomeric structures of the purified Ara h1 demonstrated strong IgE binding properties, whereas the allergenic property of the oligomeric Ara h3 could not be performed due to lack of availability of specific IgE. In addition, the polyclonal antibodies raised against the purified Ara h1 and Ara h3 showed highly specific binding to their respective antigens.
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Affiliation(s)
- Eriyanto Yusnawan
- School of Chemical Engineering, Food Science and Technology, University of New South Wales, Sydney, NSW 2052, Australia
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Identification of a new IgE-binding epitope of peanut oleosin that cross-reacts with buckwheat. Biosci Biotechnol Biochem 2012; 76:1182-8. [PMID: 22790944 DOI: 10.1271/bbb.120063] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Peanut and buckwheat induce a severe allergic reaction, anaphylaxis, which is considered to be mediated by immunoglobulin E (IgE). We identified in this study a new IgE-binding epitope of the peanut allergen that cross-reacted with buckwheat. The phosphate-buffered saline-soluble fraction of buckwheat inhibited the binding between IgE and the peanut allergen. A cross-reactive peptide was isolated from the α-chymotrypsin hydrolysate of peanut. Based on the amino acid sequence and mass spectrometric analysis data, the peptide was identified as Ser-Asp-Gln-Thr-Arg-Thr-Gly-Tyr (SDQTRTGY); this sequence is identical to amino acids 2-9 in the N-terminal hydrophilic domain of oleosin 3 which is located on the surface of the lipid storage body. Synthetic SDQTRTGY was found to bind with IgE in the sera of all eight peanut-allergic patients tested. Since many foods of plant origin contain oleosin, the possibility of an anaphylactic cross-reaction in allergic patients should always be considered.
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Koppelman SJ, Hefle SL, Taylor SL, de Jong GAH. Digestion of peanut allergens Ara h 1, Ara h 2, Ara h 3, and Ara h 6: a comparative in vitro study and partial characterization of digestion-resistant peptides. Mol Nutr Food Res 2011; 54:1711-21. [PMID: 20603832 DOI: 10.1002/mnfr.201000011] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
SCOPE There are differences in stability to pepsin between the major allergens in peanut; however, data are from different reports using different digestion models. This study provides a comprehensive comparison of the digestibility of the major peanut allergens. METHODS AND RESULTS Peanut allergens Ara h 1, Ara h 2, Ara h 3 and Ara h 6 were incubated with pepsin to mimic the effect of gastric digestion. Samples were analyzed using SDS-PAGE. To further investigate resistance to digestion, Ara h 2 was additionally subjected to digestion with trypsin and residual peptides were characterized. Ara h 1 and Ara h 3 were rapidly hydrolyzed by pepsin. On the contrary, Ara h 2 and Ara h 6 were resistant to pepsin digestion, even at very high concentrations of pepsin. In fact, limited proteolysis could only be demonstrated by SDS-PAGE performed under reducing conditions, indicating an important role for the disulfide bridges in maintaining the quaternary structure of Ara h 2 and Ara h 6. Trypsin digestion of Ara h 2 similarly resulted in large residual peptides and these were identified. CONCLUSION Ara h 2 and Ara h 6 are considerably more stable towards digestion than Ara h 1 and Ara h 3.
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Hurlburt BK, Schmitt D, Isleib TG, Cheng H, Garvey C, Koenig RL, Maleki SJ. Production of pure protein and antibodies and development of immunoassays to detect Ara h 3 levels in peanut varieties. Int J Food Sci Technol 2011. [DOI: 10.1111/j.1365-2621.2011.02645.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Glaspole IN, de Leon MP, Prickett SR, O'Hehir RE, Rolland JM. Clinical allergy to hazelnut and peanut: identification of T cell cross-reactive allergens. Int Arch Allergy Immunol 2011; 155:345-54. [PMID: 21346364 DOI: 10.1159/000321268] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Accepted: 09/15/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Peanut and tree nut allergies are life-threatening conditions for many affected individuals worldwide. Currently there is no cure. While co-allergy to peanut and tree nuts is a common clinical observation, and IgE cross-reactivity between peanut and tree nuts is reported, T cell cross-reactivity is poorly defined. METHODS Hazelnut-specific T cell lines were established using peripheral blood mononuclear cells from 5 subjects with co-allergy to hazelnut and peanut. These lines were stimulated with hazelnut and peanut extracts and purified major peanut allergens, Ara h 1 and Ara h 2. Proliferation was determined by (3)H-thymidine incorporation and secretion of key Th1 (IFN-γ) and Th2 (IL-5) cytokines analysed by ELISA. RESULTS Hazelnut-specific T cell lines from all 5 subjects proliferated upon stimulation with both hazelnut and peanut extracts and for 4 subjects, to Ara h 1 and/or Ara h 2. Proliferating cells were mainly CD4+ T cells and produced both IL-5 and IFN-γ in response to hazelnut and peanut stimulation. Mitogenicity of extracts and allergens was excluded by their lack of stimulation of house dust mite-specific T cells. CONCLUSION Our finding that hazelnut and peanut co-allergy is associated with cross-reactive T cell responses, driven partly by cross-reactivity to the major peanut allergens Ara h 1 and Ara h 2, points to future development of allergen immunotherapy by targeting cross-reactive T cells.
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Affiliation(s)
- Ian N Glaspole
- Department of Allergy, Immunology and Respiratory Medicine, Alfred Hospital, Melbourne, Vic., Australia
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Pedreschi R, Hertog M, Lilley KS, Nicolaï B. Proteomics for the Food Industry: Opportunities and Challenges. Crit Rev Food Sci Nutr 2010; 50:680-92. [DOI: 10.1080/10408390903044214] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Faeste CK, Christians U, Egaas E, Jonscher KR. Characterization of potential allergens in fenugreek (Trigonella foenum-graecum) using patient sera and MS-based proteomic analysis. J Proteomics 2010; 73:1321-33. [PMID: 20219717 DOI: 10.1016/j.jprot.2010.02.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 01/20/2010] [Accepted: 02/15/2010] [Indexed: 01/09/2023]
Abstract
BACKGROUND Fenugreek is a legume plant used as an ingredient of curry spice. Incidents of IgE-mediated food allergy to fenugreek have been reported. Coincidence with allergy to peanut, a major food allergen, seems to be common suggesting a rather high rate of cross-reactivity. OBJECTIVE Characterization of fenugreek allergens using patient sera and mass spectrometry-based proteomic analysis. METHODS Allergenic fenugreek proteins were detected by immunoblotting, using sera from 13 patients with specific IgE to peanut and fenugreek. IgE-binding proteins were analyzed by peptide mass fingerprinting and peptide sequencing. RESULTS A fenugreek protein quintet in the range from 50 kDa to 66 kDa showed high IgE-affinity, the protein at 50 kDa reaching the strongest signals in all patients. Proteomic analyses allowed the classification of several fenugreek proteins to a number of allergen families. Fenugreek 7S-vicilin and 11S-legumin were partly sequenced and revealed considerable homologies to peanut Ara h 1 and Ara h 3, respectively. The presence of a fenugreek 2S albumin and pathogenesis-related (PR-10) plant pollen protein was assumed by database searching results. CONCLUSION In this study, individual fenugreek proteins were characterised for the first time. Observed homologies to major peanut allergens provide a molecular explanation for clinical cross-reactivity.
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Schmidt H, Gelhaus C, Latendorf T, Nebendahl M, Petersen A, Krause S, Leippe M, Becker WM, Janssen O. 2-D DIGE analysis of the proteome of extracts from peanut variants reveals striking differences in major allergen contents. Proteomics 2009; 9:3507-21. [PMID: 19609960 DOI: 10.1002/pmic.200800938] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Over the last decade, an increasing prevalence of peanut allergies was observed worldwide. Peanuts are meanwhile categorized among the most dangerous food allergens. This is particularly relevant since peanut-derived ingredients are widely used in industrial food production. To minimize the problem of hidden food allergens causing severe anaphylactic reactions, pre-packaged food containing peanut components needs to be classified according to European ruling since 2005. Food companies search for strategies to reduce the allergenicity of peanut-derived food additives either by genetically altering the allergen content or by identifying peanut varieties with low levels of major allergens. In our study, we focused on peanut extracts from Indonesia that apparently contain lower levels of the major Arachis hypogaea allergen 1 (Ara h 1). Basic extracts of Virginia-type and Indonesian peanuts were compared by 1- and 2-DE. We identified more than hundred individual components in these extracts by MS and provide a high-resolution allergen map that also includes so far unknown fragments of major peanut allergens. The reduced level of Ara h 1 associated with a significantly lower abundance of the most potent peanut allergen Ara h 2 in various Indonesian peanuts was also confirmed by Western blotting with monoclonal antibodies and sera of allergic patients.
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Affiliation(s)
- Hendrik Schmidt
- Laboratory for Molecular Immunology, Institute for Immunology, University Hospital Schleswig-Holstein Campus Kiel, Kiel, Germany
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Chassaigne H, Trégoat V, Nørgaard JV, Maleki SJ, van Hengel AJ. Resolution and identification of major peanut allergens using a combination of fluorescence two-dimensional differential gel electrophoresis, Western blotting and Q-TOF mass spectrometry. J Proteomics 2009; 72:511-26. [PMID: 19223023 DOI: 10.1016/j.jprot.2009.02.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2008] [Revised: 02/04/2009] [Accepted: 02/05/2009] [Indexed: 12/16/2022]
Abstract
Peanut allergy is triggered by several proteins known as allergens. In this study, the complexity the peanut allergome is investigated with proteomic tools. The strength of this investigation resides in combining the high-resolving power and reproducibility of fluorescence two-dimensional differential gel electrophoresis with specific immunological detection as well as polypeptide sequencing by high-resolution mass spectrometry. Matching of the peanut proteins in 2D gels was achieved by differential labelling whereby peanut proteins and purified allergens (Ara h 1, Ara h 2 or Ara h 3/4) were run on the same gel. Ten protein spots on a mass line of ca. 63-68 kDa were likely to correspond to Ara h 1. Two doublets on two different mass lines at ca. 16 and 18 kDa matched with purified allergen Ara h 2. The basic and acidic sub-units of Ara h 3/4 were observed at masses of ca. 25 kDa and 40-45 kDa, respectively. Subsequently the antibody-binding capacity of spots corresponding to peanut allergens was investigated by Western blotting of 2D gels using antibodies (IgY) raised against Ara h 1, Ara h 2 and the recombinant 40 kDa sub-unit of Ara h 3/4. Final confirmation of the identity of the protein spots matched after 2D electrophoresis and identified by Western blotting was obtained by in-gel digestion of protein spots and analysis by quadrupole time-of-flight mass spectrometry. By using the method developed in our work, the location and identification of two different isoforms of the allergen Ara h 1, the allergen Ara h 2 and six isoforms of the allergen Ara h 3/4 in 2D peanut protein maps was established.
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Affiliation(s)
- Hubert Chassaigne
- Institute for Reference Materials and Measurements, European Commission-Joint Research Centre, Geel, Belgium.
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Scaravelli E, Brohée M, Marchelli R, van Hengel AJ. Development of three real-time PCR assays to detect peanut allergen residue in processed food products. Eur Food Res Technol 2007. [DOI: 10.1007/s00217-007-0797-3] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Chassaigne H, Nørgaard JV, Hengel AJV. Proteomics-based approach to detect and identify major allergens in processed peanuts by capillary LC-Q-TOF (MS/MS). JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2007; 55:4461-73. [PMID: 17474754 DOI: 10.1021/jf063630e] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
An MS-based method, combining reversed-phase capillary liquid chromatography (capillary LC) with quadrupole time-of-flight tandem mass spectrometry (nano-ESI Q-TOF MS/MS), was developed with the aim of identifying a set of peptides that can function as markers for peanut allergens. Emphasis was given to the identification of the three major peanut allergens Ara h 1, Ara h 2, and Ara h 3, because these proteins are considered to represent >30% of the total protein content of peanut and are directly relevant for the allergenic potential of this food. The analytical data obtained were used to perform databank searching in combination with de novo sequencing and led to the identification of a multitude of sequence tags for all three peanut allergens. Food processing such as roasting of peanuts is known to affect the stability of proteins and was shown to influence the detection of allergen sequence tags. The analysis of raw and roasted peanuts allowed the identification of five peanut-specific sequence tags that can function as markers of the specific allergenic proteins. For Ara h 1, two peptide markers were proposed, namely, VLEENAGGEQEER (m/z 786.88, charge 2+) and DLAFPGSGEQVEK (m/z 688.85, charge 2+), whereas for Ara h 2 only one peptide, RQQWELQGDR (m/z 439.23, charge 3+), was found to satisfy the required conditions. For Ara h 3, the two specific peptides, SPDIYNPQAGSLK (m/z 695.35, charge 2+) and SQSENFEYVAFK (m/z 724.84, charge 2+), were selected. Other peptides have been proposed as indicative for food processing.
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Affiliation(s)
- Hubert Chassaigne
- Food Safety and Quality Unit, Institute for Reference Materials and Measurements, European Commission - DG Joint Research Centre, Retieseweg 111, B-2440 Geel, Belgium.
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Chassaigne H, Brohée M, Nørgaard JV, van Hengel AJ. Investigation on sequential extraction of peanut allergens for subsequent analysis by ELISA and 2D gel electrophoresis. Food Chem 2007. [DOI: 10.1016/j.foodchem.2007.04.055] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Peiren N, de Graaf DC, Evans JD, Jacobs FJ. Genomic and transcriptional analysis of protein heterogeneity of the honeybee venom allergen Api m 6. INSECT MOLECULAR BIOLOGY 2006; 15:577-81. [PMID: 17069633 PMCID: PMC1761135 DOI: 10.1111/j.1365-2583.2006.00669.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Several components of honeybee venom are known to cause allergenic responses in humans and other vertebrates. One such component, the minor allergen Api m 6, has been known to show amino acid variation but the genetic mechanism for this variation is unknown. Here we show that Api m 6 is derived from a single locus, and that substantial protein-level variation has a simple genome-level cause, without the need to invoke multiple loci or alternatively spliced exons. Api m 6 sits near a misassembled section of the honeybee genome sequence, and we propose that a substantial number of indels at and near Api m 6 might be the root cause of this misassembly. We suggest that genes such as Api m 6 with coding-region or untranslated region indels might have had a strong effect on the assembly of this draft of the honeybee genome.
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Affiliation(s)
- N Peiren
- Laboratory of Zoophysiology, Ghent University, Ghent, Belgium
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van Boxtel EL, van Beers MMC, Koppelman SJ, van den Broek LAM, Gruppen H. Allergen Ara h 1 occurs in peanuts as a large oligomer rather than as a trimer. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2006; 54:7180-6. [PMID: 16968080 DOI: 10.1021/jf061433+] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Ara h 1, a major peanut allergen, is known as a stable trimeric protein. Nevertheless, upon purification of native Ara h 1 from peanuts using only size exclusion chromatography, the allergen appeared to exist in an oligomeric structure, rather than as a trimeric structure. The oligomeric structure was independent of the salt concentration applied. Subjecting the allergen to anion exchange chromatography induced the allergen to dissociate into trimers. Ammonium sulfate precipitation did not bring about any structural changes, whereas exposing the allergen to hydrophobic interaction chromatography caused it to partly dissociate into trimers, with increasing amounts of trimers at higher ionic strengths. The (partial) dissociation into trimers led to a change in the tertiary structure of the monomeric subunits of the allergen, with the monomers in Ara h 1 oligomers having a more compact tertiary structure compared with the monomers in Ara h 1 trimers. As structural characteristics are important for a protein's allergenicity, this finding may imply a different allergenicity for Ara h 1 than previously described.
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Affiliation(s)
- Evelien L van Boxtel
- Laboratory of Food Chemistry, Wageningen University, PO Box 8129, 6700 EV Wageningen, The Netherlands
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