1
|
Foo ACY, Nesbit JB, Gipson SAY, DeRose EF, Cheng H, Hurlburt BK, Kulis MD, Kim EH, Dreskin SC, Mustafa S, Maleki SJ, Mueller GA. Structure and IgE Cross-Reactivity among Cashew, Pistachio, Walnut, and Peanut Vicilin-Buried Peptides. J Agric Food Chem 2023; 71:2990-2998. [PMID: 36728846 PMCID: PMC10402694 DOI: 10.1021/acs.jafc.2c07061] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Peanut and tree-nut allergies are frequently comorbid for reasons not completely understood. Vicilin-buried peptides (VBPs) are an emerging family of food allergens whose conserved structural fold could mediate peanut/tree-nut co-allergy. Peptide microarrays were used to identify immunoglobulin E (IgE) epitopes from the N-terminus of the vicilin allergens Ara h 1, Ana o 1, Jug r 2, and Pis v 3 using serum from three patient diagnosis groups: monoallergic to either peanuts or cashew/pistachio, or dual allergic. IgE binding peptides were highly prevalent in the VBP domains AH1.1, AO1.1, JR2.1, and PV3.1, but not in AO1.2, JR2.2, JR2.3, and PV3.2 nor the unstructured regions. The IgE profiles did not correlate with diagnosis group. The structure of the VBPs from cashew and pistachio was solved using solution-NMR. Comparisons of structural features suggest that the VBP scaffold from peanuts and tree-nuts can support cross-reactivity. This may help understand comorbidity and cross-reactivity despite a distant evolutionary origin.
Collapse
Affiliation(s)
- Alexander C Y Foo
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, 111 T.W. Alexander Drive, MD-MR01, Durham, North Carolina 27709, United States
| | - Jacqueline B Nesbit
- Agricultural Research Service, United States Department of Agriculture, 1100 Allen Toussaint Boulevard, New Orleans, Louisiana 70124, United States
| | - Stephen A Y Gipson
- Agricultural Research Service, United States Department of Agriculture, 1100 Allen Toussaint Boulevard, New Orleans, Louisiana 70124, United States
| | - Eugene F DeRose
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, 111 T.W. Alexander Drive, MD-MR01, Durham, North Carolina 27709, United States
| | - Hsiaopo Cheng
- Agricultural Research Service, United States Department of Agriculture, 1100 Allen Toussaint Boulevard, New Orleans, Louisiana 70124, United States
| | - Barry K Hurlburt
- Agricultural Research Service, United States Department of Agriculture, 1100 Allen Toussaint Boulevard, New Orleans, Louisiana 70124, United States
| | - Michael D Kulis
- Department of Pediatrics, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599-7220, United States
| | - Edwin H Kim
- Department of Pediatrics, University of North Carolina School of Medicine, Chapel Hill, North Carolina 27599-7220, United States
| | - Stephen C Dreskin
- Division of Allergy and Clinical Immunology, University of Colorado Denver School of Medicine, Aurora, Colorado 80045-2560, United States
| | - Shahzad Mustafa
- Rochester Regional Health, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642, United States
| | - Soheila J Maleki
- Agricultural Research Service, United States Department of Agriculture, 1100 Allen Toussaint Boulevard, New Orleans, Louisiana 70124, United States
| | - Geoffrey A Mueller
- Genome Integrity and Structural Biology Laboratory, National Institute of Environmental Health Sciences, 111 T.W. Alexander Drive, MD-MR01, Durham, North Carolina 27709, United States
| |
Collapse
|
2
|
Kronfel CM, Cheng H, McBride JK, Nesbit JB, Krouse R, Burns P, Cabanillas B, Crespo JF, Ryan R, Simon RJ, Maleki SJ, Hurlburt BK. IgE epitopes of Ara h 9, Jug r 3, and Pru p 3 in peanut-allergic individuals from Spain and the US. Front Allergy 2023; 3:1090114. [PMID: 36698378 PMCID: PMC9869384 DOI: 10.3389/falgy.2022.1090114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 12/16/2022] [Indexed: 01/11/2023] Open
Abstract
Non-specific lipid transfer proteins (LTPs) are well studied allergens that can lead to severe reactions, but often cause oral allergy syndrome in the Mediterranean area and other European countries. However, studies focused on LTP reactivity in allergic individuals from the United States are lacking because they are not considered major allergens. The goal of this study is to determine if differences in immunoglobulin (Ig) E binding patterns to the peanut allergen Ara h 9 and two homologous LTPs (walnut Jug r 3 and peach Pru p 3) between the US and Spain contribute to differences observed in allergic reactivity. Synthetic overlapping 15-amino acid-long peptides offset by five amino acids from Ara h 9, Jug r 3, and Pru p 3 were synthesized, and the intact proteins were attached to microarray slides. Sera from 55 peanut-allergic individuals from the US were tested for IgE binding to the linear peptides and IgE binding to intact proteins using immunofluorescence. For comparison, sera from 17 peanut-allergic individuals from Spain were also tested. Similar IgE binding profiles for Ara h 9, Jug r 3, and Pru p 3 were identified between the US and Spain, with slight differences. Certain regions of the proteins, specifically helices 1 and 2 and the C-terminal coil, were recognized by the majority of the sera more often than other regions of the proteins. While serum IgE from peanut-allergic individuals in the US binds to peptides of Ara h 9 and its homologs, only IgE from the Spanish subjects bound to the intact LTPs. This study identifies Ara h 9, Jug r 3, and Pru p 3 linear epitopes that were previously unidentified using sera from peanut-allergic individuals from the US and Spain. Certain regions of the LTPs are recognized more often in US subjects, indicating that they represent conserved and possible cross-reactive regions. The location of the epitopes in 3D structure models of the LTPs may predict the location of potential conformational epitopes bound by a majority of the Spanish patient sera. These findings are potentially important for development of peptide or protein-targeting diagnostic and therapeutic tools for food allergy.
Collapse
Affiliation(s)
- Christina M. Kronfel
- United States Department of Agriculture, Agriculture Research Service, Southern Regional Research Center, New Orleans, LA, United States
| | - Hsiaopo Cheng
- United States Department of Agriculture, Agriculture Research Service, Southern Regional Research Center, New Orleans, LA, United States
| | - Jane K. McBride
- United States Department of Agriculture, Agriculture Research Service, Southern Regional Research Center, New Orleans, LA, United States
| | - Jacqueline B. Nesbit
- United States Department of Agriculture, Agriculture Research Service, Southern Regional Research Center, New Orleans, LA, United States
| | | | - Preston Burns
- Rho Federal Systems Division, Durham, NC, United States
| | - Beatriz Cabanillas
- Department of Allergy, Research Institute Hospital 12 de Octubre, Madrid, Spain
| | - Jesus F. Crespo
- Department of Allergy, Research Institute Hospital 12 de Octubre, Madrid, Spain
| | - Robert Ryan
- Aimmune Therapeutics, a Nestlé Health Science Company, Brisbane, CA, United States
| | - Reyna J. Simon
- Aimmune Therapeutics, a Nestlé Health Science Company, Brisbane, CA, United States
| | - Soheila J. Maleki
- United States Department of Agriculture, Agriculture Research Service, Southern Regional Research Center, New Orleans, LA, United States,Correspondence: Soheila J. Maleki
| | - Barry K. Hurlburt
- United States Department of Agriculture, Agriculture Research Service, Southern Regional Research Center, New Orleans, LA, United States
| |
Collapse
|
3
|
Foo AC, Nesbit JB, Gipson SA, Cheng H, Bushel P, DeRose EF, Schein CH, Teuber SS, Hurlburt BK, Maleki SJ, Mueller GA. Structure, Immunogenicity, and IgE Cross-Reactivity among Walnut and Peanut Vicilin-Buried Peptides. J Agric Food Chem 2022; 70:2389-2400. [PMID: 35139305 PMCID: PMC8959100 DOI: 10.1021/acs.jafc.1c07225] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Vicilin-buried peptides (VBPs) from edible plants are derived from the N-terminal leader sequences (LSs) of seed storage proteins. VBPs are defined by a common α-hairpin fold mediated by conserved CxxxCx(10-14)CxxxC motifs. Here, peanut and walnut VBPs were characterized as potential mediators of both peanut/walnut allergenicity and cross-reactivity despite their low (∼17%) sequence identity. The structures of one peanut (AH1.1) and 3 walnut (JR2.1, JR2.2, JR2.3) VBPs were solved using solution NMR, revealing similar α-hairpin structures stabilized by disulfide bonds with high levels of surface similarity. Peptide microarrays identified several peptide sequences primarily on AH1.1 and JR2.1, which were recognized by peanut-, walnut-, and dual-allergic patient IgE, establishing these peanut and walnut VBPs as potential mediators of allergenicity and cross-reactivity. JR2.2 and JR2.3 displayed extreme resilience against endosomal digestion, potentially hindering epitope generation and likely contributing to their reduced allergic potential.
Collapse
Affiliation(s)
- Alexander C.Y. Foo
- National Institute of Environmental Health Sciences, 111 T.W. Alexander Dr, MD-MR01, Research Triangle Park, NC 27615
| | - Jacqueline B. Nesbit
- US Department of Agriculture -Agricultural Research Service, 1100 Robert E. Lee Blvd, New Orleans, LA 70122
| | - Stephen A.Y. Gipson
- US Department of Agriculture -Agricultural Research Service, 1100 Robert E. Lee Blvd, New Orleans, LA 70122
| | - Hsiaopo Cheng
- US Department of Agriculture -Agricultural Research Service, 1100 Robert E. Lee Blvd, New Orleans, LA 70122
| | - Pierre Bushel
- National Institute of Environmental Health Sciences, 111 T.W. Alexander Dr, MD-MR01, Research Triangle Park, NC 27615
| | - Eugene F. DeRose
- National Institute of Environmental Health Sciences, 111 T.W. Alexander Dr, MD-MR01, Research Triangle Park, NC 27615
| | - Catherine H. Schein
- Department of Biochemistry and Molecular Biology, Institute for Human Infections and Immunity, University of Texas Medical Branch, 301 University Blvd., Galveston, TX 77555
| | - Suzanne S. Teuber
- University of California Davis School of Medicine, 2315 Stockton Blvd, Sacramento, CA 95817
| | - Barry K. Hurlburt
- US Department of Agriculture -Agricultural Research Service, 1100 Robert E. Lee Blvd, New Orleans, LA 70122
| | - Soheila J. Maleki
- US Department of Agriculture -Agricultural Research Service, 1100 Robert E. Lee Blvd, New Orleans, LA 70122
| | - Geoffrey A. Mueller
- National Institute of Environmental Health Sciences, 111 T.W. Alexander Dr, MD-MR01, Research Triangle Park, NC 27615
| |
Collapse
|
4
|
Nesbit JB, Schein CH, Braun BA, Gipson SAY, Cheng H, Hurlburt BK, Maleki SJ. Epitopes with similar physicochemical properties contribute to cross reactivity between peanut and tree nuts. Mol Immunol 2020; 122:223-231. [PMID: 32442779 DOI: 10.1016/j.molimm.2020.03.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 02/11/2020] [Accepted: 03/26/2020] [Indexed: 12/28/2022]
Abstract
Many individuals with peanut (PN) allergy have severe reactions to tree nuts (TN) such as walnuts or cashews. Although allergenic proteins in TN and PN have overall low identity, they share discrete sequences similar in physicochemical properties (PCP) to known IgE epitopes. Here, PCP-consensus peptides (cp, 13 aa and 31 aa) were identified from an alignment of epitope rich regions of walnut vicilin, Jug r 2, leader sequence (J2LS) and cross-reactive epitopes in the 2S albumins of peanut and synthesized. A peptide similarity search in the Structural Database of Allergenic Proteins (SDAP) revealed a network of peptides similar (low property distance, PD) to the 13 aa cp (13cp) in many different plant allergens. Peptides similar to the 13cp in PN and TN allergens bound IgE from sera of patients allergic to PN and TN in peptide microarray analysis. The 13cp was used to produce a rabbit consensus peptide antibody (cpAB) that detected proteins containing repeats similar to the 13cp in western blots of various nut extracts, in which reactive proteins were identified by mass spectrometry. The cpAB bound more specifically to allergens and nut extracts containing multiple repeats similar to the 13 cp, such as almond (Pru du 6), peanut (Ara h 2) and walnut (Jug r 2). IgE binding to various nut extracts is inhibited by recombinant J2LS sequence and synthetic 31cp. Thus, several repeated sequences similar to the 13cp are bound by IgE. Multiple similar repeats in several allergens could account for reaction severity and clinically relevant cross-reactivity to PN and TN. These findings may help improve detection, diagnostic, and therapeutic tools.
Collapse
Affiliation(s)
- Jacqueline B Nesbit
- Dept of Agriculture-Agricultural Research Service-Southern Regional Research Center (USDA-ARS-SRRC), New Orleans, LA, United States
| | - Catherine H Schein
- Department of Biochemistry and Molecular Biology, Institute for Human Infection and Immunity, University of Texas Medical Branch at Galveston (UTMB), TX, United States.
| | - Benjamin A Braun
- Department of Computer Science, Stanford University, United States
| | - Stephen A Y Gipson
- Dept of Agriculture-Agricultural Research Service-Southern Regional Research Center (USDA-ARS-SRRC), New Orleans, LA, United States
| | - Hsiaopo Cheng
- Dept of Agriculture-Agricultural Research Service-Southern Regional Research Center (USDA-ARS-SRRC), New Orleans, LA, United States
| | - Barry K Hurlburt
- Dept of Agriculture-Agricultural Research Service-Southern Regional Research Center (USDA-ARS-SRRC), New Orleans, LA, United States
| | - Soheila J Maleki
- Dept of Agriculture-Agricultural Research Service-Southern Regional Research Center (USDA-ARS-SRRC), New Orleans, LA, United States.
| |
Collapse
|
5
|
Maleki SJ, Nesbit JB, Hurlburt BK, Foo AC, DeRose EF, Cheng H, Mueller GA. The NMR structure and IgE Epitopes of Ara h 1 Leader Sequence. J Allergy Clin Immunol 2019. [DOI: 10.1016/j.jaci.2018.12.733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
6
|
Nesbit JB, Cheng H, Hurlburt BK, Maleki SJ. Identification and assessment of the IgE epitopes of Ara h 1 and Jug r 2 leader sequences. J Allergy Clin Immunol 2018. [DOI: 10.1016/j.jaci.2017.12.571] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
7
|
Hurlburt BK, McBride JK, Nesbit JB, Ruan S, Maleki SJ. Purification of Recombinant Peanut Allergen Ara h 1 and Comparison of IgE Binding to the Natural Protein. Foods 2014; 3:642-657. [PMID: 28234343 PMCID: PMC5302246 DOI: 10.3390/foods3040642] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Revised: 11/24/2014] [Accepted: 11/29/2014] [Indexed: 11/16/2022] Open
Abstract
Allergic reactions to food are on the rise worldwide and there is a corresponding increase in interest to understand the molecular mechanisms responsible. Peanut allergies are the most problematic because the reaction often persists into adulthood and can be as severe as anaphylaxis and death. The purpose of the work presented here was to develop a reproducible method to produce large quantities of pure recombinant Ara h 1(rAra h 1) that will enable standardization of immunological tests for patients and allow structural and immunological studies on the wild type and mutagenized forms of the protein. Ara h 1 is initially a pre-pro-protein which, following two endoproteolytic cleavages, becomes the mature form found in peanut. The mature form however has flexible regions that make it refractory to some structural studies including crystallography. Therefore, independent purification of the mature and core regions was desirable. Expression constructs were synthesized cDNA clones for each in a pET plasmid vector without tags. Codons were optimized for expression in E. coli. High-level expression was achieved in BL21 strains. Purification to near homogeneity was achieved by a combination of ammonium sulfate precipitation and ion exchange chromatography. The purified rAra h 1 was then compared with natural Ara h 1 for IgE binding. All patients recognized both the folded natural and rAra h 1, but the IgE binding to the rArah1 was significantly reduced in comparison to the natural allergen, which could potentially make it useful for immunotherapeutic purposes.
Collapse
Affiliation(s)
- Barry K Hurlburt
- Southern Regional Research Center, Agricultural Research Service, United States Department of Agriculture, 1100 Robert E. Lee, Blvd., New Orleans, LA 70124, USA.
| | - Jane K McBride
- Southern Regional Research Center, Agricultural Research Service, United States Department of Agriculture, 1100 Robert E. Lee, Blvd., New Orleans, LA 70124, USA.
| | - Jacqueline B Nesbit
- Southern Regional Research Center, Agricultural Research Service, United States Department of Agriculture, 1100 Robert E. Lee, Blvd., New Orleans, LA 70124, USA.
| | - Sanbao Ruan
- Southern Regional Research Center, Agricultural Research Service, United States Department of Agriculture, 1100 Robert E. Lee, Blvd., New Orleans, LA 70124, USA.
| | - Soheila J Maleki
- Southern Regional Research Center, Agricultural Research Service, United States Department of Agriculture, 1100 Robert E. Lee, Blvd., New Orleans, LA 70124, USA.
| |
Collapse
|
8
|
Lokken AA, Achille NJ, Chang MJ, Lin JJ, Kuntimaddi A, Leach BI, Malik B, Nesbit JB, Zhang S, Bushweller JH, Zeleznik-Le NJ, Hemenway CS. Importance of a specific amino acid pairing for murine MLL leukemias driven by MLLT1/3 or AFF1/4. Leuk Res 2014; 38:1309-15. [PMID: 25282333 DOI: 10.1016/j.leukres.2014.08.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 08/06/2014] [Accepted: 08/16/2014] [Indexed: 11/26/2022]
Abstract
Acute leukemias caused by translocations of the MLL gene at chromosome 11 band q23 (11q23) are characterized by a unique gene expression profile. More recently, data from several laboratories indicate that the most commonly encountered MLL fusion proteins, MLLT1, MLLT3, and AFF1 are found within a molecular complex that facilitates the elongation phase of mRNA transcription. Mutational analyses suggest that interaction between the MLLT1/3 proteins and AFF family proteins are required for experimental transformation of hematopoietic progenitor cells (HPCs). Here, we define a specific pairing of two amino acids that creates a salt bridge between MLLT1/3 and AFF proteins that is critically important for MLL-mediated transformation of HPCs. Our findings, coupled with the newly defined structure of MLLT3 in complex with AFF1, should facilitate the development of small molecules that block this amino acid interaction and interfere with the activity of the most common MLL oncoproteins.
Collapse
Affiliation(s)
- Alyson A Lokken
- The Molecular Biology Program, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, United States
| | - Nicholas J Achille
- Oncology Research Institute, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, United States
| | - Ming-Jin Chang
- Department of Biochemistry, Tulane University School of Medicine, New Orleans, LA 70112, United States
| | - Jeffrey J Lin
- Department of Biochemistry, Tulane University School of Medicine, New Orleans, LA 70112, United States
| | - Aravinda Kuntimaddi
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, United States
| | - Benjamin I Leach
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, United States
| | - Bhavna Malik
- The Molecular Biology Program, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, United States
| | - Jacqueline B Nesbit
- Department of Biochemistry, Tulane University School of Medicine, New Orleans, LA 70112, United States
| | - Shubin Zhang
- Oncology Research Institute, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, United States
| | - John H Bushweller
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, United States
| | - Nancy J Zeleznik-Le
- Oncology Research Institute, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, United States; Department of Medicine, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, United States.
| | - Charles S Hemenway
- Oncology Research Institute, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, United States; Department of Pediatrics, Loyola University Chicago Health Sciences Division, Maywood, IL 60153, United States.
| |
Collapse
|
9
|
Nesbit JB, Hurlburt BK, Schein CH, Cheng H, Wei H, Maleki SJ. Ara h 1 structure is retained after roasting and is important for enhanced binding to IgE. Mol Nutr Food Res 2012; 56:1739-47. [PMID: 22996799 DOI: 10.1002/mnfr.201100815] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 07/18/2012] [Accepted: 08/06/2012] [Indexed: 12/22/2022]
Abstract
SCOPE Ara h 1 from roasted peanut binds higher levels of serum immunoglobulin E than raw peanuts and this is likely due to the Maillard reaction. While Ara h 1 linear IgE epitopes have been mapped, the presence and importance of structural epitopes is not clear. METHODS AND RESULTS Mass spectrometry, immunoblot, ELISA, circular dichroism (CD), and structural analysis were used to compare structural and subsequent IgE-binding differences in Ara h 1 purified from raw (N) and roasted peanuts (R) and denatured Ara h 1 (D). Although N and R had similar CD spectra, the latter bound significantly more IgE. Decreased IgE binding was seen with the loss of secondary structure. This same IgE-binding pattern [R > N > D] was seen for the sera of ten peanut allergic patients. While the majority of linear epitopes are located on surface and structured regions of Ara h 1, our study shows that conformational epitopes of Ara h 1 bind better to IgE than linear epitopes. CONCLUSION Enhanced IgE binding to roasted Ara h 1 could be due to alterations such as chemical modifications to individual amino acids or increased epitope exposure. IgE binding is significantly reduced with loss of structure.
Collapse
Affiliation(s)
- Jacqueline B Nesbit
- US Department of Agriculture, Agricultural Research Service, Southern Regional Research Center, New Orleans, LA 70124, USA
| | | | | | | | | | | |
Collapse
|
10
|
Liu GM, Cheng H, Nesbit JB, Su WJ, Cao MJ, Maleki SJ. Effects of boiling on the IgE-binding properties of tropomyosin of shrimp (Litopenaeus vannamei). J Food Sci 2010; 75:T1-5. [PMID: 20492208 DOI: 10.1111/j.1750-3841.2009.01391.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The thermal stability and IgE binding of raw and boiled shrimp extracts and the tropomyosins (TM) have not been reported. In this study, we compare the stability of raw and boiled shrimp TM of Litopenaeus vannamei and evaluate how boiling may alter the allergenicity of L. vannamei. Extracts were prepared from raw and boiled shrimp and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and two-dimensional electrophoresis. The IgE-binding of the extracts was determined by western-blot and competitive inhibition enzyme-linked immunosorbent assay (iELISA). The TM was then purified from raw and boiled shrimp, the secondary structures analyzed by circular dichroism (CD) spectroscopy, and the IgE binding compared by slot blot analysis. The soluble protein content decreased and the higher molecular weight proteins increased in the extracts from boiled versus raw shrimp. Similar IgE binding characteristics were seen by extracts when using western blot analysis. Although iELISA results showed that extracts from raw shrimp bound higher IgE than extracts from boiled shrimp, dot-blot assay demonstrates higher IgE binding to purified TM from boiled shrimp than raw shrimp. The purified TM had a typical alpha-helical secondary structure and the stability of boiled TM was lower than that of raw TM. Extracts from boiled shrimp produce lower IgE binding than extracts from raw shrimp, which suggest that boiling can be used as a tool in attempting to reduce shrimp allergenicity. However, the purified TM from boiled shrimp, which shows enhanced IgE binding over that of raw shrimp, may be a more effective antigen in diagnosing shrimp allergy through immunoassay.
Collapse
Affiliation(s)
- Guang-Ming Liu
- College of Biological Engineering, The Key Lab. of Science and Technology for Aquaculture and Food Safety, Jimei Univ., 43 Yindou Rd., Xiamen, Fujian, China
| | | | | | | | | | | |
Collapse
|
11
|
Schmitt DA, Nesbit JB, Hurlburt BK, Cheng H, Maleki SJ. Processing can alter the properties of peanut extract preparations. J Agric Food Chem 2010; 58:1138-1143. [PMID: 20028112 DOI: 10.1021/jf902694j] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
As peanut allergy is an increasing public health risk, affecting over 1% of the United States and United Kingdom school children, it is important that methods and reagents for accurate diagnosis of food allergy and detection of allergenic foods are reliable and consistent. Given that most current experimental, diagnostic, and detection tests rely on the presence of soluble allergens in food extracts, we investigated the effects of thermal processing on the solubility and IgE binding of the major peanut allergens, Ara h 1 and Ara h 2. The soluble and insoluble fractions of peanuts that were boiled, fried, and roasted were subjected to electrophoresis and Western blot analysis using anti-Ara h 1 and anti-Ara h 2 antibodies and serum IgE from peanut allergic individuals. Overall protein solubility is reduced with processing and IgE binding increases in the insoluble fractions, due mostly to the increase in the amount of insoluble proteins, with increased time of heating in all processes tested. Therefore, it can be concluded that thermal processing of peanuts alters solubility, and the differences in protein solubility within various extract preparations may contribute to inconsistent skin prick test and immunoassay results, particularly when nonstandardized reagents are used.
Collapse
Affiliation(s)
- David A Schmitt
- US Department of Agriculture, Agriculture Research Service, Southern Regional Research Center, 1100 Robert E Lee Boulevard, New Orleans, Louisiana 70124, USA
| | | | | | | | | |
Collapse
|
12
|
Srinivasan RS, Nesbit JB, Marrero L, Erfurth F, LaRussa VF, Hemenway CS. The synthetic peptide PFWT disrupts AF4–AF9 protein complexes and induces apoptosis in t(4;11) leukemia cells. Leukemia 2004; 18:1364-72. [PMID: 15269783 DOI: 10.1038/sj.leu.2403415] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The MLL gene at chromosome band 11q23 is commonly involved in reciprocal translocations detected in acute leukemias. A number of experiments show that the resulting MLL fusion genes directly contribute to leukemogenesis. Among the many known MLL fusion partners, AF4 is relatively common, particularly in acute lymphoblastic leukemia in infants. The AF4 protein interacts with the product of another gene, AF9, which is also fused to MLL in acute leukemias. Based on mapping studies of the AF9-binding domain of AF4, we have developed a peptide, designated PFWT, which disrupts the AF4-AF9 interaction in vitro and in vivo. We provide evidence that this peptide is able to inhibit the proliferation of leukemia cells with t(4;11) chromosomal translocations expressing MLL-AF4 fusion genes. Further, we show that this inhibition is mediated through apoptosis. Importantly, the peptide does not affect the proliferative capacity of hematopoietic progenitor cells. Our findings indicate that the AF4-AF9 protein complex is a promising new target for leukemia therapy and that the PFWT peptide may serve as a lead compound for drug development.
Collapse
Affiliation(s)
- R S Srinivasan
- Program in Molecular and Cellular Biology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | | | | | | | | | | |
Collapse
|