Soybean protein hydrolysate stimulated cholecystokinin secretion and inhibited feed intake through calcium-sensing receptors and intracellular calcium signalling in pigs.

Although soybean protein is the major component in livestock feeds, its effect on pigs' appetites is largely unknown. Recently, the importance of gut nutrient-sensing for appetite modulation by regulating anorectic gut hormone release has been recognised. This study investigates the roles of soybean proteins in appetite regulation, anorectic gut hormone secretion, and underlying mechanisms. The duodenal-cannulated piglets were used to evaluate the effects of soybean protein hydrolysate (SPH) on feed intake and anorectic hormone release, including cholecystokinin (CCK), peptide YY (PYY), glucagon-like peptide 1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) in the hepatic vein by infusing SPH. Identifying which nutrient-sensing receptor in pig duodenum response to SPH stimulation for gut hormone release was conducted. Using its antagonist, the role of the identified receptor in feed intake and anorectic hormone release was also investigated. Combination with an ex vivo perfusion system, the possible mechanism by which SPH exerts the effects in porcine duodenum was further illustrated. Results in vivo showed that intraduodenal infusion of SPH inhibited short-term feed intake in pigs and promoted CCK, PYY, and GIP secretion in the hepatic vein. SPH also increased duodenum calcium-sensing receptor (CaSR) expression. Pre-treated with CaSR antagonist NPS 2143, the feed intake of pigs tended to be attenuated by SPH (P = 0.09), and CCK release was also suppressed (P < 0.05), indicating that CaSR was involved in SPH-stimulated CCK release and inhibited feed intake in pigs. The ex vivo perfused duodenum tissues revealed that SPH-triggered CCK secretion was likeliest due to the activation of the intracellular Ca2+/TRPM5 pathway. Overall, this study's result illustrates that the diet soybean protein might decrease appetite in pigs by triggering duodenum CCK secretion by activating CaSR and the intracellular Ca2+/TRPM5 pathway.

Separation of Storage Proteins (7S and 11S) from Soybean Seed, Meals and Protein Isolate Using an Optimized Method Via Comparison of Yield and Purity.

The primary purpose of this study was to extract ß-conglycinin (7S) and glycinin (11S) from soybean seed, soybean meals and soybean protein isolate and compare their yield and purity. The previous methods were modified for the extraction and isolation of 7S and 11S globulins. The adjustment mainly included sample to solution ratio of 1:10 (previously 1:15). Comparing the yield of 11S fraction in Tris-HCl and water as extractable solutions, it was almost doubled in soybean seed (16.97% to 32.41%) with purity from 96 to 98% respectively. In case of soybean meal, samples yield increased from 45.46 to 61.86% with purity from 94 to 98%. On contrary, 7S yield was significantly improved in soybean protein isolate sample from 30.33 to 53.81% along with no contamination in its purity while soybean seed and soybean meal samples had less increase in both yield and purity in Tris-HCl and water as extractable solutions. Results of this study will bring new insights into soybean 7S and 11S separation and purification techniques as well as pave the way for their application in food industry.

Visible on-site detection of Ara h 1 by the switchable-linker-mediated precipitation of gold nanoparticles.

Biosensors have been widely applied in tests for allergens, but on-site detection remains a challenge. Herein, we proposed a detection procedure for peanut Ara h 1 as a representative allergen, which was extracted from a cookie, thereby minimising the need for any complex pretreatment that was difficult to perform, and enabling the visual detection of the target without the use of analytical equipment. The extraction procedure was performed in less than 30 min using a syringe and filter (0.45 µm). The detection method for Ara h 1 was based on the aggregation of switchable linkers (SL) and gold nanoparticles (AuNP), and the presence of 0.19 mg peanut protein per 30 g of cookie could be confirmed within 30 min based on the AuNP/SL concentration ratio by the precipitation. This proposed procedure could be successfully applied to the detection of a wide range of food allergens.

Crystal structure of timothy grass allergen Phl p 12.0101 reveals an unusual profilin dimer.

Timothy grass pollen is a source of potent allergens. Among them, Phl p 1 and Phl p 5 are thought to be the most important, as a majority of timothy grass-allergic individuals have IgE antibodies directed against these two allergens. The profilin from timothy grass (Phl p 12) has been registered as a minor allergen, with up to 35% of individuals in populations of grass pollen allergic patients showing IgE binding to Phl p 12. Profilins are primarily minor allergens and are known for a high likelihood of co-sensitization as well as cross-reactivity situations caused by their sequence and structure similarity. The crystal structure of Phl p 12.0101 was determined and it revealed that this allergen may form an unusual dimer not previously observed among any profilins. For example, the Phl p 12 dimer has a completely different geometry and interface when compared with the latex profilin (Hev b 8) dimer that has its crystal structure determined. The structure of Phl p 12.0101 is described in the context of allergenic sensitization and allergy diagnostics. Moreover, the structure of the Phl p 12.0101 dimer is discussed, taking into account the production of recombinant allergens and their storage.

Purification and molecular characterization of a truncated-type Ara h 1, a major peanut allergen: oligomer structure, antigenicity, and glycoform.

Peanut allergies are among the most severe food allergies, and several allergenic proteins referred to as Ara h 1-Ara h 17 have been identified from peanut seeds. The molecular characterization of Ara h 1 (63 kDa), a glycosylated allergen, has almost been completed, and the occurrence of two homologous genes (clone 41B and clone P17) has been identified. In this study, we found a new variant of Ara h 1 i.e. 54 kDa, in which the N-terminal amino acid sequence was EGREGEQ-, indicating that the N-terminal domain of 63 kDa Ara h 1 had been removed. This new isoform was obtained from the run-through fraction of hydrophobic interaction chromatography while 63 kDa Ara h 1 was tightly bound to the hydrophobic resins, suggesting that the removal of the N-terminal domain resulted in extreme hydrophilic properties. We found that 63 kDa Ara h 1 occurs as higher order homo-oligomeric conformations such as decamer or nonamer, while 54 kDa Ara h 1 occurs exclusively as a homotrimer, indicating that the N-terminal domain of the 63 kDa molecule may be involved in higher order oligomerization. When antisera from peanut-allergic patients were treated with both the Ara h 1 molecules, the immunoglobulin E (IgE) antibodies in these sera reacted with each Ara h 1 molecule, suggesting that the C-terminal as well as the N-terminal domains of Ara h 1 contribute significantly to the epitope formations of this peanut glycoallergen. Furthermore, the glycoform analyses of N-glycans linked to 63 kDa and 54 kDa Ara h 1 subunits revealed that both typical high-mannose type and ß-xylosylated type N-glycans are linked to the molecules. The cross-reactivity of IgE against Ara h 1 in the serum of one peanut allergy patient was completely lost by de-N-glycosylation, indicating the N-glycan of Ara h 1 was the sole epitope for the Ara h 1- specific IgE in the patient.

Structural Characterization of Act c 10.0101 and Pun g 1.0101-Allergens from the Non-Specific Lipid Transfer Protein Family.

(1) Background: Non-specific lipid transfer proteins (nsLTPs), which belong to the prolamin superfamily, are potent allergens. While the biological role of LTPs is still not well understood, it is known that these proteins bind lipids. Allergen nsLTPs are characterized by significant stability and resistance to digestion. (2) Methods: nsLTPs from gold kiwifruit (Act c 10.0101) and pomegranate (Pun g 1.0101) were isolated from their natural sources and structurally characterized using X-ray crystallography (3) Results: Both proteins crystallized and their crystal structures were determined. The proteins have a very similar overall fold with characteristic compact, mainly α-helical structures. The C-terminal sequence of Act c 10.0101 was updated based on our structural and mass spectrometry analysis. Information on proteins' sequences and structures was used to estimate the risk of cross-reactive reactions between Act c 10.0101 or Pun g 1.0101 and other allergens from this family of proteins. (4) Conclusions: Structural studies indicate a conformational flexibility of allergens from the nsLTP family and suggest that immunoglobulin E binding to some surface regions of these allergens may depend on ligand binding. Both Act c 10.0101 and Pun g 1.0101 are likely to be involved in cross-reactive reactions involving other proteins from the nsLTP family.

Soy ß-Conglycinin Peptide Attenuates Obesity and Lipid Abnormalities in Obese Model OLETF Rats.

We previously reported that soy ß-conglycinin (ßCG) improves obesity-induced metabolic abnormalities, but not obesity, in obese model Otsuka Long-Evans Tokushima fatty (OLETF) rats. In the present study, we aimed to investigate the effects of ßCG-derived peptide consumption on obesity and lipid abnormality in OLETF rats. To this end, wild-type Long-Evans Tokushima Otsuka and OLETF rats were provided a normal diet containing 20% casein for four weeks as a control. In addition, we prepared ßCG peptide by enzymatic hydrolysis, and OLETF rats were fed a diet in which half of the casein was replaced by ßCG peptide (ßCG peptide group). Consequently, rats in the ßCG peptide group showed decreased abdominal white adipose tissue weight and lipid content (serum and liver triglycerides, and serum and liver cholesterol) compared to control OLETF rats. Further analysis demonstrated that ßCG peptide consumption decreased lipogenic enzyme activity and increased lipolytic enzyme activity in the liver of OLETF rats. In addition, suppressive effects on both synthesis and absorption of cholesterol were observed in ßCG peptide-fed OLETF rats. These findings suggest that peptidization of ßCG enhanced the anti-obese and hypolipidemic effects of ßCG.

Effect of high pressure and pulsed electric field on denaturation and allergenicity of Pru p 3 protein from peach.

The effect of high pressure (HP) and pulsed electric field (PEF) treatments combined or not with heat on denaturation and allergenicity of Pru p 3, the major allergenic protein of peach, was studied. Denaturation of Pru p 3, determined by ELISA using rabbit IgG, occurred when the protein was treated at 500 and 600 MPa at 20 °C and at 400 MPa at 50 °C. PEF treatment at 25 kV/cm at 50 °C denatures Pru p 3. Allergenicity of Pru p 3 was estimated in vitro by a competitive fluorescent immunoassay using three pools of sera from peach allergic patients. Any treatment applied did not show to influence the binding of Pru p 3 to IgE. When HP and PEF treated samples were tested by the prick test, the skin response was dependent on the particular sensitization of each patient, obtaining an increased reaction in more than 50% of individuals.

Detection and identification of allergens from Canadian mustard varieties of Sinapis alba and Brassica juncea.

Currently, information on the allergens profiles of different mustard varieties is rather scarce. Therefore, the objective of this study was to assess protein profiles and immunoglobulin E (IgE)-binding patterns of selected Canadian mustard varieties. Optimization of a non-denaturing protein extraction from the seeds of selected mustard varieties was first undertaken, and the various extracts were quantitatively and qualitatively analyzed by means of protein recovery determination and protein profiling. The IgE-binding patterns of selected mustard seeds extracts were assessed by immunoblotting using sera from mustard sensitized and allergic individuals. In addition to the known mustard allergens-Sin a 2 (11S globulins), Sin a 1, and Bra j 1 (2S albumins)-the presence of other new IgE-binding protein bands was revealed from both Sinapis alba and Brassica juncea varieties. Mass spectrometry (MS) analysis of the in-gel digested IgE-reactive bands identified the unknown ones as being oleosin, ß-glucosidase, enolase, and glutathione-S transferase proteins. A bioinformatic comparison of the amino acid sequence of the new IgE-binding mustard proteins with those of know allergens revealed a number of strong homologies that are highly relevant for potential allergic cross-reactivity. Moreover, it was found that Sin a 1, Bra j 1, and cruciferin polypeptides exhibited a stronger IgE reactivity under non-reducing conditions in comparison to reducing conditions, demonstrating the recognition of conformational epitopes. These results further support the utilization of non-denaturing extraction and analysis conditions, as denaturing conditions may lead to failure in the detection of important immunoreactive epitopes.

Extraction Conditions Affect the Immunoreactivity of Peanut Allergens.

Peanut allergic consumers rely on food package labels to avoid foods containing peanut. The inadvertent presence of peanut in foods due to cross-contact can be fatal if ingestion of such food leads to an allergic reaction. Analytical methods are available to detect undeclared peanut in foods. However, depending on the type of food matrix and food processing parameters, method performance can be adversely affected due to reduction in the extraction efficiency of peanut proteins. Temperature and probe sonication were used as a preincubation treatment for peanut flour slurries to assess their effect on the total peanut protein solubility from raw, light-roasted, and dark-roasted peanut flours. The effect of these treatments on the immunoreactivity of peanut allergens (Ara h 1, Ara h 2, Ara h 3, and Ara h 6) was determined by an indirect enzyme-linked immunosorbent assay using antibodies raised against these individual peanut proteins. Preincubation at 50 °C did not significantly improve the peanut protein solubility, whereas an increase in protein solubility was observed when light- and dark-roasted peanut flour slurries were preincubated at 90 °C or sonicated. The immunoreactivity of peanut allergens varied depending on the degree of peanut flour roasting and type of preincubation treatment. Overall, the immunoreactivity of peanut allergens from most peanut flour slurries was unaffected when preincubated at 50 °C for up to 60 min or sonicated with a probe for up to 5 min, whereas preincubation at 90 °C resulted in a time-dependent reduction in immunoreactivity of peanut allergens. Sonication treatment may improve peanut protein extraction without markedly affecting their immunoreactivity. PRACTICAL APPLICATION: Extraction of peanut proteins is vital for developed analytical methods to estimate peanut allergens in foods. The manuscript describes the effect of two different temperatures (50 and 90 °C) and probe-type sonication on peanut protein solubility. The findings suggest sonication can improve peanut protein solubility without markedly affecting their immunoreactivity.

Identification of polcalcin as a novel allergen of Amaranthus retroflexus pollen

Introduction: Amaranthus retroflexus (Redroot Pigweed) is one of the main sources of allergenic pollens in temperate areas. Polcalcin is a well-known panallergen involved in cross-reactivity between different plants. The aim of this study was the molecular cloning and expression of polcalcin, as well as evaluating its IgE-reactivity with A. retroflexus sensitive patients' sera. Methods: Allergenic extract was prepared from A. retroflexus pollen and the IgE-reactivity profile was determined by ELISA and immunoblotting using sera from twenty A. retroflexus sensitive patients. Polcalcin-coding sequence was amplified by conventional PCR method and the product was inserted into pET-21b(+) vector. The recombinant protein was expressed in E. coli BL21 and purified by metal affinity chromatography. The IgE-binding capability of the recombinant protein was analyzed by ELISA and immunoblotting assays, and compared with crude extract. Results: Of 20 skin prick test positive patients, 17 patients were positive in IgE-specific ELISA. Western blotting confirmed that approximately 53% of ELISA positive patients reacted with 10kDa protein in crude extract. The A. retroflexus polcalcin gene, encoding to 80 amino acid residues was cloned and expressed as a soluble protein and designated as Ama r 3. The recombinant polcalcin showed rather identical IgE-reactivity in ELISA and western blotting with 10 kDa protein in crude extract. These results were confirmed by inhibition methods, too. Conclusion: The recombinant form of A. retroflexus polcalcin (Ama r 3) could be easily produced in E. coli in a soluble form and shows rather similar IgE-reactivity with its natural counterpart

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Identification of polcalcin as a novel allergen of Amaranthus retroflexus pollen.

INTRODUCTION: Amaranthus retroflexus (Redroot Pigweed) is one of the main sources of allergenic pollens in temperate areas. Polcalcin is a well-known panallergen involved in cross-reactivity between different plants. The aim of this study was the molecular cloning and expression of polcalcin, as well as evaluating its IgE-reactivity with A. retroflexus sensitive patients' sera. METHODS: Allergenic extract was prepared from A. retroflexus pollen and the IgE-reactivity profile was determined by ELISA and immunoblotting using sera from twenty A. retroflexus sensitive patients. Polcalcin-coding sequence was amplified by conventional PCR method and the product was inserted into pET-21b(+) vector. The recombinant protein was expressed in E. coli BL21 and purified by metal affinity chromatography. The IgE-binding capability of the recombinant protein was analyzed by ELISA and immunoblotting assays, and compared with crude extract. RESULTS: Of 20 skin prick test positive patients, 17 patients were positive in IgE-specific ELISA. Western blotting confirmed that approximately 53% of ELISA positive patients reacted with 10kDa protein in crude extract. The A. retroflexus polcalcin gene, encoding to 80 amino acid residues was cloned and expressed as a soluble protein and designated as Ama r 3. The recombinant polcalcin showed rather identical IgE-reactivity in ELISA and western blotting with 10kDa protein in crude extract. These results were confirmed by inhibition methods, too. CONCLUSION: The recombinant form of A. retroflexus polcalcin (Ama r 3) could be easily produced in E. coli in a soluble form and shows rather similar IgE-reactivity with its natural counterpart.

Comprehensive analysis of the peanut allergome combining 2-DE gel-based and gel-free proteomics.

In this work, we explored the "deep" seed peanut proteome by using both two dimensional electrophoresis (2-DE)-based analysis run under reducing and non-reducing condition (protein-centric) and LC-MS/MS gel-free proteomic (peptide-centric). The former approach allowed to identify high molecular weight disulfide-linked Ara h 1 and Ara h 3 heteroligomers and Ara h 1 homoligomers linked through covalent bonds other than disulfides. The occurrence of these protein complexes revealed natural interactions between Ara(s) subunits with a possible involvement in the allergenic potential of peanut. The second approach, also referred to as shot-gun proteomics, allowed the identification of 149 gene products, including low-abundance proteins escaped the 2-DE detection. Interestingly, we identified 60 proteins never catalogued previously. The complementary exploitation of two proteomic approaches enabled the access to new relevant information about the complexity of the peanut proteome, with special emphasis to the complement of allergens (allergome).

Characterizing the Structural and Functional Properties of Soybean Protein Extracted from Full-Fat Soybean Flakes after Low-Temperature Dry Extrusion.

The soy protein isolates (SPI) extracted from different extruded full-fat soybean flakes (FFSF), and their conformational and functional properties were characterized. Overall, the free thiol (SH) content of SPI increased when the extrusion temperature was below 80 °C and decreased at higher temperatures. Soy glycinin (11S) showed higher stability than ß-conglycinin (7S) during extrusion. Results also indicated that the increase in some hydrophobic groups was due to the movement of hydrophobic groups from the interior to the surface of the SPI molecules at extrusion temperatures from 60 to 80 °C. However, the aggregation of SPI molecules occurred at extrusion temperatures of 90 and 100 °C, with decreasing levels of hydrophobic groups. The extrusion temperature negatively affected the emulsifying activity index (EAI); on the other side, it positively affected the emulsifying stability index (ESI), compared to unextruded SPI.

Purification and Characterization of Naturally Occurring Post-Translationally Cleaved Ara h 6, an Allergen That Contributes Substantially to the Allergenic Potency of Peanut.

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.

Structural basis for cross-reactivity and conformation fluctuation of the major beech pollen allergen Fag s 1.

Fag s 1 is a member of the Pathogen Related protein family 10 (PR-10) and can elicit cross-reaction with IgE antibodies produced against the birch pollen allergen Bet v 1. The Nuclear Magnetic Resonance (NMR) structure of Fag s 1 is presented along with its dynamic properties. It shares 66% identity with Bet v 1 and exhibits the expected three α-helices and seven ß-sheets arranged as a semi-beta barrel and exposing the residues mapped as the Bet v 1 IgE epitope. The structural dynamics of Fag s 1 were monitored on the fast and intermediate timescales, using relaxation rates. The complex dynamics of Fag s 1 are closely related to the internal cavity, and they modulate IgE and ligand binding.

A subset of walnut allergic adults is sensitized to walnut 11S globulin Jug r 4.

BACKGROUND: The role of sensitization to commercially available allergens of English walnut (Juglans regia) Jug r 1, 2 and 3 in walnut allergy has been previously investigated in walnut allergic adults and was unable to explain all cases of walnut allergy. OBJECTIVES: Identify recognized walnut allergens, other than the ones previously investigated (Jug r 1-3), in walnut allergic adults and determine the sensitization frequency and diagnostic value. METHODS: Three different in-house walnut extracts were prepared and analysed on SDS-PAGE blots to identify allergenic walnut proteins. Immunoblots and immunoprecipitation, followed by LC-MS analysis, were performed to screen for, and confirm, IgE binding to walnut allergens in selected walnut allergic adults. In a cohort of 55 walnut challenged adults, including 33 allergic and 22 tolerant, sensitization to native and recombinant walnut allergen Jug r 4 was assessed using immunoblotting and immuno-line blot (EUROLINE), respectively. RESULTS: Screening of sera of 8 walnut allergic adults identified Jug r 4 as an allergen in our population. In the total cohort of 55 subjects, 5 were positive for Jug r 4 on immunoblot and 10 on EUROLINE. All but one EUROLINE positive subject had a positive food challenge (sensitivity 27%, specificity 95%, PPV 90%, NPV 47%). All 5 subjects positive on immunoblot were also positive on EUROLINE. LC-MS analysis showed a lack of Jug r 4 in the ImmunoCAP extract. Co-sensitization to other 11S albumins (eg hazelnut Cor a 9) was common in Jug r 4 sensitized subjects, potentially due to cross-reactivity. CONCLUSIONS: Walnut 11S globulin Jug r 4 is a relevant minor allergen, recognized by 27% of walnut allergic adults. It has a high positive predictive value of 90% for walnut allergy. Specific IgE against Jug r 4 occurred mostly with concomitant sensitization to other walnut components, mainly Jug r 1.

Expression, purification and epitope analysis of Pla a 2 allergen from Platanus acerifolia pollen.

Platanus acerifolia is one of the major sources of outdoor allergens to humans, and can induce allergic asthma, rhinitis, dermatitis and other allergic diseases. Pla a 2 is a polygalacturonase and represents the major allergen identified in P. acerifolia pollen. The aim of the present study was to express and purify Pla a 2, and to predict B and T cell epitopes of Pla a 2. The gene encoding Pla a 2 was cloned into the pET28a vector and subsequently transfected into ArcticExpress™ (DE3) Escherichia coli cells; purified Pla a 2 was analyzed by western blot analysis. The results of the present study revealed that the Pla a 2 allergen has the ability to bind immunoglobulin E within the sera of patients allergic to P. acerifolia pollen. In addition, the B cell epitopes of Pla a 2 were predicted using the DNAStar Protean system, Bioinformatics Predicted Antigenic Peptides and BepiPred 1.0 software; T cell epitopes were predicted using NetMHCIIpan ­3.0 and ­2.2. In total, eight B cell epitopes (15­24, 60­66, 78­86, 109­124, 232­240, 260­269, 298­306 and 315­322) and five T cell epitopes (62­67, 86­91, 125­132, 217­222 and 343­350) were predicted in the present study. These findings may be used to improve allergen immunotherapies and reduce the frequency of pollen­associated allergic reactions.

Specific allergen profiles of peanut foods and diagnostic or therapeutic allergenic products.

BACKGROUND: Generic immunoassays for peanut cannot discriminate between allergen levels in peanut-derived food products or therapeutics. Clinical trials of oral immunotherapy (OIT) are strengthened by using standardized peanut preparations with defined doses of major allergens. OBJECTIVE: This article describes measurement of Ara h 1, Ara h 2, and Ara h 6 in peanut foods and in peanut flour extracts used for allergy diagnosis and OIT. METHODS: Monoclonal antibody-based enzyme immunoassays for Ara h 1, Ara h 2, and Ara h 6 were used to compare allergen levels in peanut (n = 16) and tree nut (n = 16) butter, peanut flour (n = 11), oils (n = 8), extracts used for diagnosis and OIT (n = 5), and the National Institute for Standards and Technology Peanut Butter Standard Reference Material 2387. RESULTS: Roasted peanut butters contained 991 to 21,406 µg/g Ara h 1 and exceeded Ara h 2 and Ara h 6 levels by 2- to 4-fold. Similarly, National Institute for Standards and Technology Peanut Butter Standard Reference Material 2387 contained 11,275 µg/g Ara h 1, 2,522 µg/g Ara h 2, and 2,036 µg/g Ara h 6. In contrast, peanut flours contained 787 to 14,631 µg/g Ara h 2 and exceeded Ara h 1 levels by 2- to 20-fold. Flour extracts used for OIT contained 394 to 505 µg/mL Ara h 1, 1,187 to 5,270 µg/mL Ara h 2, and 1,104 to 8,092 µg/mL Ara h 6. In most cases specific peanut allergens were not detected in tree nut butters or peanut oils. CONCLUSIONS: The results show marked differences in specific peanut allergen profiles in peanut butter and flour and peanut preparations for clinical use. Roasting can increase Ara h 1 levels in peanut butter. Variability in allergen levels could affect the outcome of clinical trials of peanut OIT, especially with respect to Ara h 1. Specific allergen measurements will improve standardization and provide accurate dosing of peanut preparations that are being used for OIT.

Identification of lipoproteins from sunflower seeds in 2 monosensitized anaphylaxis patients

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