scholarly journals The Reactivity and Allergenic Potential of Hazelnut Peptides

Author(s):  
Lavinia Florina Calinoiu ◽  
Dan Cristian Vodnar ◽  
Carmen Socaciu

The aim of this paper was to focus on proteins present in some food products, like hazelnuts and to investigate their allergenic potential. Several techniques were used to characterize these extracted proteins, with respect to their composition, degradability by digestive proteolytic enzymes and their reactivity with specific antibodies. It was important to analyse which proteins were present in the hazelnuts, to see if there were proteins present to trigger an allergic reaction and if the digestion enzymes trypsin and pepsin influence the presence of the (allergic) protein compounds. Allergies to tree nuts and seeds can cause life-threatening and sometimes fatal reactions. To examine the properties of Hazelnut protein it was important to solubilize it by extraction. After extraction, it was investigated how hazelnut protein can be modified by proteases and what the effect was on the immune reaction. The Bradford method is a fast and sensitive method to determine the concentration of soluble protein. When the Bradford reagent (Coomassie Brilliant Blue) binds to the protein, the colour changes from red to purple and the absorption maximum changes from 495 to 595 nm. The value obtained as the final concentration of proteins was 7.3495. SDS-PAGE is a method to separate mixtures of proteins by electrophoresis. Protein molecules are negatively charged by binding of SDS molecules; subsequently they are separated in an electric field. Their differences in size (molecular weight) leads to separation. In this case the method is used to follow proteolytic degradation of hazelnut proteins (allergens) by intestinal proteases (trypsin, pepsin). A different, more specific and sensitive method is immunoblotting (Western Blot) in which the SDS-PAGE separated proteins are transferred from the gel to a membrane and specific antibodies are used in a series of reactions to visualize specific allergens on this membrane. The remarked spots represented a positive identification of allergenic proteins. This means that peptide fragments of various size, produced during the digestion of a protein can still be immunological active. As it was shown there was still reactivity between proteins and specific antibodies. The Dot Blot is a simple immunoblotting technique used to detected specific proteins in a mixture of different proteins and/or other molecules. No separation technique prior to the actual immuno-detection is necessary. Also, Dot Blot confirmed the presence of allergenic proteins made visible through the light spots on the membrane.

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 954 ◽  
Author(s):  
Carmen Cuadrado ◽  
Africa Sanchiz ◽  
Fatima Vicente ◽  
Isabel Ballesteros ◽  
Rosario Linacero

Tree nuts confer many health benefits due to their high content of vitamins and antioxidants, and they are increasingly consumed in the last few years. Food processing is an important industrial tool to modify allergenic properties of foods, in addition to ensuring safety and enhancing organoleptic characteristics. The effect of high pressure, without and with heating, on SDS-PAGE and immunodetection profile of potential allergenic proteins (anti-11S, anti-2S and anti-LTP) of pistachio, cashew, peanut, hazelnut, almond, and chestnut was investigated. Processing based on heat and/or pressure and ultra-high pressure (HHP, 300–600 MPa) without heating was applied. After treating the six tree nuts with pressure combined with heat, a progressive diminution of proteins with potential allergenic properties was observed. Moreover, some tree nuts proteins (pistachio, cashew, and peanut) seemed to be more resistant to technological processing than others (hazelnut and chestnut). High pressure combined with heating processing markedly reduce tree nut allergenic potential as the pressure and treatment time increases. HHP do not alter hazelnut and almond immunoreactivity.


Author(s):  
Carmen Cuadrado ◽  
Africa Sanchiz ◽  
Fatima Vicente ◽  
Isabel Ballesteros ◽  
Rosario Linacero

Tree nuts confer many health benefits because of their high content of vitamins and antioxidants and they are increasingly consumed in the last the years. Food processing is an important industrial tool to modify allergenic properties of foods, in addition to ensure safety and to enhance organoleptic characteristics. The effect of high pressure, without and with heating, on SDS-PAGE and immunodetection profile of potential allergenic proteins (anti-11S, anti-2S and anti-LTP) of pistachio, cashew, peanut, hazelnut, almond and chestnut was investigated. Processing based on heat and /or pressure and Ultra high pressure (HHP, 300-600 MPa) without heating was applied. After treating the six tree nuts with pressure combined with heat a progressive diminution of proteins with potential allergenic properties was observed. Moreover, some tree nuts proteins (pistachio, cashew and peanut) seemed to be more resistant to technological processing than others (hazelnut and chestnut). Differences among tree nut varieties were found regarding to protein content, SDS and immunoblotting profile. High pressure combined with heating processing markedly reduce tree nut allergenic potential as the pressure and treatment time increases. HHP do not alter hazelnut and almond immunoreactivity


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2647
Author(s):  
Sabrina Groth ◽  
Christoph Budke ◽  
Timo Weber ◽  
Susanne Neugart ◽  
Sven Brockmann ◽  
...  

Notable parts of the population in Europe suffer from allergies towards apples. To address this health problem, the analysis of the interactions of relevant allergens with other substances such as phenolic compounds is of particular importance. The aim of this study was to evaluate the correlations between the total phenolic content (TPC), polyphenol oxidase (PPO) activity, antioxidant activity (AOA), and the phenolic compound profile and the content of the allergenic protein Mal d 1 in six apple cultivars. It was found that the PPO activity and the content of individual phenolic compounds had an influence on the Mal d 1 content. With regard to the important constituents, flavan-3-ols and phenolic acids, it was found that apples with a higher content of chlorogenic acid and a low content of procyanidin trimers and/or epicatechin had a lower allergenic potential. This is probably based on the reaction of phenolic compounds (when oxidized by the endogenous PPO) with proteins, thus being able to change the conformation of the (allergenic) proteins, which further corresponds to a loss of antibody recognition. When apples were additionally biofortified with selenium, the composition of the apples, with regard to TPC, phenolic profile, AOA, and PPO, was significantly affected. Consequently, this innovative agronomic practice seems to be promising for reducing the allergenic potential of apples.


2000 ◽  
Vol 83 (01) ◽  
pp. 60-64 ◽  
Author(s):  
Seiji Miyamoto ◽  
Atsushi Iwasa ◽  
Masao Ishii ◽  
Kenji Okajima ◽  
Yu-ichi Kamikubo

SummaryWe recently observed a patient with acquired inhibitor-induced F.VII deficiency whose plasma level of F.VII was < 1.0%. However, the biochemical nature of the inhibitor has not yet been clarified. In the present study, we purified the F.VII inhibitor from the patient’s plasma by using activated F.VII (F.VIIa)-conjugated gel and characterized the inhibitor. The results showed that the inhibitor comprised two kinds of antibodies: one was eluted with EDTA (antibody 1) and the other with glycine-HCl buffer (pH 2.3) (antibody 2) from the F.VIIa affinity gel. SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting analysis of these inhibitors demonstrated that both antibodies had features of immunoglobulin G1 (IgG1) with κ and λ-light chains. Antibody 1 bound to the immobilized F.VIIa with a high affinity in the presence of calcium ion, while antibody 2 bound to the F.VIIa very weakly and the binding was independent of calcium ion. Immunoblotting analysis demonstrated that antibody 1 bound to the light chain of F.VIIa after reduction with 2-mercaptoethanol, while it did not react with either the γ carboxyglutamic acid (Gla)-domainless light chain of F.VIIa or the heavy chain with the protease domain. Antibody 1 markedly inhibited the activity of tissue factor-F.VIIa complex. Based on these observations, it is suggested that F.VIIa autoantibody (antibody 1) recognizes the calcium-dependent conformation within or near the Gla domain and inhibits F.VIIa activity by interacting with the light chain.


Nutrients ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1679 ◽  
Author(s):  
Elisabetta De Angelis ◽  
Simona Bavaro ◽  
Graziana Forte ◽  
Rosa Pilolli ◽  
Linda Monaci

Almond is consumed worldwide and renowned as a valuable healthy food. Despite this, it is also a potent source of allergenic proteins that can trigger several mild to life-threatening immunoreactions. Food processing proved to alter biochemical characteristics of proteins, thus affecting the respective allergenicity. In this paper, we investigated the effect of autoclaving, preceded or not by a hydration step, on the biochemical and immunological properties of almond proteins. Any variation in the stability and immunoreactivity of almond proteins extracted from the treated materials were evaluated by total protein quantification, Enzyme Linked Immunosorbent Assay (ELISA), and protein profiling by electrophoresis-based separation (SDS-PAGE). The sole autoclaving applied was found to weakly affect almond protein stability, despite what was observed when hydration preceded autoclaving, which resulted in a loss of approximately 70% of total protein content compared to untreated samples, and a remarkable reduction of the final immunoreactivity. The final SDS-PAGE protein pattern recorded for hydrated and autoclaved almonds disclosed significant changes. In addition, the same samples were further submitted to human-simulated gastro-intestinal (GI) digestion to evaluate potential changes induced by these processing methods on allergen digestibility. Digestion products were identified by High Pressure Liquid Chromatography-High Resolution Tandem Mass Spectrometry (HPLC-HRMS/MS) analysis followed by software-based data mining, and complementary information was provided by analyzing the proteolytic fragments lower than 6 kDa in size. The autoclave-based treatment was found not to alter the allergen digestibility, whereas an increased susceptibility to proteolytic action of digestive enzymes was observed in almonds subjected to autoclaving of prehydrated almond kernels. Finally, the residual immunoreactivity of the GI-resistant peptides was in-silico investigated by bioinformatic tools. Results obtained confirm that by adopting both approaches, no epitopes associated with known allergens survived, thus demonstrating the potential effectiveness of these treatments to reduce almond allergenicity.


1971 ◽  
Vol 49 (7) ◽  
pp. 1021-1024 ◽  
Author(s):  
T. S. Sahota

The failure of ovarian development in Douglas-fir bark beetles denied of their natural gallery environment and maintained on host bark chips was investigated. Such insects possessed a high activity of proteolytic enzymes in their guts but relatively small amounts of female-specific proteins both in haemolymph and the oocytes. Topical application of farnesyl methyl ether did not increase the activity of gut proteases but resulted in increased amounts of female-specific proteins in haemolymph and ovaries. Thus it appears that the Douglas-fir bark beetles maintained on bark chips do not suffer from an inability to break down the ingested proteins, but synthesize and transfer less than normal amounts of female-specific proteins to the developing oocytes.


2010 ◽  
Vol 10 (1) ◽  
pp. 132-137
Author(s):  
Chanif Mahdi ◽  
Aulaniam Aulaniam

Formaldehyde is a simplest organic compound of aldehyde or alkanal group. Formaldehyde is a toxic and carcinogenic substance. Formaldehyde contamination through food or feeding diet continuously is very dangerous for the body, especially for bodies organ for instances likes hepar and kidney. Because formaldehyde is sources of reactive oxygen species (ROS) and free radicals substances for the body. This purpose of the study is to know the effect of formaldehyde exposure and yogurt supplementation on profile and characters of rats (Rattus norvegicus) protein hepar tissues. The research methods is laboratory methods. The protein profiles determined by electrophoresis (SDS-PAGE) methods. The character of hepar protein tissue determined by ELISA, Dot Blot and Western Blot methods. The result showed that formaldehyde exposure through the feeding diet of rats affect on profile of hepar protein tissue, that characterized by appear of new band of specific protein with molecule weigh is 29.6 kDa (PSForm 29.6). Yogurt supplementation on rat that exposure by formaldehyde through the feeding diet of rat, that characterized by expressing of new band of specific protein with relative molecule weight 24.8 kDa (PSYogh 24.8 kDa), and followed by depressed or dispear of protein specific band of 29.6 kDa(PSForm 29.6 kDa). The result showed that isolated protein PSForm 29.6 kDa have a antigenecity character.   Keywords: Formaldehyde exposure, yogurt, ROS, profile and protein character


2015 ◽  
Vol 16 (1) ◽  
pp. 31
Author(s):  
Kusdianawati Kusdianawati ◽  
Apon Zaenal Mustopa ◽  
Suharsono Suharsono ◽  
Bugi Ratno Budiarto ◽  
Fatimah Fatimah ◽  
...  

Plantaricin is one of bacteriocins that have the potential to be used as food preservative. Plantaricin is safe for human consumption because it can be easily degraded by proteolytic enzymes. The objective of this study was to express and purify recombinant pre-mature peptide of plantaricin F from <em>Lactobacillus plantarum</em> S34 in <em>Escherichia coli</em>. Plantaricin gene-specific primer was used to obtain pln F structural gene amplicon from L. <em>plantarum</em> S34. This amplicon was cloned in pET32a vector and expressed in E. coli BL21 (DE3) pLysS. Pre-mature plantaricin F peptide was expressed as Histagged-fusion protein and separated by Co2+-chelating affinity chromatography. L. <em>plantarum</em> S34-derived pre-mature plantaricin F peptide fused with thioredoxin-(His)6tag had successfully been expressed in E. <em>coli</em> BL21 (DE3) pLysS using pET32a as an expression vector. The fused recombinant pln F as pre-mature state expressed had a molecular mass of +24 kDa, meanwhile the fused recombinant that contained only the leader peptide of pln F appeared as +20 kDa based on SDS-PAGE separations. The optimal production of fused recombinant pln F as soluble fraction was obtained when culture condition was added with 0.5 mM of IPTG and incubated at 22°C for 5 hours (OD~1). Furthermore, the expression of fused recombinant pln F as its pre-mature peptide pointed out that the pln F’s leader peptide could be proteolytically cleaved by a system in heterologous cells. Overall, heterologous pln F production as pre-mature peptide fused with thioredoxin-(His)6tag had been well established. From this research, we expect plantaricin F can be expressed and purified in E. coli.


PEDIATRICS ◽  
1982 ◽  
Vol 70 (3) ◽  
pp. 468-471
Author(s):  
Aaron R. Zucker ◽  
Samuel J. Lacina ◽  
D. S. DasGupta ◽  
H. A. Fozzard ◽  
David Mehlman ◽  
...  

Digitalis poisoning is a rare problem in children, but it may be life threatening. A case of massive overdose of digoxin in a 2½-year-old boy that produced prolonged ventricular fibrillation refractory to conventional therapy is reported. After two hours the boy was given digoxin-specific Fab fragments of antibody in sufficient quantity to bind his estimated dose of 10 mg. By completion of the treatment minutes later, normal rhythm and circulation were restored. The serum free digoxin level before antibody administration was &gt; 100 ng/ml, and it rapidly fell to undetectable levels after antibody was given. Digoxin bound to the antibody had a clearance half-life of approximately 48 hours. The child had no apparent neurologic damage and his intellectual function was normal on discharge. He had a transient hematuria and a residual incomplete right bundle branch block. Administration of purified Fab fragments of digoxin-specific antibodies can be life saving in children with digitalis poisoning, and prolonged cardiopulmonary resuscitation in children is justified when the cause of cardiac arrest is potentially reversible.


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