scholarly journals Identification of Common and Novel Major Crab Allergens in Scylla tranquebarica and the Allergen Stability in Untreated and Vinegar-treated Crab

Author(s):  
Hasan Ali Jasim ◽  
Rosmilah Misnan ◽  
Zailatul Hani Mohamad Yadzir ◽  
Noormalin Abdullah ◽  
Faizal Bakhtiar ◽  
...  

Crab allergy is reported as a serious form of food allergy in many countries. This study was aimed to identify the major allergens of the local mud crab, Scylla tranquebarica (S. tranquebarica), and subsequently, determine the effect of vinegar treatments on the crab allergens. Crab muscles were treated with synthetic and natural vinegar. Crab proteins were then extracted from the untreated and vinegar-treated crabs. All extracts were then fractionated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and analyzed by immunoblotting; using sera from crab-allergic patients. The crab proteins were then further fractionated by two-dimensional electrophoresis (2-DE) and analyzed by mass spectrometry (MS). The untreated crab had 38 protein bands, while that was only a few bands between 18 to 73 kDa for the vinegar-treated crabs. Immunoblotting of untreated crab revealed 20 IgE-binding bands, whereas the vinegar-treated crabs could only retain a few IgE-binding bands. Five major allergens were identified with molecular weightsof38, 42, 49, 63, and 73 kDa in the untreated crab. In contrast, the vinegar-treated crabs had only a few major allergens with molecular weights of 38, 42, and 73 kDa. MS identified the 43 and 49 kDa as arginine kinase, while the 38, 63, and 73 kDa were identified as tropomyosin, actin, and hemocyanin, respectively. In conclusion, we found three common major allergens for S. tranquebarica including tropomyosin, arginine kinase, and actin, and one novel allergen known as hemocyanin. All the major allergens could retain minimal allergenic capability in vinegar-treated crabs, suggesting that vinegar treatments might be useful to reduce crab allergenicity. These data would assist the clinicians in the management of crab-allergic patients worldwide.

2000 ◽  
Vol 66 (1) ◽  
pp. 252-256 ◽  
Author(s):  
Katsuichi Saito ◽  
Kazuya Kondo ◽  
Ichiro Kojima ◽  
Atsushi Yokota ◽  
Fusao Tomita

ABSTRACT Streptomyces exfoliatus F3-2 produced an extracellular enzyme that converted levan, a β-2,6-linked fructan, into levanbiose. The enzyme was purified 50-fold from culture supernatant to give a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The molecular weights of this enzyme were 54,000 by SDS-PAGE and 60,000 by gel filtration, suggesting the monomeric structure of the enzyme. The isoelectric point of the enzyme was determined to be 4.7. The optimal pH and temperature of the enzyme for levan degradation were pH 5.5 and 60°C, respectively. The enzyme was stable in the pH range 3.5 to 8.0 and also up to 50°C. The enzyme gave levanbiose as a major degradation product from levan in an exo-acting manner. It was also found that this enzyme catalyzed hydrolysis of such fructooligosaccharides as 1-kestose, nystose, and 1-fructosylnystose by liberating fructose. Thus, this enzyme appeared to hydrolyze not only β-2,6-linkage of levan, but also β-2,1-linkage of fructooligosaccharides. From these data, the enzyme from S. exfoliatus F3-2 was identified as a novel 2,6-β-d-fructan 6-levanbiohydrolase (EC 3.2.1.64 ).


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Aleksandra M. Torbica ◽  
Jasna S. Mastilović ◽  
Milica M. Pojić ◽  
Žarko S. Kevrešan

The effects of wheat bug infestation (Eurygasterspp. andAeliaspp.) on the composition of wheat gluten proteins and its influence on flour technological quality were investigated in the present study. Wheat samples of six wheat varieties, collected from two localities in northern Serbia, were characterized by significantly different level of wheat bug infestation. Composition of wheat gluten proteins was determined using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS PAGE), while the selected parameters of technological quality were determined according to standard and modified empirical rheological methods (Farinograph, Extensograph, Alveograph, and Gluten Index). The surface morphology of the selected samples was viewed using scanning electron microscopy (SEM). Wheat from wheat bug-infested locality regardless of the variety had deteriorated technological quality expressed with higher Farinograph softening degree, lower or immeasurable Extensograph energy, and Alveograph deformation energy. The most important changes in the gluten proteins composition of bug-infested wheat were related to gliadin subunits with molecular weights below 75 kDa, which consequently caused deterioration of uniaxial and biaxial extensibility and dough softening during mixing.


1983 ◽  
Vol 29 (10) ◽  
pp. 1361-1368 ◽  
Author(s):  
Thomas P. Poirier ◽  
Stanley C. Holt

Capnocytophaga ochracea acid (AcP; EC 3.1.3.2) and alkaline (AlP; EC 3.1.3.1) phosphatase was isolated by Ribi cell disruption and purified by sodium dodecyl sulphate – polyacrylamide gel electrophoresis (SDS–PAGE.) Both phosphatases eluted from Sephadex G-150 consistent with molecular weights (migration) of 140 000 and 110 000. SDS–PAGE demonstrated a 72 000 and 55 000 subunit molecular migration for AcP and AlP, respectively. The kinetics of activity of purified AcP and AIP on p-nitrophenol phosphate and phosphoseryl residues of the phosphoproteins are presented.


Blood ◽  
1990 ◽  
Vol 76 (5) ◽  
pp. 887-891 ◽  
Author(s):  
BP Schick

The relationship of protein synthesis to megakaryocyte maturation has been studied in guinea pigs in vivo. Guinea pigs were injected with a single dose of [35S]methionine. Megakaryocytes and platelets were isolated daily for 4 days, and proteins from both cells were isolated by DEAE-Sephacel chromatography and analyzed by sodium dodecyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE) and fluorography. All proteins in megakaryocytes corresponding to stained bands on the SDS- PAGE gels were radiolabeled at 3 hours after injection. The greatest loss of radioactivity from the megakaryocytes occurred between 1 and 3 days after injection. Only trace labeling of platelet proteins was seen at 3 hours, representing almost entirely three bands at molecular weights 47,000, 52,000, and 66,000. At 24 hours only about 13% of the maximal labeling was present, but not all proteins were labeled. The maximal labeling was at 3 days. The pattern of labeling of platelets at 3 days was identical to that of megakaryocytes at 3 hours. The protein pattern of nonmegakaryocytic marrow cells was different from that of the platelets and megakaryocytes. Data presented here suggest that most protein synthesis in megakaryocytes is completed at least 24 hours before release of the platelets to the circulation, and suggest some specificity in the proteins that are synthesized at the terminal stages of maturation.


Author(s):  
Greffa J ◽  
Vilcacundo E ◽  
Altuna J ◽  
Carrillo W

Objective: The aim of this study was to obtain Kahai protein concentrate from Caryodendron orinocense Karst cultivated in the Amazonic region of Ecuador, to characterize its proteins using the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and native electrophoresis methods, and to determine its content of total polyphenols.Methods: Kahai seeds (C. orinocense Karst) were utilized to obtain Kahai protein concentrate at pH 3.0, pH 4.0, pH 5.0, and pH 6.0 using the isoelectric precipitation method. The proteins were characterized using the SDS-PAGE and native-PAGE electrophoresis methods. Total polyphenols were determined using the colorimetric assay method.Results: The best treatment to obtain Kahai protein concentrate was at pH 5.0 with a 21.91% yield using the cold extraction method. The best treatment was at pH 6.0 with a 11.07% yield using the heat extraction method. Kahai concentrates presented a complex profile of proteins with molecular weights between 14 and 97 kDa. It was possible to obtain at the same time polyphenols at pH 5.0 with a value of 1028.58 mg gallic acid equivalents/100 g protein of sample.Conclusion: This study suggests that Kahai protein concentrates possess a high content of proteins and polyphenols that can be used to elaborate functional foods.


1982 ◽  
Vol 205 (3) ◽  
pp. 543-549 ◽  
Author(s):  
A De Caro ◽  
L Multigner ◽  
H Vérine

Two major proteins have been identified in sodium citrate extracts of bovine pancreatic stones from 15 glands with lithiasis. They were found to have a molecular weight of about 24 000 and were further characterized by a variety of methods, including polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate, isoelectric focusing, two-dimensional electrophoresis, immunodiffusion, immunoelectrophoresis and determination of N-terminal residues. These two immunologically and electrophoretically different proteins were definitely shown to be immunoreactive forms of anionic and cationic trypsinogens, which are normal components of pancreatic juice. However, in contrast with both secretory trypsinogens, the stone proteins displayed an important charge heterogeneity under isoelectric-focusing conditions. A possible role for both secretory trypsinogens in pancreatic lithogenesis is suggested by the reproducibility of the data. Finally, two minor proteins with a lower molecular weight (about 11 000-13 000) have also been found to be present in all extracts, but have not yet been identified.


Blood ◽  
1990 ◽  
Vol 76 (5) ◽  
pp. 887-891 ◽  
Author(s):  
BP Schick

Abstract The relationship of protein synthesis to megakaryocyte maturation has been studied in guinea pigs in vivo. Guinea pigs were injected with a single dose of [35S]methionine. Megakaryocytes and platelets were isolated daily for 4 days, and proteins from both cells were isolated by DEAE-Sephacel chromatography and analyzed by sodium dodecyl sulfate- polyacrylamide gel electrophoresis (SDS-PAGE) and fluorography. All proteins in megakaryocytes corresponding to stained bands on the SDS- PAGE gels were radiolabeled at 3 hours after injection. The greatest loss of radioactivity from the megakaryocytes occurred between 1 and 3 days after injection. Only trace labeling of platelet proteins was seen at 3 hours, representing almost entirely three bands at molecular weights 47,000, 52,000, and 66,000. At 24 hours only about 13% of the maximal labeling was present, but not all proteins were labeled. The maximal labeling was at 3 days. The pattern of labeling of platelets at 3 days was identical to that of megakaryocytes at 3 hours. The protein pattern of nonmegakaryocytic marrow cells was different from that of the platelets and megakaryocytes. Data presented here suggest that most protein synthesis in megakaryocytes is completed at least 24 hours before release of the platelets to the circulation, and suggest some specificity in the proteins that are synthesized at the terminal stages of maturation.


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