海鲈鱼鱼肉发酵过程中小清蛋白IgE结合能力的变化

为探究微生物发酵对鱼肉过敏原小清蛋白Ig E结合能力的影响,选用木糖葡萄球菌(Staphylococcus xylosus,Sx)作为发酵剂,以海鲈鱼(Lateolabrax japonicus)为研究对象,利用兔抗鲈鱼多克隆抗体及鱼过敏患者血清,通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(sodium dodecyl sulfate-polyacrylamide gel electrophoresis,SDSPAGE)、免疫印迹及间接酶联免疫吸附(enzyme linked immunosorbent assay,ELISA)对发酵过程中鱼肉过敏原蛋白进行鉴定,通过模拟胃液(simulated gastric fluid,SGF)消化实验分析发酵后的鱼肉蛋白的消化稳定性。SDSPAGE图谱显示,在发酵过程中大量蛋白质被降解,但分子质量为10 k D左右的小清蛋白(parvalbumin,PV)依然存在。免疫印迹及间接ELISA结果显示,发酵60 h后PV的Ig G结合能力下降26.9%,Ig E结合能力下降22.3%。在体外SGF消化实验中,未发酵的鱼肉蛋白20 min后PV被胃蛋白酶分解,而发酵60 h后的鱼肉中PV被酶解的时间提前至5 min。研究结果表明,经Sx发酵后鱼肉蛋白的Ig E结合能力降低,并且发酵后的PV更易被胃蛋白酶分解。

Effect of Fermentation on IgE Binding Ability of Sea Bass (Lateolabrax japonicus) Parvalbumin

This study aimed to observe the changes in IgE binding ability of parvalbumin (major allergen) from sea bass Lateolabrax japonicus during fermentation by Staphylococcus xylosu (Sx). The alterations of proteins were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The effects of fermentation by Sx on the allergenicity of allergens were investigated by Western blot and enzyme linked immunosorbent assay (ELISA) with rabbit anti-parvalbumin polyclonal antibody and sera from fish allergic patients. Subsequently, digestion of sarcoplasmic proteins by simulated gastric fluid (SGF) was carried out to evaluate the digestive stability. The results of SDS-PAGE showed that many proteins were degraded, although no obvious changes in parvalbumin (PV) were detected whose molecular mass was about 10 kD. The IgG binding ability of PV was decreased by 26.9% while the IgE binding ability was decreased by 22.3% after 60 h of fermentation. In SGF system, PV in fish fermented for 60 h was decomposed after being digested for 5 min, compared with 20 min of digestion for unfermented fish. In conclusion, the IgE binding ability of sea bass PV could be significantly reduced by fermentation with Sx, and PV was more readily degraded by pepsin after being fermented for 60 h.