还原协同加热处理对花生过敏原Ara h2结构及抗原性的影响

Synergistic Effect of Cysteine Reduction and Thermal Treatment on Structure and Antigenicity of Peanut Allergen Ara h2

花生过敏能引起荨麻疹、呕吐甚至休克等症状,通常是终生性过敏。本研究运用加热处理、半胱氨酸还原对Ara h2进行单独和复合处理,采用圆二色谱、紫外扫描光谱、间接竞争酶联免疫吸附法分别检测蛋白加工前后的结构与抗原性变化。结果显示,单一的加热和半胱氨酸还原处理过的蛋白结构与抗原性只发生部分变化。而复合处理中,在加热条件下,半胱氨酸还原蛋白的能力明显增强,还原后的蛋白二级结构与三级结构发生大幅变化,抗原性显著降低。研究结果表明,二硫键对于蛋白Ara h2结构稳定具有重要作用,二硫键被还原和加热过程破坏后,蛋白的抗原性和结构即发生重大变化。还原协同加热处理有望大幅改善2S球蛋白的结构和致敏性,可以作为蛋白脱敏加工的备选方法。

Peanut is listed among the eight major food allergens by the FAO,and peanut allergy is life-long and could causehives,vomiting or other symptoms.In the present study,thermal treatment and cysteine reduction were applied individuallyand in combination on peanut allergen Ara h2to study their effect on the allergenic protein.The changes in the structureand antigenicity of Ara h2were characterized by circular dichroism(CD)spectroscopy,UV spectroscopy and indirectcompetitive enzyme linked immunosorbent assay(ELISA),respectively.The results showed that thermal treatment andcysteine reduction could individually change the structure of Ara h2,leading to a slight decrease in the antigenicity.But thecombined treatment resulted in a significant decrease in the antigenicity of Ara h2due to the enhanced reducing capacity ofcysteine under thermal conditions and consequent remarkable changes in the secondary and tertiary structures of the protein.Moreover,the disulfide bonds played important roles in the structural stability of Ara h2.When they were destroyed byreduction and heating,the structure and antigenicity changed significantly.These results indicated that reduction combinedwith heating may be an effective method for eliminating the allergenicity of Ara h2.