美拉德反应对菲律宾蛤仔原肌球蛋白结构及免疫活性的影响

Effect of Maillard Reaction on IgE Binding Capacity and Conformational Structure of Tropomyosin from Short-Neck Clam(Ruditapes philippinarum)

以菲律宾蛤仔原肌球蛋白为研究对象,探讨美拉德反应导致核糖糖化后对其结构及免疫原性的影响。利用酶联免疫及点印记技术分析核糖对原肌球蛋白IgE/IgG结合能力的影响。通过圆二色谱(circular dichroism,CD)、有效赖氨酸含量测定等分析蛋白二级结构及相关基团的变化。结果表明,以美拉德反应为基础的与核糖的糖化反应时间达到12h后,产物的IgE结合能力下降76.2%,IgG结合能力下降了86.8%,α-螺旋含量下降了71.7%,蛋白表面疏水性增加了192%,有效赖氨酸含量降低了45.5%。实验表明,与核糖的糖基化反应时间达到4h后能够有效地改变菲律宾蛤仔原肌球蛋白的结构,从而降低其免疫活性。

The aim of the present study was to assess changes in conformational structures and potential allergenicity of tropomyosin from short-neck clams after glycation with ribose. Changes in potential allergenicity were characterized by immunological techniques, while circular dichroism（CD） and available lysine were determined to defi ne conformational changes. An unfolded structure was found as glycation proceeded. Correspondingly, the amount of available lysine was reduced by 45.5% and surface hydrophobicity was increased by 192% when the reaction time was 12 h. Indirect enzyme linked immunosorbent assay（ELISA） and dot-blot results of glycation showed that potential allergenicity correlated well with structural changes. Allergenicity decreased significantly after unfolding of the protein. These results showed that conformational changes in tropomyosin induced by glycation signifi cantly infl uenced the allergenicity of tropomyosin.