酪蛋白糖巨肽对花生过敏原免疫反应性的影响

Effects of casein glycomacropeptide on the immunoreactivity of peanut allergens

中文关键词:  酪蛋白糖巨肽  花生  过敏原  免疫反应性  蛋白质相互作用  分子对接

英文关键词:glycomacropeptides  peanut  allergen  immunoreactivity  protein interaction  molecular docking

中文摘要:

      目的 探究酪蛋白糖巨肽与花生过敏原相互作用并降低其免疫反应性的潜力。方法 通过蛋白-蛋白分子对接技术探讨酪蛋白糖巨肽(casein glycomacropeptides, CGMP)与Ara h1、Ara h2是否有相互作用的潜力。进一步通过混合水浴加热制备CGMP与花生蛋白的混合溶液(mixed solution of casein glycomacropeptides and peanut proteins, MCGP),建立MCGP致敏、花生蛋白激发的BALB/c小鼠模型,研究MCGP对花生过敏反应的影响。最后使用圆二色谱法研究酪蛋白糖巨肽与Ara h1、Ara h2的相互作用力及对其结构的影响。结果 CGMP与Ara h1、Ara h2间存在次级键(盐桥、氢键、范德华力),部分作用于过敏原表位；MCGP致敏组血清中的花生蛋白特异性免疫球蛋白E(Specific immunoglobulin E, sIgE)、sIgG₁、sIgG_2a含量显著下降,白介素-4(interleukin-4, IL-4)、IL-5、转化生长因子-β(transforming growth factor-β, TGF-β)、组胺水平显著下降,肿瘤坏死因子-α(tumor necrosis factor-α, TNF-α)水平显著升高, MCGP中Ara h2的α-螺旋与β-折叠的比例改变。结论 CGMP能够改变Ara h2的结构,遮蔽花生过敏原表位,抑制sIgE、sIgG结合Ara h1、Ara h2,降低部分花生过敏原的免疫反应性。

英文摘要:

      Objective To investigate the potential of casein glycomacropeptides (CGMP) to interact with peanut allergens and reduce their immunoreactivity. Methods A mixed solution of CGMP and peanut proteins (MCGP) was prepared by heating to establish a BALB/c mouse model of MCGP sensitization and peanut proteins challenge. This aimed to study the effect of MCGP on peanut allergic reaction. Furthermore, the effect of MCGP on the immunoreactivity of peanut major allergens (Ara h 1 and Ara h 2) was confirmed by enzyme linked immunosorbent assay (ELISA). Additionally, the interaction force of CGMP with Ara h 1 or Ara h 2 and its effect on their secondary structure were investigated by protein-protein molecular docking and circular dichroism. Results The levels of interleukin-4 (IL-4), IL-5, transforming growth factor-β (TGF-β) and histamine were significantly reduced in the MCGP sensitized group, the levels of tumor necrosis factor-α (TNF-α) were significantly increased, and the serum levels of specific immunoglobulin E (sIgE), sIgG1, and sIgG2a of peanut were significantly decreased. The binding ability of Ara h 1 and Ara h 2 to specific antibodies was inhibited after they were mixed with CGMP, respectively. Subsequently, the existence of secondary bonds between CGMP and Ara h 1 and Ara h 2 ( salt bridges, hydrogen bonds, van der Waals forces) was found, and the ratio of α-helix to β-folding of Ara h 2 in MCGP was altered. Conclusion CGMP has the ability to modify the structure of Ara h 2, inhibit sIgE and sIgG binding to both Ara h 1 and Ara h 2, and reduce the immunoreactivity of some peanut allergens.