拟穴青蟹原肌球蛋白抗原表位适配体小肽的筛选与鉴定

目的筛选对拟穴青蟹过敏原原肌球蛋白(tropomyosin,TM)抗原表位具有特异性结合能力的适配体小肽,并鉴定适配体小肽对TM的免疫结合活性的抑制作用。方法采用ExPASy peptide cutter软件预测TM分子中胰蛋白酶酶切位点,结合TM线性表位设计反义小肽,经AutoDock 4.0软件模拟分子对接,筛选得到适配体小肽。采用抑制性ELISA的方法,检测筛选的适配体小肽对TM与特异性IgG抗体结合活性的抑制作用。结果 TM氨基酸序列中有25个胰蛋白酶酶切位点,设计TM的31条反义小肽,利用分子对接筛选得到12个适配体小肽。抑制性ELISA结果显示,12条适配体小肽均能明显抑制TM与IgG抗体的特异性结合,其中适配体小肽5抑制能力最强,其抑制率为36.2%。结论通过分子对接筛选得到能明显抑制TM免疫结合活性的适配体小肽,为降低TM致敏性的研究提供理论参考。

Screening and identification of peptide aptamer targeting tropomyosin epitope from mud crab

Objective To screen the peptide aptamers that can specifically bind with tropomyosin (TM) epitopes, and to identify the inhibition ability of IgG reactivity of TM by these peptide aptamers. Methods ExPASy peptide cutter program was used to predict the trypsin cutting sites of TM, the antisense peptides were designed basing on the linear epitopes and trypsin cutting sites, and then screened by AutoDock 4.0 program. The inhibition ELISA was applied to detect the inhibitory effect of synthetic aptamer peptides on TM immunobinding activity using TM specific IgG antibody. Results There were 25 trypsin cutting sites of TM, 31 antisense peptides were designed, and then 12 peptide aptamers were screened by molecular docking. Shown from the results of inhibition ELISA, all the 12 peptide aptamers were able to obviously inhibit the IgG-binding activity of TM, especially peptide aptamer 5, with the inhibition rate of about 36.2%. Conclusion The aptamer peptides screened by molecular docking can obviously inhibit the immunobinding activity of TM, in order to provide theoretical references for the study on reducing TM allergenicity.