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目的确定肠道病毒71型(enterovirus 71,EV71)H3-TY株衣壳蛋白VP1~VP3的优势线性B细胞抗原决定簇位点。方法用生物信息学软件DNAStar中的Protean程序分析EV71 H3-TY株衣壳蛋白VP1~VP3氨基酸序列的亲水性、抗原性和表面可能性,预测出包含潜在线性B细胞抗原决定簇位点的区段,并计算各区段上述指数的加权平均值。人工合成相应的多肽片段,用多肽-酶联免疫吸附检测(多肽-ELISA)检测其与明确感染EV71的临床病患儿童血清的阳性反应与否和程度。结果根据抗原性强、亲水性强和表面性好的要求,共预测出15个可能的线性B细胞抗原决定簇位点。相应的人工合成多肽与感染EV71的临床病患儿童血清均呈现为阳性反应但程度不同,其中免疫显性最高的肽段为包含VP1氨基酸残基208~222位的VP1D。结论成功预测并用实验证实了EV71 H3-TY株衣壳蛋白VP1~VP3的优势线性B细胞抗原决定簇位点,有助于揭示EV71衣壳蛋白抗原特异性的分子基础。
Objective To determine the predominant linear B cell epitopes of capsid proteins VP1 ~ VP3 of enterovirus 71 (EV71) H3-TY strain. Methods The hydrophilicity, antigenicity and surface potential of the VP1 ~ VP3 amino acid sequences of the capsid protein of EV71 H3-TY strain were analyzed using Protean program of DNAStar, a bioinformatics software, and the predicted sites containing potential linear B cell epitopes Section and calculate the weighted average of the above indices in each section. The corresponding polypeptide fragments were synthesized by artificial ELISA, and the detection of the positive reaction to the serum of clinical children with EV71 infection by polypeptide-ELISA. Results According to the requirements of strong antigenicity, strong hydrophilicity and good surface appearance, 15 possible linear B-cell epitopes were predicted. The corresponding artificial synthetic peptides and sera from clinical patients infected with EV71 all showed positive reaction but with different degrees. The most immunodominant peptide was VP1D containing amino acid residues 208-222 of VP1. Conclusion The predominant linear B-cell epitopes of capsid protein VP1-VP3 of EV71 H3-TY strain were successfully predicted and validated by experiments, which is helpful to reveal the molecular basis of antigen specificity of EV71 capsid protein.