Objective To identify the IgE-binding epitopes in the allergen Der p 1 of main house dust mites, which can be recognized by the specific IgE in the sera from allergic individuals, and obtain a hypoallergen derived from the T-B epitope fused peptide for potential use in specific immunotherapy (SIT). Methods Thirty-one peptides containing 15 amino acids each, which covered the full 222 amino acids of Der p 1 protein sequence, were synthesized on the cellulous membrane by solid-phase peptide (SPOTs) synthesis, with 8 overlapping amino acids between every two neighboring peptides. The membrane bearing the spots of the synthesized peptides were incubated with the allergic serum pools consisting of the sera from 5 allergic individuals. The membrane was then probed with HRP-conjugated anti-human IgE, followed by enhanced chemiluminescence (ECL) for visualization and gray scale analysis of the positive peptide spots. Results Three strong IgE-binding epitopes were identified in the amino acid sequence of Der p 1 molecule, namely Epl (amino acids 85-99), Ep2 (amino acids 106-120) and Ep3 (amino acids 190-204). Conclusion The 3 IgE-binding epitopes (B cell epitopes) identified in Der p 1 confirm the presence of linear epitopes in Der p 1, suggesting the possibility of constructing T/B epitope-fused hypoallergens.%目的 对屋尘螨主要变应原(Der P 1)蛋白分子中与过敏病人血清特异性IgE相结合的表位序列的鉴定.进而获得基于串联表位的小分子低毒过敏原以作为新的免疫治疗剂.方法 采用全蛋白序列重叠扫描法对DerP 1蛋白进行全表位筛选,即合成了覆盖DerP 1全蛋白222个氨基酸的31段各含15个氨基酸的多肽,且相邻肽段间有8个氨基酸的重叠.并将这些肽段按点状同相多肽合成法依顺序合成于纤维膜上.再将该膜与由数份过敏血清组成的血清池孵育,经抗人IgE-HRP二抗结合及X光片显影后对阳性点进行灰度比对及分析.结果 经对X光片阳性点的比对及分析,我们确定出了DerP 1过敏原蛋白中的3个强阳性表位序列.它们是位于第85～99位的氨基酸序列(表位1,Epl),第106～120位的氨基酸序列(表位2,Ep2)及第190～204位的氨基酸序列(表位3,Ep3).结论 我们获得了Der P 1中3个15肽的线性IgE结合表位(B细胞表位)序列.证实了Der P 1分子中存在IgE结合的线性表位.为进一步构建T/B细胞串联表位的小分子低毒过敏原提供了物质基础.
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