鸡蛋致敏原溶菌酶的B细胞IgG线性表位定位

Identification of IgG-binding epitope of linear B-cell in egg allergen lysozyme

中文关键词:  鸡蛋致敏原  溶菌酶  IgG  线性表位  生物信息学  斑点杂交法

英文关键词:egg allergen  lysozyme  IgG  linear epitope  bioinformatics  dot-blot hybridization method

中文摘要:

      目的 探究鸡蛋致敏原溶菌酶的B细胞线性表位。方法 先使用DNAStar、Immunomedicine Group、BepiPred、Bcepred和ABCpred对其氨基酸序列分析, 预测其潜在的B细胞线性表位, 同时合成覆盖其完整氨基酸序列的重叠肽, 然后利用斑点杂交法筛选出与抗溶菌酶兔血清IgG特异性结合的多肽片段, 从而定位出溶菌酶的B细胞IgG线性表位。结果 通过生物信息学工具综合分析预测出了鸡蛋溶菌酶的4个B细胞线性表位, 分别为AA18~21 (DNYR)、AA39~51 (NTQATNRNTDGST)、AA62~78 (WWCNDGRTPGSRNLCNI)、AA109~117 (VAWRNRCKG); 利用dot-blot定位出5个鸡蛋溶菌酶的B细胞IgG线性表位, 分别为AA1~15 (KVFGRCELAAAMKRH)、AA28~30 (WVC)、AA70~78 (PGSRNLCNI)、AA103~117 (NGMNAWVAWRNRCKG)、AA124~126 (IRG)。研究结果表明, 采用生物信息学工具预测的B细胞线性表位与已知的溶菌酶的B细胞IgE线性表位的重合率达75%, 与用dot-blot定位的B细胞IgG线性表位的重合率达40%, 一定程度上证实了利用生物信息学预测致敏原表位的可行性, 但预测结果的准确性仍需进一步验证。结论 本研究确定的溶菌酶B细胞线性表位可为进一步开展溶菌酶的精准检测和低致敏食品等研发工作提供关键的结构信息。

英文摘要:

      Objective To explore the linear B-cell epitopes of egg allergen lysozyme. Methods The DNAStar, Immunomedicine Group, BepiPred, Bcepred and ABCpred were first chosen to analyze the amino acid sequence and forecast the potential linear B-cell epitopes. Moreover, overlapping peptides covering the complete amino acid sequence of lysozyme were synthesised, and then the peptide fragments that can specifically binding to the rabbit sera IgG were identified using dot-blot hybridization method, which was IgG-binding epitope of linear B-cell in lysozyme. Results Four linear B-cell epitopes were predicted by bioinformatics tools, which were AA18-21 (DNYR), AA39-51 (NTQATNRNTDGST), AA62-78 (WWCNDGRTPGSRNLCNI) and AA109-117 (VAWRNRCKG), five IgG-binding epitope of linear B-cell were identified by dot-blot assay, which were AA1-15 (KVFGRCELAAAMKRH), AA28-30 (WVC), AA70-78 (PGSRNLCNI), AA103-117 (NGMNAWVAWRNRCKG), AA124-126 (IRG). The results showed that the coincidence rate of the linear B-cell epitopes predicted by bioinformatics tools was 75% with the known IgE-binding linear epitope of B-cell in lysozyme, and 40% with the IgG-binding epitope of linear B-cell identified by dot-blot, indicated that bioinformatics could be used to predict the allergenic epitope to some extent. Nevertheless, the accuracy of the prediction results needed to be further verified. Conclusion The linear B-cell epitopes of lysozyme determined in this study will provide the key structure information of lysozyme for further accurate detection and the development of hypoallergenic foods.