柑橘PGIP的B细胞抗原表位分析和原核表达

柑橘是重要的经济园艺植物，但是部分人群在食用柑橘后会造成过敏现象，其中多聚半乳糖醛酸酶抑制蛋白（PGIP）是柑橘中重要的过敏原。本文利用Jameson-Wolf法、Kyte-Doolittle法、Emini法和Karplus-Schulz法对柑橘过敏原蛋白PGIP的抗原指数、亲水性、蛋白表面可及性及柔韧性进行分析，通过构建PET-28 a-PGIP载体转移到大肠杆菌(Escherichia coli)中进行原核表达。结果表明：当PGIP二级结构是β-转角和无规则卷曲，同时氨基酸序列的抗原指数>0、柔韧性>0、亲水性>0和蛋白表面可及性>1时的氨基酸时，过敏原蛋白PGIP的B细胞表位结合氨基酸的序列区域是在19~22、37~41、49~52、68~69、117~120、163~164、173~177、221~226、236~240。通过分析氨基酸的区域及原核表达，为寻找柑橘过敏原蛋白PGIP的B细胞抗原表位的最佳优势区域提供支持，同时也为消除柑橘过敏原蛋白PGIP对人体的影响的进一步研究提供理论基础。
Citrus is an important horticulture. However consumption of citrus fruits could cause allergen for some people. With the method of Jameson-Wolf, Kyte-Doolittle, Emini and Karplus-Schulz, the antigenicity, hydrophilicity, protein surface accessibility and flexibility of citrus allergen protein PGIP (polygalacturonase inhibitor protein) were predicted. Meanwhile PET-28 a-PGIP vector was constructed, and then transfer to Escherichia coli. The target gene was induced and expressed. The results showed: When the secondary structure of amino acid was β-angle and irregular curl, the antigen index>0, the flexibility>0, the hydrophilicity>0, the protein surface accessibility>1 amino acid region, the sequences of the B cell epitope binding amino acid were 19~22, 37~41, 49~52, 68~69, 117~120, 163~164, 173~177, 221~226, 236~240. By estimating the amino acid region, it provides support for finding the best possible region of the B cell epitope of citrus allergen protein PGIP, and also provides a theoretical basis for the further study of citrus allergen protein PGIP.