MAGE-A家族抗原共同B细胞表位预测分析

Comprehensive mapping of common immunodominant B-cell epitopes of MAGE-A subfamily

目的：预测和筛选黑色素瘤抗原A（MAGE-A）家族抗原的共同B细胞表位。方法：以MAGE-A1的全长氨基酸序列为基础,利用生物信息学软件,采用Hopp＆Woods的亲水性方案、Zimmerman极性参数和Jameson-Wolf抗原指数方案和Emini表面可及性方案等,结合MAGE-A1的二级结构与其柔性区域及跨膜区域对MAGE-A1的优势B表位区段进行综合分析,进一步运用抗原指数分析预测MAGE-A1的B细胞表位,并将其与MAGE-A家族中其他成员（MAGE-A2至A12）进行比对,以预测MAGE-A家族抗原的共同B细胞表位。结果：MAGE-A1的全长为309个氨基酸,相对分子质量为46 kDa,为可溶性蛋白。经综合分析,其B细胞优势表位可能存在于氨基酸序列N端的9~14,84~88,118~124,160~165,208~214,233~240区段;经与MAGE-A家族中其他成员的氨基酸序列比对,MAGE-A1的9~14,84~88,118~124及233~240区段,即HCKPEE,EEEGP,RAREPVTK,GEPRKLLT肽段可能为MAGE-A家族抗原共同B细胞优势表位。结论：利用生物信息学预测发现MAGE-A1的优势B细胞表位中,9~14,84~88,118~124及233~240区段可能为MAGE-A家族抗原的共同B细胞表位,可为表位疫苗的研制等提供理论依据。

Objective： To predict and screen the common B-cell epitopes of the melanoma antigen A（MAGE- A） subfamily. Methods： Base on the full-length amino acid sequence of the MAGE-A1, the B-cell epitopes of the MAGE-A1 protein was predicted by bioinformatics software, including the hydrophilic plot technique, polarity parameters, surface probability, antigenic index, and the secondary structure, along with its flexible regions and transmembrane region analysis, then antigenic index calculation was further taken as a standard to determine target epitopes. The amino acid sequence alignment of the predicting B epitopes of MAGE-A1 was blasted with the remain members of MAGE-A family（MAGE-A2 to A12） to predict the common B-cell epitope of MAGE-A subfamily. Results： The MAGE-A1 gene codes for a 46 kDa soluble protein consisted of 309 AA. The predicted B-cell epitopes of the MAGE-A1 might exist N-terminal of amino acid sequence： 9~14, 84~88, 118~124, 160~165, 208~214, 233~240. Four of them, that is, the peptides about 9~14（HCKPEE）, 84~88（EEEGP）, 118~124（RAREPVTK） and 233~240（GEPRKLLT） might be the common B cell epitopes of MAGE-A subfamily. Conclusion： Bioinformatics prediction provides a theoretical basis for the common B cell epitopes of MAGE-A subfamily.