Bovine and goat milk α-casein were very similar in the aspect of nutrition and func-tion ,but they induced different allergen reaction in consumers because of the differences in protein subclass structure and content .The purpose of this paper was to analyze and identify the B cell epitopes by predicting the secondary structure ,hydrophilicity ,antigenicity index , surface accessibility and flexibility of major allergic proteinαs1-casein from cow and goat milk using DNAStar Protean software ,SOPMA and the BepiPred 1 .0 server .Prepared the casein antibody by synthesizing the corresponding epitope peptide sequence and then used an indi-rect ELISA method to identify the immunoreactivity of the synthetic polypeptide .The results showed that the amino acid sequence homology of cow and goat milk αs1-CN was 89% ,but the epitopes were different .The number of epitopes of goat milk was similar compared with cow milk αs1-CN ,but there was a certain overlap between the two epitope regions .The pep-tide fragment P-1037 (26~31 ,LSPEVP) ,P-1040 (140~142 ,EGN ) synthesized by the goat milk αs1-CN and the peptide P-1038 (189~208 ,TDAPSFSDIPNPIGSENSEK ) ,P-1039(99~102 ,EDVP) synthesized by the cow milk αs1-CN had the immunoreactivity ,which provided the basis for the selection of the allergen epitope ,and provided the theoretical basis for the comparison of sensitization and modification of cow and goat milk .%牛羊乳的α-酪蛋白营养功能相似,但蛋白质亚类结构和含量不同,可能是造成其过敏性差异的原因.本文旨在利用生物信息学DNAStar Protean软件、SOPMA以及the BepiPred 1.0服务器对牛羊乳主要过敏蛋白αs1-酪蛋白(Casein,CN)的二级结构、亲水性、抗原指数、表面可及性和柔韧性进行预测,分析鉴定主要B细胞抗原表位.合成相应表位肽段序列,制备酪蛋白抗体,采用间接ELISA法分析验证合成多肽的免疫反应性.结果表明:牛羊乳αs1-CN的氨基酸序列同源性89%,但抗原表位存在差异,与牛乳αs1-CN相比,羊乳抗原表位数目相差不大,但两者抗原表位区域存在一定的包含重叠关系.且羊乳αs1-CN合成肽段P-1037(26~31,LSPEVP)、P-1040(140~142,EGN)和牛乳αs1-CN合成肽段P-1038(189~208,TDAPSFS-DIPNPIGSENSEK)、P-1039(99~102,EDVP)都具有免疫反应性,该结果为过敏原表位的选择提供基础,为牛羊乳过敏原性比较及改性加工提供理论依据.
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