猪流行性腹泻病毒S蛋白胞内区线性B细胞表位最小基序鉴定

背景] S蛋白是猪流行性腹泻病毒（Porcine Epidemic Diarrhea Virus，PEDV）的主要结构蛋白和免疫原性蛋白，在前期的研究中，本课题组在S蛋白的胞内区鉴定到2个包含线性B细胞表位的短肽。目的] 鉴定PEDV S蛋白胞内区线性B细胞表位的最小基序。方法] 原核表达2个短肽的每次后移1个氨基酸的系列8肽，以兔抗S蛋白血清为一抗，通过Western Blot筛选阳性反应8肽，鉴定S蛋白胞内区线性B细胞表位的最小基序。结果] S蛋白胞内区的2个包含线性B细胞表位的短肽共享一个表位，该表位的最小基序为¹³⁷¹QPYE¹³⁷⁴。同源性分析显示该B细胞表位基序为保守性表位。结论] 确定了S蛋白胞内区线性B细胞表位的最小基序为¹³⁷¹QPYE¹³⁷⁴；S蛋白抗原表位的鉴定有助于提高对其结构和功能的理解。

Identification of minimal motif of linear B cell epitope on the cytoplasmic domain of porcine epidemic diarrhea virus S protein

Background] S protein is the main structural and immunogenic protein of PEDV. In our previous work, two linear B cell epitopes (BCE) containing short peptides were identified in the cytoplasmic domain of S protein. Objective] To identify the minimal motif of the linear BCE were identified in the cytoplasmic domain of PEDV S protein. Methods] Serial 8-mers, advancing one aa once on the short peptide, were prokaryotically expressed. Positive 8-mers were identified by Western Blot using rabbit anti-S serum as the primary antibody and the minimal motif of the linear BCE was identified within the cytoplasmic domain of S protein. Results] The two short peptides within the cytoplasmic domain of S protein contained the same epitope, and the minimum motif of the epitope was ¹³⁷¹QPYE¹³⁷⁴. Homologous analysis showed that the BCE motif was conserved. Conclusion] The minimum motif of the BCE within the cytoplasmic domain of S protein was determined as ¹³⁷¹QPYE¹³⁷⁴. Identification of antigen epitope on S protein helps to improve the understanding of its structure and function.