Design-improved stable fusion precursor porcine diarrhea virus S protein and application thereof

The invention discloses design improvement on a spinous process S protein of a porcine epidemic diarrhea virus on the basis of a protein three-dimensional structure, and amino acid residues at specific sites of the spinous process S protein are subjected to mutation of proline, cysteine and the like and shear substitution, so that the stability of trimer conformation and antigen of an S protein fusion precursor is enhanced; the expression quantity and the uniformity of the recombinant protein are improved. When the vaccine is used as a vaccine or a vaccine component, the immunogenicity is increased, and an immunized animal can be induced to generate a high-level neutralizing antibody. The invention also comprises a vector for coding and expressing the improved S protein mutant, and also can be a composition containing the recombinant protein and application thereof. 本申请公开了在蛋白质三维结构基础上对猪流行性腹泻病毒的棘突S蛋白进行的设计改良，通过对其特定位点的氨基酸残基进行脯氨酸、半胱氨酸等突变以及剪切替换，增强了S蛋白融合前体三聚体构象和抗原的稳定性，提高了重组蛋白的表达量和均一性。做为疫苗或者疫苗组分使用时免疫原性增加，能够诱导受免疫动物产生较