中文摘要：

为获得具有无乳链球菌膜表面相关蛋白sip和磷酸甘油激酶pgk双重活性的融合蛋白,探讨其作为无乳链球菌亚单位疫苗候选抗原的可行性。根据GenBank中已发表的无乳链球菌sip、pgk基因的核苷酸序列,设计合成4条引物,通过重叠PCR技术将2个基因主要抗原区域进行融合表达;在2个基因连接处引入45bp连接肽的核苷酸序列;重组蛋白通过pET30a（＋）载体及BL21表达菌实现原核表达,表达的蛋白大小约为47 000;Western blot检测表明,重组蛋白可被无乳链球菌多抗识别,具有较好地免疫生物学活性。本研究为奶牛乳腺炎无乳链球菌亚单位疫苗的研发提供了一定的理论依据。

英文摘要：

In order to get the fusion protein with the bioactivities of both surface immunogenic protein and phospho glycerate kinase and to explore the feasibility of the fusion protein as immunoadjuvant.Based on the reported sipand pgk gene nucleotide sequences of Streptococcus agalactiae,four primers were designed to get a fusion gens of sipand pgk by overlap PCR.Inserted a 45 bp size of linker peptide between the two genes,then the fusion gene was expressed by pET30a（＋）expression vector in BL21 E.coli.The interested protein can be identified by polyclonal antibody of Streptococcus agalactiae.This study lays a foundation for the functional study of bovine mastitis Streptococcus agalactiae sip/pgk fusion protein.