Subcloning and expression of SO9 gene, Saponaria Officinalis plant in E.coli and investigation of antibody titer in mouse

Introduction: Saponaria officinalis have various saponin isoforms. Saponin is a ribosome-inactivating protein (RIP). The SO9 isoform of saponins depurinates the adenine 4324 in the preserved GAGA sequence resulting in impairment of protein production. In this study, the S09 isoform was expressed in E. coli and its antibody titers were evaluated in Mouse. Methods: The S09 gene was synthesized and isolated from the pUC57-S09 recombinant plasmid using the restriction enzymes BamH1 and Sal1, and then cloned in the expression vector pET28a(+). Expression of the new recombinant protein was induced by IPTG. The recombinant S09 protein was purified by Ni affinity chromatography. The recombinant protein was confirmed through western blotting. The Mouse were vaccinated through intraperitoneal injection of the purified protein and serum IgG titer was measured through ELISA.Results: Subcloning of S09 gene in the pET28a(+) expression vector was confirmed by PCR and enzymatic digestion. The presence of 29 kDa protein band in SDS-PAGE showed the high expression of recombinant protein. The recombinant S09 protein was detected by polyclonal antibody. After injection of the protein to the test groups, the antibody titer was measured by ELISA. Conclusion: The adjuvant property and immunogenicity of the purified recombinant S09 antigen showed that this antibody can be used to detect the presence of S09 in Saponaria officinal is, as a candidate for vaccine, for production of diagnostic kits, and in human cells anticancer studies.