ABSTRACT
Objective To construct prokaryotic expression vector of XTP3 gene and induce the expression of fusion protein in E.coli,and prepare XTP3-specific rabbit polyclonal antibody,detect the specificity of the antibody in hepatic carcinoma tissue and normal liver tissue.Methods DNA fragment of XTP3 amplified by PCR was inserted into pET-32a(+) to construct prokaryotic expression vector pET-32a(+)-XTP3.After identified by sequencing,pET-32a(+)-XTP3 was transformed into E.coli BL21 and induced with IPTG.After analyzed by SDS-PAGE and Western blotting,the induced expression product was purified and renatured by Ni+ affinity column chromatography.The purified protein was used to immunize New Zealand rabbits to gain polyclonal antibody,and the polyclonal antibody was then detected by ELISA,immunohistochemistry and Western blotting.Results Prokaryotic expression vector pET-32a(+)-XTP3 was successfully constructed,and the XTP3 fusion protein of about 52kD was highly expressed in E.coli.DS-PAGE showed that the protein product was mainly in inclusion body.The purified protein and polyclonal antibody were obtained successfully.It was manifested by ELISA that the titer of polyclonal antibody was over 1∶128 000.Immunohistochemistry showed that XTP3 antibody presented membrane-positive in hepatic carcinomous tissue.Conclusions The recombinant XTP3 protein and polyclonal antibody have been obtained successfully.These results lay a foundation for studying the immuneogenicity and bionomics of XTP3 protein.