中国生物工程杂志

The gene of human Islet neogenesis associated protein (INGAP）was amplified with RT-PCR and cloned into prokaryotic expression vector pET22b(+). INGAP was expressed in the E.coli BL21(DE3) and purified by affinity chromatography and gel filtration chromatography. The inclusion bodies of the expressed protein were extracted and dissolved in 8mol/L. The heparin Agrose affinity chromatography was used to separated the desired protein, and the further purified protein was obtained by the Superdex75 the gel filtration chromatography. The purified INGAP protein immune the rabbits by injection,and the polyclonal antibody against INGAP protein was prepared. The immunological activity of expressed and purified LexA protein was detected by ELISA , and Western blot. The result showed that the INGAP was accounted for about 40 % of the total bacteria protein. The final purity of the INGAP was 98.81%, which was determined by the HPLC. The expressed and purified LexA protein had satisfactory immunological activity, which was confirmed by immunodiffusion and ELISA