Abstract:

In order to construct the plasmid of hlL-2/IFN-γ chimeric gene and screen high-level expressing bacteria,hlL-2/IFN-γ chimeric gene amlzIlifted by PCR with specific primers was cloned into NcoⅠ/Hindn Ⅲ sites of pPROEX HTb plasmid vector,and the recombinant was screened by means of double enzyme digestion and sequencing.The proteins expressed by recombinant E.coli Top10 F’/[hlL-2/IFN-γ ]were analyzed with SDS-PAGE,and tested its antigenecity and biological activity.thus successfully constructing the plasmid.After optimizing the expression conditions.the recombinant strain expresses the target fusion protein with a relative molecular mass of 34 ku and comprises 30% of the total bacteria protein.The results of EHSA and Western-blot analyses indicate that the recombinant strain can specially combine with anti-IFN-γ- antibody.Moreover,the results of activity measuration indicate that the activities of lL-2 and IFN-γ respectively achieve 1.7×10⁷ U/mg and 3.2×10⁶U/mg.

Key words: hlL-2, IFN-&gamma, chimeric gene, expression, E.coli