Removal of N-terminal methionine of human interferon α-2b by co-producing with Pyrococcus furiosus methionine aminopeptidase in Escherichia coli

In our previous studies, expression of human interferon alpha-2b gene in Escherichia coli gave three types of polypeptide chains in nearly equimolar ratio. They include molecules with N-terminal methionine, molecules without N-terminal methionine, and molecules with acetylated N-terminal. This heterogeneity is not required in therapeutic applications. In order to improve the removal rate of N-terminus methionine, co-expression of human interferon alpha-2b and methionine aminopeptidase genes was performed in E. coli. The co-expression resulted in production of human interferon alpha-2b with dominance of molecules without N-terminal methionine and very few of them were acetylated at the N-terminus. Our findings contribute significantly to efforts for the production of homogenous therapeutic proteins which represent the exact recombinant replica of their native proteins.