PROCESS FOR PRODUCING RECOMBINANT PROTEIN USING NOVEL FUSION PARTNER

A method for preparing a polypeptide is provided to be used for mass-producing human insulin industrially and be efficiently applicable to produce a recombinant protein such as a growth hormone, a neutrophil proliferation factor, and a bone morphogenetic protein-2(BMP-2). A method for preparing a polypeptide comprises a step of culturing a transgenic microorganism transformed by a gene encoding an A-B type fusion protein is used, wherein A is a fusion partner which is composed of at least 25 amino acids and is a peptide having at least 30% of negative charge consisting of glutamic acid and asparaginic acid, and B is a target protein to be produced. A includes the MKIEEGKL sequence in the end of amino. A method for producing insulin comprises the steps of: (a) preparing a pro-insulin or an analogue thereof using the method above; and (b) subjecting the pro-insulin or the analogue thereof to protease hydrolysis or chemical cleavage. A growth hormone or an analogue thereof is produced by the method for preparing the polypeptide.