PLASMID, TRANSFORMED ZOOBLAST AND PRODUCTION OF FOREIGN PROTEIN

摘要

PURPOSE:To efficiently mass produce foreign protein by culturing zooblasts transformed with a specific plasmid. CONSTITUTION:A DNA encoding foreign protein, having an upper stream part to which a promoter of controlling manifestation with zooblasts, is integrated with a DNA encoding dihydrofolate reductase (DHFR) having an upper stream part to which urokinase (UK) promoter is added to give a plasmid (A). Then zooblasts such as Chinese hamster ovarian cells: ATCC CCL61 is transformed with the component A by calcium phosphate precipitation method to give a transformant (B). Then the transformant B is selectively cultured in a medium containing methotrexate (MTX) to give a transformant (C) having high manifestation amplification degree. Then the strain C is cultured to produce foreign protein.