Verfahren zur Synthese von loeslichen, rekombinanten Proteinen aus Bakterienzellen

Production of soluble recombinant protein (A) in bacteria that carry a plasmid containing the complete gene downstream of a promoter comprises: (a) growing the cells to optical density (OD) 0.4-0.6 at 600 nm; (b) cooling the culture to 20-26 deg. C over 15-40 min; (c) inducing synthesis by adding 10-55 mu M inducer (I); (d) carrying out the induction step at 20-26 deg. C for 3.5-6.5 hr; (e) separating the resulting cell pellet, in a buffer, into inclusion bodies (IB) and a protein-containing supernatant, and (f) isolating (A) exclusively from the supernatant. USE - The method is specified for production of interferon- gamma (IFN- gamma ) or its variants, including truncated and disulphide-bridged forms. ADVANTAGE - The method provides much increased yields compared with known methods, typically for IFN- gamma 50% against 10%, without the need for refolding of (A) to active form (refolding takes place in the bacterium). After induction, 20-60% of (A) is in soluble form and the rest in I B, compare 95% in IB in known methods where induction is at higher temperature. Soluble IFN- gamma is hardly antigenic, unlike material isolated from IB.