Maximizing the expression of recombinant Kringle 1 (Streptokinase) synthesized in Escherichia coli. Influence of culture and induction conditions

Summary We examined the influence of culture conditions on the production of the recombinant fused protein Kringle 1 (Streptokinase) (K1(SK)) expressed in E. coli under the control of the Ipp-lac promoter. The growth and the protein production were severely inhibited at glucose concentrations higher than 5 g/L. The highest yield of K1(SK) from the soluble extract was obtained using synthetic medium. Concentrations of inducer between 0.1 and 1 mM of IPTG did not significantly affect the production level of K1(SK) or the final cell density. Under optimal conditions the K1(SK) protein was expressed in an intracellular soluble form at about 3–4% of the total cellular protein.