Optimization and High Level Production of Recombinant Synthetic Streptokinase in E. coli Using Response Surface Methodology

Streptokinase (SK) is an extracellular protein comprising 414 amino acids with considerable clinical importance as a commonly used thrombolytic agent. Due to its wide spread application and clinical importance designing more efficient SK production platforms worth investigation. In this regard, a synthetic SK gene was optimized and cloned in to pET21b plasmid for periplasmic expression. Response surface methodology was used to design a total of 20 experiments for optimization of IPTG concentration, post-induction period, and cell density of induction (OD600). The optimum levels of the selected parameters were successfully determined to be 0.28 mM for IPTG concentration, 9.889 H for post induction period, and 3.40768 for cell density (OD600). These settings result in 4.14fold increase in SK production rate of optimum expression conditions (7663 IU/mL) in comparison to the primary expression conditions (1853 IU/mL). Achieving higher yields of SK production in shake flask could lead to more cost effective industrial production of this drug which is the ultimate aim of SK production studies.