Enhanced Expression of Recombinant Activin A in Escherichia coli by Optimization of Induction Parameters

Activin A is a member of the transforming growth factor β super family. Because of its extensive clinical usages, its recombinant production is beneficial. In this study, activin A was expressed in E. coli using the pET 21a expression vector. The optimization of the activin A production in E. coli was done by using the response surface methodology (RSM). At this stage, the effect of IPTG and lactose concentration as inducers on protein production was investigated. The effect of different post-induction time and temperature on protein production was then studied in two strains of E. coli (BL21(DE3) and BL21(DE3) plysS). For enhanced expression, the optimum IPTG and lactose concentrations were 1.5 mM and 0% W/V respectively. In the DE3 strain, the optimum post-induction time and temperature were 10 hours and 30°C respectively while in DE3 (plysS) these were 4 hours and 35°C respectively .