Evaluation of Phycocyanin Promoter Function in Bacteria by Investigating the Expression of HBsAg

MANY items affect the yields of every recombinant protein production. Promoters are one of the key regulatory elements which control the level of recombinant protein expression in the host. Although in some studies (Hepatitis B Surface Antigen) HBsAg was cloned in E. coli, in many of them common promoters were used. In this study two co-vectors (PHK and PHGK) were designed and used. Both of them were shuttle types based on phycocyanin-specific promoter and each was a combination of two types of vectors: a plasmid and a transposon. ELISA results, in line with Western blot results, showed the ability of phycocyanin promoter as well as revealed the expression level of HBsAg in transgenes from the Top10 PHK vector is higher than those of Top10 PHGK. The expression of HBsAg under the phycocyanin promoter in the present study is 7.5 mu g/lit. In the current study as a pilot step, our attitude and objective of bacteria expression are to evaluate the function of the phycocyanin promoter based on the HBsAg gene. Due to the nature of the shuttle vector, in continuation of the present study to reduce the non-responsive populations, high antigen expression, meet the need for renewal and, other benefits, expression of HBsAg in other than bacterial host is under investigation.