بيان همزمان تركيب چاپرون هاي Gro EL/Tig و tig با رشد فيبروبلاستي بازي انساني در E.coli به منظور كاهش پروتئين هاي نامحلول نوتركيب

Co-expression of two molecular chaperones combinations (Gro EL /Tig) and (Tig) with hbFGF to reduce insolubility of recombinant protein in Escherichia coli

During the production of recombinant protein, hbFGF loses the correct conformation and is deposited into the insoluble form. The aggregates accumulate into inclusion bodies, which are known to be inactive. Protein aggregation is one of the major challenges of recombinant protein production. Therefore, increasing solubility is a primary goal of recombinant protein production. The general strategy for preventing or decreasing aggregation in the host cell is co-expression of molecular chaperones along with the target protein. TF-16, pG-Tf2 and pET-1008 (human basic Fibroblast Growth Factor cDNA inserted to pET-22b) were transformed separately by CaCl2 and heat shock into the E.coli. The chaperones and hbFGF were induced and co-expressed by L-arabinose, tetracycline and IPTG. The soluble and insoluble fraction of hbFGF were separated and then compared by SDS-PAGE, western blotting and ELISA. Our results clearly indicate that trigger factor (TF) could increase solubility of hbFGF, but simultaneous over expression of TF and GroEL promote total hbFGF degradation. However, over expression of TF alone appeared to be sufficient for preventing aggregation of hbFGF but TF and GroEL-GroES play cooperative roles in assisting degradation of hbFGF. It is showed that plasmid TF-16 was able to decrease the insolubility of hbFGF and could increase the soluble fraction.