High-level Expression and Purification of Active Human FGF-2 in Escherichia coli by Codon and Culture Condition Optimization

BACKGROUND Basic fibroblast growth factor (bFGF) is a member of a highly conserved superfamily of proteins that are involved in cell proliferation, differentiation, and migration. OBJECTIVES The objective of this study was to overexpress and purify the high-level active human bFGF in Escherichia coli (E. coli). MATERIALS AND METHODS This experimental study was conducted in the Islamic Republic of Iran. After codon optimization and gene synthesis, the optimized FGF-2 gene was subcloned into plasmid pET-32a. pET32-FGF-2 was transformed into E. coli BL21 for expression. The cultivation parameters were optimized to produce a high yield of FGF-2. RESULTS The optimal conditions were determined as follows: cultivation at 37°C in TB medium, with 1 mM isopropyl-β-D-thiogalactopyranoside (IPTG), followed by post-induction expression for 6 h. Under the abovementioned conditions, the expression volumetric productivity of FGF-2 reached 1.48 g/L. CONCLUSIONS A fusion tag from the pET32 expression plasmid permits the recovery of the recombinant fusion FGF-2 from E. coli, without affecting its biological activity.