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.