[Study on high-expression of soluble hbFGF in Escherichia coli]

The formation of inclusion body is correlated with the overexpression of foreign proteins in Escherichia coli. Controlling of the expression level seems to be critical to increase the soluble component. With the prerequisite of no alterations in amino acid sequence, the wobble bases of the first 3 codons downstream the initiation codon ATG of a hbFGF high-expression mutation, established previously, were changed into the bases of the native hbFGF sequences. Seven primers were synthesized for retro-mutations, after PCR were undertaken, the products were cloned into pET-3c, and recombinants were transformed into BL21 (DE3) plysS for expression. One strain with high solubility and bioactivity were identified, indicating that restriction of the expression level of recombinant protein is helpful for high-solubility.