Bacterial expression and purification of biologically active human TFF3.

A glutathione S-transferase (GST) fusion protein expression system for the production and purification of recombinant human trefoil factor family-domain peptide 3 (hTFF3) was established. The hTFF3 gene, prepared by PCR, was cloned into a pBluescript KS(+) plasmid, and inserted into a pGEX-4T-1 GST fusion vector. The GST-hTFF3 fusion protein was expressed in Escherichia coli, and hTFF3 was purified with Glutathione Sepharose 4B affinity chromatography, yielding about 3-4 mg of pure hTFF3 in one liter of culture broth. The biological activity of purified hTFF3 was tested in two previously reported rat gastric ulcer models. Oral administration of recombinant hTFF3 has a dose dependent protective effect against ethanol-induced or pylorus ligation-induced gastric mucosa injury in rat, which indicates that our recombinant hTFF3 is biologically active.