Pilot-scale expression， purification， and bioactivity of recombinant human TGF-β from Escherichia coli.

TGF-β， a subtype of transforming growth factor-β (TGF-β)， is essential to various biological processes， including endoderm development， organogenesis， epithelial hyperplasia， synthesis of extracellular matrix， and immune response. Essentially， TGF-β engages the TGF-β/Smad signaling pathway to stimulate mesenchymal lineage cells， inhibit epithelial or neuroectodermal lineage cells， and regulate repair， remodeling， and potential scarring after cutaneous wounding. We have now expressed recombinant human TGF-β in Escherichia coli Origami B (DE3)， with yield 300 ± 17 mg/L monomeric protein at pilot scale. Identity was confirmed by western blot and HPLC-based peptide mapping. After purification and refolding， dimeric proteins were found to induce chondro-related genes in adipose-derived stem cells， and to suppress scarring in injured rabbit ears. Thus， the recombinant protein has excellent potential for medical applications.