Expression and Purification of Soluble Human Hepassocin in Escherichia coli

Objective:To express and purify soluble human Hepassocin in prokaryotic expression system. Methods:The gene of human Hepassocin was cloned into expression vector pET40b(+),and DsbC-Hepassocin fusion protein from transformed E.coli BL21 (DE3) after induction by 0.1 mmol / L IPTG at 28℃ for 6 hours was purified using Ni-NTA affinity chromatography column. Then the fusion protein was digested by enterokinase to remove extra exogenous amino acid residues followed by purification with Ni-NTA affinity chromatography again and ultrafiltration. The ultimate purified product was characterized by Western blot. Results:The recombinant prokaryotic expression vector pET40b-Hepassocin was constructed successfully. Soluble and high-purity protein about 32 kD was obtained after twice Ni-NTA affinity chromatography and enterokinase digestion. Then it was confirmed by Western blot with specific antibody for Hepassocin. Conclusion:It laid a foundation for preparation of monoclonal antibody and research of the functions of Hepassocin in future.