Cloning, Expression and Identification of Human Hp cDNA in Escherichia Coli

Objective: To clone, express and identificate human Haptoglobin cDNA in Escherichia coli(E. coli). Methods: Human Hp cDNA was obtained from total RNA isolated from Hela cells by reverse transcription PCR method, then it was inserted into prokaryotic expression vectors pET-32 a and PGEX-4T-1 for the IPTG-induced expression in E. coli BL21, and it was identified by SDS-PAGE and Western blot. Results: The expression plasmid pET-32a-Hp and PGEX-4T-1-Hp were constructed successfully. Western blot analysis showed that fusion protein pET-32a-Hp with 30 kD molecular weight and PGEX-4T-1-Hp with 37 kD expressed in E. coli.The purification of fusion protein was more than 90% after purification using Ni2+-NTA ion exchange resin. Conclusion: Fusion protein human Hp was successfully expressed in E.coli and purified, which settled a foundation for further development of human Hp diagnostic reagents.