[Optimization of Prokaryotic Expression Conditions of Human β2-microglobulin in E. Coli and Its Purification]

To obtain recombinant human β2-microglobulin (rhβ2M) with properties of good solubility and high purity from E. coli, prokaryotic expression conditions were optimized and protein purification was performed in this study. After testing the effect of different IPTG concentrations, temperatures and induction times on the production of rhβ2M, the optimum expression conditions were determined, i. e. joining IPTG to final concentration being 0.8 mmol/L and inducing time 6 h and at temperature of 25 degrees C. Under the optimum induction conditions, the ratio of soluble rhβ2M to soluble bacterial protein was 63.7%. After purified by Ni Sepharose 6 Fast Flow, the purity of rhβ2M achieved a greater value of 95%. Western blot analysis revealed that rhβ2M possessed the antigen property that specifically interacted with anti-β2M antibody.