Expression, Purification, and Characterization of Humanized Anti-HBs Fab Fragment

抄録

Anti-HBs Fab fragment has considerable potential for use in the prevention and treatment of liver diseases by HBV. Here we established a high-level expression system to directly produce anti-HBs Fab fragment in Pichia pastoris. This was achieved by cointegration of the genes encoding the heavy and light chains both under the genome of the yeast cells. The Fab fragment was efficiently secreted into medium at a concentration of 50mg/liter. The authenticity of the Fab fragment was confirmed by immunoblot analysis, which yielded one band of _??_50 kDa under nonreducing conditions and two bands of _??_28 kDa under reducing conditions. The anti-HBs Fab fragment was prepared with a purity of 95% by affinity chromatography. The affinity activity of the recombinant Fab was detected by ELISA, which indicated that 1mg of recombinant Fab was equivalent to 40 IU HBIG (20 IU/mg). The results demonstrated that the recombinant Fab fragment could sufficiently neutralize the HBsAg.