Objective: To purify and identify recombinant antigen B of hydatid disease.
Methods: The recombinant plasmid pMalc2x-AgB was expressed in E. coli JM109. The fusion protein rAgB-MBP was made up of antigen B and MBP (maltose binding protein) which was designed to absorb the antigen B onto the amylose column. In order to get the pure antigen as the probe for selecting phage displayed antibody library, factor Xa protease was used to digest the fusion protein rAgB-MBP so that MBP was cut off from the special cleavage site. Flowing through the amylose resin column and hydroxyapatite column, rAgB was purified by the method of affinity chromatography. Its specificity was proved by patient sera with Western blotting.
Results: The recombinant antigen B was Mr 12 000, and it showed the capability to combine with the specific antibody.
Conclusion: Hydatid disease antigen B can be produced by molecular method and applied in monoclonal antibody production and phage antibody library scanning.