PURIFICATION OF A RECOMBINANT PROTEIN PRODUCED IN A BACULOVIRUS EXPRESSION SYSTEM BY IMMOBILIZED METAL AFFINITY-CHROMATOGRAPHY

Over the past 10 years, the baculovirus-insect cell system has become a powerful and versatile tool for the expression of a variety of heter ologous proteins. In order to simplify separation of a cloned protein from the baculovirus-insect expression system, we have cloned a gene e ncoding for the protein of interest, a structural protein (VP2) of a s train (E/DEL) of infectious bursal disease virus (IBDV), with a metal ion binding site (His)(5) at its C-terminus. This chimeric protein (VP 2H) has been expressed and one-step affinity purified with immobilized metal ions (Ni+2). With antigen capture-enzyme-linked immunosorbent a ssay (AC-ELISA), we determined that the conformation of this chimeric protein was no different from the recombinant wild-type VP2 protein. H owever, the two proteins (VP2 and VP2H) can be distinguished and resol ved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS- PAGE) and detected immunologically following Western blotting. (C) 199 4 John Wiley and Sons, Inc.