Expression of Cytochromes P450 in a Baculovirus System

The baculovirus expression system is a highly effective system for the largescale productron of recombinant proteins in insect cells. The major attraction of baculovn-us as an expression vector system is the virus-encoded polyhedrin and p 10 genes. These genes produce large amounts of polyhedrin and p 10 proteins in virus-infected insect cells in the later stages of the virus-replication cycle. The polyhedrin protein, controlled by the polh promoter, is required m the normal infection cycle to package virus partrcles wrthm occlusron bodies or polyhedra, which protect the virus particles from the environment during the period between mfectton of susceptrble hosts. The function of the p 10 protein is not clear as yet but it is thought to be involved in polyhedra formation and is controlled by the p10 promoter. Polyhedrin and p10 are not required to maintain an infection in cultured cells in vitro. The polyhedrm and p10 genes can be replaced with foreign gene sequences thus enabling expression of recombinant protein from the polyhedrin (polh ) and p10 promoters.