Methods to Improve Baculovirus-Based Protein Production in Insect Cells

Abstract

The Baculovirus Expression Vector System (BEVS) is a vital part of drug discovery research. It is a very efficient and reliable system used to produce recombinant proteins that can be utilized in drug discovery. The system relies on bacmids which are the circular baculovirus genomes with added components for growth in E. coli, including an F’ origin of replication. It is thought that the F’ origin itself is intrinsically unstable and that baculovirus may have a maximum packaging capacity that the F’ origin does not align with (Pijlman, et al., 2003). To investigate this instability, two new strains of baculovirus were generated with large deletions of several sop genes. One strain is referenced as DE143 (deleted delta sopD, sopG, sopH, polyhedrin with helper plasmid) and reliably produced at least one copy of the deleted type. Unlike DE143, there was evidence of wild-type bacmid in association with the deletion mutant in the second strain, DE144 (deletion of sopC and sopAB operon). Both new strains of baculovirus produced mNeonGreen signals similar to the standard bacmid strain, indicating that they are potentially useful for recombinant protein production, and we will continue to investigate the exogenous genes in these strains.