Production of SV40 Proteins in Insect Cells and In Vitro Packaging of Virions and Pseudovirions

The use of insect cells and lytic baculovirus for expression of biologically active mammalian proteins has been the method of choice of many investigators. Although prokaryotic expression systems provide higher yields and are technically simpler to use, obtaining biologically active eukaryotic proteins in these systems can be problematic. Posttranslational modifications such as glycosylation and phosphorylation do not occur in prokaryotic systems owing to the lack of enzymatic machinery. On the other hand, insect cells provide an appropriate environment for posttranslational modifications and lead to proper folding and correct assembly of recombinant proteins (1 ).