BV/ODV-E26: An Envelope Protein for Simple Purification of Fusion Foreign Protein in Baculovirus Expression System

The baculovirus expression system (BES) is widely used to express the foreign proteins. However, purification of expression products is not only complex and expensive, but also be detracted from high throughput: Here, we investigated the envelope protein BV/ODV-E26 from Autographa californica multiple nucleopolyherovirus (AcMNPV) and Bombyx mori NPV (BmNPV), with fusion to a marker protein- Enhanced green fluorescent protein (EGFP) at C-terminal, respectively, and expression in Spodoptera frugiperda (SF9) and B. mori (BmN) cells. Fluorescent particles were observed under fluorescent microscope at 72 h post infection (p.i.). The results indicated that the fusion protein (Da26-EGFP) can be bound to the occluded-bodies (OBs). According to purifying Da26-EGFP particles by ultrasonic disruption and differential centrifugations, these proteins were still binding to the OBs. Furthermore, by treatment with 1 % DTT (w/v) and 2 % SDS (w/v), the fusion proteins could not be eluted from OBs. It indicated that using baculovirus BV/ODV-E26 as fusion protein could make it easy and rapid to purify the foreign proteins by differential centrifugation.