Expression of the Severe Acute Respiratory Syndrome Coronavirus 3a Protein and the Assembly of Coronavirus-Like Particles in the Baculovirus Expressio

The Bac-to-Bac Baculovirus expression system was used to generate a recombinant baculovirus capable of expressing the severe acute respiratory syndrome (SARS)-coronavirus (CoV) 3a protein. Using the same expression system, two structural proteins, membrane (M) and envelope (E), were co-expressed to form SARS-CoV virus-like particles (VLPs) within an insect cell. Expression of viral proteins was confirmed by Western blot analysis and the formation of VLPs was studied by transmission electron microscopy.