Expression and Ni-NTA-Agarose Purification of Recombinant Hepatitis C Virus E2 Ectodomain Produced in a Baculovirus Expression System

In this protocol, we describe the production and purification of the ectodomain of the E2(661) envelope protein (amino acids 384-661) of the Hepatitis C virus, which plays a fundamental role in the entry of the virus into the host cell. This protein has been expressed in both prokaryotic and eukaryotic systems but in small quantities or without native protein characteristics. In our case, we use the Baculovirus expression system in insect cells. E2(661) is secreted into the extracellular medium and purified by means of affinity chromatography a Ni-NTA-column because the protein has a tag of six histidines at its amino terminal end. The purified protein possesses a native-like conformation and it is produced in large quantities, around 5-6 mg per liter.