The glycoprotein E2 contains major antigenic determinants and involved in inducing neutralization antibodies.A truncated form of the CSFV glycoprotein E2 was expressed in baculovirus.The signal sequences of E2 gene were replaced with the honeybee melittin signal sequence,allowing efficient entrance into the secretory pathway in insect cell.In addition,the hydrophobic transmembrane anchors at the carboxyl termini of E2 proteins were removed to enable secretion rather than maintenance in the cellular membranes.Recombinant E2 protein was purified from the supernatant of infected cells by employing Ni2+ affinity chromatography.Protein purified was recognized by at least three anti-E2 pig sera and WH211 monoclonal antibody.WH211 monoclonal antibody couldn′t recognize the protein expressed in E.coli,indicating that it retain native structure.Thus,E2 expressed in insect cells can be used as a tool for diagnostic tests as well as obtaining material that could be suitable for X-ray crystallography studies.
