N-linked Glycosylated HN Protein of NDV Strain AF2240 Expressed in Baculovirus-Infected Sf9 Cells

摘要

The recombinant baculovirus (recHNAF2240) carrying the haemagglutinin-neuraminidase (HN) gene of Newcastle disease virus (NDV) strain AF2240 was expressed in Spodoptera frugiperda (Sf9) cells. A time course study by means of pulse-labelled [ super(35)S] methionine of the HN glycoprotein in baculovirus-infected cells showed that the protein was susceptible to tunicamycin treatment indicating that the expressed protein is glycosylated and is N-linked by nature. Unglycosylated HN-expressed protein appears to be 3-fold higher than the glycosylated form. The intra-cellular recombinant virus expression was most obvious at 48 h post infection (h.p.i.) and this is in agreement with the very late expression driven by the polyhedrin promoter of Autographa californica nuclear polyhedrosis virus (AcNPV).