title: Characterization of a truncated soluble form of the baculovirus (AcMNPV) major envelope protein Gp64.
abstract: A truncated tagged form of the Autographica californica multiple nuclear polyhedrosis virus major surface glycoprotein, gp64, has been expressed using the baculovirus expression system and purified to homogeneity by immune-affinity chromatography. The protein, which is responsible for virus-cell fusion, was a trimer in solution and retained this oligomeric form at pH 5, the pH of fusion. Circular dichroism spectroscopy indicated a protein with mixed alpha-helix and beta-sheet content that did not undergo significant change at pH 5. The soluble protein showed no detectable binding to the insect cell surface. These data suggest a novel fusion mechanism for gp64 compared to models such as the influenza HA. In a crystal screen, deglycosylated, but not glycosylated, preparations of the protein were found to form small needle-shaped crystals that may form the basis of a dedicated structural study.
authors.affiliation: NERC Institute of Virology, Mansfield Road, Oxford OX1 3SR, United Kingdom.
authors.forename: Weixian
authors.initials: W
authors.lastname: Lu
authors.forename: Susan D
authors.initials: SD
authors.lastname: Chapple
authors.forename: Olga
authors.initials: O
authors.lastname: Lissini
authors.forename: Ian M
authors.initials: IM
authors.lastname: Jones
mesh_terms: D016367:Baculoviridae / Q000737:chemistry; D002846:Chromatography, Affinity; D002942:Circular Dichroism; D015202:Protein Engineering; D017510:Protein Folding; D012995:Solubility; D014760:Viral Fusion Proteins / Q000737:chemistry*
chemical_list: D014760:Viral Fusion Proteins