title: The N terminus of the herpes simplex virus type 1 triplex protein, VP19C, cannot be detected on the surface of the capsid shell by using an antibody (hemagglutinin) epitope tag.
abstract: The herpes simplex virus (HSV) triplex is a complex of three protein subunits, VP19C and a dimer of VP23 that is essential for capsid assembly. We have derived HSV-1 recombinant viruses that contain monomeric red fluorescent protein (mRFP1), a Flu hemagglutinin (HA) epitope, and a six-histidine tag fused to the amino terminus of VP19C. These viruses were capable of growth on Vero cells, indicating that the amino terminus of VP19C could tolerate these fusions. By use of immunoelectron microscopy methods, capsids that express VP19C-mRFP but not VP19C-HA were labeled with gold particles when incubated with the corresponding antibody. Our conclusion from the data is that a large tag at the N terminus of VP19C was sufficiently exposed on the capsid surface for polyclonal antibody reactivity, while the small HA epitope was inaccessible to the antibody. These data indicate that an epitope tag at the amino terminus of VP19C is not exposed at the capsid surface for reactivity to its antibody.
authors.affiliation: Viral Oncology Program, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, 353 CRB 1, 1650 Orleans Street, The Johns Hopkins University, Baltimore, MD 21231, USA.
authors.forename: Marieta
authors.initials: M
authors.lastname: Solé
authors.forename: Edward M
authors.initials: EM
authors.lastname: Perkins
authors.forename: Augusto
authors.initials: A
authors.lastname: Frisancho
authors.forename: Eugene
authors.initials: E
authors.lastname: Huang
authors.forename: Prashant
authors.initials: P
authors.lastname: Desai
mesh_terms: D000906:Antibodies / Q000276:immunology*; D002213:Capsid / Q000378:metabolism* / Q000648:ultrastructure; D036022:Capsid Proteins / Q000235:genetics / Q000276:immunology*; D002460:Cell Line; D000939:Epitopes; D018259:Herpesvirus 1, Human / Q000378:metabolism*; D006801:Humans; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D000906:Antibodies; D036022:Capsid Proteins; D000939:Epitopes; D021122:Protein Subunits; D011993:Recombinant Fusion Proteins; C082563:VP19 protein, Human herpesvirus 1