title: Disulfide bond assignment of the Ebola virus secreted glycoprotein SGP.
abstract: The non-structural glycoprotein (SGP) of Ebola virus (EboV) is secreted in large amounts from infected cells as a disulfide-linked homodimer. In this communication, highly purified SGP, derived from Vero E6 cultures infected with the Zaire species of EboV, was used to determine the correct localization of inter- and intrachain disulfide bonds. Matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry analysis of proteolytic cleavage fragments indicates that all cysteines (six per monomeric unit) form unique disulfide bonds. Monomers of the SGP homodimer are joined in a parallel manner by two intersubunit disulfide bonds formed between paired N-terminal and C-terminal cysteines (C53-C53' and C306-C306'). The remaining cysteines are involved in intrachain disulfide bonding (paired as C108-C135 and C121-C147), which resembles the disulfide bond topology of fibronectin type II domains. The findings presented here provide the foundation for future studies aimed at defining the structural and functional properties of SGP.
authors.affiliation: Special Pathogens Branch, Division of Viral and Rickettsial Diseases, Scientific Resources Program, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: Laura G
authors.initials: LG
authors.lastname: Barrientos
authors.forename: Amy M
authors.initials: AM
authors.lastname: Martin
authors.forename: Pierre E
authors.initials: PE
authors.lastname: Rollin
authors.forename: Anthony
authors.initials: A
authors.lastname: Sanchez
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D003545:Cysteine / Q000737:chemistry*; D019281:Dimerization; D004220:Disulfides / Q000737:chemistry*; D029043:Ebolavirus / Q000378:metabolism*; D006023:Glycoproteins / Q000737:chemistry*; D008969:Molecular Sequence Data; D011485:Protein Binding; D011487:Protein Conformation; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D014764:Viral Proteins / Q000737:chemistry*
chemical_list: D004220:Disulfides; D006023:Glycoproteins; D014764:Viral Proteins; C110613:secreted glycoprotein, Ebola virus; D003545:Cysteine