title: Viral characterization by direct analysis of capsid proteins.
abstract: Matrix-assisted laser desorption/ionization mass spectrometry has enabled viral coat proteins to be characterized directly from the virus. This analysis, demonstrated here with tobacco mosaic virus U2, a bacteriophage MS2, and equine encephalitis TRD, is achieved with a combination of organic acid, UV-absorbing matrix, and high-energy desorption with a nitrogen laser. The molecular weights of these proteins are determined with sufficient accuracy to allow differentiation among viral species and strains. The abundant hydrophobic MS2 coat protein was analyzed in aliquots of culture medium and of the tobacco mosaic virus coat protein in infected leaves. This method provides rapid detection of coat protein in the low-femtomole range, as estimated by titering plaque-forming units of MS2.
authors.affiliation: Department of Chemistry and Biochemistry, University of Maryland, Baltimore 21250, USA.
authors.forename: J J
authors.initials: JJ
authors.lastname: Thomas
authors.forename: B
authors.initials: B
authors.lastname: Falk
authors.forename: C
authors.initials: C
authors.lastname: Fenselau
authors.forename: J
authors.initials: J
authors.lastname: Jackman
authors.forename: J
authors.initials: J
authors.lastname: Ezzell
mesh_terms: D002213:Capsid / Q000032:analysis*; D036022:Capsid Proteins; D004666:Encephalitis Virus, Venezuelan Equine / Q000737:chemistry; D013045:Species Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014027:Tobacco Mosaic Virus / Q000737:chemistry; D014764:Viral Proteins / Q000032:analysis; D014780:Viruses / Q000737:chemistry*
chemical_list: D036022:Capsid Proteins; C009496:H protein, Tobacco mosaic virus; D014764:Viral Proteins; C037227:lysis protein, Enterobacterio phage MS2