title: Purification, characterization, and seroactivity of a 20-kilodalton Brucella protein antigen.
abstract: An internal protein was purified from cell extracts of Brucella melitensis B115 by a combination of preparative isoelectric focusing and high-performance size exclusion chromatography. The protein has an apparent molecular mass of 230 kDa as determined by size exclusion chromatography. The protein was resolved to a single band of 20 kDa after sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The native protein had an isoelectric point of 4.9. The N-terminal sequence of the 20-kDa protein was determined. The 20-kDa protein has been identified as antigen A-2 with a previously described anti-antigen A-2 serum (B. Stemshorn, K. Nielsen, and B. Samagh, Can. J. Comp. Med. 45:77-81, 1981). Antigen A-2 reacted with sera from infected sheep in immunoblotting and may be useful in developing diagnostic tests for brucellosis.
authors.affiliation: Laboratoire de Pathologie Infectieuse et Immunologie, Institut National de la Recherche Agronomique, Nouzilly, France.
authors.forename: M S
authors.initials: MS
authors.lastname: Zygmunt
authors.forename: F B
authors.initials: FB
authors.lastname: Gilbert
authors.forename: G
authors.initials: G
authors.lastname: Dubray
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000942:Antigens, Bacterial / Q000737:chemistry / Q000302:isolation & purification*; D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification*; D017347:Brucella melitensis / Q000737:chemistry* / Q000276:immunology; D015151:Immunoblotting; D007525:Isoelectric Focusing; D008969:Molecular Sequence Data; D008970:Molecular Weight; D012756:Sheep
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins