title: Expression of the Mycobacterium tuberculosis 19-kilodalton antigen in Mycobacterium smegmatis: immunological analysis and evidence of glycosylation.
abstract: The gene encoding a 19-kDa antigen from Mycobacterium tuberculosis was expressed as a recombinant protein in the rapid-growing species Mycobacterium smegmatis. The recombinant antigen was expressed at a level approximately ninefold higher than in M. tuberculosis and, like the native antigen, was found in the pellet fraction after high-speed centrifugation of bacterial extracts. The 19-kDa antigen in crude bacterial extracts, and the purified recombinant antigen, bound strongly to concanavalin A, indicating the possibility of posttranslational glycosylation. The recombinant antigen stimulated T-cell proliferation in vitro when added to assays either in the form of whole recombinant bacteria or as a purified protein. Homologous expression of mycobacterial antigens in a rapid-growing mycobacterial host may be particularly useful for the immunological characterization of proteins which are subject to posttranslational modification.
authors.affiliation: Medical Research Council Tuberculosis and Related Infections Unit, Royal Postgraduate Medical School, Hammersmith Hospital, London, United Kingdom.
authors.forename: T
authors.initials: T
authors.lastname: Garbe
authors.forename: D
authors.initials: D
authors.lastname: Harris
authors.forename: M
authors.initials: M
authors.lastname: Vordermeier
authors.forename: R
authors.initials: R
authors.lastname: Lathigra
authors.forename: J
authors.initials: J
authors.lastname: Ivanyi
authors.forename: D
authors.initials: D
authors.lastname: Young
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000942:Antigens, Bacterial / Q000096:biosynthesis* / Q000276:immunology*; D015153:Blotting, Western; D003208:Concanavalin A / Q000378:metabolism; D004306:Dose-Response Relationship, Immunologic; D004591:Electrophoresis, Polyacrylamide Gel; D006031:Glycosylation; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009161:Mycobacterium / Q000378:metabolism*; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D011499:Protein Processing, Post-Translational; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000276:immunology; D013601:T-Lymphocytes / Q000166:cytology
chemical_list: D000942:Antigens, Bacterial; D011994:Recombinant Proteins; D003208:Concanavalin A