title: Isolation of a 19-kDa mycobacterium, bovis-specific antigen, different from MPB70/80, by chromatofocusing.
abstract: Two antigens, 19-kDa each, were purified from Mycobacterium bovis culture filtrate protein extract by chromatofocusing. Antigen I had a 4.5 pI, and its amino terminal (DPVDAVINTTCNYGQVVAALNATDP) showed a 100% homology with the hypothetical protein Rv1174c. Antigen II had a pI of 6.0 pI and its amino terminal (GDLVGPGCAEYAAANPTGPASVQGM) showed a 100% homology with M. bovis MPB70/80. Antigen I is a hetero-dimer formed by a glycosylated, 10.5-kDa, monomer and a non-glycosylated 8-kDa monomer with identical amino terminal sequences. Both antigens were recognized by the sera of PPD+ animals, but antigen I did not crossreact with sera of human PPD+ individuals. Antigen I was a weak inducer of lymphocyte proliferation and IFN-gamma production. Our results show that M. bovis expresses a 19 kDa glycoprotein, homologue to the product of M. tuberculosis gen Rv1174c, which may prove useful for bovine TB diagnostic assays.
authors.affiliation: Depto. Biología Celular, Instituto Nacional de Cardiologia "Ignacio Chávez," Juan Badiano 1, Tlalpan 14080, México.
authors.forename: Elvira
authors.initials: E
authors.lastname: Varela
authors.forename: Felipe
authors.initials: F
authors.lastname: Massó
authors.forename: Araceli
authors.initials: A
authors.lastname: Páez
authors.forename: Roberto
authors.initials: R
authors.lastname: Zenteno
authors.forename: Edgar
authors.initials: E
authors.lastname: Zenteno
authors.forename: Luis F
authors.initials: LF
authors.lastname: Montaño
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000942:Antigens, Bacterial / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D002417:Cattle; D015151:Immunoblotting; D007525:Isoelectric Focusing; D008969:Molecular Sequence Data; D009163:Mycobacterium bovis / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D017433:Protein Structure, Secondary
chemical_list: D000942:Antigens, Bacterial