title: A new Paracoccidioides brasiliensis 70-kDa heat shock protein reacts with sera from paracoccidioidomycosis patients.
abstract: A cDNA coding for a new member of the 70-kDa heat shock proteins (HSP70) family from the dimorphic and pathogenic fungus, Paracoccidioides brasiliensis, was cloned and characterized. The cDNA-deduced sequence coded for 655 amino acid residues and showed 95% identity to a previously described P. brasiliensis hsp70 gene. Cytoplasmic and typical nuclear localization signals, which indicate induction upon stress, were identified in the deduced peptide. The complete hsp70 cDNA coding region was cloned into a pGEX 4T-3 plasmid and expressed in Escherichia coli as a glutathione-S-transferase-tagged fusion protein. The recombinant protein reacted with a rabbit polyclonal antibody against HSP70. Western immunoblot experiments demonstrated that sera from paracoccidioidomycosis patients recognized the purified recombinant protein, suggesting an immunological role for this protein in the infectious process. The antigenicity analysis of rHSP70 detected three internal peptides that could act as activators of T-cell proliferation.
authors.affiliation: Laboratório de Biologia Molecular, Universidade de Brasília, Brazil.
authors.forename: Laura C
authors.initials: LC
authors.lastname: Bisio
authors.forename: Silvana P
authors.initials: SP
authors.lastname: Silva
authors.forename: Ildinete Silva
authors.initials: IS
authors.lastname: Pereira
authors.forename: Mauro A S
authors.initials: MA
authors.lastname: Xavier
authors.forename: Emerson J
authors.initials: EJ
authors.lastname: Venâncio
authors.forename: Rosana
authors.initials: R
authors.lastname: Puccia
authors.forename: Célia M A
authors.initials: CM
authors.lastname: Soares
authors.forename: Maria Sueli S
authors.initials: MS
authors.lastname: Felipe
mesh_terms: D000595:Amino Acid Sequence; D000908:Antibodies, Fungal / Q000097:blood; D000946:Antigens, Fungal / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D001483:Base Sequence; D018840:HSP70 Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D006801:Humans; D015151:Immunoblotting; D008969:Molecular Sequence Data; D010228:Paracoccidioides / Q000276:immunology* / Q000378:metabolism; D010229:Paracoccidioidomycosis / Q000097:blood / Q000276:immunology*; D017433:Protein Structure, Secondary; D012331:RNA, Fungal / Q000737:chemistry / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013499:Surface Properties
chemical_list: D000908:Antibodies, Fungal; D000946:Antigens, Fungal; D018840:HSP70 Heat-Shock Proteins; D012331:RNA, Fungal; D011994:Recombinant Proteins