A new Paracoccidioides brasiliensis 70-kDa heat shock protein reacts with sera from paracoccidioidomycosis patients.
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.
Bisio
Laura C
LC
Laboratório de Biologia Molecular, Universidade de Brasília, Brazil.
Silva
Silvana P
SP
Pereira
Ildinete Silva
IS
Xavier
Mauro A S
MA
Venâncio
Emerson J
EJ
Puccia
Rosana
R
Soares
Célia M A
CM
Felipe
Maria Sueli S
MS
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
D000908:Antibodies, Fungal; D000946:Antigens, Fungal; D018840:HSP70 Heat-Shock Proteins; D012331:RNA, Fungal; D011994:Recombinant Proteins