Cloning, characterization, and epitope expression of the major diagnostic antigen of Paracoccidioides brasiliensis
Data
1996-02-23
Autores
Cisalpino, Patricia Silva 
Puccia, Rosana
Yamauchi, Lucy Megumi
Cano, Maria Isabel Nogueira
Silveira, Jose Franco da
Mostrar mais
Tipo
Artigo
Título da Revista
ISSN da Revista
Título de Volume
Resumo
The 43,000-Da glycoprotein (gp43) of Paracoccidioides brasiliensis is an immunodominant antigen for antibody-dependent and immune cellular responses in patients with paracoccidioidomycosis. In order to identify the peptide epitopes involved in the immunological reactivities of the gp43 and to obtain highly specific recombinant molecules for diagnosis of the infection, genomic and cDNA clones representing the entire coding region of the antigen were sequenced. The gp43 open reading frame was found in a 1,329-base pair fragment with 2 exons interrupted by an intron of 78 nucleotides. The gene is present in very few copies per genome, as indicated by Southern blotting and chromosomal mega-restriction analysis. A single transcript of 1.5 kilobase pairs was verified in the yeast phase. The gene encodes a polypeptide of 416 amino acids (M(r) 45,947) with a leader peptide of 35 residues; the mature protein has at single N-glycosylation site. The deduced amino acid sequence showed similarities of 56-58% with exo-1,3-beta-D-glucanases hom Saccharomyces cerevisiae and Candida albicans. However, the gp43 is devoid of hydrolase activity and does not cross-react immunologically with the fungal glucanases. Internal and COOH-terminal gene fragments of the gp43 were expressed as recombinant fusion proteins, which reacted with antibodies elicited against the native antigen.
Descrição
Citação
Journal Of Biological Chemistry. Bethesda: Amer Soc Biochemistry Molecular Biology Inc, v. 271, n. 8, p. 4553-4560, 1996.