title: Identification, N-terminal region sequencing and similarity analysis of differentially expressed proteins in Paracoccidioides brasiliensis.
abstract: Paracoccidioides brasiliensis is the causal agent of paracoccidioidomycosis, which is a systemic mycosis in Latin America. This human pathogen is a dimorphic fungus existing as mycelium (26 degrees C) and in infected tissues as a yeast form (36 degrees C). The in vitro differentiation process is reversible and dependent on temperature shift. In the present study, the total proteins from both forms of P. brasiliensis (isolate Pb01) were analysed by two-dimensional electrophoresis. Differentially expressed proteins were identified. Two of these proteins, PbM46 (mycelium) and PbY20 (yeast), were submitted to automated protein sequencing of their N-terminal regions. The 15 amino acid residue sequence of PbM46, AITKIFALKVYDSSG, is similar to enolases from several sources, and specially those from Saccharomyces cerevisiae (80%) and Candida albicans (67%), when compared to the NR database at NCBI using the BLASTP program. The 34 amino acid residue sequence of PbY20, APKIAIVFYSLYGHIQKLAEAQKKGIEAAGGTAD, could probably represent an allergen protein since it is very similar (90%) to the minor allergen protein of Alternaria alternata and 82% similar to the allergen protein of Cladosporium herbarum. This comparative analysis of proteins from mycelium and yeast forms has allowed the identification and characterization of differentially expressed proteins, probably related to differential gene expression in P. brasiliensis.
authors.affiliation: Laboratorio de Biologia Molecular, Centro Brasileiro de Sequenciamento de Proteinas, ICB, Universidade de Brasilia, Brasilia, Brazil.
authors.forename: A F
authors.initials: AF
authors.lastname: Cunha
authors.forename: M V
authors.initials: MV
authors.lastname: Sousa
authors.forename: S P
authors.initials: SP
authors.lastname: Silva
authors.forename: R S
authors.initials: RS
authors.lastname: Jesuíno
authors.forename: C M
authors.initials: CM
authors.lastname: Soares
authors.forename: M S
authors.initials: MS
authors.lastname: Felipe
mesh_terms: D000595:Amino Acid Sequence; D015180:Electrophoresis, Gel, Two-Dimensional; D005656:Fungal Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D006801:Humans; D008969:Molecular Sequence Data; D010228:Paracoccidioides / Q000235:genetics* / Q000254:growth & development; D010229:Paracoccidioidomycosis / Q000382:microbiology*; D010751:Phosphopyruvate Hydratase / Q000235:genetics; D016415:Sequence Alignment
chemical_list: D005656:Fungal Proteins; C120354:PbM46 protein, Paracoccidioides brasiliensis; C120355:Y20 protein, Paracoccidioides brasiliensis; D010751:Phosphopyruvate Hydratase