title: Anionogenic groups and surface sialoglycoconjugate structures of yeast forms of the human pathogen Paracoccidioides brasiliensis.
abstract: The surface anionogenic groups and sialoglycoconjugate structures of Paracoccidioides brasiliensis yeast forms were analysed by cell microelectrophoresis, binding assays with lectins and viral particles, ultrastructural cytochemistry, enzymic digestion and flow cytofluorimetry. P. brasiliensis yeast forms, particularly the budding primordia, reacted strongly with cationized ferritin. Binding assays showed that the reaction with sialic-acid-specific Limax flavus lectin (LFA) was distributed over the entire P. brasiliensis cell wall. Treatment of yeast forms with neuraminidase significantly reduced their negative surface charge and LFA labelling, which suggests that sialic acid residues are major anionogenic groups exposed on the P. brasiliensis surface. Furthermore, after neuraminidase treatment, labelling with Arachis hypogaea (peanut) agglutinin increased due to unmasking of subterminal beta-D-galactopyranosyl residues. The sialic acid linkages to galactose are alpha 2,6 and alpha 2,3 as assessed, respectively, by fungal attachment to M1/5 and M1/5 HS8 strains of influenza A virus and binding of Sambucus niger and Maackia amurensis agglutinins. The alpha 2,6 linkage clearly predominated in both experiments. Flow cytofluorimetry analysis revealed the heterogenicity of P. brasiliensis yeast cell populations, which comprised young and mature budding yeasts. Both express binding sites to LFA and Limulus polyphemus agglutinin.
authors.affiliation: Instituto de Microbiologia Professor Paulo de Góes, UFRJ, Ilha do Fundão, 21941-590, Rio de Janeiro, RJ, Brazil.
authors.forename: Regina M A
authors.initials: RMA
authors.lastname: Soares
authors.affiliation: Instituto de Biofísica Carlos Chagas Filho, UFRJ, Ilha do Fundão, 21949-970, Rio de Janeiro, RJ, Brazil.
authors.forename: Fernando Costa
authors.initials: FC
authors.lastname: Silva-Filho
authors.affiliation: Instituto de Biofísica Carlos Chagas Filho, UFRJ, Ilha do Fundão, 21949-970, Rio de Janeiro, RJ, Brazil.
authors.forename: Sonia
authors.initials: S
authors.lastname: Rozental
authors.affiliation: Instituto de Microbiologia Professor Paulo de Góes, UFRJ, Ilha do Fundão, 21941-590, Rio de Janeiro, RJ, Brazil.
authors.forename: Jayme
authors.initials: J
authors.lastname: Angluster
authors.affiliation: Centro de Biociěcias e Biotecnologia, Universidade Estadual do Norte Fluminense, 28015-620, Campos, RJ, Brazil.|Instituto de Biofísica Carlos Chagas Filho, UFRJ, Ilha do Fundão, 21949-970, Rio de Janeiro, RJ, Brazil.
authors.forename: Wanderley
authors.initials: W
authors.lastname: de Souza
authors.affiliation: Instituto de Microbiologia Professor Paulo de Góes, UFRJ, Ilha do Fundão, 21941-590, Rio de Janeiro, RJ, Brazil.
authors.forename: Celuta S
authors.initials: CS
authors.lastname: Alviano
authors.affiliation: Disciplina de Biologia Celular, Universidade Federal de São Paulo, 04023-062, São Paulo, SP, Brazil.
authors.forename: Luiz R
authors.initials: LR
authors.lastname: Travassos
mesh_terms: D000373:Agglutinins / Q000378:metabolism; D002473:Cell Wall / Q000737:chemistry / Q000378:metabolism; D005293:Ferritins / Q000493:pharmacokinetics; D005434:Flow Cytometry; D005656:Fungal Proteins / Q000378:metabolism; D005690:Galactose / Q000378:metabolism; D009980:Influenza A virus / Q000378:metabolism; D037102:Lectins / Q000378:metabolism; D008854:Microscopy, Electron; D019158:N-Acetylneuraminic Acid / Q000032:analysis* / Q000378:metabolism*; D009439:Neuraminidase / Q000494:pharmacology; D010228:Paracoccidioides / Q000737:chemistry* / Q000378:metabolism* / Q000648:ultrastructure; D011485:Protein Binding; D011956:Receptors, Cell Surface / Q000378:metabolism
chemical_list: D000373:Agglutinins; D005656:Fungal Proteins; D037102:Lectins; D011956:Receptors, Cell Surface; D005293:Ferritins; D009439:Neuraminidase; D019158:N-Acetylneuraminic Acid; D005690:Galactose