title: Cytosolic neutral proteinases of Paracoccidioides brasiliensis.
abstract: Cytosolic proteinases were assayed in both morphological phases of Paracoccidioides brasiliensis. Preparations from the mycelial phase were more active in vitro than those from the yeast cells. Optimal proteinase activities for both phases occurred at pH's between 6.0 and 9.0, and at 45 degrees C. Gelatin-SDS-PAGE electrophoresis separated several bands (58-112 kDa) in mycelial preparations; a single band (70 kDa) was seen in yeast preparations. Enzymatic activities were inhibited by antipain, phenyl methyl sulfonyl fluoride (PMSF), and chymostatin, suggestive of serine proteinases. Partial inhibition of the mycelial enzymes by ethylene diamine tetraacetic acid (EDTA), 1,10-phenanthroline, and iodoacetamide, also suggested the presence of cysteine- and metallo-proteinases. The enzymatic activity increased in preparations extracted from yeast cells transforming to mycelia, and decreased in preparations obtained from the reverse process.
authors.affiliation: Instituto Venezolano de Investigaciones Cientificas (IVIC), Centro de Microbiología y Biología Celular, Apartado 21827, Caracas 1020A, Venezuela.
authors.forename: G
authors.initials: G
authors.lastname: San-Blas
authors.forename: F
authors.initials: F
authors.lastname: Sorais
authors.forename: G
authors.initials: G
authors.lastname: Niño-Vega
authors.forename: C
authors.initials: C
authors.lastname: Méndez
authors.forename: F
authors.initials: F
authors.lastname: San-Blas
mesh_terms: D000976:Antipain / Q000494:pharmacology; D001426:Bacterial Proteins / Q000032:analysis / Q000037:antagonists & inhibitors / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D002614:Chelating Agents / Q000494:pharmacology; D003600:Cytosol / Q000201:enzymology*; D004492:Edetic Acid / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases / Q000032:analysis / Q000187:drug effects / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007460:Iodoacetamide / Q000494:pharmacology; D009842:Oligopeptides / Q000494:pharmacology; D010228:Paracoccidioides / Q000166:cytology / Q000187:drug effects / Q000201:enzymology*; D010664:Phenylmethylsulfonyl Fluoride / Q000494:pharmacology; D011480:Protease Inhibitors / Q000494:pharmacology; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology; D012967:Sodium Dodecyl Sulfate; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D002614:Chelating Agents; D004791:Enzyme Inhibitors; D009842:Oligopeptides; D011480:Protease Inhibitors; D015842:Serine Proteinase Inhibitors; D012967:Sodium Dodecyl Sulfate; D000976:Antipain; D010664:Phenylmethylsulfonyl Fluoride; C002101:chymostatin; D004492:Edetic Acid; D010450:Endopeptidases; D007460:Iodoacetamide