Phosphatase activity on the cell wall of Fonsecaea pedrosoi.

摘要: The activity of a phosphatase was characterized in intact mycelial forms Fonsecaea pedrosoi, pathogenic fungus that causes chromoblastomycosis. At pH 5.5, this hydrolyzed p-nitrophenylphosphate (p-NPP) to p-nitrophenol (p-NP) at rate 12.78 +/- 0.53 nmol p-NP per h mg hyphal dry weight. values Vmax and apparent Km for p-NPP hydrolyses were measured as 17.89 0.92 weight 1.57 0.26 mmol/l, respectively. This inhibited increased pH, finding compatible with an acid phosphatase. enzymatic strongly by classical inhibitors phosphatases such sodium orthovanadate (Ki = 4.23 micromol/l), molybdate 7.53 micromol/l) fluoride 126.78 dose-dependent manner. Levamizole (1 mmol/l) tartrate (10 mmol/l), had no effect on the enzyme activity. Cytochemical localization showed electrondense cerium phosphate deposits cell wall, visualized transmission electron microscopy. Phosphatase F. pedrosoi seems be associated parasitism, sclerotic cells, which are fungal mainly detected chromoblastomycosis lesions, much higher activities than conidia mycelia did. A strain recently isolated from human case also activity, suggesting expression surface may stimulated interaction host.