Surface phosphatase in Rhinocladiella aquaspersa: biochemical properties and its involvement with adhesion.
Rhinocladiella aquaspersa is an etiologic agent of chromoblastomycosis, a subcutaneous chronic infectious disease. In the present work, we found that the three morphological forms of this fungus (conidia, mycelia and sclerotic bodies) expressed different levels of ecto-phosphatase activity. Our results demonstrated that surface conidial enzyme is an acid phosphatase, inhibited by sodium salts of molybdate, orthovanadate and fluoride and that the inhibition caused by orthovanadate and molybdate was irreversible. The conidial ecto-phosphatase efficiently released phosphate groups from different phosphorylated substrates, causing a higher rate of phosphate removal when p-nitrophenylphosphate was used as substrate. This ecto-enzyme of R. aquaspersa is modulated by Co(2 +) ions and inorganic phosphate (Pi). Accordingly, removal of Pi from the culture medium resulted in a marked (121-fold) increase of ecto-phosphatase activity. Surface phosphatase activity is apparently involved in fungal adhesive properties, since the attachment of R. aquaspersa to epithelial cells was reversed by the pre-treatment of the conidia with orthovanadate, molybdate and anti-phosphatase antibody. Corroborating this finding, conidia with greater ecto-phosphatase activity (grown in Pi-depleted medium) showed higher adherence to epithelial cells than fungi cultivated in the presence of Pi.
Laboratório de Taxonomia, Bioquímica e Bioprospecção de Fungos, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil. lucimar@ioc.fi ocruz.br
Lucimar F
LF
Kneipp
Andressa S
AS
Magalhães
Erika A
EA
Abi-Chacra
Lucieri O P
LO
Souza
Celuta S
CS
Alviano
André L S
AL
Santos
José R
JR
Meyer-Fernandes
D000135:Acid Phosphatase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D001203:Ascomycota / Q000187:drug effects / Q000201:enzymology* / Q000302:isolation & purification; D016466:CHO Cells; D002448:Cell Adhesion; D002862:Chromoblastomycosis / Q000382:microbiology; D006224:Cricetinae; D003470:Culture Media / Q000737:chemistry; D004789:Enzyme Activation; D057075:Enzyme Assays; D004791:Enzyme Inhibitors / Q000494:pharmacology; D048690:Fruiting Bodies, Fungal / Q000187:drug effects / Q000201:enzymology*; D005656:Fungal Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D006801:Humans; D008982:Molybdenum / Q000494:pharmacology; D025282:Mycelium / Q000187:drug effects / Q000201:enzymology*; D010710:Phosphates / Q000494:pharmacology; D013172:Spores, Fungal / Q000187:drug effects / Q000201:enzymology*; D013997:Time Factors; D014638:Vanadates / Q000494:pharmacology
D000906:Antibodies; D003470:Culture Media; D004791:Enzyme Inhibitors; D005656:Fungal Proteins; D010710:Phosphates; C044659:molybdate; D014638:Vanadates; D008982:Molybdenum; D000135:Acid Phosphatase