Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2007-5-21
pubmed:abstractText
This study describes the biochemical characterization of a phosphatase activity present on the cell surface of Candida parapsilosis, a common cause of candidemia. Intact yeasts hydrolyzed p-nitrophenylphosphate to p-nitrophenol at a rate of 24.30+/-2.63 nmol p-nitrophenol h(-1) 10(-7) cells. The cell wall distribution of the Ca. parapsilosis enzyme was demonstrated by transmission electron microscopy. The duration of incubation of the yeast cells with the substrate and cell density influenced enzyme activity linearly. Values of V(max) and apparent K(m) for p-nitrophenylphosphate hydrolysis were 26.80+/-1.13 nmol p-nitrophenol h(-1) 10(-7) cells and 0.47+/-0.05 mM p-nitrophenylphosphate, respectively. The ectophosphatase activity was strongly inhibited at high pH as well as by classical inhibitors of acid phosphatases, such as sodium orthovanadate, sodium molybdate, sodium fluoride, and inorganic phosphate, the final product of the reaction. Only the inhibition caused by sodium orthovanadate was irreversible. Different phophorylated amino acids were used as substrates for the Ca. parapsilosis ectoenzyme, and the highest rate of phosphate hydrolysis was achieved using phosphotyrosine. A direct relationship between ectophosphatase activity and adhesion to host cells was established. In these assays, irreversible inhibition of enzyme activity resulted in decreased levels of yeast adhesion to epithelial cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1567-1356
pubmed:author
pubmed:issnType
Print
pubmed:volume
7
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
621-8
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
An ectophosphatase activity in Candida parapsilosis influences the interaction of fungi with epithelial cells.
pubmed:affiliation
Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Cidade Universitária, Rio de Janeiro, Brazil.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't