Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.6.1.3 (ATPase)
 65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In this work, we characterized an ecto-ATPase activity in intact mycelial forms of Fonsecaea pedrosoi, the primary causative agent of chromoblastomycosis. In the presence of 1 mM EDTA, fungal cells hydrolyzed adenosine-5'-triphosphate (ATP) at a rate of 84.6 +/- 11.3 nmol Pi h(-1) mg(-1) mycelial dry weight. The ecto-ATPase activity was increased at about five times (498.3 +/- 27.6 nmol Pi h(-1) mg(-1)) in the presence of 5 mM MgCl2, with values of Vmax and apparent Km for Mg-ATP(2-) corresponding to 541.9 +/- 48.6 nmol Pi h(-1) mg(-1) cellular dry weight and 1.9 +/- 0.2 mM, respectively. The Mg2+-stimulated ecto-ATPase activity was insensitive to inhibitors of intracellular ATPases such as vanadate (P-ATPases), bafilomycin A1(V-ATPases), and oligomycin (F-ATPases). Inhibitors of acid phosphatases (molybdate, vanadate, and fluoride) or alkaline phosphatases (levamizole) had no effect on the ecto-ATPase activity. The surface of the Mg2+ -stimulated ATPase in F. pedrosoi was confirmed by assays in which 4,4'-diisothiocyanostylbene-2,2'-disulfonic acid (DIDS), a membrane impermeant inhibitor, and suramin, an inhibitor of ecto-ATPase and antagonist of P2 purinoreceptors. Based on the differential expression of ecto-ATPases in the different morphological stages of F. pedrosoi, the putative role of this enzyme in fungal biology is discussed.
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PMID:Characterization of an ecto-ATPase activity in Fonsecaea pedrosoi. 1652 35

Fonsecaea pedrosoi, a dematiaceous fungus, is the main agent responsible for chromoblastomycosis, a chronic and progressive mycosis of the skin and subcutaneous tissues. This disease can cause different types of lesions depending on the immune status of the host. Its treatment is complicated by the toxicity of available antifungal agents as well as drug resistance. In this work, an ATP-binding cassette (ABC) transporter in this fungus was characterised, with the degree of expression related to the drug resistance of two strains (a patient isolated strain and a laboratory strain). A 150 kDa protein was detected by western blotting. The ATPase activity of membrane preparations was also evaluated. The F. pedrosoi transporter appears to behave like Pdr5p, a well-studied multidrug resistance transporter in Saccharomyces cerevisiae with the ability to hydrolyse different triphosphate nucleotides, as well as its response to classical inhibitors tested. Finally, a reverse transcription polymerase chain reaction (RT-PCR) approach was used and a 400 bp product was detected, corresponding to the highly conserved ATP-binding domain of ABC transporters. We suggest that an ABC transporter must be involved in F. pedrosoi multidrug resistance, and a complete understanding of this protein could bring an important contribution to antifungal treatment of this disease.
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PMID:Putative role of an ABC transporter in Fonsecaea pedrosoi multidrug resistance. 2299 64