PMID- 15951247
OWN - NLM
STAT- MEDLINE
DCOM- 20050907
LR  - 20131121
IS  - 1567-1356 (Print)
IS  - 1567-1356 (Linking)
VI  - 5
IP  - 10
DP  - 2005 Jul
TI  - Characterization of an ecto-ATPase activity in Cryptococcus neoformans.
PG  - 899-907
AB  - Cryptococcus neoformans is the causative agent of pulmonary cryptococcosis and 
      cryptococcal meningoencephalitis, which are major clinical manifestations in 
      immunosuppressed patients. In the present study, a surface ATPase (ecto-ATPase) 
      was identified in C. neoformans yeast cells. Intact yeasts hydrolyzed 
      adenosine-5'-triphosphate (ATP) at a rate of 29.36+/-3.36nmol Pi/hx10(8) cells. 
      In the presence of 5 mM MgCl(2), this activity was enhanced around 70 times, and 
      an apparent K(m) for Mg-ATP corresponding to 0.61mM was determined. Inhibitors of 
      phosphatases, mitochondrial Mg(2+)-ATPases, V-ATPases, Na(+)-ATPases or P-ATPases 
      had no effect on the cryptococcal ATPase, but extracellular impermeant compounds 
      reduced enzyme activity in living cells. ATP was the best substrate for the 
      cryptococcal ecto-enzyme, but it also efficiently hydrolyzed inosine 
      5'-triphosphate (ITP), cytidine 5'-triphosphate (CTP), guanosine 5'-triphosphate 
      (GTP) and uridine-5'-triphosphate (UTP). In the presence of ATP, C. neoformans 
      became less susceptible to the antifungal action of fluconazole. Our results are 
      indicative of the occurrence of a C. neoformans ecto-ATPase that may have a role 
      in fungal physiology.
FAU - Junior, Itallo Collopy
AU  - Junior IC
AD  - Instituto de Bioquimica Medica, Universidade Federal do Rio de Janeiro, CCS, 
      Bloco H, Cidade Universitaria, Ilha do Fundao, 21541-590 Rio de Janeiro, RJ, 
      Brazil.
FAU - Rodrigues, Marcio L
AU  - Rodrigues ML
FAU - Alviano, Celuta S
AU  - Alviano CS
FAU - Travassos, Luiz R
AU  - Travassos LR
FAU - Meyer-Fernandes, Jose Roberto
AU  - Meyer-Fernandes JR
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - FEMS Yeast Res
JT  - FEMS yeast research
JID - 101085384
RN  - 0 (Antifungal Agents)
RN  - 02F3473H9O (Magnesium Chloride)
RN  - 132-06-9 (Inosine Triphosphate)
RN  - 65-47-4 (Cytidine Triphosphate)
RN  - 86-01-1 (Guanosine Triphosphate)
RN  - 8L70Q75FXE (Adenosine Triphosphate)
RN  - 8VZV102JFY (Fluconazole)
RN  - EC 3.6.1.- (Adenosine Triphosphatases)
RN  - UT0S826Z60 (Uridine Triphosphate)
SB  - IM
MH  - Adenosine Triphosphatases/*metabolism
MH  - Adenosine Triphosphate/metabolism
MH  - Antifungal Agents/pharmacology
MH  - Cell Wall/metabolism
MH  - Cryptococcus neoformans/drug effects/*enzymology
MH  - Cytidine Triphosphate/metabolism
MH  - Dose-Response Relationship, Drug
MH  - Fluconazole/pharmacology
MH  - Guanosine Triphosphate/metabolism
MH  - Inosine Triphosphate/metabolism
MH  - Magnesium Chloride/pharmacology
MH  - Uridine Triphosphate/metabolism
EDAT- 2005/06/14 09:00
MHDA- 2005/09/08 09:00
CRDT- 2005/06/14 09:00
PHST- 2005/02/01 00:00 [received]
PHST- 2005/04/05 00:00 [revised]
PHST- 2005/04/18 00:00 [accepted]
PHST- 2005/06/14 09:00 [pubmed]
PHST- 2005/09/08 09:00 [medline]
PHST- 2005/06/14 09:00 [entrez]
AID - S1567-1356(05)00083-8 [pii]
AID - 10.1016/j.femsyr.2005.04.005 [doi]
PST - ppublish
SO  - FEMS Yeast Res. 2005 Jul;5(10):899-907. doi: 10.1016/j.femsyr.2005.04.005.