Trypanosoma brucei brucei: Biochemical characterization of ecto-nucleoside triphosphate diphosphohydrolase activities

dc.creatorLeite, MDS
dc.creatorThomaz, R
dc.creatorFonseca, FV
dc.creatorPanizzutti, R
dc.creatorVercesi, AE
dc.creatorMeyer-Fernandes, JR
dc.date2007
dc.dateAPR
dc.date2014-11-14T07:04:10Z
dc.date2015-11-26T16:05:02Z
dc.date2014-11-14T07:04:10Z
dc.date2015-11-26T16:05:02Z
dc.date.accessioned2018-03-28T22:54:09Z
dc.date.available2018-03-28T22:54:09Z
dc.identifierExperimental Parasitology. Academic Press Inc Elsevier Science, v. 115, n. 4, n. 315, n. 323, 2007.
dc.identifier0014-4894
dc.identifier1090-2449
dc.identifierWOS:000245446000001
dc.identifier10.1016/j.exppara.2006.09.002
dc.identifierhttp://www.repositorio.unicamp.br/jspui/handle/REPOSIP/77035
dc.identifierhttp://www.repositorio.unicamp.br/handle/REPOSIP/77035
dc.identifierhttp://repositorio.unicamp.br/jspui/handle/REPOSIP/77035
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/1265636
dc.descriptionin this work we describe the ability of living cells of Trypanosoma brucei brucei to hydrolyze extracellular ATP. In these intact parasites there was a low level of ATP hydrolysis in the absence of any divalent metal (4.72 +/- 0.51 nmol Pi x 10(-7) cells x h(-1)). The ATP hydrolysis was stimulated by MgCl2 and the Mg-dependent ecto-ATPase activity was 27.15 +/- 2.91 nmol Pi x 10(-7) cells x h(-1). This stimulatory activity was also observed when MgCl2 was replaced by MnCl2. CaCl2 and ZnCl2 were also able to stimulate the ATPase activity, although less than MgCl2. The apparent K-m for ATP was 0.61 mM. This ecto-ATPase activity was insensitive to inhibitors of other ATPase and phosphatase activities. To confirm that this Mg-dependent ATPase activity is an ecto-ATPase activity, we used an impermeable inhibitor, DIDS (4, 4'-diisothiocyanostylbene 2'-2'-disulfonic acid), as well as suramin, an antagonist of P-2 purinoreceptors and inhibitor of some ecto-ATPases. These two reagents inhibited the Mg2+-dependent ATPase activity in a dose-dependent manner. Living cells sequentially hydrolyzed the ATP molecule generating ADP, AMP and adenosine, and supplementation of the culture medium with ATP was able to sustain the proliferation of T brucei brucei as well as adenosine supplementation. Furthermore, the E-NTPDase activity of T brucei brucei is modulated by the availability of purines in the medium. These results indicate that this surface enzyme may play a role in the salvage of purines from the extracellular medium in T brucei brucei. (c) 2006 Elsevier Inc. All rights reserved.
dc.description115
dc.description4
dc.description315
dc.description323
dc.languageen
dc.publisherAcademic Press Inc Elsevier Science
dc.publisherSan Diego
dc.publisherEUA
dc.relationExperimental Parasitology
dc.relationExp. Parasitol.
dc.rightsfechado
dc.rightshttp://www.elsevier.com/about/open-access/open-access-policies/article-posting-policy
dc.sourceWeb of Science
dc.subjectTrypanosoma brucei brucei
dc.subjectEcto-ATPase
dc.subjectadenosine
dc.subjectPhosphatase-activity Present
dc.subjectAtpase Activity
dc.subjectExtracellular Atp
dc.subjectSmooth-muscle
dc.subjectDifferential Expression
dc.subjectLeishmania-amazonensis
dc.subjectMalpighian Tubules
dc.subjectRhodnius-prolixus
dc.subjectProcyclic Forms
dc.subjectCells
dc.titleTrypanosoma brucei brucei: Biochemical characterization of ecto-nucleoside triphosphate diphosphohydrolase activities
dc.typeArtículos de revistas


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