title: Toxoplasma gondii: localization of purine nucleoside phosphorylase activity in vitro and in vivo by electron microscopy.
abstract: Purine nucleoside phosphorylase (PNP, EC 2.4.2.1) activity was revealed by enzyme histochemistry in Toxoplasma gondii ME49 strain isolated from murine cerebral cysts and from in vitro cultivation. The activity of the enzyme was revealed by an insoluble electron-opaque precipitate of lead phosphate at the site of the reaction. In bradyzoites and tachyzoites of T. gondii, the enzyme activity could be observed only in the cytoplasm. In bradyzoites, one or two foci of important PNP activity were detected near the nucleus. In tachyzoites, an important PNP activity underlined the plasma membrane. For both bradyzoites and tachyzoites, localization neither in the nucleus nor in cytoplasmic organelles could be detected.
authors.affiliation: Pharmaceutical Department of Parasitology and Medical Mycology, ISPB-Faculté de Pharmacie, Claude Bernard University, Lyon I, 8, Avenue Rockefeller, 69373, Lyon, Cedex 08, France. agherardi@free.fr
authors.forename: Arnaud
authors.initials: A
authors.lastname: Gherardi
authors.forename: Simone
authors.initials: S
authors.lastname: Peyrol
authors.forename: Marie-Elisabeth
authors.initials: ME
authors.lastname: Sarciron
mesh_terms: D000818:Animals; D001692:Biological Transport; D001921:Brain / Q000648:ultrastructure; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000648:ultrastructure; D002467:Cell Nucleus / Q000648:ultrastructure; D003560:Cysts / Q000648:ultrastructure; D003593:Cytoplasm / Q000648:ultrastructure; D051379:Mice; D008854:Microscopy, Electron; D011683:Purine-Nucleoside Phosphorylase / Q000032:analysis / Q000378:metabolism* / Q000648:ultrastructure*; D014122:Toxoplasma / Q000201:enzymology*
chemical_list: D011683:Purine-Nucleoside Phosphorylase