title: Isolation of two pyruvate kinase activities in the parasitic protozoan Leishmania mexicana amazonensis.
abstract: Using phosphocellulose affinity chromatography we were able to separate two pyruvate kinase (EC 2.7.1.40) activities in the parasitic protozoan Leishmania mexicana amazonesis. One activity (PYK1) showed hyperbolic kinetics and was decreased by fructose 2,6-bisphosphate, whereas the second activity (PYK2) showed sigmoidal kinetics for the substrate phosphoenolpyruvate and was activated by fructose 2,6-bisphosphate. Molecular sieve chromatography (Sephacryl S-400) of PYK1 produced a single peak of apparent molecular mass around 200,000, while PYK2 eluted at a position corresponding to M(r) 55,000.
authors.affiliation: Cátedra de Fisiologia, Escuela de Medicina Luis Razetti, Instituto de Medicina Experimental, Caracas, Venezuela.
authors.forename: A
authors.initials: A
authors.lastname: Ponte-Sucre
authors.forename: G
authors.initials: G
authors.lastname: Alonso
authors.forename: C
authors.initials: C
authors.lastname: Martinez
authors.forename: A
authors.initials: A
authors.lastname: Hung
authors.forename: L
authors.initials: L
authors.lastname: Rivas
authors.forename: J L
authors.initials: JL
authors.lastname: Ramirez
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000201:enzymology; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003600:Cytosol / Q000201:enzymology; D004591:Electrophoresis, Polyacrylamide Gel; D007527:Isoenzymes / Q000302:isolation & purification* / Q000378:metabolism*; D007700:Kinetics; D007894:Leishmania mexicana / Q000201:enzymology*; D008970:Molecular Weight; D011770:Pyruvate Kinase / Q000302:isolation & purification* / Q000378:metabolism*
chemical_list: D007527:Isoenzymes; D011770:Pyruvate Kinase