title: Trypanosoma evansi contains two auxiliary enzymes of glycolytic metabolism: Phosphoenolpyruvate carboxykinase and pyruvate phosphate dikinase.
abstract: Trypanosoma evansi is a monomorphic protist that can infect horses and other animal species of economic importance for man. Like the bloodstream form of the closely related species Trypanosoma brucei, T. evansi depends exclusively on glycolysis for its free-energy generation. In T. evansi as in other kinetoplastid organisms, the enzymes of the major part of the glycolytic pathway are present within organelles called glycosomes, which are authentic but specialized peroxisomes. Since T. evansi does not undergo stage-dependent differentiations, it occurs only as bloodstream forms, it has been assumed that the metabolic pattern of this parasite is identical to that of the bloodstream form of T. brucei. However, we report here the presence of two additional enzymes, phosphoenolpyruvate carboxykinase and PPi-dependent pyruvate phosphate dikinase in T. evansi glycosomes. Their colocalization with glycolytic enzymes within the glycosomes of this parasite has not been reported before. Both enzymes can make use of PEP for contributing to the production of ATP within the organelles. The activity of these enzymes in T. evansi glycosomes drastically changes the model assumed for the oxidation of glucose by this parasite.
authors.affiliation: Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela.
authors.forename: Luz Amira
authors.initials: LA
authors.lastname: Rivero
authors.affiliation: Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela.
authors.forename: Juan Luis
authors.initials: JL
authors.lastname: Concepción
authors.affiliation: Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela.
authors.forename: Ender
authors.initials: E
authors.lastname: Quintero-Troconis
authors.affiliation: Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela.
authors.forename: Wilfredo
authors.initials: W
authors.lastname: Quiñones
authors.affiliation: Centre for Immunity, Infection and Evolution, and Centre for Translational and Chemical Biology, School of Biological Sciences, University of Edinburgh, United Kingdom.
authors.forename: Paul A M
authors.initials: PA
authors.lastname: Michels
authors.affiliation: Laboratorio de Enzimología de Parásitos, Facultad de Ciencias, Universidad de Los Andes, Mérida 5101, Venezuela. Electronic address: hectoracosta@ula.ve.
authors.forename: Héctor
authors.initials: H
authors.lastname: Acosta
mesh_terms: D000818:Animals; D004072:Digitonin / Q000494:pharmacology; D005954:Glucosephosphate Dehydrogenase / Q000302:isolation & purification / Q000378:metabolism; D006019:Glycolysis; D006593:Hexokinase / Q000302:isolation & purification / Q000378:metabolism; D006736:Horses; D007202:Indicators and Reagents / Q000494:pharmacology; D008291:Malate Dehydrogenase / Q000302:isolation & purification / Q000378:metabolism; D051379:Mice; D008830:Microbodies / Q000201:enzymology; D008856:Microscopy, Fluorescence; D010539:Permeability / Q000187:drug effects; D019764:Phosphoenolpyruvate Carboxykinase (ATP) / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D010735:Phosphoglycerate Kinase / Q000302:isolation & purification / Q000378:metabolism; D010751:Phosphopyruvate Hydratase / Q000302:isolation & purification / Q000378:metabolism; D011772:Pyruvate, Orthophosphate Dikinase / Q000302:isolation & purification / Q000378:metabolism*; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar; D014345:Trypanosoma / Q000187:drug effects / Q000201:enzymology*
chemical_list: D007202:Indicators and Reagents; D008291:Malate Dehydrogenase; D005954:Glucosephosphate Dehydrogenase; D006593:Hexokinase; D010735:Phosphoglycerate Kinase; D011772:Pyruvate, Orthophosphate Dikinase; D019764:Phosphoenolpyruvate Carboxykinase (ATP); D010751:Phosphopyruvate Hydratase; D004072:Digitonin
keywords: Glycosome; Metabolism; Phosphoenolpyruvate carboxykinase; Phosphoglycerate kinase; Pyruvate phosphate dikinase; Trypanosoma evansi