The pentose phosphate pathway in Trypanosoma cruzi: a potential target for the chemotherapy of Chagas disease.

Trypanosoma cruzi is highly sensitive to oxidative stress caused by reactive oxygen species. Trypanothione, the parasite's major protection against oxidative stress, is kept reduced by trypanothione reductase, using NADPH; the major source of the reduced coenzyme seems to be the pentose phosphate pathway. Its seven enzymes are present in the four major stages in the parasite's biological cycle; we have cloned and expressed them in Escherichia coli as active proteins. Glucose 6-phosphate dehydrogenase, which controls glucose flux through the pathway by its response to the NADP/NADPH ratio, is encoded by a number of genes per haploid genome, and is induced up to 46-fold by hydrogen peroxide in metacyclic trypomastigotes. The genes encoding 6-phosphogluconolactonase, 6-phosphogluconate dehydrogenase, transaldolase and transketolase are present in the CL Brener clone as a single copy per haploid genome. 6-phosphogluconate dehydrogenase is very unstable, but was stabilized introducing two salt bridges by site-directed mutagenesis. Ribose-5-phosphate isomerase belongs to Type B; genes encoding Type A enzymes, present in mammals, are absent. Ribulose-5-phosphate epimerase is encoded by two genes. The enzymes of the pathway have a major cytosolic component, although several of them have a secondary glycosomal localization, and also minor localizations in other organelles.

[1]  Laurent Salmon,et al.  Ribose 5-phosphate isomerase type B from Trypanosoma cruzi: kinetic properties and site-directed mutagenesis reveal information about the reaction mechanism. , 2007, The Biochemical journal.

[2]  J. Cazzulo,et al.  The pentose phosphate pathway in Trypanosoma cruzi. , 2004, FEMS microbiology letters.

[3]  L. Reitzer,et al.  The pentose cycle. Control and essential function in HeLa cell nucleic acid synthesis. , 1980, The Journal of biological chemistry.

[4]  S. Wilkinson,et al.  Distinct Mitochondrial and Cytosolic Enzymes Mediate Trypanothione-dependent Peroxide Metabolism in Trypanosoma cruzi * , 2000, The Journal of Biological Chemistry.

[5]  Michael P Barrett,et al.  The trypanosomiases , 2003, The Lancet.

[6]  M. Barrett,et al.  Pentose phosphate metabolism in Leishmania mexicana. , 2003, Molecular and biochemical parasitology.

[7]  R. Docampo Sensitivity of parasites to free radical damage by antiparasitic drugs. , 1990, Chemico-biological interactions.

[8]  Stefania Hanau,et al.  Synthesis and biological evaluation of substrate-based inhibitors of 6-phosphogluconate dehydrogenase as potential drugs against African trypanosomiasis. , 2003, Bioorganic & medicinal chemistry.

[9]  J. Cazzulo,et al.  The 6-phosphogluconate dehydrogenase from Trypanosoma cruzi: the absence of two inter-subunit salt bridges as a reason for enzyme instability. , 2004, Molecular and biochemical parasitology.

[10]  D. Nolan,et al.  The enzymes of the classical pentose phosphate pathway display differential activities in procyclic and bloodstream forms of Trypanosoma brucei , 1989, FEBS letters.

[11]  H. Wood,et al.  The use of C14O2 yields from glucose-1- and -6-C14 for the evaluation of the pathways of glucose metabolism. , 1963, The Journal of biological chemistry.

[12]  Michael P. Barrett,et al.  Crystallographic studies on 6-phosphogluconate dehydrogenase from Trypanosoma brucei , 1993 .

[13]  M. Miles,et al.  The Trypanosoma cruzi Enzyme TcGPXI Is a Glycosomal Peroxidase and Can Be Linked to Trypanothione Reduction by Glutathione or Tryparedoxin* , 2002, The Journal of Biological Chemistry.

[14]  A. Perl,et al.  Glutathione Levels and Sensitivity to Apoptosis Are Regulated by Changes in Transaldolase Expression* , 1996, The Journal of Biological Chemistry.

[15]  A. Frasch,et al.  Two forms of 'malic' enzyme with different regulatory properties in Trypanosoma cruzi. , 1979, The Biochemical journal.

[16]  Á. Balogh,et al.  Redox modulation of glucose‐6‐P dehydrogenase in Anacystis nidulans and its ‘uncoupling’ by phage infection , 1981, FEBS letters.

[17]  S. Wilkinson,et al.  TcGPXII, a glutathione-dependent Trypanosoma cruzi peroxidase with substrate specificity restricted to fatty acid and phospholipid hydroperoxides, is localized to the endoplasmic reticulum. , 2002, The Biochemical journal.

[18]  H. Ginsburg,et al.  Hexose-monophosphate shunt activity in intact Plasmodium falciparum-infected erythrocytes and in free parasites. , 1994, Molecular and biochemical parasitology.

[19]  A. von Schaewen,et al.  Identification of the Cysteine Residues Involved in Redox Modification of Plant Plastidic Glucose-6-phosphate Dehydrogenase* , 1997, The Journal of Biological Chemistry.

[20]  R. Mancilla,et al.  COMPARATIVE METABOLISM OF C14-GLUCOSE IN TWO STRAINS OF TRYPANOSOMA CRUZI. , 1964, The Journal of protozoology.

[21]  A. Sols,et al.  Rat liver 6-phosphogluconolactonase: a low Km enzyme. , 1976, Biochemical and biophysical research communications.

[22]  Samson O Obado,et al.  Trypanosoma cruzi expresses a plant-like ascorbate-dependent hemoperoxidase localized to the endoplasmic reticulum , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[23]  T. Takizawa,et al.  Glucose-6-phosphate dehydrogenase cytochemistry using a copper ferrocyanide method and its application to rapidly frozen cells , 1999, Histochemistry and Cell Biology.

[24]  E. Segura,et al.  Purification and some properties of the NADP-linked glutamate dehydrogenase from Trypanosoma cruzi. , 1978, The International journal of biochemistry.

[25]  M. Barrett,et al.  6-Phosphogluconate dehydrogenase from Trypanosoma brucei. Kinetic analysis and inhibition by trypanocidal drugs. , 1996, European journal of biochemistry.

[26]  M. Delarue,et al.  Three dimensional structure and implications for the catalytic mechanism of 6-phosphogluconolactonase from Trypanosoma brucei. , 2007, Journal of molecular biology.

[27]  I. Raw Some Aspects of Carbohydrate Metabolism of Cultural Forms of Trypanosoma cruzi. , 1959 .

[28]  C. Cervellati,et al.  Sugar derivatives as new 6-phosphogluconate dehydrogenase inhibitors selective for the parasite Trypanosoma brucei. , 2003, Bioorganic & medicinal chemistry.

[29]  Chuan Yi Tang,et al.  A 2.|E|-Bit Distributed Algorithm for the Directed Euler Trail Problem , 1993, Inf. Process. Lett..

[30]  J Van Roy,et al.  Molecular characterization of the first two enzymes of the pentose-phosphate pathway of Trypanosoma brucei. Glucose-6-phosphate dehydrogenase and 6-phosphogluconolactonase. , 2000, The Journal of biological chemistry.

[31]  Selective inhibition of Trypanosoma brucei 6-phosphogluconate dehydrogenase by high-energy intermediate and transition-state analogues. , 2004, Journal of medicinal chemistry.

[32]  P. Heinrich,et al.  Behavior of transaldolase (EC 2.2.1.2) and transketolase (EC 2.2.1.1) Activities in normal, neoplastic, differentiating, and regenerating liver. , 1976, Cancer research.

[33]  F. Opperdoes,et al.  Evolution of energy metabolism and its compartmentation in Kinetoplastida , 2003, Kinetoplastid biology and disease.

[34]  F. Opperdoes,et al.  Purification, localisation and characterisation of glucose-6-phosphate dehydrogenase of Trypanosoma brucei. , 1999, Molecular and biochemical parasitology.

[35]  M. Barrett,et al.  A 2.8 A resolution structure of 6-phosphogluconate dehydrogenase from the protozoan parasite Trypanosoma brucei: comparison with the sheep enzyme accounts for differences in activity with coenzyme and substrate analogues. , 1998, Journal of molecular biology.

[36]  F. Young Biochemistry , 1955, The Indian Medical Gazette.

[37]  M. Igoillo-Esteve,et al.  The glucose-6-phosphate dehydrogenase from Trypanosoma cruzi: its role in the defense of the parasite against oxidative stress. , 2006, Molecular and biochemical parasitology.

[38]  Y. Lindqvist,et al.  Transketolase from Leishmania mexicana , 2004 .

[39]  A. Frasch,et al.  The NADP+-linked glutamate dehydrogenase from Trypanosoma cruzi: sequence, genomic organization and expression. , 1998, The Biochemical journal.