New Insights into the Role of the Aldo-Keto Reductase AKR.

Chagas disease is a zoonotic infectious disease caused by the protozoan parasite . It is distributed worldwide, affecting around 7 million people; there is no effective treatment, and it constitutes a leading cause of disability and premature death in the Americas. Only two drugs are currently approved for the treatment, Benznidazole and Nifurtimox, and both have to be activated by reducing the nitro-group.

Anaerobic ATP synthesis pathways and inorganic phosphate transport and their possible roles in encystment in Acanthamoeba castellanii.

Acanthamoeba castellanii is the etiological agent of amoebic keratitis and is present in the environment in trophozoite or cyst forms. Both forms can infect the vertebrate host and colonize different tissues. The high resistance of cysts to standard drugs used in clinics contributes to the lack of effective treatments.

E-NTPDases: Possible Roles on Host-Parasite Interactions and Therapeutic Opportunities.

Belonging to the GDA1/CD39 protein superfamily, nucleoside triphosphate diphosphohydrolases (NTPDases) catalyze the hydrolysis of ATP and ADP to the monophosphate form (AMP) and inorganic phosphate (Pi). Several NTPDase isoforms have been described in different cells, from pathogenic organisms to animals and plants. Biochemical characterization of nucleotidases/NTPDases has revealed the existence of isoforms with different specificities regarding divalent cations (such as calcium and magnesium) and substrates.

Higher expression of proline dehydrogenase altered mitochondrial function and increased Trypanosoma cruzi differentiation in vitro and in the insect vector.

The pathogenic protist Trypanosoma cruzi uses kissing bugs as invertebrate hosts that vectorize the infection among mammals. This parasite oxidizes proline to glutamate through two enzymatic steps and one nonenzymatic step. In insect vectors, T.

3-Bromopyruvate: A new strategy for inhibition of glycolytic enzymes in Leishmania amazonensis.

The compound 3-bromopyruvate (3-BrPA) is well-known and studies from several researchers have demonstrated its involvement in tumorigenesis. It is an analogue of pyruvic acid that inhibits ATP synthesis by inhibiting enzymes from the glycolytic pathway and oxidative phosphorylation. In this work, we investigated the effect of 3-BrPA on energy metabolism of L.

Differential regulation of E-NTPdases during Leishmania amazonensis lifecycle and effect of their overexpression on parasite infectivity and virulence.

Infections caused by Leishmania amazonensis are characterized by a persistent parasitemia due to the ability of the parasite to modulate the immune response of macrophages. It has been proposed that ecto-nucleoside triphosphate diphosphohydrolase (E-NTPDases) could be able to suppress the host immune defense by reducing the ATP and ADP levels. The AMP generated from E-NTPDase activity can be subsequently hydrolyzed by ecto-nucleotidases, increasing the levels of adenosine, which can reduce the inflammatory response.

Blood meal drives de novo lipogenesis in the fat body of Rhodnius prolixus.

In insects, lipids are stored in the fat body mainly as triacylglycerol. Lipids can be directly provided by digestion and incorporated from the hemolymph, or synthesized de novo from other substrates such as carbohydrates and amino acids. The first step in de novo lipid synthesis is catalyzed by acetyl-CoA carboxylase (ACC), which carboxylates acetyl-CoA to form malonyl-CoA.

Leishmania amazonensis inorganic phosphate transporter system is increased in the proliferative forms.

Here we characterize a high-affinity Pi transport system energized by a H gradient in Leishmania amazonensis. P uptake and transcription of LamPho84 gene are differentially regulated during parasite life cycle. Our data suggest that P acquisition could be a pivotal task for the success of the parasite throughout its life cycle.

Tartrate-resistant phosphatase type 5 in Trypanosoma cruzi is important for resistance to oxidative stress promoted by hydrogen peroxide.

Trypanosoma cruzi (the causative agent of Chagas disease) presents a complex life cycle that involves adaptations in vertebrate and invertebrate hosts. As a protozoan parasite of hematophagous insects and mammalian hosts, T. cruzi is exposed to reactive oxygen species (ROS).

Ectophosphatase activity in the early-diverging fungus Blastocladiella emersonii: Biochemical characterization and possible role on cell differentiation.

Blastocladiella emersonii is an interesting model for studding the evolution of cell differentiation in eukaryotic cell because of its taxonomic position towards the base of the fungal phylogenetic tree and because it undergoes radical morphological and biochemical changes throughout its life cycle. In this work, we biochemically characterized a high alkaline phosphotyrosine phosphatase activity present on the cell surface (ectophosphatase) of B. emersonii.

Evolutionary conservation of a core fungal phosphate homeostasis pathway coupled to development in Blastocladiella emersonii.

The model yeast Saccharomyces cerevisiae elicits a transcriptional response to phosphate (P) depletion. To determine the origins of the phosphate response (PHO) system, we bioinformatically identified putative PHO components in the predicted proteomes of diverse fungi. Our results suggest that the PHO system is ancient; however, components have been expanded or lost in different fungal lineages.

NTPDase activities: possible roles on Leishmania spp infectivity and virulence.

Nucleoside triphosphate diphosphohydrolases (NTPDases) are enzymes that belong to the GDA1/CD39 protein superfamily. These enzymes catalyze the hydrolysis of ATP and ADP to the monophosphate form (AMP). Biochemical characterization of the nucleotidases/NTPDases from various types of cells, including those from plants, animals, and pathogenic organisms, has revealed the existence of several isoforms with different specificities with respect to divalent cations (magnesium, calcium, manganese, and zinc) and substrates.

Inhibitory effects promoted by 5'-nucleotides on the ecto-3'-nucleotidase activity of Leishmania amazonensis.

The protozoan parasite Leishmania amazonensis is the etiological agent of cutaneous leishmaniasis. During its life cycle, the flagellated metacyclic promastigote forms are transmitted to vertebrate hosts by sandfly bites, and they develop into amastigotes inside macrophages, where they multiply. L.

Identification and characterization of an ecto-pyrophosphatase activity in intact epimastigotes of Trypanosoma rangeli.

In this study, we performed the molecular and biochemical characterization of an ecto-enzyme present in Trypanosoma rangeli that is involved with the hydrolysis of extracellular inorganic pyrophosphate. PCR analysis identified a putative proton-pyrophosphatase (H(+)-PPase) in the epimastigote forms of T. rangeli.

Leishmania amazonensis: Increase in ecto-ATPase activity and parasite burden of vinblastine-resistant protozoa.

Leishmania amazonensis is a protozoan parasite that induces mucocutaneous and diffuse cutaneous lesions upon infection. An important component in treatment failure is the emergence of drug-resistant parasites. It is necessary to clarify the mechanism of resistance that occurs in these parasites to develop effective drugs for leishmaniasis treatment.