A5000347866- Trypanosoma species research and implications
- Research on Leishmaniasis Studies
- Biochemical and Molecular Research
- Synthesis and Biological Evaluation
- Adenosine and Purinergic Signaling
- Polyamine Metabolism and Applications
- Parasites and Host Interactions
- Insect and Pesticide Research
- Toxin Mechanisms and Immunotoxins
- Adolescent and Pediatric Healthcare
- Signaling Pathways in Disease
Oregon Health & Science University
2006-2018
Institut Langevin
2010
Arkema (France)
2010
TD Bank
2006
Studies of Leishmania donovani have shown that both ornithine decarboxylase and spermidine synthase, two enzymes the polyamine biosynthetic pathway, are critical for promastigote proliferation required maximum infection in mice. However, importance arginase (ARG), first enzyme pathway Leishmania, has not been analyzed L. To test ARG function intact parasites, we generated Δarg null mutants evaluated their ability to proliferate vitro trigger infections The knockout was incapable growth...
Mutations within the polyamine biosynthetic pathway of Leishmania donovani, etiological agent visceral leishmaniasis, confer auxotrophy to insect vector or promastigote form parasite. However, whether infectious amastigote parasite requires an intact has remained open question. To address this issue, conditionally lethal Deltaodc mutants lacking ornithine decarboxylase (ODC), rate-limiting enzyme in biosynthesis, were created by double targeted gene replacement a virulent strain L. donovani....
The final two steps of de novo uridine 5'-monophosphate (UMP) biosynthesis are catalyzed by orotate phosphoribosyltransferase (OPRT) and orotidine decarboxylase (OMPDC). In most prokaryotes simple eukaryotes these enzymes encoded separate genes, whereas in mammals they expressed as a bifunctional gene product called UMP synthase (UMPS), with OPRT at the N terminus OMPDC C terminus. Leishmania some closely related organisms also express enzyme for steps, but domain order is reversed relative...
ABSTRACT Endochin-like quinolones (ELQs) are potent and specific inhibitors of cytochrome bc 1 from Plasmodium falciparum Toxoplasma gondii show promise for novel antiparasitic drug development. To determine whether the mitochondrial electron transport chain Leishmania parasites could be targeted similarly development, we investigated activity 134 structurally diverse ELQs. A cohort ELQs was selectively toxic to amastigotes mexicana L. donovani , with 50% inhibitory concentrations (IC 50 s)...
Leishmania donovani cannot synthesize purines de novo and express a multiplicity of enzymes that enable them to salvage from their hosts. Previous efforts generate an L. strain deficient in both hypoxanthine-guanine phosphoribosyl-transferase (HGPRT) xanthine phosphoribosyltransferase (XPRT) using gene replacement approaches were not successful, lending indirect support the hypothesis either HGPRT or XPRT is crucial for purine by parasite. We now report genetic confirmation this through...
Protozoan parasites of the Leishmania genus express metabolic machinery to synthesize pyrimidine nucleotides via both de novo and salvage pathways. To evaluate relative contributions biosynthesis homeostasis in life cycle stages donovani, individual mutant lines deficient either carbamoyl phosphate synthetase (CPS), first enzyme biosynthesis, uracil phosphoribosyltransferase (UPRT), a enzyme, or CPS UPRT were constructed. The Δcps lesion conferred auxotrophy growth requirement for medium...
To facilitate a greater understanding of the biological processes in medically important Leishmania donovani parasite, combination differential and density-gradient ultracentrifugation techniques were used to achieve comprehensive subcellular fractionation promastigote stage. An in-depth label-free proteomic LC-MS/MS analysis density gradients resulted identification ∼50% proteome (3883 proteins detected), which included ∼645 integral membrane 1737 uncharacterized proteins. Clustering...
Summary Purine salvage by Leishmania is an obligatory nutritional process that impacts both cell viability and growth. Previously, we have demonstrated the removal of purines in culture provokes significant metabolic changes enable to survive prolonged periods purine starvation. In order understand how sense respond their environment, exploited several pathway mutants, some which adenine guanine nucleotide metabolism uncoupled. While wild type parasites grow any one a variety naturally...
Adenine aminohydrolase (AAH) is an enzyme that not present in mammalian cells and found exclusively Leishmania among the protozoan parasites infect humans. AAH plays a paramount role purine metabolism this genus by steering 6-aminopurines into 6-oxypurines. donovani 38 23% identical to Saccharomyces cerevisiae human adenosine deaminase enzymes, respectively, catalyzes adenine deamination hypoxanthine with apparent K(m) of 15.4 μM, does recognize as substrate. Western blot analysis...
The Leishmania guanosine 5'-monophosphate reductase (GMPR) and inosine dehydrogenase (IMPDH) are purine metabolic enzymes that function maintaining the cellular adenylate guanylate nucleotide. Interestingly, both contain a cystathionine-β-synthase domain (CBS). To investigate this regulation, GMPR was cloned shown to be sufficient complement guaC (GMPR), but not guaB (IMPDH), mutation in Escherichia coli. Kinetic studies confirmed catalyzed strict NADPH-dependent reductive deamination of GMP...
<i>Leishmania donovani</i> cannot synthesize purines <i>de novo</i> and obligatorily scavenge from the host. Previously, we described a conditional lethal Δ<i>hgprt</i>/Δ<i>xprt</i> mutant of <i>L. (Boitz, J. M., Ullman, B. (2006) <i>J. Biol. Chem.</i> 281, 16084–16089) that establishes salvages primarily through hypoxanthine-guanine phosphoribosyltransferase (HGPRT) xanthine (XPRT). Unlike wild type donovani</i>, knock-out grow on 6-oxypurines displays an absolute requirement for adenine or...