A5013947996- Trypanosoma species research and implications
- Research on Leishmaniasis Studies
- Biochemical and Molecular Research
- Insect symbiosis and bacterial influences
- Calcium signaling and nucleotide metabolism
- Parasites and Host Interactions
- Microbial Community Ecology and Physiology
- Folate and B Vitamins Research
- bioluminescence and chemiluminescence research
- Neonatal Health and Biochemistry
- Protist diversity and phylogeny
- Synthesis and Biological Evaluation
- Diatoms and Algae Research
- Studies on Chitinases and Chitosanases
- Peptidase Inhibition and Analysis
- Protease and Inhibitor Mechanisms
- Synthesis and Characterization of Heterocyclic Compounds
- Ubiquitin and proteasome pathways
- Carbohydrate Chemistry and Synthesis
Wellcome Sanger Institute
2020-2024
University of Dundee
2009-2018
Wellcome Trust
2016
American Academy in Berlin
2012
New School
2012
University of Washington
2008
Leishmania parasites are pteridine auxotrophs that use an NADPH-dependent reductase 1 (PTR1) and NADH-dependent quinonoid dihydropteridine (QDPR) to salvage maintain intracellular pools of tetrahydrobiopterin (H(4)B). However, the African trypanosome lacks a credible candidate QDPR in its genome despite maintaining apparent activity. Here we provide evidence activity previously reported by others is assay artifact. Using HPLC-based enzyme assay, demonstrate there associated with both TbPTR1...
Heterokont algae form a monophyletic group within the stramenopile branch of tree life. These organisms display wide morphological diversity, ranging from minute unicells to massive, bladed forms. Surprisingly, chloroplast genome sequences are available only for diatoms, representing two (Coscinodiscophyceae and Bacillariophyceae) approximately 18 classes that comprise this taxonomic cluster. A universal challenge sequencing studies is retrieval highly purified DNA in quantities sufficient...
Summary Gene knockout and knockdown methods were used to examine essentiality of pteridine reductase (PTR1) in pterin metabolism the African trypanosome. Attempts generate PTR1 null mutants bloodstream form Trypanosoma brucei proved unsuccessful; despite integration drug selectable markers at target locus, gene for was either retained same locus or elsewhere genome. However, RNA interference (RNAi) resulted complete endogenous protein after 48 h, followed by cell death 4 days. This lethal...
SCYX-7158, an oxaborole, is currently in Phase I clinical trials for the treatment of human African trypanosomiasis. Here we investigate possible modes action against Trypanosoma brucei using orthogonal chemo-proteomic and genomic approaches. SILAC-based proteomic studies oxaborole analogue immobilised onto a resin was used either competition with soluble or inactive control to identify thirteen proteins common both strategies. Cell-cycle analysis cells incubated sub-lethal concentrations...
Bifunctional dihydrofolate reductase–thymidylate synthase (DHFR-TS) is a chemically and genetically validated target in African trypanosomes, causative agents of sleeping sickness humans nagana cattle. Here we report the kinetic properties sensitivity recombinant enzyme to range lipophilic classical antifolate drugs. The purified enzyme, expressed as fusion protein with elongation factor Ts (Tsf) ThyA- Escherichia coli, retains DHFR activity, but lacks any TS activity. activity was found be...
Abstract Genetic studies indicate that the enzyme pteridine reductase 1 (PTR1) is essential for survival of protozoan parasite Trypanosoma brucei . Herein, we describe development and optimisation a novel series PTR1 inhibitors, based on benzo[ d ]imidazol‐2‐amine derivatives. Data are reported 33 compounds. This was initially discovered by virtual screening campaign ( J. Med. Chem ., 2009 , 52 4454). The inhibitors adopted an alternative binding mode to those natural ligands, biopterin...
Activity of the pterin- and folate-salvaging enzymes pteridine reductase 1 (PTR1) dihydrofolate reductase-thymidylate synthetase (DHFR-TS) is commonly measured as a decrease in absorbance at 340 nm, corresponding to oxidation nicotinamide adenine dinucleotide phosphate (NADPH). Although this assay has been adequate study biology these enzymes, it not amenable support any degree routine inhibitor assessment because its restricted linearity incompatible with enhanced throughput microtiter...
African trypanosomes are capable of both de novo synthesis and salvage pyrimidines. The last two steps in catalysed by UMP synthase (UMPS) - a bifunctional enzyme comprising orotate phosphoribosyl transferase (OPRT) orotidine monophosphate decarboxylase (OMPDC). To investigate the essentiality pyrimidine biosynthesis Trypanosoma brucei, we generated umps double knockout (DKO) line gene replacement. DKO was unable to grow pyrimidine-depleted medium vitro, unless supplemented with uracil,...
De novo synthesis of threonine from aspartate occurs via the β-aspartyl phosphate pathway in plants, bacteria and fungi. However, Trypanosoma brucei genome encodes only last two steps this pathway: homoserine kinase (HSK) synthase. Here, we investigated possible roles for incomplete through biochemical, genetic nutritional studies. Purified recombinant TbHSK specifically phosphorylates L-homoserine displays kinetic properties similar to other HSKs. HSK null mutants generated bloodstream...
Abstract Visceral leishmaniasis is an infectious parasitic disease caused by the protozoan parasites Leishmania donovani and infantum . The drugs currently used to treat visceral suffer from toxicity emergence of parasite resistance, so a better solution would be development effective subunit vaccine; however, no approved vaccine exists. comparative testing large number candidates requires quantitative reproducible experimental murine infection model, but parameters that influence pathology...
Visceral leishmaniasis is a deadly infectious disease and one of the world's major neglected health problems. Because symptoms infection are similar to other endemic diseases, accurate diagnosis crucial for appropriate treatment. Definitive using splenic or bone marrow aspirates highly invasive, so, serological assays preferred, including direct agglutination test (DAT) rK39 strip test. These tests, however, either difficult perform in field lack specificity some regions (rK39), making...
Previous metabolic studies have demonstrated that leishmania parasites are able to synthesise proline from glutamic acid and threonine aspartic acid. The first committed step in both biosynthetic pathways involves an amino kinase, either a glutamate 5-kinase (G5K; EC2.7.2.11) or aspartokinase (EC2.7.2.4). Bioinformatic analysis of multiple genomes identifies single acid-kinase gene (LdBPK 262740.1) variously annotated as putative aspartate kinase. To establish the catalytic function this...
Leishmaniasis is an infectious disease caused by protozoan parasites belonging to the genus Leishmania for which there are no approved human vaccines. Infections localise different tissues in a species-specific manner with visceral form of donovani and L . infantum being most deadly humans. Although spp. predominantly intracellular, can be prevented dogs vaccinating complex mixture secreted products from cultures promastigotes. With logic that extracellular parasite proteins make good...
The folate pathway has been extensively studied in a number of organisms, with its essentiality exploited by drugs. However, there little success developing drugs that target metabolism the kinetoplastids. Despite compounds being identified which show significant inhibition parasite enzymes, this activity does not translate well into cellular and animal models disease. Understanding to enzymes antifolates bind under physiological conditions how corresponds phenotypic response could provide...
Abstract Trypanosomes are protozoan parasites that cause infectious diseases including human African trypanosomiasis (sleeping sickness), and nagana in economically-important livestock animals 1,2 . An effective vaccine against trypanosomes would be an important control tool, but the parasite has evolved sophisticated immunoprotective mechanisms antigenic variation 3 present apparently insurmountable barrier to vaccination. Here we show using a systematic genome-led vaccinology approach 4...
January 01 2012 Being Contemporary Babette Mangolte, Mangolte is an experimental filmmaker who has lived in New York City since 1970. She known for her photo archives covering theatre, dance, and performance from the 1970s 1980s. Recently, she created a complex architectural photo/film installation Whitney Biennale 2010 entitled how to look … now finishing film Roof Piece on High Line, with choreography by Trisha Brown, shot June 2011. Search other works this author on: This Site Google...
An amendment to this paper has been published and can be accessed via a link at the top of paper.