The ultimate goal of this research is to identify biochemical differences between mammalian host and parasite that can be exploited for the development of new and better chemotherapeutic compounds against diseases caused by Trypanosoma cruzi (Chagas' disease), Leishmania spp. (cutaneous, mucocutaneous and visceral Leishmaniasis) and T.rhodesiense or T.gambiense (human African trypanosomiasis). The general approach relies on the identification of novel and unique pathways, essential for the survival of the parasite, but not the human host. By characterizing such biochemical pathways and, in particular, gaining an understanding at the molecular level of the chemical mechanisms of key enzymatic reactions, it is hoped to provide a rational basis for the design of new inhibitors. The present application is a continuation of a previous grant, which led to the discovery of the novel dithiol spermidine-peptide, trypanothione (bis(glutathionyl)-spermidine). Three unique and key target enzymes have been identified so far: trypanothione reductase, trypanothione synthetase and trypanothione peroxidase. During the next grant period, it is intended to focus on T.cruzi (using C.fascicufata as a model, where appropriate) in order to achieve the following specific aims: 1. To purify and characterize trypanothione synthetase from C.fasciculata, the enzyme required for biosynthesis of trypyanothione and glutathionylspermidine. To design and test analogs of glutathione, spermidine and glutathionylspermidine as inhibitors. 2. To clone and sequence the genes encoding enzymes related to trypanothione metabolism, particularly with a view to expressing and producing T.cruzi trypanothione reductase and trypanothione synthetase in large amounts for drug development and crystallographic studies. 3. To further elucidate the roles of glutathione, glutathionylspermidine and trypanothione in the metabolism of these parasites, with particular emphasis given to: a) how glutathionylspermidine modulates intracellular levels of free spermidine. b) purification and characterization of trypanothione-dependent peroxidase activity. c) a comprehensive search for other glutathione- or trypanothione-dependent enzymes.

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Research Project (R01)
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Tropical Medicine and Parasitology Study Section (TMP)
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University of London
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Rifkin, M R; Strobos, C A; Fairlamb, A H (1995) Specificity of ethanolamine transport and its further metabolism in Trypanosoma brucei. J Biol Chem 270:16160-6
Smith, K; Nadeau, K; Bradley, M et al. (1992) Purification of glutathionylspermidine and trypanothione synthetases from Crithidia fasciculata. Protein Sci 1:874-83
Aboagye-Kwarteng, T; Smith, K; Fairlamb, A H (1992) Molecular characterization of the trypanothione reductase gene from Crithidia fasciculata and Trypanosoma brucei: comparison with other flavoprotein disulphide oxidoreductases with respect to substrate specificity and catalytic mechanism. Mol Microbiol 6:3089-99
el-Waer, A; Douglas, K T; Smith, K et al. (1991) Synthesis of N-benzyloxycarbonyl-L-cysteinylglycine 3-dimethylaminopropylamide disulfide: a cheap and convenient new assay for trypanothione reductase. Anal Biochem 198:212-6
Hunter, W N; Smith, K; Derewenda, Z et al. (1990) Initiating a crystallographic study of trypanothione reductase. J Mol Biol 216:235-7
Henderson, G B; Yamaguchi, M; Novoa, L et al. (1990) Biosynthesis of the trypanosomatid metabolite trypanothione: purification and characterization of trypanothione synthetase from Crithidia fasciculata. Biochemistry 29:3924-9
Henderson, G B; Ulrich, P; Fairlamb, A H et al. (1988) ""Subversive"" substrates for the enzyme trypanothione disulfide reductase: alternative approach to chemotherapy of Chagas disease. Proc Natl Acad Sci U S A 85:5374-8
Shim, H; Fairlamb, A H (1988) Levels of polyamines, glutathione and glutathione-spermidine conjugates during growth of the insect trypanosomatid Crithidia fasciculata. J Gen Microbiol 134:807-17
Henderson, G B; Fairlamb, A H; Ulrich, P et al. (1987) Substrate specificity of the flavoprotein trypanothione disulfide reductase from Crithidia fasciculata. Biochemistry 26:3023-7
Henderson, G B; Fairlamb, A H; Cerami, A (1987) Trypanothione dependent peroxide metabolism in Crithidia fasciculata and Trypanosoma brucei. Mol Biochem Parasitol 24:39-45

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