Análise do transporte de glutamato e GABA em epimastigotas de Trypanosama cruzi (2007)
- Authors:
- Autor USP: ROJAS, ROBERT LEONARDO GALVEZ - ICB
- Unidade: ICB
- Sigla do Departamento: BMP
- Subjects: PARASITOLOGIA; DOENÇA DE CHAGAS; METABOLISMO; GLUTAMATOS; GABA; QUIMIOTERAPIA
- Language: Português
- Abstract: The role of amino acids in trypanosomatids goes beyond protein synthesis, involving processes such as differentiation, osmoregulation and energy metabolism. The availability of the amino acids involved in those functions depends, among other things, on their transport into the cell. Here we characterize a glutamate transporter and GABA transport from the human protozoan parasite Trypanosoma cruzi. In the glutamate transport, data kinetics show a single saturable system with a Km of 0.30 mM and a maximum velocity of 98.34 pmoles min-1 per 2 x 107 cells for epimastigotes and 20 pmoles min-1 per 2 x 107 cells for trypomastigotes, and, a Vmax de 84.45 pmoles/min/20x106 cells and a Km of 0.4 mM for GABA transport system. Transport was not affected by parasite nutrient starvation for up to 3h in the two transport system. Aspartate, alanine, glutamine, asparagine, methionine, oxaloacetate and alpha-ketoglutarate competed with the substrate in 10-fold excess concentrations in the glutamate incorporation. Interestingly, the glutamate transport was strongly increased in the presence of GABA. Glutamate uptake was strongly dependent on pH, but not on Na+ or K+ concentrations in the extracellular medium, and the GABA transport was strongly dependent of K+. These data were consistent with the sensitivity of the system to the H+ ionophore carbonyl cyanide p-trifluoromethoxyphenylhydrazone, suggesting that transport is driven by H+ concentration gradient across the cytoplasmmembrane in two transport systems. The glutamate and GABA transport increased linearly with temperature in a range from 15 to 40 degrees C
- Imprenta:
- Data da defesa: 09.08.2007
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ABNT
GALVEZ ROJAS, Robert Leonardo. Análise do transporte de glutamato e GABA em epimastigotas de Trypanosama cruzi. 2007. Dissertação (Mestrado) – Universidade de São Paulo, São Paulo, 2007. Disponível em: http://www.teses.usp.br/teses/disponiveis/42/42135/tde-19102007-142527/. Acesso em: 16 ago. 2024. -
APA
Galvez Rojas, R. L. (2007). Análise do transporte de glutamato e GABA em epimastigotas de Trypanosama cruzi (Dissertação (Mestrado). Universidade de São Paulo, São Paulo. Recuperado de http://www.teses.usp.br/teses/disponiveis/42/42135/tde-19102007-142527/ -
NLM
Galvez Rojas RL. Análise do transporte de glutamato e GABA em epimastigotas de Trypanosama cruzi [Internet]. 2007 ;[citado 2024 ago. 16 ] Available from: http://www.teses.usp.br/teses/disponiveis/42/42135/tde-19102007-142527/ -
Vancouver
Galvez Rojas RL. Análise do transporte de glutamato e GABA em epimastigotas de Trypanosama cruzi [Internet]. 2007 ;[citado 2024 ago. 16 ] Available from: http://www.teses.usp.br/teses/disponiveis/42/42135/tde-19102007-142527/
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