Active Transport of Glutamate in Leishmania (Leishmania) amazonensis

Autor(es)

Paes, Lisvane S. ^[1] ; Rojas, Robert L. Galvez ^[1] ; Daliry, Anissa ^[2] ; Floeter-Winter, Lucile M. ^[3] ; Ramirez, Marcel I. ^[2] ; Silber, Ariel M. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Ciencias Biomed, Dept Parasitol, BR-05508 Sao Paulo - Brazil

^[2] Fundacao Oswaldo Cruz, Dept Bioquim & Biol Mol, Rio De Janeiro - Brazil

^[3] Univ Sao Paulo, Inst Biociencias, Dept Fisiol, BR-05508 Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Eukaryotic Microbiology; v. 55, n. 5, p. 382-387, SEP-OCT 2008.
• Citações Web of Science: 7

Resumo

Leishmania spp. are the causative agents of leishmaniasis, a complex of diseases with a broad spectrum of clinical manifestations. Leishmania (Leishmania) amazonensis is a main etiological agent of diffuse cutaneous leishmaniasis. Leishmania spp., as other trypanosomatids, possess a metabolism based significantly on the consumption of amino acids. However, the transport of amino acids in these organisms remains poorly understood with few exceptions. Glutamate transport is an important biological process in many organisms. In the present work, the transport of glutamate is characterized. This process is performed by a single kinetic system (K-m=0.59 +/- 0.04 mM, V-max=0.123 +/- 0.003 nmol/min per 20 x 10(6) cells) showing an energy of activation of 52.38 +/- 4.7 kJ/mol and was shown to be partially inhibited by analogues, such as glutamine, aspartate, alpha-ketoglutarate and oxaloacetate, methionine, and alanine. The transport activity was sensitive to the extracellular concentration of H+ but not to Na+ or K+. However, unlike other amino acid transporters presently characterized, the treatment with specific ionophores confirmed the participation of a K+, and not H+ membrane gradient in the transport process. (AU)

• Processo FAPESP: 03/13257-8 - Clonagem e caracterização de transportadores de aminoácidos em Trypanosoma cruzi: uma abordagem pós-genômica
• Beneficiário: Ariel Mariano Silber
• Linha de fomento: Auxílio à Pesquisa - Apoio a Jovens Pesquisadores