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Active Transport of Glutamate in Leishmania ( Leishmania ) amazonensis
Author(s) -
PAES LISVANE S.,
GALVEZ ROJAS ROBERT L.,
DALIRY ANISSA,
FLOETERWINTER LUCILE M.,
RAMIREZ MARCEL I.,
SILBER ARIEL M.
Publication year - 2008
Publication title -
journal of eukaryotic microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.067
H-Index - 77
eISSN - 1550-7408
pISSN - 1066-5234
DOI - 10.1111/j.1550-7408.2008.00346.x
Subject(s) - biology , leishmania , biochemistry , amino acid , glutamine , leishmania mexicana , extracellular , alanine , citrate synthase , glutamate receptor , metabolism , microbiology and biotechnology , enzyme , parasite hosting , receptor , world wide web , computer science
.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 × 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, α‐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.