title: Effect of aliphatic, monocarboxylic, dicarboxylic, heterocyclic and sulphur-containing amino acids on Leishmania spp. chemotaxis.
abstract: In the sand-fly mid gut, Leishmania promastigotes are exposed to acute changes in nutrients, e.g. amino acids (AAs). These metabolites are the main energy sources for the parasite, crucial for its differentiation and motility. We analysed the migratory behaviour and morphological changes produced by aliphatic, monocarboxylic, dicarboxylic, heterocyclic and sulphur-containing AAs in Leishmania amazonensis and Leishmania braziliensis and demonstrated that L-methionine (10-12 m), L-tryptophan (10-11 m), L-glutamine and L-glutamic acid (10-6 m), induced positive chemotactic responses, while L-alanine (10-7 m), L-methionine (10-11 and 10-7 m), L-tryptophan (10-11 m), L-glutamine (10-12 m) and L-glutamic acid (10-9 m) induced negative chemotactic responses. L-proline and L-cysteine did not change the migratory potential of Leishmania. The flagellum length of L. braziliensis, but not of L. amazonensis, decreased when incubated in hyperosmotic conditions. However, chemo-repellent concentrations of L-alanine (Hypo-/hyper-osmotic conditions) and L-glutamic acid (hypo-osmotic conditions) decreased L. braziliensis flagellum length and L-methionine (10-11 m, hypo-/hyper-osmotic conditions) decreased L. amazonensis flagellum length. This chemotactic responsiveness suggests that Leishmania discriminate between slight concentration differences of small and structurally closely related molecules and indicates that besides their metabolic effects, AAs play key roles linked to sensory mechanisms that might determine the parasite's behaviour.
authors.affiliation: Laboratory of Molecular Physiology,Institute of Experimental Medicine,School of Medicine Luis Razetti,Faculty of Medicine,Universidad Central de Venezuela,Caracas,Venezuela.
authors.forename: E
authors.initials: E
authors.lastname: Diaz
authors.affiliation: Laboratory of Molecular Physiology,Institute of Experimental Medicine,School of Medicine Luis Razetti,Faculty of Medicine,Universidad Central de Venezuela,Caracas,Venezuela.
authors.forename: A K
authors.initials: AK
authors.lastname: Zacarias
authors.affiliation: Laboratory of Molecular Physiology,Institute of Experimental Medicine,School of Medicine Luis Razetti,Faculty of Medicine,Universidad Central de Venezuela,Caracas,Venezuela.
authors.forename: S
authors.initials: S
authors.lastname: Pérez
authors.affiliation: Laboratory of Molecular Physiology,Institute of Experimental Medicine,School of Medicine Luis Razetti,Faculty of Medicine,Universidad Central de Venezuela,Caracas,Venezuela.
authors.forename: O
authors.initials: O
authors.lastname: Vanegas
authors.affiliation: Department of Genetics, Cell and Immunobiology,Semmelweis University,Budapest,Hungary.
authors.forename: L
authors.initials: L
authors.lastname: Köhidai
authors.affiliation: Laboratory of Molecular Physiology,Institute of Experimental Medicine,School of Medicine Luis Razetti,Faculty of Medicine,Universidad Central de Venezuela,Caracas,Venezuela.
authors.forename: M
authors.initials: M
authors.lastname: Padrón-Nieves
authors.affiliation: Laboratory of Molecular Physiology,Institute of Experimental Medicine,School of Medicine Luis Razetti,Faculty of Medicine,Universidad Central de Venezuela,Caracas,Venezuela.
authors.forename: A
authors.initials: A
authors.lastname: Ponte-Sucre
mesh_terms: D000596:Amino Acids / Q000737:chemistry / Q000494:pharmacology*; D000600:Amino Acids, Dicarboxylic / Q000494:pharmacology; D000603:Amino Acids, Sulfur / Q000494:pharmacology; D002633:Chemotaxis / Q000187:drug effects*; D005407:Flagella / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D006571:Heterocyclic Compounds / Q000494:pharmacology; D007891:Leishmania / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D007892:Leishmania braziliensis / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D007894:Leishmania mexicana / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D009994:Osmolar Concentration
chemical_list: D000596:Amino Acids; D000600:Amino Acids, Dicarboxylic; D000603:Amino Acids, Sulfur; D006571:Heterocyclic Compounds
keywords: Amino acids; Leishmania amazonensis; Leishmania braziliensis; chemotaxis; flagellum length; osmotic stress; parasite's motility