title: Nitric oxide synthase (NOS) characterization in Leishmania amazonensis axenic amastigotes.
abstract: BACKGROUND
  Although Leishmania virulence may be modulated by environmental and genetic factors of their mammalian hosts and sand fly vectors, molecular determinants of Leishmania sp. are the key elements. This work evidences that Leishmania amazonensis axenic amastigotes produce comparatively more NO than infective promastigotes.
  
  
  METHODS
  A soluble NOS was purified from L. amazonensis axenic amastigotes by affinity chromatography (2',5'-ADP-agarose), and on SDS-PAGE the enzyme migrates as a single protein band.
  
  
  RESULTS
  The presence of a constitutive NOS was detected through immunofluorescence using antibody against neuronal NOS (nNOS) and in NADPH consumption assays.
  
  
  CONCLUSIONS
  The present data show that NOS is prominent in axenic amastigote preparations, suggesting an association with the infectivity and/or an escaping mechanism of the parasite. The relationship between the NO-generating systems in the parasite and in their host cell warrants further investigation.
authors.affiliation: Department of Immunology, Oswaldo Cruz Foundation, FIOCRUZ, Rio de Janeiro, Brazil. genestra@ioc.fiocruz.br
authors.forename: Marcelo
authors.initials: M
authors.lastname: Genestra
authors.forename: Damiana
authors.initials: D
authors.lastname: Guedes-Silva
authors.forename: Wilson J S
authors.initials: WJ
authors.lastname: Souza
authors.forename: Léa
authors.initials: L
authors.lastname: Cysne-Finkelstein
authors.forename: Rômulo José
authors.initials: RJ
authors.lastname: Soares-Bezerra
authors.forename: Fabiane Pereira
authors.initials: FP
authors.lastname: Monteiro
authors.forename: Leonor L
authors.initials: LL
authors.lastname: Leon
mesh_terms: D000818:Animals; D007891:Leishmania / Q000145:classification / Q000201:enzymology* / Q000254:growth & development*; D009569:Nitric Oxide / Q000096:biosynthesis; D019001:Nitric Oxide Synthase / Q000378:metabolism*
chemical_list: D009569:Nitric Oxide; D019001:Nitric Oxide Synthase