title: Leishmania amazonensis: early proteinase activities during promastigote-amastigote differentiation in vitro.
abstract: Leishmania proteinase activity is known as parasite differentiation marker, and has been considered relevant for leishmanial survival and virulence. These properties suggest that Leishmania proteinases can be promising targets for development of anti-leishmania drugs. Here, we analyze the activities of four proteinases during the early phase of the Leishmania amazonensis promastigotes differentiation into amastigotes induced by heat shock. We have examined activities of cysteine-, metallo-, serine-, and aspartic-proteinase by hydrolysis of specific chromogenic substrates at pH 5.0 and at the optimal pH for each enzyme. Our results show that metallo-, serine-, and aspartic-proteinases activities were down-regulated during the shock-induced transformation of promastigotes into amastigotes. In contrast, cysteine-proteinase activity increased concomitantly with the promastigote differentiation. Immunocytochemical localization using two anti-cysteine-proteinase monospecific rabbit antibodies detected the enzyme in several cell compartments of both parasite stages. Our results show different proteinase activity modulation and expression during the early phases of the shock-induced parasite transformation.
authors.affiliation: Departamento Bioquímica e Biologia Molecular, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, RJ, Brazil. calves@ioc.fiocruz.br
authors.forename: C R
authors.initials: CR
authors.lastname: Alves
authors.forename: S
authors.initials: S
authors.lastname: Corte-Real
authors.forename: S C
authors.initials: SC
authors.lastname: Bourguignon
authors.forename: C S
authors.initials: CS
authors.lastname: Chaves
authors.forename: E M B
authors.initials: EM
authors.lastname: Saraiva
mesh_terms: D000818:Animals; D002863:Chromogenic Compounds / Q000378:metabolism; D022162:Cytoplasmic Vesicles / Q000201:enzymology; D005407:Flagella / Q000201:enzymology; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007106:Immune Sera / Q000276:immunology; D015151:Immunoblotting; D007150:Immunohistochemistry; D007894:Leishmania mexicana / Q000201:enzymology* / Q000254:growth & development / Q000648:ultrastructure; D010447:Peptide Hydrolases / Q000378:metabolism*; D015800:Protozoan Proteins / Q000378:metabolism; D011817:Rabbits
chemical_list: D002863:Chromogenic Compounds; D007106:Immune Sera; D015800:Protozoan Proteins; D010447:Peptide Hydrolases