title: A recombinant form of chagasin from Trypanosoma cruzi: inhibitory activity on insect cysteine proteinases.
abstract: BACKGROUND
  The activity of the major digestive cysteine proteinase detected in the intestinal tract of larvae of the bean weevil, Acanthoscelides obtectus (Say), was efficiently inhibited by the well-characterized cysteine proteinase synthetic inhibitor E-64 and also by a recombinant form of chagasin (r-chagasin), a tight-binding cysteine proteinase inhibitor protein from Trypanosoma cruzi.
  
  
  RESULTS
  Incorporation of r-chagasin into an artificial diet system at 0.1 g kg(-1) retarded growth rate, decreased larval survival and led to complete mortality of A. obtectus at the end of the trial. The observed differences in growth rates occurred particularly in the first and second development stages. Artificial seeds containing high levels of r-chagasin (0.5-30 g kg(-1)) completely inhibited larval penetration.
  
  
  CONCLUSIONS
  Together, the results reported in this paper support the hypothesis that the inhibitory activity of r-chagasin towards the major insect gut cysteine proteinase in vitro and in vivo is an accurate prediction of its insecticidal effects. The selectivity of this inhibitor against insect digestive proteinases supports the key role in parasite virulence by affecting the endogenous proteinase activity in its natural host.
authors.affiliation: Embrapa Recursos Genéticos e Biotecnologia, PqEB, Final W5 Norte, 70770-900, Brasília, DF, Brazil.
authors.forename: Ana Carolina
authors.initials: AC
authors.lastname: Dos Santos Monteiro
authors.forename: Osmundo Brilhante
authors.initials: OB
authors.lastname: de Oliveira Neto
authors.forename: Rafael Perseghini
authors.initials: RP
authors.lastname: Del Sarto
authors.forename: Mariana Torquato Q
authors.initials: MT
authors.lastname: de Magalhães
authors.forename: Janaina Nascimento
authors.initials: JN
authors.lastname: Lima
authors.forename: Ariane Ferreira
authors.initials: AF
authors.lastname: Lacerda
authors.forename: Raquel Sampaio
authors.initials: RS
authors.lastname: Oliveira
authors.forename: Julio
authors.initials: J
authors.lastname: Scharfstein
authors.forename: Maria Cristina Mattar
authors.initials: MC
authors.lastname: da Silva
authors.forename: Jorge W Arboleda
authors.initials: JW
authors.lastname: Valencia
authors.forename: Arnubio Valencia
authors.initials: AV
authors.lastname: Jiménez
authors.forename: Maria Fatima
authors.initials: MF
authors.lastname: Grossi-de-Sa
mesh_terms: D000818:Animals; D001517:Coleoptera / Q000187:drug effects / Q000201:enzymology* / Q000502:physiology; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D041981:Gastrointestinal Tract / Q000201:enzymology; D019476:Insect Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D007814:Larva / Q000187:drug effects / Q000201:enzymology / Q000502:physiology; D010572:Pest Control, Biological; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology
chemical_list: D015853:Cysteine Proteinase Inhibitors; D019476:Insect Proteins; D015800:Protozoan Proteins; D011994:Recombinant Proteins; C435145:chagasin, Trypanosoma; D003546:Cysteine Endopeptidases