Identification and characterization of a novel factor XIIa inhibitor in the hematophagous insect, Triatoma infestans (Hemiptera: Reduviidae)

Autor(es)

Tanaka-Azevedo, Anita M. ; Tanaka, Aparecida S. ; Campos, Ivan Torres Nicolau de ^[3]

• Tipo de documento: Artigo Científico
• Fonte: FEBS Letters; v. 577, n. 3, p. 512-516, Nov. 2004.
• Área do conhecimento: Ciências Biológicas - Bioquímica
• Assunto(s): Inibidores enzimáticos Insetos Triatoma

Resumo

Recently, we have cloned several Kazal-type serine protease inhibitors from the midgut of the Triatoma infestans bug. A single gene composed of multi Kazal-type domains, in tandem, encodes these inhibitors. In this work, we describe the purification and characterization of recombinant infestins 3-4 and 4, which are potent factor XIIa inhibitors (Ki =67 pM and 128 pM, respectively). We also identified the first native factor XIIa inhibitor from a hematophagous insect. The factor XIIa inhibitory activity of infestin 4 demonstrates extremely efficient anticoagulant activity, prolonging activated partial thromboplastin time by approximately 3 times. Our results suggest that infestins perform a very important role in the T. infestans midgut during meal acquisition and digestion by controlling blood coagulation by means of inhibiting thrombin and factor XIIa. (AU)

• Processo FAPESP: 02/13960-8 - Estudos de estrutura e funcao de anti-hemostaticos presentes em artropodes hematofagos.
• Beneficiário: Aparecida Sadae Tanaka
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 01/08325-9 - Estudo estrutural de inibidores de serinoproteases extraídos de Triatoma infestans
• Beneficiário: Ivan Torres Nicolau de Campos
• Modalidade de apoio: Bolsas no Brasil - Doutorado