RmKK, a tissue kallikrein inhibitor from Rhipicephalus microplus eggs

Autor(es)

Abreu, Patricia A. ^[1] ; Soares, Tatiane S. ^[1] ; Buarque, Diego S. ^[1] ; Torquato, Ricardo S. ^[1] ; Tanaka, Aparecida S. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Paulo, Dept Biochem, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Biochemical and Biophysical Research Communications; v. 449, n. 1, p. 69-73, JUN 20 2014.
• Citações Web of Science: 3

Resumo

Rhipicephalus microplus is an important ectoparasite that is responsible for transmission of anaplasmosis and babesiosis to cattle. Tissue kallikrein inhibitors might play an important role in R. microplus eggs. In the present work, we purified and characterized, a tissue kallikrein inhibitor presents in R. microplus eggs (RmKK), a protein which contains two Kunitz domain in tandem. Purified inhibitor was confirmed by amino terminal determination and its dissociation constant (K-i) for bovine trypsin and porcine pancreatic kallikrein were 0.6 nM and 91.5 nM, respectively. Using a cDNA library from R. microplus midgut, we cloned the cDNA fragment encoding mature RmKK and expressed the protein in Pichia pastoris system. Recombinant RmKK was purified by ion exchange chromatography and presented molecular mass of 16.3 kDa by MALDI-TOF analysis. Moreover, RmKK showed a tight binding inhibition for serine proteases as bovine trypsin (K-i = 0.2 nM) and porcine pancreatic kallikrein (PPK) (K-i = 300 nM). We performed, for the first time, the characterization of a tissue kallikrein inhibitor presents in R. microplus eggs, which the transcript is produced in the adult female gut. BmKK seems to be the strongest PPK inhibitor among all BmTIs present in the eggs and larvae (Andreotti et al., 2001; Sasaki et al., 2004). This data suggests that BmKK may participate in the development of tick egg and larvae phase. (C) 2014 Elsevier Inc. All rights reserved. (AU)

• Processo FAPESP: 05/03514-9 - Estudos da função fisiológica e potencial biotecnológico de inibidores de proteases e anti-hemostáticos presentes em artrópodes hematófagos
• Beneficiário: Aparecida Sadae Tanaka
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 12/03657-8 - Inibidores e proteases de ectoparasitas: relação de estrutura-função e identificação do papel dessas moléculas na interação de vetores de doenças e seus agentes etiológicos
• Beneficiário: Aparecida Sadae Tanaka
• Modalidade de apoio: Auxílio à Pesquisa - Temático