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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

RmKK, a tissue kallikrein inhibitor from Rhipicephalus microplus eggs

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Abreu, Patricia A. [1] ; Soares, Tatiane S. [1] ; Buarque, Diego S. [1] ; Torquato, Ricardo S. [1] ; Tanaka, Aparecida S. [1]
Total Authors: 5
[1] Univ Fed Sao Paulo, Dept Biochem, Sao Paulo - Brazil
Total Affiliations: 1
Document type: Journal article
Source: Biochemical and Biophysical Research Communications; v. 449, n. 1, p. 69-73, JUN 20 2014.
Web of Science Citations: 3

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)

FAPESP's process: 05/03514-9 - Studies of the physiological function and biotechnological potential of protease inhibitors and anti-hemostatics in hematophagous arthropods
Grantee:Aparecida Sadae Tanaka
Support Opportunities: Research Projects - Thematic Grants
FAPESP's process: 12/03657-8 - Inhibitor and proteases of ectoparasites: relationship of structure-function and identification of the role of these molecules in the interaction of diseases vector e their etiological agents
Grantee:Aparecida Sadae Tanaka
Support Opportunities: Research Projects - Thematic Grants