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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Amblyomin-X having a Kunitz-type homologous domain, is a noncompetitive inhibitor of FXa and induces anticoagulation in vitro and in vivo

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Branco, Vania G. ; Iqbal, Asif ; Alvarez-Flores, Miryam P. ; Sciani, Juliana M. ; de Andrade, Sonia A. ; Iwai, Leo K. ; Serrano, Solange M. T. ; Chudzinski-Tavassi, Ana M.
Número total de Autores: 8
Tipo de documento: Artigo Científico
Citações Web of Science: 6

Background: Cancer has long been associated with thrombosis and many of the standard chemotherapeutics used to treat cancer are pro-thrombotic. Thus, the identification of novel selective anticancer drugs that also have antithrombotic properties is of enormous significance. Amblyomin-X is an anticancer protein derived from the salivary glands of the Amblyomma cajennense tick. Methods: In this work, we determined the inhibition profile of Amblyomin-X and its effect on activated partial thromboplastin time (aPTT) and prothrombin time (PT), using various approaches such as, kinetic analyses, amidolytic assays, SDS-PAGE, and mass spectrometry. Results: Amblyomin-X inhibited factor Xa, prothrombinase and tenase activities. It was hydrolyzed by trypsin and plasmin. MS/MS data of tryptic hydrolysate of Amblyomin-X suggested the presence of Cys(8)-Cys(59) and Cys(19)-Cys(42) but not Cys(34)-Cys(55) disulfide bond. Instead of Cys(34)-Cys(55), two noncanonical Cys(34)-Cys(74) and Cys(55)-Cys(74) disulfide bonds were identified. Furthermore, when Amblyomin-X (1 mg/kg) injected in rabbits, it prolonged aPTT and PT. Conclusion: Amblyomin-X is a noncompetitive inhibitor (K-i = 3.9 mu M) of factor Xa. It is a substrate for plasmin and trypsin, but not for factor Xa and thrombin. The disulfide Cys(34)-Cys(55) bond probably scrambles with inter chain seventh free cysteine residues (Cys(74)) of Amblyomin-X. The prolongation of PT and aPTT is reversible. General Significance. In term of anticoagulant property, this is structural and functional characterization of Amblyomin-X. All together, these results and previous findings suggest that Amblyomin-X has a potential to become an anticancer drug with antithrombotic property. (C) 2016 Elsevier B.V. All rights reserved. (AU)

Processo FAPESP: 13/07467-1 - CeTICS - Centro de Toxinas, Imuno-Resposta e Sinalização Celular
Beneficiário:Hugo Aguirre Armelin
Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
Processo FAPESP: 15/50040-4 - Rational approach for searching molecular targets involved in inflammatory events and cell survival
Beneficiário:Ana Marisa Chudzinski-Tavassi
Modalidade de apoio: Auxílio à Pesquisa - Programa Centros de Pesquisa em Engenharia