Characterization of thrombin inhibitory mechanism of rAaTI, a Kazal-type inhibitor from Aedes aegypti with anticoagulant activity

13Citations
Citations of this article
32Readers
Mendeley users who have this article in their library.

Abstract

Saliva of blood-sucking arthropods contains a complex mixture of anti-haemostatic, anti-inflammatory and immune-modulator compounds. Among anti-haemostatic factors, there are anticoagulants, vasodilators and platelet aggregation inhibitors. Previous analyses of the sialotranscriptome of Aedes aegypti showed the potential presence of a Kazal-type serine protease inhibitor in the female salivary glands, carcass and also in the whole male, which inhibitor we named AaTI (A. aegypti thrombin inhibitor). Recently, we expressed and characterized rAaTI as a trypsin inhibitor, and its anticoagulant activity [1]. In this work we characterized the thrombin inhibition mechanism of rAaTI. Recombinant AaTI was able to prolong prothrombin time, activated partial thromboplastin time and thrombin time. In contrast, AaTIΔ (rAaTI truncated form) and C-terminal AaTI acidic tail prolong only thrombin time. In the competition assay, rAaTI, AaTIΔ or C-terminal AaTI acidic tail-thrombin interactions seem to be affected by heparin but not by hirudin, suggesting that rAaTI binds to thrombin exosite 2. Finally, the thrombin inhibition assay of rAaTI showed an uncompetitive inhibition mechanism. In conclusion, rAaTI can probably inhibit thrombin by interacting with thrombin exosite 2, and the interaction is not mediated by the AaTI C-terminal region, since the truncated AaTIΔ form also prolongs thrombin time. © 2010 Elsevier Masson SAS. All rights reserved.

Cite

CITATION STYLE

APA

Watanabe, R. M. O., Tanaka-Azevedo, A. M., Araujo, M. S., Juliano, M. A., & Tanaka, A. S. (2011). Characterization of thrombin inhibitory mechanism of rAaTI, a Kazal-type inhibitor from Aedes aegypti with anticoagulant activity. Biochimie, 93(3), 618–623. https://doi.org/10.1016/j.biochi.2010.12.006

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free