Lufaxin, a novel factor Xa inhibitor from the salivary gland of the sand fly lutzomyia longipalpis, blocks protease-activated receptor 2 activation and inhibits inflammation and thrombosis in vivo

0380194 - BC 2013 RIV US eng J - Článek v odborném periodiku
Collin, N. - Assumpção, T.C.F. - Mizurini, D.M. - Gilmore, D. - Dutra-Oliveira, A. - Kotsyfakis, Michalis - Sa-Nunes, A. - Teixeira, C. - Ribeiro, J.M.C. - Monteiro, R.Q. - Valenzuela, J. G. - Francischetti, I.M.B.
Lufaxin, a novel factor Xa inhibitor from the salivary gland of the sand fly lutzomyia longipalpis, blocks protease-activated receptor 2 activation and inhibits inflammation and thrombosis in vivo.
Arteriosclerosis Thrombosis and Vascular Biology. Roč. 32, č. 9 (2012), s. 2185-2198. ISSN 1079-5642. E-ISSN 1524-4636
Grant CEP: GA ČR GAP502/12/2409
Institucionální podpora: RVO:60077344
Klíčová slova: hematophagy * leishmaniasis * microcirculation * thrombosis * vector biology
Kód oboru RIV: EB - Genetika a molekulární biologie
Impakt faktor: 6.338, rok: 2012
http://atvb.ahajournals.org/content/32/9/2185

OBJECTIVE: Blood-sucking arthropods' salivary glands contain a remarkable diversity of antihemostatics. The aim of the present study was to identify the unique salivary anticoagulant of the sand fly Lutzomyia longipalpis, which remained elusive for decades. METHODS AND RESULTS: Several L. longipalpis salivary proteins were expressed in human embryonic kidney 293 cells and screened for inhibition of blood coagulation. A novel 32.4-kDa molecule, named Lufaxin, was identified as a slow, tight, noncompetitive, and reversible inhibitor of factor Xa (FXa). Notably, Lufaxin's primary sequence does not share similarity to any physiological or salivary inhibitors of coagulation reported to date. Lufaxin is specific for FXa and does not interact with FX, Dansyl-Glu-Gly-Arg-FXa, or 15 other enzymes. In addition, Lufaxin blocks prothrombinase and increases both prothrombin time and activated partial thromboplastin time. Surface plasmon resonance experiments revealed that FXa binds Lufaxin with an equilibrium constant ≈3 nM, and isothermal titration calorimetry determined a stoichiometry of 1:1. Lufaxin also prevents protease-activated receptor 2 activation by FXa in the MDA-MB-231 cell line and abrogates edema formation triggered by injection of FXa in the paw of mice. Moreover, Lufaxin prevents FeCl3-induced carotid artery thrombus formation and prolongs activated partial thromboplastin time ex vivo, implying that it works as an anticoagulant in vivo. Finally, salivary gland of sand flies was found to inhibit FXa and to interact with the enzyme. CONCLUSION: Lufaxin belongs to a novel family of slow-tight FXa inhibitors, which display antithrombotic and anti-inflammatory activities. It is a useful tool to understand FXa structural features and its role in prohemostatic and proinflammatory events.
Trvalý link: http://hdl.handle.net/11104/0210967