Guianensin, a Simulium guianense salivary protein, has broad anti-hemostatic and anti-inflammatory properties

Background Salivary glands from blood-feeding arthropods secrete several molecules that inhibit mammalian hemostasis and facilitate blood feeding pathogen transmission. The salivary functions Simulium guianense , the main vector of Onchocerciasis in South America, remain largely understudied. Here, we have characterized a protease inhibitor (Guianensin) blackfly . Materials methods A combination bioinformatic biophysical analyses, recombinant protein production, vitro vivo experiments were utilized to characterize molecula mechanism action Guianensin. Kinetics Guianensin interaction with proteases involved vertebrate inflammation coagulation carried out by surface plasmon resonance isothermal titration calorimetry. Plasma recalcification coagulometry tail bleeding assays performed understand role coagulation. Results was identified sialotranscriptome adult S. flies belongs Kunitz domain inhibitors. It targets various serine inflammation. Binding these enzymes is highly specific catalytic site not detectable for their zymogens, site-blocked human factor Xa (FXa), or thrombin. Accordingly, significantly increased both PT (Prothrombin time) aPTT (Activated partial thromboplastin plasma consequently clotting time ex also inhibited prothrombinase activity on endothelial cells. We show acts as potent anti-inflammatory molecule FXa-induced paw edema formation mice. Conclusion information generated this work highlights biological functionality an antithrombotic may play significant roles