A spider-derived Kunitz-type serine protease inhibitor that acts as a plasmin inhibitor and an elastase inhibitor

摘要: Kunitz-type serine protease inhibitors are involved in various physiological processes, such as ion channel blocking, blood coagulation, fibrinolysis, and inflammation. While spider-derived proteins show activity trypsin or chymotrypsin inhibition K+ no additional role for these has been elucidated. In this study, we identified the first spider (Araneus ventricosus) inhibitor (AvKTI) that acts a plasmin an elastase inhibitor. AvKTI possesses Kunitz domain consisting of 57-amino-acid mature peptide displays features consistent with inhibitors, including six conserved cysteine residues P1 lysine residue. Recombinant AvKTI, expressed baculovirus-infected insect cells, showed dual inhibitory against (Ki 7.34 nM) 37.75 nM), defining Additionally, detectable effects on factor Xa, thrombin, tissue plasminogen activator; however, inhibited 4.89 neutrophil 169.07 indicating it antifibrinolytic antielastolytic factor. These findings constitute molecular evidence also provide novel view functions