Snake Venom Components Affecting the Coagulation System

Abstract

Snake venoms are rich sources of proteases of medical importance that affect hemostasis. In this chapter, the factors affecting blood coagulation are classified into two separate groups: the procoagulant and the anticoagulant proteins. The procoagulant proteins are subclassified as clotting factor activators and thrombin-like enzymes. The anticoagulant proteins are able to prevent blood clotting and maintain blood incoagulability and can include phospholipases A2, fibrin(ogen)olytics, protein C activator, and L-amino acid oxidase (enzymatic anticoagulants) or C-type lectin-like proteins, three-finger toxins (TFTs), and Kunitz-type proteinase inhibitors (nonenzymatic anticoagulants). The study of toxins from snake affecting blood coagulation contributed to the current understanding of the mechanism of activation and inhibition of clotting factors. Moreover, they have been useful in the therapeutic area, for example, as defibrinogenating agents (thrombin-like enzymes) and as antithrombotic agents (fibrinolytic enzymes). Here, the recent findings will be introduced.