Thrombin light chain <p>Thrombin is a Na+-activated, allosteric serine protease that functions in blood homeostasis, inflammation and wound healing [<cite idref="PUB00045293"/>]. Thrombin (or coagulation factor II) is an enzyme that cleaves bonds after Arg and Lys, converts fibrinogen to fibrin and activates factors V, VII, VIII, and (in complex with thrombomodulin) protein C [<cite idref="PUB00045294"/>]. Sodium binding is the major driving force behind the procoagulant, prothrombotic and signaling functions of the enzyme, but is dispensable for cleavage of the anticoagulant protein C [<cite idref="PUB00045295"/>]. Prothrombin is activated on the surface of a phospholipid membrane where factor Xa removes the activation peptide and cleaves the remaining part into light and heavy chains. This domain corresponds to the light chain of thrombin. </p>