Thrombin is an enzyme that cleaves bonds after Arg and Lys,converts fibrinogen to fibrin and activates factors V, VII,VIII. Prothrombin is activated on the surface of a phospholipidmembrane where factor Xa removes the activation peptide andcleaves the remaining part into light and heavy chains. Thisdomain corresponds to the light chain of thrombin. Thrombin light chain Thrombin_light