Fibrin Fibrinase

Plasmin [EC 3.4.21.7], also known as fibrinase and fibri-nolysin, is a peptidase (a member of the peptidase family SI) that exhibits preferential cleavage at Lys—Xaa > Arg-Xaa (there is actually greater selectivity than displayed by trypsin). Plasmin converts fibrin into soluble products. It is formed from plasminogen by proteolysis, resulting in multiple forms of the active plasmin. 

Fibrin-stabilizing factor, fibrinase Fletcher factor, prekallikrein factor Fitzgerald factor,... 

Thrombin attacks synthetic esters, namely tosyl l-arginine methyl ester (TAMe), and when thrombin is treated with DIPT, the loss of esterase activity is proportional to the loss of clotting activity. Studies with synthetic esters have suggested that, as with trypsin, the reaction between thrombin and its substrates occurs in three steps an enzyme-substrate complex is formed the acyl portion of the ester is transferred to the enzyme, which becomes acylated while the alcoholic portion of the ester is released and the enzyme is deacylated and the peptide is transferred to water. The natural substrate of thrombin is fibrinogen. In addition to converting fibrinogen to fibrin, thrombin releases the contractile protein from platelets, activates fibrinase, and may participate in the conversion of prothrombin to thrombin. 

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