Purification and characterization of fibrinolytic enzyme from Kiwifruit”

When a blood vessel is injured, the body forms the blood clot (thrombus). When a thrombus causes more than 90% obstruction this can result in anoxia and infarction. Therefore, searching for effective, inexpensive and safe thrombolytic agents from various natural sources is of great interest. Hence, fibrinolytic enzyme production from kiwifruit for blood clot lysis that can be employed as a good therapeutic agent is of importance. The present investigation deals with purification, characterization and therapeutic application of kiwifruit fibrinase. Fibrinase was purified from concentrated homogenat with specific activity of 160 U mg-1 protein. The optimal pH was 6.5. The enzyme pK1 was 5.2 and pK2 was 7.3. The km value for fibrin was 1.5 g/l. The optimal temperature was 30° C. The activation energy was 10.4 KJ/mol. Fibrinase was inactivated at 60, 70 and 80° C with t1/2 values of 34, 21 and 16 min at 60, 70 and 80° C, respectively. Many compounds and metal ions like iodoacetamide, EDTA and Cu2+ inhibited the fibrinase while others like G-6-P, AMP and Ca2+ showed enzyme activation. Fibrinase displayed great affinity towards human blood clot and seems to be a promising thrombolytic agent for clinical use.