Purification and some properties of pure Cochliobolus lunatus fibrinolytic Enzyme

Purification of partially purified fibrinolytic enzyme was attempted by chromatography on DEAE‐cellulose (D‐52) column. The results indicated the resolution of three protein components and one minor component. It was shown that the first component was the major of the applied sample. Examination of fibrinolytic activity of the different fractions of components one and two indicated that only the first component possessed fibrinolytic activity. Fibrinolytic activity of the applied sample was completely recovered by the first enzyme component, and the most active fraction of this enzyme component showed 3.3‐fold purification. The pure fibrinolytic enzyme was relatively more stable at pH 6.98, which was also optimal for its activity. After heating the enzyme solution (pH = 6.98) at 55 and 60°C for 15 min, the enzyme still retained 34.7 and 17.3% of its original activity, respectively. Zinc ions partially inhibited the enzyme. Copper ions activated the enzyme. Iodine partially inhibited the fungal fibrinolytic enzyme at a final concentration of 10−4M; at 10−2M complete inactivation was brought about. The p‐chloromercuribenzoate at a final concentration of 10−2M brought about partial inhibition whereby the enzyme lost about 33% of its original activity. Reduced glutathione brought about activation of the enzyme, while trypsin inhibitor did not show any effect on enzyme activity.