Preparation and properties of fibrinolytic enzymes produced by <i>Cochliobolus lunatus</i>

Abstract

Some properties of the crude lyophilized fibrinolytic enzyme produced by Cochliobolus lunatus in surface culture were studied. Enzyme concentrations over the range from 0.16 to 10.16 mg/mL showed that concentration above a certain level ceased to be the limiting factor controlling enzyme action. At pH 6.8 and a temperature of 40 degrees C, the fibrinolytic enzyme showed maximal activity at a human fibrin concentration of 2 mg/mL. The optimum pH values for enzyme activity were 6.98 and 7.0, using Sørensen and Mcllvaine buffers, respectively. Fibrinolytic enzymes were isolated from a static culture of Cochliobolus lunatus; isolation was carried out with various agents. Ammonium sulphate yielded the highest recovered fibrinolytic activity. The fraction salted out by precipitation at 25% ammonium sulphate saturation possessed the highest recovered fibrinolytic activity compared to the ammonium sulphate, ethanol, and acetone fractions.