Elastase isolated from P. aeruginosa clinical strain hydrolyzes elastin, casein, hemoglobin, ovalbumin, gelatin, fibrin, collagen. The optimum pH ensuring the activity of the enzyme is 7.8-8.0. Elastase shows maximum stability at pH 6.6-9.0. Heating at 80 degrees C for 10 minutes results in its practically complete inactivation. Elastase is a highly radiosensitive enzyme. Chelating agents and zinc, cobalt, mercury ions suppress its activity. Sodium and ammonium chlorides selectively inhibit the elastolytic, but not proteolytic activity of the enzyme. Elastase shows pronounced dermonecrotic and keratolytic action.