The Properties of Extracellular Proteinase, an Activator of Blood Plasma Prekallikrein Produced by Aspergillus terreus 2 Micromycete

The extracellular proteinase–activator of human plasma prekallikrein was isolated from the culture fluid of the micromycete A. terreus 2, and its physicochemical, kinetic, and biochemical properties were studied. It has been established that the A. terreus 2 extracellular proteinase is a glycosylated serine proteinase with an isoelectric point of 4.6, a molecular weight of about 37 kDa, and optimum activity at pH 10.0 and a temperature of 37°C. In a number of its properties this proteinase is similar to the proteinase–activator of protein C, which is produced by the micromycete A. ochraceus L-1.