Aspergillus ochraceus as a producer of proteases with protein C and factor X activator activity

Micromycetes from Aspergillus genus are able to produce proteases capable to promote proteolysis of haemostasis proteins or, along with hydrolytic activity, to show the ability to convert proenzymes of this system activating them into an active form. In the same time, practical medicine needs in specific activators for quantitation of level of some plasma enzymes, especially protein C and factor X, the lack of which leads to the development of thromboembolic diseasesAim of the research was study of production proteinases with protein C and factor X activating activity by A. ochraceus L-1.A. ochraceus was cultivated under submerged conditions, protease activity detection was made using chromogenic peptide substrates specific for activated protein C (S-2366) and factor Xa (S-2765) after the addition of blood plasma (activator activity). It was shown, that A. ochraceus can produce extracellular proteases with protein C and factor X activator activities. The maximum of accumulation of the proteases falls on the 4th day of cultivation. Using isoelectrofocusing was demonstrated that the activation of both proenzymes may proceed via limited proteolysis induced by proteases of A. ochraceus.The activatory activity of A. ochraceus proteases toward essential hemostatic proenzymes, protein C and X factor, may be useful for practical needs. It is well known that similar enzymes, activators of protein C and X factor isolated from snake venom, South American copperhead Agkistrodon contortrix contortrix and Russell’s viper Daboia russelli russeli, respectively, are used for the in vitro diagnostics of the functional state of these proteins in blood plasm