Possibility of application of extracellular protease of micromycet Aspergillus ochraceus VKM F-4104D for determination of protein C content in human blood plasma

Abstract

It was shown that the activator activity of protein C, determined in normal plasma using Aspergillus ochraceus protease, is comparable with the activity of commercial protease analogue from the South American copperhead venom (ProtacÒ). It was found that protease of A. ochraceus can be used to determine protein C in plasma with its reduced content similar to ProtacÒ. Comparison of the activator protein C activity of A. ochraceus protease and the commercial analogue showed some excess of the activator activity of the fungal preparation, which may make it a promising substitute for the snake activator in diagnostical kits for determining the protein C content in clinical laboratories.

Gene Analysis, Cloning, and Heterologous Expression of Protease from a Micromycete Aspergillus ochraceus Capable of Activating Protein C of Blood Plasma

“…Such enzymes can find practical application both in the composition of thrombolytic drugs for therapy and as components of a diagnostic kit for determining the content of these proteins in the blood. Protease-activators of protein C and factor X, produced by Aspergillus ochraceus , have shown their effectiveness for the determination of the content of these proenzymes in vitro in comparison with commercial analog-protease-activators from snake venom [ 12 , 51 ]. It is assumed that these proteases can become a more affordable alternative for the development of diagnostic kits for the detection of blood clotting diseases in humans and animals.…”

“…Activators from snake venoms, especially from the Agkistrodon contortrix contortrix snake, which directly converts protein C into active form, are widely used in diagnostics and medicine, especially, in chromogenic and clotting protein C assays [ 9 , 10 ]. PAPC from A. ochraceus VKM-F4104D (PAPC-4104) has been shown to possess a similar ability to activate protein C, so potentially, it can be applied in practice as an easily available, less expensive alternative to activators from snake venoms [ 11 , 12 ]. However, despite the affordability of micromycete cultivation, the yield of the secreted target protein is low [ 4 , 5 ], and the purification of native PAPC is a complicated multi-step procedure.…”