Characterization of Extracellular Proteinases of the Fungus Acremonium chrysogenum 226-A
1H. Petković and V. Mrša
Laboratory of Biochemistry, Faculty of Food Technology and Biotechnology, University of Zagreb, Pierottijeva 6, 10000 Zagreb, Croatia
1Krka Pharmaceuticals, Novo mesto, Slovenia.
Received June 29, 1995
Accepted July 28, 1995
Proteolytic enzymes secreted by the fungus Acremonium chrysogenum 226-A were characterized. Three proteinases were delected in the culture broth, two enzymes were found to be serine proteinases, while the third was a metalloproteinase. Relative molecular masses of the two serine proteinases were 25000 and 16000, respectively, while that of the metalloenzyme was 42000. The 25 kDa proteinase had the isoelectric point at pH = 8.0, while the 16 kDa enzyme focused at pH about 10.0. The study of enzymatic properties of A. chrysogenum proteinases revealed that the preparation was active on casein, collagen, elastin and gelatine, but not on several aminopeptidase substrates. 95 % of the proteolytic activity was due to the two scrinelypc enzymes. The activity of the preparation zvas, therefore, strongly inhibited by phenylmethylsulphonylfluoride but also by Fe3+, Cd2+, Hg2+ and Ag+ ions. The proteinase pattern of A. chrysogenum production strain 226-A clearly differs from that of other strains of the same species.