Exploring Agaricomycetes from the Paranaense rainforest (Misiones, Argentina) as an unconventional source of fibrinolytic enzymes.

Fungal fibrinolytic enzymes, secreted by some Agaricomycetes, are recognized as important thrombolytic agents due to their ability to rapidly dissolve thromboembolic clots. The present work evaluated fibrinolytic and proteolytic secretion abilities of 35 Agaricomycetes isolates from the Paranaense rainforest (Misiones, Argentina). We detected proteolytic activity in 40% of the strains while nine strains showed fibrinolytic activity. LBM 026, LBM 223, and LBM 224 exhibited the highest levels of fibrinolytic activity. Fibrin zymography from LBM 026 and LBM 223 showed an enzyme of 27.5 kDa, while LBM 224 presented an enzyme of 29 kDa. The evaluation of the enzymatic stability of culture supernatant of these strains revealed that the fibrinolytic activity was highly stable over a wide temperature and pH range. Long-term stability of fibrinolytic activity at physiological conditions evidenced that the strains had a half-life of at least 72 h. Fibrinolytic enzymes produced by LBM 026 and LBM 223 were inhibited in the presence of EDTA indicating that they are metalloproteases. This work reveals the potential of LBM 026, LBM 223, and LBM 224 as an unconventional source of thrombolytic agents.