Characterization of pyrolysin, a hyperthermoactive serine protease from the archaebacterium Pyrococcus furiosus

From the hyperthermophilic archaebacterium Pyrococcus furiosus an oxygen-stable, extremely thermostable protease activity, which we designate pyrolysin, has been identified and characterized. Pyrolysin is a cell-envelope associated protease activity high thermo-activity and stability. The temperature optimum is 115°C and half-life values in the absence of substrate are: at least 96 h at 80°C, 9 h at 95°C, 4h at 100°C, 20 min at 105°C and 3 min at 110°C. Pyrolysin is active at a broad pH range between 6.5 and 10.5, and was classified as a serine-type protease activity. Zymogram staining showed the presence of multiple protease bands of about 140, 130, 115, 100 and 65 kDa.