Purification, kinetic characterization and properties of a novel thermo-tolerant extracellular protease from Kluyveromyces marxianus IFO 0288 with potential biotechnological interest

► A novel extracellular protease was purified and characterized kinetically. ► Optimum kcat/Km-value of novel protease was found at pH 7.75 and 35.5 °C. ► This enzyme maintained full activity at 25 °C after 30 min incubation at 10 or 60 °C. ► The Km-value of novel enzyme was decreased at increased [Ca2+] and/or [NaCl]. ► All proton inventories suggest that catalysis proceeds via a charge-relay system.