Definition of protease in US English:



  • An enzyme which breaks down proteins and peptides.

    • ‘All of the serine proteases and the zinc peptidases of pancreatic secretions are produced in the form of their respective proenzymes.’
    • ‘Whey contains many types of enzymes, including hydrolases, transferases, lyases, proteases, and lipases.’
    • ‘For instance, the set of enzymes known as serine proteases are protein-digesting enzymes in the intestine.’
    • ‘Rennin is an acid protease, meaning it breaks down protein bonds in an acidic environment.’
    • ‘Although starches and fats can be broken down without pancreatic enzymes, pancreatic proteases are crucial for protein digestion.’


Early 20th century: from protein + -ase.