Proteases (Proteinase, Peptidases or Proteolytic enzymes) are enzymes that break peptide bonds between amino acids of proteins. The process is called proteolytic cleavage, a common mechanism of activation or inactivation of enzymes especially involved in blood coagulation or digestion.
The greatest industrial use of protease is for laundry detergents where they help to remove protein based stains (such as blood and egg) from clothing.
Enzymes from calf stomach and microbial sources are used to clot milk which is one of the first steps in cheese making, another important use.
Proteases are also used for bating (softening) leather, modifying food ingredients (e.g. soy protein whipping agents), meat tenderizers, and flavor development.
Proteases have also been studied for their role in blood clotting and inflammatory diseases.