Zymogens

A zymogen is a catalytically inactive protein precursor synthesized by a cell that must be activated to function. Examples include the pancreatic proteases and the blood clotting proteins. By synthesizing proteolytic enzymes (which could be harmful if active in the wrong place) as inactive precursors, the body can control when and where such enzymes are active. Figure 11.39 illustrates the proteolytic cleavage of several proteases.

See also: Covalent Modifications to Regulate Enzyme Activity, Blood Clotting