Kinases

Kinases, specific activators (see), which convert inactive proenzymes, or zymogens, into active enzymes. By kinases, one should understand such activators which, while producing the corresponding conversion of a proenzyme into an enzyme, do not subsequently participate in the action of the latter. However, it can be considered proven that in all known cases of activation by kinases, the latter enter into a compound with the proenzymes and constitute an integral part of the active enzyme system. But in such a case, there is no difference between a kinase and a coenzyme (see), and if the concept of kinase is still preserved, it is mainly as one historically established for certain specific activators of proteolytic enzymes. Examples of kinases: enterokinase—an activator of trypsinogen; thrombokinase, which activates thrombogen (blood coagulation).