COVALENT FERMENT STRENGTH REGULATION
Regulation by means of covalent (chemical) modification is one of the types of ferment strength regulation. Covalent modification is covalent bonding or detachment of a small chemical group from a ferment. This bonding (detachment) regulates the strength of this ferment. By means of such modifications usually either completely inactive form of a ferment becomes active, or, on the contrary, a completely active ferment becomes inactivated.
When regulation of this type takes place, activity of one ferment (the converted one) changes of another ferment (the converting one). Due to the fact, that one molecule of the latter can modify many molecules of the former, enhancement effect is achieved. Sometimes the converting ferment itself can change in its turn. In this case regulatory cascade appears: ferment F1 activates ferment F2, ferment F2 activates ferment F3, etc. The converting ferment F1, which is in the beginning of the cascade, is subject to regulation of a different type. In most cases it is of the allosteric type.