Effector (biology)

In enzymatics, an effector , or allosteric effector , is a regulation molecule that changes the activity of an enzyme and thus the reaction speed of a reaction catalyzed by this enzyme. Such an effector can increase or decrease the binding capacity of the enzyme for the substrate or substrates. If it reduces the binding capacity of the enzyme, it is called an allosteric inhibitor . If the ability to bind is increased, one speaks of an allosteric activator.

As a rule, the effect caused by the allosteric effectors occurs because the enzyme can assume several spatial arrangements ( conformations ), of which only one actively acts as an enzyme. The effector attaches itself to the enzyme and stabilizes it either in the active conformation in which it unfolds its catalytic effect as an enzyme (then the effector acts as an activator), or in the inactive form (then the effector acts as an inhibitor).

Allosteric effectors play an important role in metabolism as they regulate the speed of catalyzed reactions. Control loops often occur here . See also the special cases of substrate induction, end product inhibition , feedback inhibition in the article enzyme inhibition .

See also :

• Bioeffector
• Enzyme kinetics
• Enzyme inhibition

source

• Neil A. Campbell et al .: Biology. Pearson Studium, Munich 2006, ISBN 978-3-8273-7180-5 , pp. 119 f.