allosteric enzyme

al·lo·ste·ric en·zyme

an enzyme that exhibits the property of allosterism.

allosteric enzyme

An enzyme whose activity can change when certain types of effectors, called allosteric effectors, bind to a nonactive site on the enzyme.See also: enzyme

Fig. 25 Allosteric enzyme . Active (a) and inactive (b) forms.

allosteric enzyme

a type of enzyme which has two alternative forms: one active with a functional BINDING SITE, the other inactive where the binding site has been altered in shape so as to become non-reactive. Such enzymes have a QUATERNARY PROTEIN STRUCTURE which becomes changed by the addition of a ‘modulator’ molecule producing the inactive shape, such a process resulting in NONCOMPETITIVE INHIBITION.