noncompetitive inhibition


Also found in: Dictionary, Thesaurus, Legal, Encyclopedia.
Related to noncompetitive inhibition: Uncompetitive inhibition

inhibition

 [in″hĭ-bish´un]
1. arrest or restraint of a process.
2. in psychoanalysis, the conscious or unconscious restraining of an impulse or desire. adj., adj inhib´itory.
competitive inhibition inhibition of enzyme activity by an inhibitor (a substrate analogue) that competes with the substrate for binding sites on the enzymes.
contact inhibition inhibition of cell division and cell motility in normal animal cells when in close contact with each other.
noncompetitive inhibition inhibition of enzyme activity by substances that combine with the enzyme at a site other than that utilized by the substrate.

non·com·pet·i·tive in·hi·bi·tion

a type of enzyme inhibition in which the inhibiting compound does not compete with the natural substrate for the active site on the enzyme but inhibits the reaction by combining with the enzyme-substrate complex as well as with the free enzyme.

non·com·pet·i·tive in·hi·bi·tion

(non'kŏm-pet'i-tiv in'hi-bish'ŭn)
A type of enzyme inhibition in which the inhibiting compound does not compete with the natural substrate for the active site on the enzyme, but inhibits the reaction by combining with the enzyme-substrate complex, after the latter has been formed, and with the free enzyme.

noncompetitive inhibition

a form of enzyme control in which the enzyme has two kinds of ACTIVE SITE, one for an inhibitor, the other for the enzyme substrate. The inhibitor prevents catalytic activity of the enzyme, perhaps by locking or even changing the shape of the substrate active site. Compare COMPETITIVE INHIBITION. See also ALLOSTERIC ENZYME.
References in periodicals archive ?
The Lineweaver-Burk plot obtained in Figure 2, both free and immobilized AChE, shows a typical noncompetitive inhibition. These results suggest that the inhibitor has no effect on the substrate binding after or before binding of the substrate, resulting in the formation of a catalytically inactive enzyme-substrate-inhibitor complex.
Among the tanshinones studied, only cryptotanshinone competitively inhibited CYP2E1 activity in pooled human liver microsomes, while tanshinone I showed noncompetitive inhibition (Table 2).
Double-reciprocal plots of enzyme kinetics demonstrated a noncompetitive inhibition of a-glucosidase activity (Fig.