noncompetitive inhibition

(redirected from Noncompetitive inhibitor)
Also found in: Encyclopedia.

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 in vitro data show that Sch B could strongly inhibit microsomal midazolam 1'-hydroxylation catalyzed by CYP3A with [IC.sub.50] value of 5.51[micro]M, and the possible mechanism of inhibition is shown the characteristic of noncompetitive inhibitors. However, lacking evidence for in vivo studies, the current results are not convincing enough.
Dihydrotanshinone was not only a potent competitive inhibitor of human CYP1A2 and CYP2C9, but also a potent noncompetitive inhibitor of human CYP3A4.
The [alpha]-glucosidase inhibitory studies revealed that EE and ME inhibited enzyme with I[C.sub.50] values of 0.301[+ or -]0.002 mg/mL and 0.477[+ or -]0.003 mg/mL and were determined as noncompetitive inhibitors, while AE was a competitive inhibitor.
Cysteine based novel noncompetitive inhibitors of urease (s) distinctive inhibition susceptibility of microbial and plant ureases.
Tyrosinase inhibitors can be classified into four types, namely, competitive, uncompetitive, mixed type (competitive/uncompetitive), and noncompetitive inhibitors. Kojic acid shows a typical competitive inhibitory effect of tyrosinase [10].
As noncompetitive inhibitors of the enzyme reverse transcriptase, their antiviral activity is additive or synergistic with other antiretroviral agents.
Noncompetitive inhibitors selectively disrupting the HDACs' interaction with precise DNA binding proteins and some other regulatory proteins (like 14-3-3 protein) might be potent selective outlines (Figure 4).
This alkaloid inhibited AChE in the same fashion as some AD drugs including donepezil, tacrine and rivastigmine which are noncompetitive inhibitors (Zhao and Tang 2002).