competitive inhibitor


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com·pet·i·tive in·hi·bi·tion

blocking of the action of an enzyme by a compound that binds to the free enzyme, preventing the substrate from binding and thus preventing the enzyme from acting on that substrate. The competitive inhibitor is often a substrate analogue and binds at the active site; however, this is not an absolute requirement for competitive inhibition. Saturating concentrations of substrate can remove the inhibition. Compare: isostery.

competitive inhibitor

an inhibitor of an enzyme reaction that competes with the substrate by binding at the active site.

competitive inhibitor

1. A chemical that binds to or blocks another reagent from participating in a reaction.
2. A medication, hormone, or other intercellular messenger that binds and blocks the cellular receptor or target enzyme of another agent. Drugs that act by competitive inhibition may treat or prevent disease by inactivating pathogenic enzymes or by blocking the effects of hormones or precursor molecules. For example, protease inhibitors interfere with production of human immunodeficiency virus (HIV) by binding and inactivating the protease enzyme; selective estrogen-receptor modulators limit the impact of estrogen by replacing this hormone on cells sensitive to its effects.
See also: inhibitor
References in periodicals archive ?
MA as a competitive inhibitor prevents the binding of the substrate by binding reversibly the active site of CYP3A4 enzyme.
The data in this study demonstrate that the MA was not only a weak competitive inhibitor of CYP3A4 in humans, but also a weak competitive inhibitor of CYP2C11 and 3A2 in rats, with [K.
It is clear from the in vitro inhibition kinetic studies in pooled human liver microsomes that cryptotanshinone and dihydrotanshinone can act as competitive inhibitors to human CYP2C9 which is mainly responsible for tolbutamide 4-hydroxylation.
Hirsutism stemming from hyperandrogenism often can be lessened by competitive inhibitors of the androgen receptor.
A wide variety of state-of-the-art technologies will be applied, including: (i) innovative chemical approaches for the design, synthesis and engineering of peptide and protein biosensors, (ii) biochemical, biophysical, and fluorescence-based approaches for characterization of the sensitivity, specificity and physicochemical features of the biosensors, (iii) cell biology and fluorescence imaging approaches for characterization and validation of these biosensors in cellulo and in vivo, (iv) application of fluorescent biosensors for development of diagnostic assays, and (v) application of fluorescent biosensors for development of high throughput screening assays and identification of selective non-ATP competitive inhibitors for cancer therapeutics.
The new dimerization inhibitor unveils a biologically meaningful rationale for suppressing angiogenesis in tumors that could outperform traditional competitive inhibitors of angiogenesis in tumor therapy.
Hirsutism that is associated with hyperandrogenism often can be lessened by drugs that are competitive inhibitors of the androgen receptor.
While the previous generation of p38 MAPK inhibitors suffered from side effects such as liver transaminase elevations, the newer inhibitors are more selective at targeting p38 and include non-ATP competitive inhibitors directed against the conformation epitope.
The Report discusses strategies to design peptidomimetic and non-peptidomimetic competitive inhibitors, inflammation and wounds, cancer, cardiovascular conditions, neurodegenerative diseases, and more are examined.
Currently available anti-estrogens, such as tamoxifen, are competitive inhibitors that bind to the ligand binding sites of estrogen receptors (ER).

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