Competitive Inhibitor Screen
Competitive Inhibitor Screen - Related Videos
10:33
Development of Inhibitors of Protein-protein Interactions through REPLACE: Application to the Design and Development Non-ATP Competitive CDK Inhibitors
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Cited by 4 •
2015
We describe implementation of the REPLACE strategy for targeting protein-protein interactions. REPLACE is an iterative strategy involving synthetic and computational approaches for the conversion of optimized peptidic inhibitors into drug like molecules.
11:59
Competitive Genomic Screens of Barcoded Yeast Libraries
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Cited by 44 •
2011
We have developed comprehensive, unbiased genome-wide screens to understand gene-drug and gene-environment interactions. Methods for screening these mutant collections are presented.
01:52
Eukaryotic Transcription Inhibitors
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2020
Certain biochemical processes, such as embryonic development and cell growth regulation, depend on the repression of specific genes. DNA binding proteins known as eukaryotic transcription inhibitors regulate the repression of gene expression in eukaryotes. The presence of these inhibitors at the required location and time in the cell is triggered by the presence of hormones and additional signals from other cells. Eukaryotic transcription inhibitors usually contain two distinct domains, a DNA...
05:46
Rapid Screening of HIV Reverse Transcriptase and Integrase Inhibitors
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Cited by 15 •
2014
Here we describe cellular cytotoxicity and single round infectivity assays that allow for the rapid and accurate screening of compounds to determine their cellular cytotoxicity (CC50) and IC50 values against WT and drug resistant HIV-1.
07:18
A Simple Method to Identify Kinases That Regulate Embryonic Stem Cell Pluripotency by High-throughput Inhibitor Screening
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Cited by 4 •
2017
Here, we present a quantitative and scalable protocol to perform targeted small molecule screens for kinase regulators of the naïve-primed pluripotent transition.
FAQs
The key kinetic signature is a higher apparent Km with no change in Vmax. A higher apparent Km means more substrate is required to reach a given fraction of the uninhibited system’s activity, whereas an unchanged Vmax indicates that maximal reaction capacity remains the same when substrate is sufficiently available. This pattern supports competition at the substrate-binding site.
Increasing substrate can reduce the observed effect of a competitive inhibitor because substrate and inhibitor compete for access to the same active site. At higher substrate concentrations, substrate is more likely to occupy that site, so reaction activity can move closer to the uninhibited control. This concentration dependence supports interpretation of the inhibitor’s effect as competition for substrate-site access.
An uninhibited control provides the reference needed to interpret inhibition. Reaction rates measured without inhibitor establish baseline enzyme behavior, while rates collected at defined inhibitor concentrations show how activity changes. Comparing the two sets allows investigators to evaluate whether the kinetic pattern is consistent with increased apparent Km and unchanged Vmax, rather than judging inhibition from a single rate measurement.
A basic screen varies substrate and inhibitor concentrations in a controlled enzymatic assay, measures reaction rates for each condition, and includes an uninhibited control. The resulting rate data are compared across conditions to evaluate inhibition and estimate kinetic parameters. Keeping concentrations defined is essential because the interpretation depends on how substrate availability changes the apparent inhibitor effect.
Screen results can estimate inhibitor potency and kinetic parameters while also revealing how a compound interacts with the substrate site. These measurements help separate compounds that merit additional investigation from those with less informative activity profiles. In practice, the value of the screen lies not only in detecting reduced activity, but in connecting that reduction to measurable kinetic behavior.
In biology, competitive inhibitor screens help clarify enzyme function by testing how substrate-site interactions affect reaction rates. In drug discovery, the same kinetic information supports compound prioritization and the development of selective therapeutics. A compound’s behavior across substrate and inhibitor concentrations can therefore inform both mechanistic studies of an enzyme and decisions about which molecules should advance for further study.