Related Experiment Video

Updated: Mar 22, 2026

Quantifying Agonist Activity at G Protein-coupled Receptors
11:45

Quantifying Agonist Activity at G Protein-coupled Receptors

Published on: December 26, 2011

19.9K

Quantitative Measure of Receptor Agonist and Modulator Equi-Response and Equi-Occupancy Selectivity

Rumin Zhang1, Michael Kavana1

  • 1Merck Research Laboratories, Department of In Vitro Pharmacology, Kenilworth, New Jersey, USA.

Scientific Reports
|April 28, 2016
PubMed

More Related Videos

Measuring G-protein-coupled Receptor Signaling via Radio-labeled GTP Binding10:13

Measuring G-protein-coupled Receptor Signaling via Radio-labeled GTP Binding

Published on: June 9, 2017

17.4K
Methods for the Discovery of Novel Compounds Modulating a Gamma-Aminobutyric Acid Receptor Type A Neurotransmission07:16

Methods for the Discovery of Novel Compounds Modulating a Gamma-Aminobutyric Acid Receptor Type A Neurotransmission

Published on: August 16, 2018

14.3K

Related Concept Videos

Quantitative Aspects of Drug-Receptor Interaction01:30

Quantitative Aspects of Drug-Receptor Interaction

The receptor occupancy theory connects a drug's response to the number of occupied receptors. With higher drug concentrations, more receptors are occupied, leading to increased responses. The formation of drug-receptor complexes involves association and dissociation rates, which reach equilibrium when the forward and backward reactions are equal. The equilibrium association constant (Ka) and its inverse, the equilibrium dissociation constant (Kd), indicate drug affinity. Higher Ka and lower...
2.1K
The Two-State Receptor Model01:29

The Two-State Receptor Model

The two-state receptor model explains a drug's interaction with receptors, such as G protein-coupled receptors and ligand-gated ion channels, to induce or inhibit a biological response. When no natural ligands are present, a receptor exists in an equilibrium of inactive (Ri) and active (Ra) conformations. The inactive form does not produce a response, while the active form generates a basal effect known as constitutive activity.
The binding affinity of a drug determines its interaction with...
3.4K
Dose-Response Relationship: Overview01:03

Dose-Response Relationship: Overview

Agonists can bind with and activate receptors, resulting in the formation of drug-receptor complexes. Once formed, these complexes catalyze many biochemical processes at the cellular level and subsequently induce a pharmacologic response. The degree of response is directly proportional to the fraction of activated receptors, which in turn, depends on the concentration of the drug at the receptor site as well as the sensitivity of the receptor. An increase in the administered dose contributes to...
5.7K
Spare Receptors01:30

Spare Receptors

Some receptors remain unoccupied even when an agonist produces a maximal response. Such empty ones are called spare receptors. In presence of spare receptors the maximum effect of an agonist drug is achieved with fewer than 100% of the receptors being occupied. To determine the presence of spare receptors, scientists often compare the concentration of the drug needed to produce 50% of the maximum effect (EC50) with the concentration of the drug needed to occupy 50% of the receptors (Kd). If the...
4.8K
Drug-Receptor Interaction: Agonist01:25

Drug-Receptor Interaction: Agonist

Agonists are drugs that interact with specific receptors in the body to produce a biological response. When an agonist binds to a receptor, it activates or enhances the receptor's function, leading to physiological effects. The interaction between agonist drugs and receptors is crucial for their therapeutic action in various medical treatments.
Agonists can bind to receptors in different ways. Some agonists bind directly to the receptor's active site, mimicking the endogenous...
4.6K
Drug-Receptor Interactions01:29

Drug-Receptor Interactions

Drug-receptor interaction describes the binding of receptors by drugs, but not all drug-receptor interactions result in activation and tissue response. For instance, the binding of agonists activates the receptor to generate a cellular reaction, while antagonists bind to receptors without causing their activation.
Several parameters, such as the drug's affinity for its receptor and its efficacy, which is its ability to activate the receptor, determine the drug's effect on the tissue....
8.2K