An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the agonist, while an inverse agonist causes an action opposite to that of the agonist.
From the Greek αγωνιστής (agōnistēs), contestant; champion; rival < αγων (agōn), contest, combat; exertion, struggle < αγω (agō), I lead, lead towards, conduct; drive
Receptors can be activated by either endogenous agonists (such as hormones and neurotransmitters) or exogenous agonists (such as drugs), resulting in a biological response. A physiological agonist is a substance that creates the same bodily responses but does not bind to the same receptor.
An endogenous agonist for a particular receptor is a compound naturally produced by the body that binds to and activates that receptor. For example, the endogenous agonist for serotonin receptors is serotonin, and the endogenous agonist for dopamine receptors is dopamine.
Full agonists bind to and activate a receptor with the maximum response that an agonist can elicit at the receptor. One example of a drug that can act as a full agonist is isoproterenol, which mimics the action of adrenaline at β adrenoreceptors. Another example is morphine, which mimics the actions of endorphins at μ-opioid receptors throughout the central nervous system. However, a drug can act as a full agonist in some tissues and as a partial agonist in other tissues, depending upon the relative numbers of receptors and differences in receptor coupling.
A co-agonist works with other co-agonists to produce the desired effect together. NMDA receptor activation requires the binding of both glutamate, glycine and D-serine co-agonists. Calcium can also act as a co-agonist at the IP3 receptor.
A selective agonist is selective for a specific type of receptor. E.g. buspirone is a selective agonist for serotonin 5-HT1A.
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This course introduces the student to the fudamentals of pharmacology, pharmacokinetics and drug-receptor interactions. It discusses also pharmacogenetics and chronopharmacology, to exemplify the chal
Presentation of selected signalling pathways with emphasis on both the mechanism of action of the molecules involved, molecular interactions and the role of their spatio-temporal organization within t
Ce cours permet aux étudiants ayant suivi Morphologie I de réviser et d'approfondir leurs connaissances par l'étude de l'anatomie radiologique et du développement. L'origine de malformations fréquente
Explores the relationship between ligand concentration, binding, and effect, focusing on allosteric modulators and types of pharmacological antagonists.
A receptor antagonist is a type of receptor ligand or drug that blocks or dampens a biological response by binding to and blocking a receptor rather than activating it like an agonist. Antagonist drugs interfere in the natural operation of receptor proteins. They are sometimes called blockers; examples include alpha blockers, beta blockers, and calcium channel blockers. In pharmacology, antagonists have affinity but no efficacy for their cognate receptors, and binding will disrupt the interaction and inhibit the function of an agonist or inverse agonist at receptors.
In biochemistry and pharmacology, receptors are chemical structures, composed of protein, that receive and transduce signals that may be integrated into biological systems. These signals are typically chemical messengers which bind to a receptor and produce physiological responses such as change in the electrical activity of a cell. For example, GABA, an inhibitory neurotransmitter inhibits electrical activity of neurons by binding to GABA_A receptors.
In biochemistry and pharmacology, a ligand is a substance that forms a complex with a biomolecule to serve a biological purpose. The etymology stems from Latin ligare, which means 'to bind'. In protein-ligand binding, the ligand is usually a molecule which produces a signal by binding to a site on a target protein. The binding typically results in a change of conformational isomerism (conformation) of the target protein. In DNA-ligand binding studies, the ligand can be a small molecule, ion, or protein which binds to the DNA double helix.
This course aims for a mechanistic description of mammalian brain function at the level of individual nerve cells and their synaptic interactions.
The phenomenon of allostery, a general property in proteins that has been heralded as "the second secret of life" remains elusive to our understanding and even more challenging to incorporate into protein design. One example of allosteric proteins with gre ...
EPFL2024
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G-protein-coupled receptors (GPCRs) are the largest class of cell surface receptors and drug targets, and respond to a wide variety of chemical stimuli to activate diverse cellular functions. Understanding and predicting how ligand binding triggers a speci ...
Targeting cells specific to type and state remains a challenge in developing effective therapies, sensitive diagnostics, also robust and versatile tissue engineering. A promising strategy is to focuses on improving the inherent selectivity of the targeting ...