From full agonists to inverse agonists -- explore how molecules activate receptors, drive cellular responses, and shape modern drug discovery across GPCR, ion channel, and nuclear receptor families.
GPCR Targets
Receptor Families
Drug Molecules
Understanding the spectrum of agonist activity, from full activation to constitutive receptor modulation.
Produces maximal response (Emax) by fully stabilizing the active receptor conformation. Examples: morphine (mu-opioid), isoproterenol (beta-adrenergic).
Produces sub-maximal response even at saturating concentrations. Can act as functional antagonist in presence of full agonist. Examples: buprenorphine, aripiprazole.
Reduces constitutive receptor activity below basal levels. Stabilizes inactive conformation. Examples: famotidine (H2), rimonabant (CB1).
Selectively activates one signaling pathway over another at the same receptor. Examples: oliceridine (mu-opioid, G-protein biased).
Major receptor superfamilies and their agonist pharmacology in drug development.
The largest superfamily of drug targets. GPCRs transduce extracellular signals through heterotrimeric G proteins and beta-arrestin pathways. Over 30% of FDA-approved drugs target GPCRs.
Ionotropic receptors (nAChR, GABA-A, NMDA, 5-HT3) open ion channels upon agonist binding. Sub-millisecond signaling critical in neurotransmission.
Intracellular receptors (estrogen, thyroid, glucocorticoid, PPAR) bind lipophilic agonists that cross the membrane, directly modulating gene transcription.
Growth factor receptors (EGFR, VEGFR, PDGFR) activated by dimerization. Downstream MAPK/PI3K cascades drive proliferation. Key targets in oncology.
Positive allosteric modulators (PAMs) enhance agonist response without occupying the orthosteric site. Benzodiazepines at GABA-A exemplify this pharmacology.
EC50, Hill coefficient, efficacy vs potency, Schild analysis, and operational models quantify agonist activity for drug candidate selection.
Research highlights and educational articles on agonist science and drug discovery.
How semaglutide and tirzepatide transformed metabolic medicine through incretin receptor agonism, mechanisms of action, and next-generation dual-agonists.
Read moreG-protein biased mu-opioid agonists promise pain relief with reduced respiratory depression. The structural basis and clinical implications.
Read moreHigh-resolution cryo-EM structures show how agonist binding reshapes transmembrane helices, enabling rational drug design.
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PhD pharmacologists
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