Related Experiment Video
Updated: Oct 25, 2026

Methods for the Discovery of Novel Compounds Modulating a Gamma-Aminobutyric Acid Receptor Type A Neurotransmission
Published on: August 16, 2018
Exploring a Druggable Hydrophobic Tunnel in the 5-HT2A Receptor with Potent Phenethylamines
Icaro A Simon1, Eline Pottie2, Madeleine K Jensen1
1Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 160, 2100Copenhagen, Denmark.
Abstract:
The serotonin 2A receptor is the most abundant excitatory serotonin receptor in the brain and the target for serotonergic psychedelics. Despite its importance, the mechanisms of action and structure-activity relationship of receptor agonists are not fully understood. Experimental 5-HT2AR structures have identified a hydrophobic tunnel lateral to the orthosteric site. Here, we have examined this tunnel and its implications for 5-HT2AR agonist pharmacology. The tunnel characteristics and the key role of Gly2385×43 were delineated by molecular modeling and by the design and synthesis, binding, and functional characterization of several phenethylamines. Our data demonstrate that the agonist potencies at the 5-HT2AR exhibited by analogs with substituents at C-4 of the phenyl ring, with at least four heavy atoms, are able to protrude into and form interactions within this tunnel. Thus, these findings provide new insights into the molecular basis for phenethylamine-induced 5-HT2AR activation and identify this tunnel as a druggable region.
Related Concept Videos
Drug-Receptor Interaction: Agonist
Agonists can bind to receptors in different ways. Some agonists bind directly to the receptor's active site, mimicking the endogenous ligand's action.
Drugs Affecting Neurotransmitter Release or Uptake
Adrenergic Agonists: Chemistry and Structure-Activity Relationship
Aromatic ring substitutions: Substituting the aromatic ring with –OH groups at positions 3 and 4 yields catecholamines (e.g., epinephrine), which have a high affinity for adrenoceptors. Hydrogen bonding between –OH groups and receptors enhances adrenergic activity.
Separation of the aromatic...
Adrenergic Agonists: Indirect-Acting Agents
One mechanism involves depleting stored catecholamines by displacing them from synaptic vesicles. These agents, known as "displacers," are transported into vesicles at the expense of noradrenaline. Examples include amphetamine and tyramine, which lack a catechol moiety, resulting in prolonged action, improved oral bioavailability, and...
Antipsychotic Drugs: Typical and Atypical Agents
Drug Discovery: Overview
