Related Experiment Video
Updated: May 23, 2025
09:30
Author Spotlight: Exploring Cellular Processes by Modeling Ligands in Cryo-EM Maps
Published on: July 19, 2024
1.2K
Visualizing agonist-induced M2 receptor activation regulated by aromatic ring dynamics
Summary
Molecular dynamics simulations reveal the M2 muscarinic acetylcholine receptor (M2R) activation pathway. Ligand binding induces sequential structural changes, detailing how receptor activation and agonist efficacy are encoded.
Area of Science:
- Biochemistry
- Structural Biology
- Pharmacology
Background:
- G protein-coupled receptors (GPCRs) are crucial drug targets, but their activation mechanisms remain incompletely understood.
- Resolving GPCR structures provides static snapshots, yet the dynamic transition from inactive to active states requires further investigation.
Purpose of the Study:
- To elucidate the dynamic conformational changes of the M2 muscarinic acetylcholine receptor (M2R) during agonist-induced activation.
- To explore how ligand binding modulates M2R conformational dynamics at an atomic level.
Main Methods:
- Comprehensive molecular dynamics simulations were employed to study M2R.
- Analysis focused on structural changes, intermediate conformations, and key residue dynamics.
Main Results:
- A sequential activation pathway for M2R was observed, involving orthosteric binding site contraction and TM6 opening.
- Two distinct activation intermediates were identified, differing from apo-GPCR structures.
- Specific residue dynamics (W400, F396) and side-chain rotamers (Y206) correlate with activation and agonist efficacy.
Conclusions:
- The study provides atomic-level insights into the M2R activation pathway triggered by agonists.
- A mechanism is proposed where ligand efficacy is encoded in aromatic ring dynamics, influencing receptor activation.
Related Concept Videos
01:16Adrenergic Agonists: Chemistry and Structure-Activity Relationship
2.5K
Adrenergic agonists' structure-activity relationship (SAR) determines their selectivity and efficacy. These agonists comprise a phenylethylamine moiety with an aromatic ring and an ethylamine side chain.
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...
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...
2.5K
01:25Drug-Receptor Interaction: Agonist
2.3K
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...
Agonists can bind to receptors in different ways. Some agonists bind directly to the receptor's active site, mimicking the endogenous...
2.3K
01:29The Two-State Receptor Model
1.9K
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...
The binding affinity of a drug determines its interaction with...
1.9K
01:11ortho–para-Directing Activators: –CH3, –OH, –NH2, –OCH3
5.7K
All ortho–para directors, excluding halogens, are activating groups. These groups donate electrons to the ring, making the ring carbons electron-rich. Consequently, the reactivity of the aromatic ring towards electrophilic substitution increases. For instance, the nitration of anisole is about 10,000 times faster than the nitration of benzene. The electron-donating effect of the methoxy group in anisole activates the ortho and para positions on the ring and stabilizes the corresponding...
5.7K
01:29Drug-Receptor Interactions
4.8K
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....
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....
4.8K
01:14π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds
1.2K
In aromatic compounds, such as benzene, the circulation of (4n + 2) π-electrons sets up a diamagnetic or diatropic ring current around the perimeter of the molecule. This current induces a magnetic field that opposes the external field inside the ring and reinforces it on the outside. The protons in benzene are deshielded and exhibit high chemical shifts in the range 6.5–8.5 ppm. The shielding effect at the center of the ring is evident in complex aromatic molecules, such as...
1.2K