Download MendeleyHigh-resolution structures of multiple 5-HT 3A R-setron complexes reveal a novel mechanism of competitive inhibition.
Basak, S., Kumar, A., Ramsey, S., Gibbs, E., Kapoor, A., Filizola, M., Chakrapani, S.(2020) Elife 9
- PubMed: 33063666
- DOI: https://doi.org/10.7554/eLife.57870
- Primary Citation of Related Structures:
6W1J, 6W1M, 6W1Y - PubMed Abstract:
Serotonin receptors (5-HT 3A R) play a crucial role in regulating gut movement, and are the principal target of setrons, a class of high-affinity competitive antagonists, used in the management of nausea and vomiting associated with radiation and chemotherapies. Structural insights into setron-binding poses and their inhibitory mechanisms are just beginning to emerge. Here, we present high-resolution cryo-EM structures of full-length 5-HT 3A R in complex with palonosetron, ondansetron, and alosetron. Molecular dynamic simulations of these structures embedded in a fully-hydrated lipid environment assessed the stability of ligand-binding poses and drug-target interactions over time. Together with simulation results of apo- and serotonin-bound 5-HT 3A R, the study reveals a distinct interaction fingerprint between the various setrons and binding-pocket residues that may underlie their diverse affinities. In addition, varying degrees of conformational change in the setron-5-HT 3A R structures, throughout the channel and particularly along the channel activation pathway, suggests a novel mechanism of competitive inhibition.
Organizational Affiliation:
Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, United States.
