Conformational dynamics of a nicotinic receptor neurotransmitter site

Agonists enhance receptor activity by providing net-favorable binding energy to active over resting conformations, with efficiency (η) linking binding energy to gating. Previously, we showed that in nicotinic receptors, η-values are grouped into five structural pairs, correlating efficacy and affini...

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Main Authors: Mrityunjay Singh, Dinesh C Indurthi, Lovika Mittal, Anthony Auerbach, Shailendra Asthana
Format: Article
Language:English
Published: eLife Sciences Publications Ltd 2024-12-01
Series:eLife
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Online Access:https://elifesciences.org/articles/92418
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author Mrityunjay Singh
Dinesh C Indurthi
Lovika Mittal
Anthony Auerbach
Shailendra Asthana
author_facet Mrityunjay Singh
Dinesh C Indurthi
Lovika Mittal
Anthony Auerbach
Shailendra Asthana
author_sort Mrityunjay Singh
collection DOAJ
description Agonists enhance receptor activity by providing net-favorable binding energy to active over resting conformations, with efficiency (η) linking binding energy to gating. Previously, we showed that in nicotinic receptors, η-values are grouped into five structural pairs, correlating efficacy and affinity within each class, uniting binding with allosteric activation (Indurthi and Auerbach, 2023). Here, we use molecular dynamics (MD) simulations to investigate the low-to-high affinity transition (L→H) at the Torpedo α−δ nicotinic acetylcholine receptor neurotransmitter site. Using four agonists spanning three η-classes, the simulations reveal the structural basis of the L→H transition where: the agonist pivots around its cationic center (‘flip’), loop C undergoes staged downward displacement (‘flop’), and a compact, stable high-affinity pocket forms (‘fix’). The η derived from binding energies calculated in silico matched exact values measured experimentally in vitro. Intermediate states of the orthosteric site during receptor activation are apparent only in simulations, but could potentially be observed experimentally via time-resolved structural studies.
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spelling doaj-art-d8d6d6a370fa4ab58f2e2f8a22bd7eee2024-12-18T15:46:02ZengeLife Sciences Publications LtdeLife2050-084X2024-12-011310.7554/eLife.92418Conformational dynamics of a nicotinic receptor neurotransmitter siteMrityunjay Singh0Dinesh C Indurthi1https://orcid.org/0000-0001-8837-5883Lovika Mittal2Anthony Auerbach3https://orcid.org/0000-0003-4151-860XShailendra Asthana4Computational Biophysics and CADD Group, Computational and Mathematical Biology Center,Translational Health Science and Technology Institute, Faridabad, IndiaDepartment of Physiology and Biophysics, University at Buffalo, State University of New York, Buffalo, United StatesComputational Biophysics and CADD Group, Computational and Mathematical Biology Center,Translational Health Science and Technology Institute, Faridabad, IndiaDepartment of Physiology and Biophysics, University at Buffalo, State University of New York, Buffalo, United StatesComputational Biophysics and CADD Group, Computational and Mathematical Biology Center,Translational Health Science and Technology Institute, Faridabad, IndiaAgonists enhance receptor activity by providing net-favorable binding energy to active over resting conformations, with efficiency (η) linking binding energy to gating. Previously, we showed that in nicotinic receptors, η-values are grouped into five structural pairs, correlating efficacy and affinity within each class, uniting binding with allosteric activation (Indurthi and Auerbach, 2023). Here, we use molecular dynamics (MD) simulations to investigate the low-to-high affinity transition (L→H) at the Torpedo α−δ nicotinic acetylcholine receptor neurotransmitter site. Using four agonists spanning three η-classes, the simulations reveal the structural basis of the L→H transition where: the agonist pivots around its cationic center (‘flip’), loop C undergoes staged downward displacement (‘flop’), and a compact, stable high-affinity pocket forms (‘fix’). The η derived from binding energies calculated in silico matched exact values measured experimentally in vitro. Intermediate states of the orthosteric site during receptor activation are apparent only in simulations, but could potentially be observed experimentally via time-resolved structural studies.https://elifesciences.org/articles/92418nicotinic receptorion channelallostery
spellingShingle Mrityunjay Singh
Dinesh C Indurthi
Lovika Mittal
Anthony Auerbach
Shailendra Asthana
Conformational dynamics of a nicotinic receptor neurotransmitter site
eLife
nicotinic receptor
ion channel
allostery
title Conformational dynamics of a nicotinic receptor neurotransmitter site
title_full Conformational dynamics of a nicotinic receptor neurotransmitter site
title_fullStr Conformational dynamics of a nicotinic receptor neurotransmitter site
title_full_unstemmed Conformational dynamics of a nicotinic receptor neurotransmitter site
title_short Conformational dynamics of a nicotinic receptor neurotransmitter site
title_sort conformational dynamics of a nicotinic receptor neurotransmitter site
topic nicotinic receptor
ion channel
allostery
url https://elifesciences.org/articles/92418
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