9VU1 | pdb_00009vu1

Structure of hTRPA1 complexed with LIQA

PDB DOI: https://doi.org/10.2210/pdb9VU1/pdb
EM Map EMD-65349: EMDB EMDataResource

Classification: MEMBRANE PROTEIN
Organism(s): Homo sapiens
Expression System: Homo sapiens
Mutation(s): No

Deposited: 2025-07-12 Released: 2026-07-15
Deposition Author(s): Min, Y.M., Zonglin, D.Z., Yang, Y.Y.
Funding Organization(s): National Natural Science Foundation of China (NSFC)

Experimental Data Snapshot

Method: ELECTRON MICROSCOPY
Resolution: 2.59 Å
Aggregation State: PARTICLE
Reconstruction Method: SINGLE PARTICLE

wwPDB Validation 3D Report Full Report

This is version 1.0 of the entry. See complete history.

Literature

Structural insights into TRPA1 and TRPV1 modulation by flavonoid glycosides from licorice for cough relief.

Yi, Y., Duan, G., Dai, Z., Zhou, X., Huang, J., Jin, Z., Yang, A., Li, Y., Huang, Z., Ye, M.

(2026) Phytomedicine 159: 158419-158419

PubMed: 42335638 Search on PubMed
DOI: https://doi.org/10.1016/j.phymed.2026.158419
Primary Citation Related Structures:
9VTZ, 9VU0, 9VU1

PubMed Abstract:
Transient receptor potential vanilloid 1 (TRPV1) and ankyrin 1 (TRPA1) are two nociceptive TRP channel subtypes that play central roles in cough hypersensitivity. This study evaluated the antitussive efficacy of liquiritin apioside (LIQA) and liquiritin (LIQ), two major flavonoid glycosides from licorice, in acute chemically induced cough models, and investigated their modulations of TRPA1 and TRPV1. In guinea pig models, cough was induced by capsaicin (a TRPV1 agonist) and cinnamaldehyde (a TRPA1 agonist), respectively. The inhibitory effects of LIQA and LIQ against TRPA1 and TRPV1 were assessed using electrophysiological profiling and fluorescence-based calcium assays. To elucidate the underlying mechanisms, high-resolution cryo-electron microscopy (cryo-EM) structural analysis, and molecular simulations were conducted. LIQA and LIQ significantly reduced cough frequency in the guinea pig models. Electrophysiological profiling revealed that LIQA suppressed human TRPA1 (hTRPA1) channel activity, while LIQ blocked human TRPV1 (hTRPV1) activation. High-resolution cryo-EM structures of hTRPA1/LIQA (2.59 Å) and hTRPV1/LIQ (3.05 Å) complexes were obtained. Structural analysis indicates that LIQA stabilizes hTRPA1 in a closed conformation with T624 at the coupling region site, whereas LIQ interacts with S512 through hydrogen bonding in the deep S4-S5 site of hTRPV1, thereby inhibiting pore opening. This study establishes LIQA and LIQ as lead compounds with acute antitussive activities mediated by TRPA1/TRPV1 modulation.

Organizational Affiliation

State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China; Yunnan Baiyao International Medical Research Centre, Peking University, Beijing 100191, China.

Macromolecule Content

Total Structure Weight: 512.84 kDa
Atom Count: 19,292
Modeled Residue Count: 2,420
Deposited Residue Count: 4,476
Unique protein chains: 1

Macromolecules

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| 3D Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Transient receptor potential cation channel subfamily A member 1	A, B, C, D	1,119	Homo sapiens	Mutation(s): 0 Gene Names: TRPA1, ANKTM1
UniProt & NIH Common Fund Data Resources
Find proteins for O75762 (Homo sapiens) Explore O75762 Go to UniProtKB: O75762
PHAROS: O75762 GTEx: ENSG00000104321
Entity Groups
Sequence Clusters	30% Identity 50% Identity 70% Identity 90% Identity 95% Identity 100% Identity
UniProt Group	O75762
Sequence Annotations Expand
Reference Sequence

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram	3D Interactions
A1ETS( Subject of Investigation/LOI) Query on A1ETS Download:Ideal Coordinates CCD File SDF format, chain E [auth A] SDF format, chain F [auth B] SDF format, chain G [auth C] SDF format, chain H [auth D] MOL2 format, chain E [auth A] MOL2 format, chain F [auth B] MOL2 format, chain G [auth C] MOL2 format, chain H [auth D] mmCIF format, chain E [auth A] mmCIF format, chain F [auth B] mmCIF format, chain G [auth C] mmCIF format, chain H [auth D]	E [auth A], F [auth B], G [auth C], H [auth D]	Liquiritin apioside C₂₆ H₃₀ O₁₃ FTVKHUHJWDMWIR-DWMQJYMWSA-N		Interactions Focus chain E [auth A] Focus chain F [auth B] Focus chain G [auth C] Focus chain H [auth D] Interactions & Density Focus chain E [auth A] Focus chain F [auth B] Focus chain G [auth C] Focus chain H [auth D]