9PAZ | pdb_00009paz

Solution NMR structure of conotoxin AoIA

• PDB DOI: https://doi.org/10.2210/pdb9PAZ/pdb

• Classification: TOXIN
• Organism(s): Conus araneosus
• Mutation(s): No 


• Deposited: 2025-06-25 Released: 2026-07-29 
• Deposition Author(s): Gonzalez, T.I., Rosengren, K.J.
• Funding Organization(s): Australian Research Council (ARC)

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Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Calculated: 50 
• Conformers Submitted: 20 
• Selection Criteria: Molprobity score 

Literature

Structural and functional basis of antinociceptive action of chi-conotoxin AoIA at the noradrenaline transporter.

Belleza, O.J.V., Zhang, H., Schmidhammer, H., Gonzalez, T.I., Ciotu, C.I., Tomasevic, N., Ocampo, C.M.M., Fernando, J.C., Koehbach, J., Schwarz, P., Al Makhlouf, M., Tajti, G., Hasinger, S., Kastner, N., Avsar, O., Retzl, B., Jantsch, K., Jiang, Y., Hellinger, R., Fischer, M.J.M., Rosengren, K.J., Gruber, C.W., Villaraza, A.J.L., Stockner, T., Spetea, M., Xu, H.E., Sitte, H.H.

(2026) Nat Struct Mol Biol 

• PubMed: 42481720 
• DOI: https://doi.org/10.1038/s41594-026-01838-z
• Primary Citation Related Structures: 
  9K6X, 9PAZ, 9PB0


• PubMed Abstract: 
  

  The χ-conotoxins are venom-derived peptides that specifically target the noradrenaline transporter (also known as norepinephrine transporter, NET). Regulation of noradrenergic signaling by NET affects neurophysiological processes, including pain. Therefore, the χ-conotoxin MrIA and its synthetic analogs have been previously investigated for their analgesic activity. Here we describe the synthesis and pharmacological characterization of χ-AoIA, a peptide that selectively inhibits NET with a higher potency compared to MrIA in in vitro radiotracer flux assays. Furthermore, we resolved the structure of the human NET:χ-AoIA complex by cryogenic electron microscopy, which revealed an atypical binding mode consisting of both the central binding site and the outer vestibule of the transporter. Lastly, χ-AoIA displays antinociceptive efficacy in a model of inflammatory pain after subcutaneous administration in mice. Our results demonstrate the efficacy of χ-AoIA as a highly selective ligand of NET and provide a mechanistic basis for its potential development as a nonopioid analgesic.

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Organizational Affiliation: 
• Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria.
State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.
Department of Pharmaceutical Chemistry, Institute of Pharmacy and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria.
School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia.
Institute of Physiology, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria.
Institute of Chemistry, University of the Philippines - Diliman, Quezon City, Philippines.
Department of Molecular Biology and Genetics, Faculty of Arts and Sciences, Hitit University, Corum, Türkiye.
Lingang Laboratory, Shanghai, China.
State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China. [e-mail].
Institute of Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria. [e-mail].
Hourani Center for Applied Scientific Research, Al-Ahliyya Amman University, Amman, Jordan. [e-mail].
Center for Addiction Research and Science, Medical University of Vienna, Vienna, Austria. [e-mail].

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 assigned by authors and generated by (software)

Biological Assembly Evidence: NMR Distance Restraints

Macromolecule Content 

• Total Structure Weight: 1.32 kDa 
• Atom Count: 87 
• Modeled Residue Count: 11 
• Deposited Residue Count: 11 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Chi-conotoxin-like Ar1311	A	11	Conus araneosus	Mutation(s): 0
UniProt
Find proteins for P0CI23 (Conus araneosus) Explore P0CI23  Go to UniProtKB:  P0CI23

Small Molecules

Modified Residues  1 Unique
ID	Chains	Type	Formula	2D Diagram	Parent
HYP	A	L-PEPTIDE LINKING	C5 H9 N O3		PRO

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Calculated: 50 
• Conformers Submitted: 20 
• Selection Criteria: Molprobity score 

Structure Validation

Entry History 

& Funding Information

Deposition Data

• Released Date: 2026-07-29 
Deposition Author(s): Gonzalez, T.I., Rosengren, K.J.

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Funding Organization	Location	Grant Number
Australian Research Council (ARC)	Australia	--

Revision History  

• Version 1.0: 2026-07-29
  Type: Initial release
  
• Version 1.1: 2026-08-05
  Changes: Database references