7LQR | pdb_00007lqr

Structure of conotoxin CIC

• PDB DOI: https://doi.org/10.2210/pdb7LQR/pdb

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


• Deposited: 2021-02-15 Released: 2021-04-21 
• Deposition Author(s): Evans, E.R.J., Daly, N.L.

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Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Calculated: 100 
• Conformers Submitted: 20 
• Selection Criteria: target function 

Literature

Synthesis, Structural and Pharmacological Characterizations of CIC, a Novel alpha-Conotoxin with an Extended N-Terminal Tail.

Giribaldi, J., Haufe, Y., Evans, E.R.J., Wilson, D.T., Daly, N.L., Enjalbal, C., Nicke, A., Dutertre, S.

(2021) Mar Drugs 19

• PubMed: 33801301 
• DOI: https://doi.org/10.3390/md19030141
• Primary Citation Related Structures: 
  7LQR, 7LQS


• PubMed Abstract: 
  

  Cone snails are venomous marine predators that rely on fast-acting venom to subdue their prey and defend against aggressors. The conotoxins produced in the venom gland are small disulfide-rich peptides with high affinity and selectivity for their pharmacological targets. A dominant group comprises α-conotoxins, targeting nicotinic acetylcholine receptors. Here, we report on the synthesis, structure determination and biological activity of a novel α-conotoxin, CIC, found in the predatory venom of the piscivorous species Conus catus and its truncated mutant Δ-CIC. CIC is a 4/7 α-conotoxin with an unusual extended N-terminal tail. High-resolution NMR spectroscopy shows a major influence of the N-terminal tail on the apparent rigidity of the three-dimensional structure of CIC compared to the more flexible Δ-CIC. Surprisingly, this effect on the structure does not alter the biological activity, since both peptides selectively inhibit α3β2 and α6/α3β2β3 nAChRs with almost identical sub- to low micromolar inhibition constants. Our results suggest that the N-terminal part of α-conotoxins can accommodate chemical modifications without affecting their pharmacology.

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Organizational Affiliation: 
• Institut des Biomolécules Max Mousseron, UMR 5247, Université de Montpellier, CNRS, ENSCM, 34095 Montpellier, France.
Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, Nußbaumstraße 26, 80336 Munich, Germany.
Centre for Molecular Therapeutics, Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, QLD 4878, Australia.

Biological Assembly 1  

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

Biological assembly 1 assigned by authors.

Macromolecule Content 

• Total Structure Weight: 2.11 kDa 
• Atom Count: 142 
• Modeled Residue Count: 21 
• Deposited Residue Count: 21 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Alpha-conotoxin CIC	A	21	Conus catus	Mutation(s): 0

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Calculated: 100 
• Conformers Submitted: 20 
• Selection Criteria: target function 

Structure Validation

Entry History 

Deposition Data

• Released Date: 2021-04-21 
Deposition Author(s): Evans, E.R.J., Daly, N.L.

Revision History  

• Version 1.0: 2021-04-21
  Type: Initial release
  
• Version 1.1: 2024-10-30
  Changes: Data collection, Database references, Structure summary