Structure of cyclic conotoxin MII-7

Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 50 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 

wwPDB Validation   3D Report Full Report

This is version 1.3 of the entry. See complete history


Engineering stable peptide toxins by means of backbone cyclization: Stabilization of the {alpha}-conotoxin MII.

Clark, R.J.Fischer, H.Dempster, L.Daly, N.L.Rosengren, K.J.Nevin, S.T.Meunier, F.A.Adams, D.J.Craik, D.J.

(2005) Proc Natl Acad Sci U S A 102: 13767-13772

  • DOI: https://doi.org/10.1073/pnas.0504613102
  • Primary Citation of Related Structures:  
    2AJW, 2AK0

  • PubMed Abstract: 

    Conotoxins (CTXs), with their exquisite specificity and potency, have recently created much excitement as drug leads. However, like most peptides, their beneficial activities may potentially be undermined by susceptibility to proteolysis in vivo. By cyclizing the alpha-CTX MII by using a range of linkers, we have engineered peptides that preserve their full activity but have greatly improved resistance to proteolytic degradation. The cyclic MII analogue containing a seven-residue linker joining the N and C termini was as active and selective as the native peptide for native and recombinant neuronal nicotinic acetylcholine receptor subtypes present in bovine chromaffin cells and expressed in Xenopus oocytes, respectively. Furthermore, its resistance to proteolysis against a specific protease and in human plasma was significantly improved. More generally, to our knowledge, this report is the first on the cyclization of disulfide-rich toxins. Cyclization strategies represent an approach for stabilizing bioactive peptides while keeping their full potencies and should boost applications of peptide-based drugs in human medicine.

  • Organizational Affiliation

    Institute for Molecular Bioscience and School of Biomedical Sciences, University of Queensland, Brisbane QLD 4072, Australia.


Find similar proteins by:  Sequence   |   3D Structure  

Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Alpha-conotoxin MII23N/AMutation(s): 0 
Find proteins for P56636 (Conus magus)
Explore P56636 
Go to UniProtKB:  P56636
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP56636
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 50 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2005-09-06
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2022-03-09
    Changes: Data collection, Database references, Derived calculations