2BC8

[Sec2,3,8,12]-ImI


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 1.5 of the entry. See complete history

Literature

{alpha}-Selenoconotoxins, a New Class of Potent {alpha}7 Neuronal Nicotinic Receptor Antagonists.

Armishaw, C.J.Daly, N.L.Nevin, S.T.Adams, D.J.Craik, D.J.Alewood, P.F.

(2006) J.Biol.Chem. 281: 14136-14143

  • DOI: 10.1074/jbc.M512419200
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Disulfide bonds are important structural motifs that play an essential role in maintaining the conformational stability of many bioactive peptides. Of particular importance are the conotoxins, which selectively target a wide range of ion channels tha ...

    Disulfide bonds are important structural motifs that play an essential role in maintaining the conformational stability of many bioactive peptides. Of particular importance are the conotoxins, which selectively target a wide range of ion channels that are implicated in numerous disease states. Despite the enormous potential of conotoxins as therapeutics, their multiple disulfide bond frameworks are inherently unstable under reducing conditions. Reduction or scrambling by thiol-containing molecules such as glutathione or serum albumin in intracellular or extracellular environments such as blood plasma can decrease their effectiveness as drugs. To address this issue, we describe a new class of selenoconotoxins where cysteine residues are replaced by selenocysteine to form isosteric and nonreducible diselenide bonds. Three isoforms of alpha-conotoxin ImI were synthesized by t-butoxycarbonyl chemistry with systematic replacement of one ([Sec(2,8)]ImI or [Sec(3,12)]ImI), or both ([Sec(2,3,8,12)]ImI) disulfide bonds with a diselenide bond. Each analogue demonstrated remarkable stability to reduction or scrambling under a range of chemical and biological reducing conditions. Three-dimensional structural characterization by NMR and CD spectroscopy indicates conformational preferences that are very similar to those of native ImI, suggesting fully isomorphic structures. Additionally, full bioactivity was retained at the alpha7 nicotinic acetylcholine receptor, with each selenoanalogue exhibiting a dose-response curve that overlaps with wild-type ImI, thus further supporting an isomorphic structure. These results demonstrate that selenoconotoxins can be used as highly stable scaffolds for the design of new drugs.


    Organizational Affiliation

    Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland 4072, Australia.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Alpha-conotoxin ImI
A
12Conus imperialisMutation(s): 0 
Find proteins for P50983 (Conus imperialis)
Go to UniProtKB:  P50983
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 50 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 
  • Olderado: 2BC8 Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2005-10-18 
  • Released Date: 2006-03-14 
  • Deposition Author(s): Armishaw, C.J.

Revision History 

  • Version 1.0: 2006-03-14
    Type: Initial release
  • Version 1.1: 2008-05-01
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2013-06-26
    Type: Other
  • Version 1.4: 2014-04-09
    Type: Other
  • Version 1.5: 2014-08-06
    Type: Derived calculations