2JUS

alpha RgIA, a Novel Conotoxin that Blocks the alpha9-alpha10 nAChR


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Alpha-RgIA, a novel conotoxin that blocks the alpha9alpha10 nAChR: structure and identification of key receptor-binding residues.

Ellison, M.Feng, Z.P.Park, A.J.Zhang, X.Olivera, B.M.McIntosh, J.M.Norton, R.S.

(2008) J Mol Biol 377: 1216-1227

  • DOI: 10.1016/j.jmb.2008.01.082
  • Primary Citation of Related Structures:  
    2JUQ, 2JUR, 2JUS, 2JUT

  • PubMed Abstract: 
  • Alpha-conotoxins are small disulfide-constrained peptides from cone snails that act as antagonists at specific subtypes of nicotinic acetylcholine receptors (nAChRs). The 13-residue peptide alpha-conotoxin RgIA (alpha-RgIA) is a member of the alpha-4,3 family of alpha-conotoxins and selectively blocks the alpha9alpha10 nAChR subtype, in contrast to another well-characterized member of this family, alpha-conotoxin ImI (alpha-ImI), which is a potent inhibitor of the alpha7 and alpha3beta2 nAChR subtypes ...

    Alpha-conotoxins are small disulfide-constrained peptides from cone snails that act as antagonists at specific subtypes of nicotinic acetylcholine receptors (nAChRs). The 13-residue peptide alpha-conotoxin RgIA (alpha-RgIA) is a member of the alpha-4,3 family of alpha-conotoxins and selectively blocks the alpha9alpha10 nAChR subtype, in contrast to another well-characterized member of this family, alpha-conotoxin ImI (alpha-ImI), which is a potent inhibitor of the alpha7 and alpha3beta2 nAChR subtypes. In this study, we have altered side chains in both the four-residue and the three-residue loops of alpha-RgIA, and have modified its C-terminus. The effects of these changes on activity against alpha9alpha10 and alpha7 nAChRs were measured; the solution structures of alpha-RgIA and its Y10W, D5E, and P6V analogues were determined from NMR data; and resonance assignments were made for alpha-RgIA [R9A]. The structures for alpha-RgIA and its three analogues were well defined, except at the chain termini. Comparison of these structures with reported structures of alpha-ImI reveals a common two-loop backbone architecture within the alpha-4,3 family, but with variations in side-chain solvent accessibility and orientation. Asp5, Pro6, and Arg7 in loop 1 are critical for blockade of both the alpha9alpha10 and the alpha7 subtypes. In loop 2, alpha-RgIA [Y10W] had activity near that of wild-type alpha-RgIA, with high potency for alpha9alpha10 and low potency for alpha7, and had a structure similar to that of wild type. By contrast, Arg9 in loop 2 is critical for specific binding to the alpha9alpha10 subtype, probably because it is larger and more solvent accessible than Ala9 in alpha-ImI. Our findings contribute to a better understanding of the molecular basis for antagonism of the alpha9alpha10 nAChR subtype, which is a target for the development of analgesics for the treatment of chronic neuropathic pain.


    Organizational Affiliation

    Department of Biology, University of Utah, Salt Lake City, UT 84112, USA.



Macromolecules

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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Alpha-conotoxin RgIAA13N/AMutation(s): 1 
UniProt
Find proteins for P0C1D0 (Conus regius)
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Go to UniProtKB:  P0C1D0
Entity Groups  
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UniProt GroupP0C1D0
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: structures with the lowest energy 

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2011-05-25
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2021-10-20
    Changes: Data collection, Database references