1TR6

NMR solution structure of omega-conotoxin [K10]GVIA, a cyclic cysteine knot peptide

PDB DOI: 10.2210/pdb1TR6/pdb

Classification: TOXIN
Organism(s): Conus geographus
Mutation(s): Yes

Deposited: 2004-06-21 Released: 2004-07-13
Deposition Author(s): Mould, J., Yasuda, T., Schroeder, C.I., Beedle, A.M., Doering, C.J., Zamponi, G.W., Adams, D.J., Lewis, R.J.

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.

Literature

The alpha2delta auxiliary subunit reduces affinity of omega-conotoxins for recombinant N-type (Cav2.2) calcium channels

Mould, J., Yasuda, T., Schroeder, C.I., Beedle, A.M., Doering, C.J., Zamponi, G.W., Adams, D.J., Lewis, R.J.

(2004) J Biol Chem 279: 34705-34714

PubMed: 15166237 Search on PubMed
DOI: 10.1074/jbc.M310848200
Primary Citation of Related Structures:
1TR6, 1TTL

PubMed Abstract:

The omega-conotoxins from fish-hunting cone snails are potent inhibitors of voltage-gated calcium channels. The omega-conotoxins MVIIA and CVID are selective N-type calcium channel inhibitors with potential in the treatment of chronic pain. The beta and alpha(2)delta-1 auxiliary subunits influence the expression and characteristics of the alpha(1B) subunit of N-type channels and are differentially regulated in disease states, including pain. In this study, we examined the influence of these auxiliary subunits on the ability of the omega-conotoxins GVIA, MVIIA, CVID and analogues to inhibit peripheral and central forms of the rat N-type channels. Although the beta3 subunit had little influence on the on- and off-rates of omega-conotoxins, coexpression of alpha(2)delta with alpha(1B) significantly reduced on-rates and equilibrium inhibition at both the central and peripheral isoforms of the N-type channels. The alpha(2)delta also enhanced the selectivity of MVIIA, but not CVID, for the central isoform. Similar but less pronounced trends were also observed for N-type channels expressed in human embryonic kidney cells. The influence of alpha(2)delta was not affected by oocyte deglycosylation. The extent of recovery from the omega-conotoxin block was least for GVIA, intermediate for MVIIA, and almost complete for CVID. Application of a hyperpolarizing holding potential (-120 mV) did not significantly enhance the extent of CVID recovery. Interestingly, [R10K]MVIIA and [O10K]GVIA had greater recovery from the block, whereas [K10R]CVID had reduced recovery from the block, indicating that position 10 had an important influence on the extent of omega-conotoxin reversibility. Recovery from CVID block was reduced in the presence of alpha(2)delta in human embryonic kidney cells and in oocytes expressing alpha(1B-b). These results may have implications for the antinociceptive properties of omega-conotoxins, given that the alpha(2)delta subunit is up-regulated in certain pain states.

Organizational Affiliation:

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

Macromolecules

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(by identity cutoff) | 3D Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Omega-conotoxin GVIA	A	28	Conus geographus	Mutation(s): 1
UniProt
Find proteins for P01522 (Conus geographus) Explore P01522 Go to UniProtKB: P01522
Entity Groups
Sequence Clusters	30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt Group	P01522
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Reference Sequence