Conserved Site

Conantokin, conserved site (IPR005918)

Short name: Conantokin_CS

Description

The conantokins are a family of neuroactive peptides found in the venoms of fish-hunting cone snails. They possess a relatively high number of residues (4-5) of the non-standard amino acid gamma-carboxyglutamic acid (Gla), which is generated by the post-translational modification of glutamate (Glu) residues. Conantokins are the only naturally produced peptides known to be N-methyl-D-aspartate (NMDA) receptor antagonists and show therapeutic promise in treating conditions associated with NMDA receptor dysfunction. In animal models they have exhibited anticonvulsant and anti-Parkinsonian properties and have provided neuroprotection within therapeutically acceptable times following transient focal brain ischemia [PMID: 9398296, PMID: 11554555, PMID: 11096077, PMID: 12350383].

Upon binding of Ca2+ to Gla, conantokin undergoes a conformational transition from a distorted curvilinear 3(10) helix to a linear alpha-helix. The binding of Ca2+ to conantokin leads to the exposure of a hydrophobic region on the opposite face of the helix [PMID: 9398296]. Conantokins share relatively few sequence elements, which include include sequence identity at the first four residues, homologous positioning of the two most C-terminal Gla residues, and an Arg preceding the most C-terminal Gla [PMID: 11554555].

The conantokin family is currently known to include:

  • Conotoxin G from Conus geographus (Geography cone) (Nubecula geographus).
  • Conantokin-L from Conus lynceus (Lynceus cone).
  • Conantokin-R from Conus radiatus (Rayed cone).
  • Conantokin-T from Conus tulipa (Fish-hunting cone snail) (Tulip cone).

GO terms

Biological Process

GO:0009405 pathogenesis

Molecular Function

No terms assigned in this category.

Cellular Component

GO:0035792 other organism postsynaptic membrane

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE patterns
Pfam