1ONT
NMDA RECEPTOR ANTAGONIST, CONANTOKIN-T, NMR, 17 STRUCTURES
Summary for 1ONT
| Entry DOI | 10.2210/pdb1ont/pdb |
| Descriptor | CONANTOKIN-T (1 entity in total) |
| Functional Keywords | nmda receptor, antagonist, conantokin-t |
| Biological source | Conus tulipa (tulip cone) |
| Cellular location | Secreted: P17684 |
| Total number of polymer chains | 1 |
| Total formula weight | 2686.84 |
| Authors | Skjaerbaek, N.,Nielsen, K.J.,Lewis, R.J.,Alewood, P.F.,Craik, D.J. (deposition date: 1996-08-27, release date: 1997-09-04, Last modification date: 2022-02-23) |
| Primary citation | Skjaerbaek, N.,Nielsen, K.J.,Lewis, R.J.,Alewood, P.,Craik, D.J. Determination of the solution structures of conantokin-G and conantokin-T by CD and NMR spectroscopy. J.Biol.Chem., 272:2291-2299, 1997 Cited by PubMed Abstract: Conantokin-G and conantokin-T are two paralytic polypeptide toxins originally isolated from the venom of the fish-hunting cone snails of the genus Conus. Conantokin-G and conantokin-T are the only naturally occurring peptidic compounds which possess N-methyl-D-aspartate receptor antagonist activity, produced by a selective non-competitive antagonism of polyamine responses. They are also structurally unusual in that they contain a disproportionately large number of acid labile post-translational gamma-carboxyglutamic acid (Gla) residues. Although no precise structural information has previously been published for these peptides, early spectroscopic measurements have indicated that both conantokin-G and conantokin-T form alpha-helical structures, although there is some debate whether the presence of calcium ions is required for these peptides to adopt this fold. We now report a detailed structural study of synthetic conantokin-G and conantokin-T in a range of solution conditions using CD and 1H NMR spectroscopy. The three-dimensional structures of conantokin-T and conantokin-G were calculated from 1H NMR-derived distance and dihedral restraints. Both conantokins were found to contain a mixture of alpha- and 310 helix, that give rise to curved and straight helical conformers. Conantokin-G requires the presence of divalent cations (Zn2+, Ca2+, Cu2+, or Mg2+) to form a stable alpha-helix, while conantokin-T adopts a stable alpha-helical structure in aqueous conditions, in the presence or absence of divalent cations (Zn2+, Ca2+, Cu2+, or Mg2+). PubMed: 8999936DOI: 10.1074/jbc.272.4.2291 PDB entries with the same primary citation |
| Experimental method | SOLUTION NMR |
Structure validation
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