1onu
From Proteopedia
(New page: 200px<br /><applet load="1onu" size="450" color="white" frame="true" align="right" spinBox="true" caption="1onu" /> '''NMDA RECEPTOR ANTAGONIST, CONANTOKIN-G, NMR,...) |
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| - | [[Image:1onu.jpg|left|200px]]<br /><applet load="1onu" size=" | + | [[Image:1onu.jpg|left|200px]]<br /><applet load="1onu" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1onu" /> | caption="1onu" /> | ||
'''NMDA RECEPTOR ANTAGONIST, CONANTOKIN-G, NMR, 17 STRUCTURES'''<br /> | '''NMDA RECEPTOR ANTAGONIST, CONANTOKIN-G, NMR, 17 STRUCTURES'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Conantokin-G and conantokin-T are two paralytic polypeptide toxins | + | 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+). |
==About this Structure== | ==About this Structure== | ||
| - | 1ONU is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Conus_geographus Conus geographus] with NH2 as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1ONU is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Conus_geographus Conus geographus] with <scene name='pdbligand=NH2:'>NH2</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ONU OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Conus geographus]] | [[Category: Conus geographus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Alewood, P | + | [[Category: Alewood, P F.]] |
| - | [[Category: Craik, D | + | [[Category: Craik, D J.]] |
| - | [[Category: Lewis, R | + | [[Category: Lewis, R J.]] |
| - | [[Category: Nielsen, K | + | [[Category: Nielsen, K J.]] |
[[Category: Skjaerbaek, N.]] | [[Category: Skjaerbaek, N.]] | ||
[[Category: NH2]] | [[Category: NH2]] | ||
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[[Category: nmda receptor]] | [[Category: nmda receptor]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:19:46 2008'' |
Revision as of 12:19, 21 February 2008
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NMDA RECEPTOR ANTAGONIST, CONANTOKIN-G, NMR, 17 STRUCTURES
Overview
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+).
About this Structure
1ONU is a Single protein structure of sequence from Conus geographus with as ligand. Full crystallographic information is available from OCA.
Reference
Determination of the solution structures of conantokin-G and conantokin-T by CD and NMR spectroscopy., Skjaerbaek N, Nielsen KJ, Lewis RJ, Alewood P, Craik DJ, J Biol Chem. 1997 Jan 24;272(4):2291-9. PMID:8999936
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