1nxn
From Proteopedia
(New page: 200px<br /><applet load="1nxn" size="450" color="white" frame="true" align="right" spinBox="true" caption="1nxn" /> '''SOLUTION STRUCTURE OF CONTRYPHAN-VN'''<br />...) |
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| - | [[Image:1nxn.gif|left|200px]]<br /><applet load="1nxn" size=" | + | [[Image:1nxn.gif|left|200px]]<br /><applet load="1nxn" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1nxn" /> | caption="1nxn" /> | ||
'''SOLUTION STRUCTURE OF CONTRYPHAN-VN'''<br /> | '''SOLUTION STRUCTURE OF CONTRYPHAN-VN'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The solution structure of contryphan-Vn, a cyclic peptide with a double | + | The solution structure of contryphan-Vn, a cyclic peptide with a double cysteine S-S bridge and containing a D-tryptophan extracted from the venom of the cone snail Conus ventricosus, has been determined by NMR spectroscopy using a variety of homonuclear and heteronuclear NMR methods and restrained molecular dynamics simulations. The main conformational features of backbone contryphan-Vn are a type IV beta-turn from Gly 1 to Lys 6 and a type I beta-turn from Lys 6 to Cys 9. As already found in other contryphans, one of the two prolines--the Pro4--is mainly in the cis conformation while Pro7 is trans. A small hydrophobic region probably partly shielded from solvent constituted from the close proximity of side chains of Pro7 and Trp8 was observed together with a persistent salt bridge between Asp2 and Lys6, which has been revealed by the diagnostic observation of specific nuclear Overhauser effects. The salt bridge was used as a restraint in the molecular dynamics in vacuum but without inserting explicit electrostatic contribution in the calculations. The backbone of the unique conformational family found of contryphan-Vn superimposes well with those of contryphan-Sm and contryphan-R. This result indicates that the contryphan structural motif represents a robust and conserved molecular scaffold whose main structural determinants are the size of the intercysteine loop and the presence and location in the sequence of the D-Trp and the two Pro residues. |
==About this Structure== | ==About this Structure== | ||
| - | 1NXN is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ] with NH2 as [http://en.wikipedia.org/wiki/ligand ligand]. This structure | + | 1NXN is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ] with <scene name='pdbligand=NH2:'>NH2</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. This structure supersedes the now removed PDB entry 1N3V. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NXN OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Protein complex]] | [[Category: Protein complex]] | ||
[[Category: Ascenzi, P.]] | [[Category: Ascenzi, P.]] | ||
| - | [[Category: Cicero, D | + | [[Category: Cicero, D O.]] |
[[Category: Eliseo, T.]] | [[Category: Eliseo, T.]] | ||
| - | [[Category: Massilia, G | + | [[Category: Massilia, G R.]] |
[[Category: Paci, M.]] | [[Category: Paci, M.]] | ||
[[Category: Polticelli, F.]] | [[Category: Polticelli, F.]] | ||
| - | [[Category: Schinina, M | + | [[Category: Schinina, M E.]] |
[[Category: NH2]] | [[Category: NH2]] | ||
[[Category: cis-trans isomerism]] | [[Category: cis-trans isomerism]] | ||
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[[Category: toxin]] | [[Category: toxin]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:11:17 2008'' |
Revision as of 12:11, 21 February 2008
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SOLUTION STRUCTURE OF CONTRYPHAN-VN
Overview
The solution structure of contryphan-Vn, a cyclic peptide with a double cysteine S-S bridge and containing a D-tryptophan extracted from the venom of the cone snail Conus ventricosus, has been determined by NMR spectroscopy using a variety of homonuclear and heteronuclear NMR methods and restrained molecular dynamics simulations. The main conformational features of backbone contryphan-Vn are a type IV beta-turn from Gly 1 to Lys 6 and a type I beta-turn from Lys 6 to Cys 9. As already found in other contryphans, one of the two prolines--the Pro4--is mainly in the cis conformation while Pro7 is trans. A small hydrophobic region probably partly shielded from solvent constituted from the close proximity of side chains of Pro7 and Trp8 was observed together with a persistent salt bridge between Asp2 and Lys6, which has been revealed by the diagnostic observation of specific nuclear Overhauser effects. The salt bridge was used as a restraint in the molecular dynamics in vacuum but without inserting explicit electrostatic contribution in the calculations. The backbone of the unique conformational family found of contryphan-Vn superimposes well with those of contryphan-Sm and contryphan-R. This result indicates that the contryphan structural motif represents a robust and conserved molecular scaffold whose main structural determinants are the size of the intercysteine loop and the presence and location in the sequence of the D-Trp and the two Pro residues.
About this Structure
1NXN is a Protein complex structure of sequences from [1] with as ligand. This structure supersedes the now removed PDB entry 1N3V. Full crystallographic information is available from OCA.
Reference
Solution structure of the cyclic peptide contryphan-Vn, a Ca2+-dependent K+ channel modulator., Eliseo T, Cicero DO, Romeo C, Schinina ME, Massilia GR, Polticelli F, Ascenzi P, Paci M, Biopolymers. 2004 Jun 15;74(3):189-98. PMID:15150794
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