1ad7: Difference between revisions
New page: left|200px<br /><applet load="1ad7" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ad7" /> '''NMR STRUCTURE OF METAL-FREE CONANTOKIN G, 1 ... |
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[[Image:1ad7.gif|left|200px]]<br /><applet load="1ad7" size=" | [[Image:1ad7.gif|left|200px]]<br /><applet load="1ad7" size="350" color="white" frame="true" align="right" spinBox="true" | ||
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'''NMR STRUCTURE OF METAL-FREE CONANTOKIN G, 1 STRUCTURE'''<br /> | '''NMR STRUCTURE OF METAL-FREE CONANTOKIN G, 1 STRUCTURE'''<br /> | ||
==Overview== | ==Overview== | ||
Conantokin G is a gamma-carboxyglutamic acid-containing conotoxin from the | Conantokin G is a gamma-carboxyglutamic acid-containing conotoxin from the venom of the marine cone snail Conus geographus. The 17-residue peptide, which contains five gamma-carboxyglutamic acid (Gla) residues and an amidated C-terminal asparagine amide, was synthesized chemically in a form identical to the natural conantokin G. To gain insight into the role of gamma-carboxyglutamic acid in the structure of this peptide, we determined the three-dimensional structure of conantokin G by 1H NMR and compared its structure to other conotoxins and to the gamma-carboxyglutamic acid-containing regions of the vitamin K-dependent blood-clotting proteins. Complete resonance assignments were made by two-dimensional 1H NMR spectroscopy in the absence of metal ions. NOE cross-peaks d(alphaN), d(NN), and d(betaN) provided interproton distance information, and vicinal spin-spin coupling constants 3J(HN alpha) were used to calculate phi torsion angles. Distance geometry and simulated annealing methods were used to derive 20 convergent structures from a set of 227 interproton distance restraints and 13 torsion angle measurements. The backbone rmsd to the geometric average for 20 final structures is 0.8 +/- 0.1 A. Conantokin G consists of a structured region commencing at Gla 3 and extending through arginine 13. This structure includes a partial loop centered around Gla 3 and Gla 4, a distorted type I turn between glutamine 6 and glutamine 9, and two type I turns involving Gla 10, leucine 11, and isoleucine 12 and arginine 13. Together, these two turns define approximately 1.6 turns of a distorted 3(10) helix. The observed structure possesses structural elements similar to those seen in the disulfide-linked conotoxins. | ||
==About this Structure== | ==About this Structure== | ||
1AD7 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:// | 1AD7 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=1AD7 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Conus geographus]] | [[Category: Conus geographus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Baleja, J | [[Category: Baleja, J D.]] | ||
[[Category: Furie, B.]] | [[Category: Furie, B.]] | ||
[[Category: Furie, B | [[Category: Furie, B C.]] | ||
[[Category: Rigby, A | [[Category: Rigby, A C.]] | ||
[[Category: NH2]] | [[Category: NH2]] | ||
[[Category: conantokin g]] | [[Category: conantokin g]] | ||
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[[Category: gamma-carboxyglutamic acid]] | [[Category: gamma-carboxyglutamic acid]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:43:15 2008'' | ||
Revision as of 09:43, 21 February 2008
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NMR STRUCTURE OF METAL-FREE CONANTOKIN G, 1 STRUCTURE
Overview
Conantokin G is a gamma-carboxyglutamic acid-containing conotoxin from the venom of the marine cone snail Conus geographus. The 17-residue peptide, which contains five gamma-carboxyglutamic acid (Gla) residues and an amidated C-terminal asparagine amide, was synthesized chemically in a form identical to the natural conantokin G. To gain insight into the role of gamma-carboxyglutamic acid in the structure of this peptide, we determined the three-dimensional structure of conantokin G by 1H NMR and compared its structure to other conotoxins and to the gamma-carboxyglutamic acid-containing regions of the vitamin K-dependent blood-clotting proteins. Complete resonance assignments were made by two-dimensional 1H NMR spectroscopy in the absence of metal ions. NOE cross-peaks d(alphaN), d(NN), and d(betaN) provided interproton distance information, and vicinal spin-spin coupling constants 3J(HN alpha) were used to calculate phi torsion angles. Distance geometry and simulated annealing methods were used to derive 20 convergent structures from a set of 227 interproton distance restraints and 13 torsion angle measurements. The backbone rmsd to the geometric average for 20 final structures is 0.8 +/- 0.1 A. Conantokin G consists of a structured region commencing at Gla 3 and extending through arginine 13. This structure includes a partial loop centered around Gla 3 and Gla 4, a distorted type I turn between glutamine 6 and glutamine 9, and two type I turns involving Gla 10, leucine 11, and isoleucine 12 and arginine 13. Together, these two turns define approximately 1.6 turns of a distorted 3(10) helix. The observed structure possesses structural elements similar to those seen in the disulfide-linked conotoxins.
About this Structure
1AD7 is a Single protein structure of sequence from Conus geographus with NH2 as ligand. Full crystallographic information is available from OCA.
Reference
Three-dimensional structure of a gamma-carboxyglutamic acid-containing conotoxin, conantokin G, from the marine snail Conus geographus: the metal-free conformer., Rigby AC, Baleja JD, Furie BC, Furie B, Biochemistry. 1997 Jun 10;36(23):6906-14. PMID:9188685
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