1c4e
From Proteopedia
(New page: 200px<br /><applet load="1c4e" size="450" color="white" frame="true" align="right" spinBox="true" caption="1c4e" /> '''GURMARIN FROM GYMNEMA SYLVESTRE'''<br /> ==...) |
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| - | [[Image:1c4e.jpg|left|200px]]<br /><applet load="1c4e" size=" | + | [[Image:1c4e.jpg|left|200px]]<br /><applet load="1c4e" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1c4e" /> | caption="1c4e" /> | ||
'''GURMARIN FROM GYMNEMA SYLVESTRE'''<br /> | '''GURMARIN FROM GYMNEMA SYLVESTRE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Gurmarin is a 35-residue polypeptide from the Asclepiad vine Gymnema | + | Gurmarin is a 35-residue polypeptide from the Asclepiad vine Gymnema sylvestre. It has been utilised as a pharmacological tool in the study of sweet-taste transduction because of its ability to selectively inhibit the neural response to sweet tastants in rats. We have chemically synthesised and folded gurmarin and determined its three-dimensional solution structure to high resolution using two-dimensional NMR spectroscopy. Structure calculations utilised 612 interproton-distance, 19 dihedral-angle, and 18 hydrogen-bond restraints. The structure is well defined for residues 3-34, with backbone and heavy atom rms differences of 0.27 +/- 0.09 A and 0.73 +/- 0.09 A, respectively. Gurmarin adopts a compact structure containing an antiparallel beta-hairpin (residues 22-34), several well-defined beta-turns, and a cystine-knot motif commonly observed in toxic and inhibitory polypeptides. Despite striking structural homology with delta-atracotoxin, a spider neurotoxin known to slow the inactivation of voltage-gated Na+ channels, we show that gurmarin has no effect on a variety of voltage-sensitive channels. |
==About this Structure== | ==About this Structure== | ||
| - | 1C4E is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Gymnema_sylvestre Gymnema sylvestre]. This structure | + | 1C4E is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Gymnema_sylvestre Gymnema sylvestre]. This structure supersedes the now removed PDB entry 2GUR. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1C4E OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Gymnema sylvestre]] | [[Category: Gymnema sylvestre]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Dingley, A | + | [[Category: Dingley, A J.]] |
| - | [[Category: Fletcher, J | + | [[Category: Fletcher, J I.]] |
| - | [[Category: King, G | + | [[Category: King, G F.]] |
[[Category: cystine knot]] | [[Category: cystine knot]] | ||
[[Category: gurmarin]] | [[Category: gurmarin]] | ||
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[[Category: sweet taste transduction]] | [[Category: sweet taste transduction]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:02:18 2008'' |
Revision as of 10:02, 21 February 2008
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GURMARIN FROM GYMNEMA SYLVESTRE
Overview
Gurmarin is a 35-residue polypeptide from the Asclepiad vine Gymnema sylvestre. It has been utilised as a pharmacological tool in the study of sweet-taste transduction because of its ability to selectively inhibit the neural response to sweet tastants in rats. We have chemically synthesised and folded gurmarin and determined its three-dimensional solution structure to high resolution using two-dimensional NMR spectroscopy. Structure calculations utilised 612 interproton-distance, 19 dihedral-angle, and 18 hydrogen-bond restraints. The structure is well defined for residues 3-34, with backbone and heavy atom rms differences of 0.27 +/- 0.09 A and 0.73 +/- 0.09 A, respectively. Gurmarin adopts a compact structure containing an antiparallel beta-hairpin (residues 22-34), several well-defined beta-turns, and a cystine-knot motif commonly observed in toxic and inhibitory polypeptides. Despite striking structural homology with delta-atracotoxin, a spider neurotoxin known to slow the inactivation of voltage-gated Na+ channels, we show that gurmarin has no effect on a variety of voltage-sensitive channels.
About this Structure
1C4E is a Single protein structure of sequence from Gymnema sylvestre. This structure supersedes the now removed PDB entry 2GUR. Full crystallographic information is available from OCA.
Reference
High-resolution solution structure of gurmarin, a sweet-taste-suppressing plant polypeptide., Fletcher JI, Dingley AJ, Smith R, Connor M, Christie MJ, King GF, Eur J Biochem. 1999 Sep;264(2):525-33. PMID:10491100
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