1gur
From Proteopedia
(New page: 200px<br /><applet load="1gur" size="450" color="white" frame="true" align="right" spinBox="true" caption="1gur" /> '''GURMARIN, A SWEET TASTE-SUPPRESSING POLYPEPT...) |
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| - | [[Image:1gur.gif|left|200px]]<br /><applet load="1gur" size=" | + | [[Image:1gur.gif|left|200px]]<br /><applet load="1gur" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1gur" /> | caption="1gur" /> | ||
'''GURMARIN, A SWEET TASTE-SUPPRESSING POLYPEPTIDE, NMR, 10 STRUCTURES'''<br /> | '''GURMARIN, A SWEET TASTE-SUPPRESSING POLYPEPTIDE, NMR, 10 STRUCTURES'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The solution structure of gurmarin was studied by two-dimensional proton | + | The solution structure of gurmarin was studied by two-dimensional proton NMR spectroscopy at 600 MHz. Gurmarin, a 35-amino acid residue polypeptide recently discovered in an Indian-originated tree Gymnema sylvestre, selectively suppresses the neural responses of rat to sweet taste stimuli. Sequence-specific resonance assignments were obtained for all backbone protons and for most of the side-chain protons. The three-dimensional solution structure was determined by simulated-annealing calculations on the basis of 135 interproton distance constraints derived from NOEs, six distance constraints for three hydrogen bonds and 16 dihedral angle constraints derived from coupling constants. A total of 10 structures folded into a well-defined structure with a triple-stranded antiparallel beta-sheet. The average rmsd values between any two structures were 1.65 +/- 0.39 A for the backbone atoms (N, C alpha, C) and 2.95 +/- 0.27 A for all heavy atoms. The positions of the three disulfide bridges, which could not be determined chemically, were estimated to be Cys3-Cys18, Cys10-Cys23 and Cys17-Cys33 on the basis of the NMR distance constraints. This disulfide bridge pattern in gurmarin turned out to be analogous to that in omega-conotoxin and Momordica charantia trypsin inhibitor-II, and the topology of folding was the same as that in omega-conotoxin. |
==About this Structure== | ==About this Structure== | ||
| - | 1GUR is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Gymnema_sylvestre Gymnema sylvestre]. Full crystallographic information is available from [http:// | + | 1GUR is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Gymnema_sylvestre Gymnema sylvestre]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GUR OCA]. |
==Reference== | ==Reference== | ||
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[[Category: sweet-taste]] | [[Category: sweet-taste]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:54:10 2008'' |
Revision as of 10:54, 21 February 2008
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GURMARIN, A SWEET TASTE-SUPPRESSING POLYPEPTIDE, NMR, 10 STRUCTURES
Overview
The solution structure of gurmarin was studied by two-dimensional proton NMR spectroscopy at 600 MHz. Gurmarin, a 35-amino acid residue polypeptide recently discovered in an Indian-originated tree Gymnema sylvestre, selectively suppresses the neural responses of rat to sweet taste stimuli. Sequence-specific resonance assignments were obtained for all backbone protons and for most of the side-chain protons. The three-dimensional solution structure was determined by simulated-annealing calculations on the basis of 135 interproton distance constraints derived from NOEs, six distance constraints for three hydrogen bonds and 16 dihedral angle constraints derived from coupling constants. A total of 10 structures folded into a well-defined structure with a triple-stranded antiparallel beta-sheet. The average rmsd values between any two structures were 1.65 +/- 0.39 A for the backbone atoms (N, C alpha, C) and 2.95 +/- 0.27 A for all heavy atoms. The positions of the three disulfide bridges, which could not be determined chemically, were estimated to be Cys3-Cys18, Cys10-Cys23 and Cys17-Cys33 on the basis of the NMR distance constraints. This disulfide bridge pattern in gurmarin turned out to be analogous to that in omega-conotoxin and Momordica charantia trypsin inhibitor-II, and the topology of folding was the same as that in omega-conotoxin.
About this Structure
1GUR is a Single protein structure of sequence from Gymnema sylvestre. Full crystallographic information is available from OCA.
Reference
Three-dimensional structure of gurmarin, a sweet taste-suppressing polypeptide., Arai K, Ishima R, Morikawa S, Miyasaka A, Imoto T, Yoshimura S, Aimoto S, Akasaka K, J Biomol NMR. 1995 Apr;5(3):297-305. PMID:7787425
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