1gur
From Proteopedia
OCA (Talk | contribs)
(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...)
Next diff →
Revision as of 14:10, 20 November 2007
|
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
Page seeded by OCA on Tue Nov 20 16:17:58 2007
