1gur

GURMARIN, A SWEET TASTE-SUPPRESSING POLYPEPTIDE, NMR, 10 STRUCTURES

spinqualitylabelsall models 1gur Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1gur is a 1 chain structure with sequence from Gymnema sylvestre. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Solution NMR, 10 models Ligands: PCA Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function GUR_GYMSY Suppresses strongly the sweet taste responses in the rat with high specificity to sucrose, glucose, glycine, and saccharin. This effect is reversible, but complete recovery of the suppressed responses required at least 3h. Gurmarin showed no effect or only a very weak effect on the sweet taste sensation in humans. Publication Abstract from PubMed 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. 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 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

Proteopedia Page Contributors and Editors (what is this?)

OCA