1cmr

NMR SOLUTION STRUCTURE OF A CHIMERIC PROTEIN, DESIGNED BY TRANSFERRING A FUNCTIONAL SNAKE BETA-HAIRPIN INTO A SCORPION ALPHA/BETA SCAFFOLD (PH 3.5, 20C), NMR, 18 STRUCTURES

spinqualitylabelsall models 1cmr, 18 NMR models Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1cmr is a 1 chain structure. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [KAX11_LEIQH] Potent selective inhibitor of high conductance (maxi-K), different medium and small conductance calcium-activated potassium channels (KCa/KCNM), as well as a voltage-dependent potassium channel (Kv1.3/KCNA3). It appears to block channel activity by a simple bimolecular inhibition process. Has a pH-specific antimicrobial activity against bacteria (B.subtilis, E.coli and S.aureus) and the fungus C.albicans. Publication Abstract from PubMed The alpha/beta scorpion fold is shared by scorpion toxins, insect defensins, and plant thionins. This small and functionally versatile template contains an alpha-helix and a triple beta-sheet linked by three disulfide bridges. With the view to introduce novel functional centers within this fold, we replaced the sequence (the cysteines and glycines excepted) of the original beta-hairpin of a scorpion toxin by the sequence of a beta-hairpin that forms part of the site by which snake neurotoxins bind to nicotinic acetylcholine receptors (AcChOR). The resulting chimeric protein, synthesized by chemical means, binds to AcChOR, though with a lower affinity than the snake toxins [Drakopoulou; E., Zinn-Justin, S., Guenneugues, M., Gilquin, B., Menez, A., & Vita, C. (1996) J. Biol. Chem. 271, 11979-11987]. The work described in this paper is an attempt to clarify the structural consequences associated with the transfer of the beta-hairpin. We report the determination of the three-dimensional solution structure of the chimeric protein by proton NMR spectroscopy and molecular dynamics calculations. Comparison of the structure of the chimera with those of the scorpion alpha/beta toxin and of the snake neurotoxin shows that (i) the new protein folds as an alpha/beta motif and (ii) the beta-hairpins of the chimera and of the curaremimetic toxin adopt a similar conformation. A closer inspection of the differences between the structures of the original and transferred beta-hairpins allows rationalization of the biological properties of the chimera. Transfer of a beta-hairpin from the functional site of snake curaremimetic toxins to the alpha/beta scaffold of scorpion toxins: three-dimensional solution structure of the chimeric protein.,Zinn-Justin S, Guenneugues M, Drakopoulou E, Gilquin B, Vita C, Menez A Biochemistry. 1996 Jul 2;35(26):8535-43. PMID:8679614 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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