1kfh
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Solution Structure of alpha-Bungarotoxin by NMR Spectroscopy
OverviewOverview
We report a new, higher resolution NMR structure of alpha-bungarotoxin, that defines the structure-determining disulfide core and beta-sheet, regions. We further report the NMR structure of the stoichiometric complex, formed between alpha-bungarotoxin and a recombinantly expressed 19-mer, peptide ((178)IPGKRTESFYECCKEPYPD(196)) derived from the alpha7 subunit of, the chick neuronal nicotinic acetylcholine receptor. A comparison of these, two structures reveals binding-induced stabilization of the flexible tip, of finger II in alpha-bungarotoxin. The conformational rearrangements in, the toxin create an extensive binding surface involving both sides of the, alpha7 19-mer hairpin-like structure. At the contact zone, Ala(7), Ser(9), and Ile(11) in finger I and Arg(36), Lys(38), Val(39), and Val(40) in, finger II of alpha-bungarotoxin interface with Phe(186), Tyr(187), Glu(188), and Tyr(194) in the alpha7 19-mer underscoring the importance of, receptor aromatic residues as critical neurotoxin-binding determinants., Superimposing the structure of the complex onto that of the, acetylcholine-binding protein (1I9B), a soluble homologue of the, extracellular domain of the alpha7 receptor, places alpha-bungarotoxin at, the peripheral surface of the inter-subunit interface occluding the, agonist-binding site. The disulfide-rich core of alpha-bungarotoxin is, suggested to be tilted in the direction of the membrane surface with, finger II extending into the proposed ligand-binding cavity.
About this StructureAbout this Structure
1KFH is a Single protein structure of sequence from Bungarus multicinctus. Full crystallographic information is available from OCA.
ReferenceReference
NMR structural analysis of alpha-bungarotoxin and its complex with the principal alpha-neurotoxin-binding sequence on the alpha 7 subunit of a neuronal nicotinic acetylcholine receptor., Moise L, Piserchio A, Basus VJ, Hawrot E, J Biol Chem. 2002 Apr 5;277(14):12406-17. Epub 2002 Jan 14. PMID:11790782
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