1kcp

3D STRUCTURE OF K-CONOTOXIN PVIIA, A NOVEL POTASSIUM CHANNEL-BLOCKING TOXIN FROM CONE SNAILS, NMR, 22 STRUCTURES

spinqualitylabelsall models 1kcp, 22 NMR models Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1kcp is a 1 chain structure with sequence from Conpu. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. NonStd Res: HYP, NH2 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [CO17A_CONPU] Kappa-conotoxins bind and inhibit voltage-gated potassium channels (Kv). This toxin inhibits the Shaker channel from insects. The interaction site between the Shaker channel and this toxin is within the S5-S6 loop of the Shaker channel. In fish, this toxin induces hyperactivity, followed by continuous contraction and extension of major fins, without immobilization or death. Injection of this peptide together with the delta-conotoxin PVIA causes the sudden tetanus of prey (STOP) syndrome, which is a single, lethal "fin-pop" in envenomed fish. In mice, induces hyperactivity. Publication Abstract from PubMed kappa-Conotoxin PVIIA from the venom of Conus purpurascens is the first cone snail toxin that was described to block potassium channels. We synthesized chemically this toxin and showed that its disulfide bridge pattern is similar to those of omega- and delta-conotoxins. kappa-conotoxin competes with radioactive alpha-dendrotoxin for binding to rat brain synaptosomes, confirming its capacity to bind to potassium channels; however, it behaves as a weak competitor. The three-dimensional structure of kappa-conotoxin PVIIA, as elucidated by NMR spectroscopy and molecular modeling, comprises two large parallel loops stabilized by a triple-stranded antiparallel beta-sheet and three disulfide bridges. The overall fold of kappa-conotoxin is similar to that of calcium channel-blocking omega-conotoxins but differs from those of potassium channel-blocking toxins from sea anemones, scorpions, and snakes. Local topographies of kappa-conotoxin PVIIA that might account for its capacity to recognize Kv1-type potassium channels are discussed. Three-dimensional structure of kappa-conotoxin PVIIA, a novel potassium channel-blocking toxin from cone snails.,Savarin P, Guenneugues M, Gilquin B, Lamthanh H, Gasparini S, Zinn-Justin S, Menez A Biochemistry. 1998 Apr 21;37(16):5407-16. PMID:9548922 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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