Electrophysiological Characterization of a Novel Conotoxin That Blocks Molluscan Sodium Channels |
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Authors: | Arik Hasson Michael Fainzilber Eliahu Zlotkin Micha Spira |
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Affiliation: | Department of Neurobiology, The Hebrew University of Jerusalem, and The Interuniversity Institute for Marine Sciences, Eilat, Israel;Department of Animal and Cell Biology, The Hebrew University of Jerusalem, Jerusalem, Israel |
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Abstract: | A novel peptide toxin, PnIVB, isolated from the venom of Conus pennaceus blocks voltage-gated sodium current in Aplysia neurons. Complete blockade is obtained at a PnIVB concentration of 80±2.2 nM and 50% blockade at 16±0.86 nM. The potency of PnIVB in blocking Aplysia sodium current is four orders of magnitude larger than that of tetrodotoxin. The toxin has no paralytic activity when injected into fish. The rapid blockade of sodium current by PnIVB is not associated with a change in the activation or inactivation kinetics of the current, or with the reversal potential. Sodium current blockade is reversible after a 30 min wash with 50 times the bath volume. The novel conotoxin PnlVB can be used as a powerful tool for mollusc neurobiological research and as a molecular probe to explore the structure-function relations of voltage-gated sodium channel subtypes. |
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Keywords: | Aplysia conotoxin voltage clamp cultured neurons |
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