2axk: Difference between revisions
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'''Solution structure of discrepin, a scorpion venom toxin blocking K+ channels.''' | '''Solution structure of discrepin, a scorpion venom toxin blocking K+ channels.''' | ||
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==About this Structure== | ==About this Structure== | ||
2AXK is a [[Single protein]] structure | 2AXK is a [[Single protein]] structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2AXK OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Satake, H.]] | [[Category: Satake, H.]] | ||
[[Category: Suze, G D.]] | [[Category: Suze, G D.]] | ||
[[Category: | [[Category: A-current]] | ||
[[Category: | [[Category: Discrepin]] | ||
[[Category: | [[Category: K+-channel]] | ||
[[Category: | [[Category: Nmr]] | ||
[[Category: | [[Category: Scorpion toxin]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 19:35:50 2008'' | |||
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Revision as of 16:35, 3 May 2008
Solution structure of discrepin, a scorpion venom toxin blocking K+ channels.
Overview
Discrepin, isolated from the venom of the Venezuelan scorpion Tityus discrepans, blocks preferentially the I(A) currents of the voltage-dependent K+ channel of rat cerebellum granular cells in an irreversible way. It contains 38 amino acid residues with a pyroglutamic acid as the N-terminal residue [D'Suze, G., Batista, C. V., Frau, A., Murgia, A. R., Zamudio, F. Z., Sevcik, C., Possani, L. D., and Prestipino, G. (2004) Arch. Biochem. Biophys. 430, 256-63]. It is the most distinctive member of the alpha-KTx15 subfamily of scorpion toxins. Six members of the alpha-KTx15 subfamily have been reported so far to be specific for this subtype of the K+ channel; however, none of them have had their three-dimensional structure determined, and no information for the residues possibly involved in channel recognition and binding is available. Natural discrepin (n-discrepin) was prepared from scorpion venom, and its synthetic analogue (s-discrepin) was obtained by solid-phase synthesis. Analysis of two-dimensional 1H NMR spectra of n- and s-discrepin indicates that both peptides have the same structure. Here we report the solution structure of s-discrepin determined by NMR using 565 meaningful distance constraints derived from the volume integration of the two-dimensional NOESY spectrum, 22 dihedrals, and three hydrogen bonds. Discrepin displays the alpha/beta scaffold, characteristic of scorpion toxins. Some features of the proposed interacting surface between the toxin and channel as well as the opposite "alpha-helix surface" are discussed in comparison with those of other alpha-KTx15 members. Both n- and s-discrepin exhibit similar physiological actions as verified by patch-clamp and binding and displacement experiments.
About this Structure
2AXK is a Single protein structure. Full crystallographic information is available from OCA.
Reference
Solution structure of discrepin, a new K+-channel blocking peptide from the alpha-KTx15 subfamily., Prochnicka-Chalufour A, Corzo G, Satake H, Martin-Eauclaire MF, Murgia AR, Prestipino G, D'Suze G, Possani LD, Delepierre M, Biochemistry. 2006 Feb 14;45(6):1795-804. PMID:16460026 Page seeded by OCA on Sat May 3 19:35:50 2008
