2axk: Difference between revisions

<StructureSection load='2axk' size='340' side='right'caption='[[2axk]]' scene=''>

<table><tr><td colspan='2'>[[2axk]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Tityus_discrepans Tityus discrepans]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2AXK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2AXK FirstGlance]. <br>

</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR, 10 models</td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2axk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2axk OCA], [https://pdbe.org/2axk PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2axk RCSB], [https://www.ebi.ac.uk/pdbsum/2axk PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2axk ProSAT]</span></td></tr>

[https://www.uniprot.org/uniprot/KA156_TITDI KA156_TITDI] Irreversibly blocks the A-type voltage-gated potassium channels in rat cerebellum granular cells.<ref>PMID:15369825</ref> <ref>PMID:16460026</ref>

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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.

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<ref>PMID:16460026</ref>

==See Also==

*[[Potassium channel toxin 3D structures|Potassium channel toxin 3D structures]]

== References ==

[[Category: Large Structures]]

[[Category: Tityus discrepans]]

[[Category: Corzo G]]

[[Category: D'Suze G]]

[[Category: Delepierre M]]

[[Category: Martin-Eauclaire M-F]]

[[Category: Murgia AR]]

[[Category: Possani LD]]

[[Category: Prestipino G]]

[[Category: Prochnicka-Chalufour A]]

[[Category: Satake H]]