| Structural highlights
Function
TXH4_CYRSC This lethal neurotoxin (without cyclization at position 53) inhibits neuronal voltage-gated sodium channel Nav1.2/SCN2A (IC(50)=10-150 nM), rNav1.3/SCN3A (IC(50)=338 nM), Nav1.6/SCN8A (IC(50)=117 nM), and hNav1.7/SCN9A (IC(50)=9.6-33 nM) (PubMed:18628201, PubMed:20855463, PubMed:25658507, PubMed:29703751,PubMed:31234412, PubMed:23760503). It inhibits activation of sodium channel by trapping the voltage sensor of domain II (DIIS4) in the closed configuration (PubMed:18628201, PubMed:23760503). The toxin neither shifts the Nav1.7/SCN9A activation curve nor modifies the slope factor (PubMed:20855463). It does not slow fast-inactivation of hNav1.7/SCN9A channels (PubMed:20855463). In addition, it has only a weak affinity for lipid membranes (PubMed:18054060, PubMed:29703751, PubMed:28115115). This toxin also exists with a pyroglutamate at position 53 (PubMed:23826086). The sole difference observed between modified (mHwTx-IV) and unmodified toxins is that moderate or high depolarization voltages (200 mV) permit the unmodified toxin to dissociate, whereas mHwTx-IV toxin does not dissociate, even at high depolarization voltages (PubMed:23826086). These data indicate that mHwTx-IV strongly binds to voltage sensor of sodium channel even at extreme depolarization voltages (PubMed:23826086).[1] [2] [3] [4] [5] [6] [7] [8] [9] [10]
Publication Abstract from PubMed
We have isolated a highly potent neurotoxin from the venom of the Chinese bird spider, Selenocosmia huwena. This 4.1-kDa toxin, which has been named huwentoxin-IV, contains 35 residues with three disulfide bridges: Cys-2-Cys-17, Cys-9-Cys-24, and Cys-16-Cys-31, assigned by a chemical strategy including partial reduction of the toxin and sequence analysis of the modified intermediates. It specifically inhibits the neuronal tetrodotoxin-sensitive (TTX-S) voltage-gated sodium channel with the IC(50) value of 30 nm in adult rat dorsal root ganglion neurons, while having no significant effect on the tetrodotoxin-resistant (TTX-R) voltage-gated sodium channel. This toxin seems to be a site I toxin affecting the sodium channel through a mechanism quite similar to that of TTX: it suppresses the peak sodium current without altering the activation or inactivation kinetics. The three-dimensional structure of huwentoxin-IV has been determined by two-dimensional (1)H NMR combined with distant geometry and simulated annealing calculation by using 527 nuclear Overhauser effect constraints and 14 dihedral constraints. The resulting structure is composed of a double-stranded antiparallel beta-sheet (Leu-22-Ser-25 and Trp-30-Tyr-33) and four turns (Glu-4-Lys-7, Pro-11-Asp-14, Lys-18-Lys-21 and Arg-26-Arg-29) and belongs to the inhibitor cystine knot structural family. After comparison with other toxins purified from the same species, we are convinced that the positively charged residues of loop IV (residues 25-29), especially residue Arg-26, must be crucial to its binding to the neuronal tetrodotoxin-sensitive voltage-gated sodium channel.
Function and solution structure of huwentoxin-IV, a potent neuronal tetrodotoxin (TTX)-sensitive sodium channel antagonist from Chinese bird spider Selenocosmia huwena.,Peng K, Shu Q, Liu Z, Liang S J Biol Chem. 2002 Dec 6;277(49):47564-71. Epub 2002 Sep 11. PMID:12228241[11]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Peng K, Shu Q, Liu Z, Liang S. Function and solution structure of huwentoxin-IV, a potent neuronal tetrodotoxin (TTX)-sensitive sodium channel antagonist from Chinese bird spider Selenocosmia huwena. J Biol Chem. 2002 Dec 6;277(49):47564-71. Epub 2002 Sep 11. PMID:12228241 doi:10.1074/jbc.M204063200
- ↑ Xiao Y, Luo X, Kuang F, Deng M, Wang M, Zeng X, Liang S. Synthesis and characterization of huwentoxin-IV, a neurotoxin inhibiting central neuronal sodium channels. Toxicon. 2008 Feb;51(2):230-9. doi: 10.1016/j.toxicon.2007.09.008. Epub 2007 Sep , 29. PMID:18054060 doi:http://dx.doi.org/10.1016/j.toxicon.2007.09.008
- ↑ Xiao Y, Bingham JP, Zhu W, Moczydlowski E, Liang S, Cummins TR. Tarantula huwentoxin-IV inhibits neuronal sodium channels by binding to receptor site 4 and trapping the domain ii voltage sensor in the closed configuration. J Biol Chem. 2008 Oct 3;283(40):27300-13. doi: 10.1074/jbc.M708447200. Epub 2008 , Jul 14. PMID:18628201 doi:10.1074/jbc.M708447200
- ↑ Xiao Y, Blumenthal K, Jackson JO 2nd, Liang S, Cummins TR. The tarantula toxins ProTx-II and huwentoxin-IV differentially interact with human Nav1.7 voltage sensors to inhibit channel activation and inactivation. Mol Pharmacol. 2010 Dec;78(6):1124-34. doi: 10.1124/mol.110.066332. Epub 2010 Sep, 20. PMID:20855463 doi:http://dx.doi.org/10.1124/mol.110.066332
- ↑ Xiao Y, Jackson JO 2nd, Liang S, Cummins TR. Common molecular determinants of tarantula huwentoxin-IV inhibition of Na+ channel voltage sensors in domains II and IV. J Biol Chem. 2011 Aug 5;286(31):27301-10. doi: 10.1074/jbc.M111.246876. Epub 2011, Jun 9. PMID:21659528 doi:http://dx.doi.org/10.1074/jbc.M111.246876
- ↑ Revell JD, Lund PE, Linley JE, Metcalfe J, Burmeister N, Sridharan S, Jones C, Jermutus L, Bednarek MA. Potency optimization of Huwentoxin-IV on hNav1.7: a neurotoxin TTX-S sodium-channel antagonist from the venom of the Chinese bird-eating spider Selenocosmia huwena. Peptides. 2013 Jun;44:40-6. doi: 10.1016/j.peptides.2013.03.011. Epub 2013 Mar, 19. PMID:23523779 doi:http://dx.doi.org/10.1016/j.peptides.2013.03.011
- ↑ Minassian NA, Gibbs A, Shih AY, Liu Y, Neff RA, Sutton SW, Mirzadegan T, Connor J, Fellows R, Husovsky M, Nelson S, Hunter MJ, Flinspach M, Wickenden AD. Analysis of the Structural and Molecular Basis of Voltage-sensitive Sodium Channel Inhibition by the Spider Toxin Huwentoxin-IV (mu-TRTX-Hh2a). J Biol Chem. 2013 Aug 2;288(31):22707-20. doi: 10.1074/jbc.M113.461392. Epub 2013, Jun 12. PMID:23760503 doi:10.1074/jbc.M113.461392
- ↑ Murray JK, Ligutti J, Liu D, Zou A, Poppe L, Li H, Andrews KL, Moyer BD, McDonough SI, Favreau P, Stocklin R, Miranda LP. Engineering potent and selective analogues of GpTx-1, a tarantula venom peptide antagonist of the Na(V)1.7 sodium channel. J Med Chem. 2015 Mar 12;58(5):2299-314. doi: 10.1021/jm501765v. Epub 2015 Feb 19. PMID:25658507 doi:http://dx.doi.org/10.1021/jm501765v
- ↑ Agwa AJ, Lawrence N, Deplazes E, Cheneval O, Chen RM, Craik DJ, Schroeder CI, Henriques ST. Spider peptide toxin HwTx-IV engineered to bind to lipid membranes has an increased inhibitory potency at human voltage-gated sodium channel hNaV1.7. Biochim Biophys Acta. 2017 Jan 20;1859(5):835-844. doi:, 10.1016/j.bbamem.2017.01.020. PMID:28115115 doi:http://dx.doi.org/10.1016/j.bbamem.2017.01.020
- ↑ Correnti CE, Gewe MM, Mehlin C, Bandaranayake AD, Johnsen WA, Rupert PB, Brusniak MY, Clarke M, Burke SE, De Van Der Schueren W, Pilat K, Turnbaugh SM, May D, Watson A, Chan MK, Bahl CD, Olson JM, Strong RK. Screening, large-scale production and structure-based classification of cystine-dense peptides. Nat Struct Mol Biol. 2018 Mar;25(3):270-278. doi: 10.1038/s41594-018-0033-9. Epub, 2018 Feb 26. PMID:29483648 doi:http://dx.doi.org/10.1038/s41594-018-0033-9
- ↑ Peng K, Shu Q, Liu Z, Liang S. Function and solution structure of huwentoxin-IV, a potent neuronal tetrodotoxin (TTX)-sensitive sodium channel antagonist from Chinese bird spider Selenocosmia huwena. J Biol Chem. 2002 Dec 6;277(49):47564-71. Epub 2002 Sep 11. PMID:12228241 doi:10.1074/jbc.M204063200
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