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1oaw

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OMEGA-AGATOXIN IVA

Structural highlights

1oaw is a 1 chain structure with sequence from Agelenopsis aperta. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	Solution NMR, 14 models
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

TX23A_AGEAP Omega-agatoxins inhibit neuronal voltage-gated calcium channels. This toxin acts by modifying the gating of the high voltage activated P-type Cav2.1/CACNA1A channel. Is a potent blocker in both insect and mammalian central neurons.^[1] ^[2] ^[3] ^[4] ^[5] ^[6] ^[7]

Publication Abstract from PubMed

The three-dimensional solution structure of omega-agatoxin IVA, which is a specific blocker of the P-type calcium channel isolated from funnel web spider venom and has a molecular mass of 5.2 kDa, was determined by two dimensional 1H NMR spectroscopy, combined with simulated annealing calculations. On the basis of 563 experimental constraints, including 516 distance constraints obtained from the nuclear Overhauser effect, 21 torsion angle (phi, chi 1) constraints, and 26 constraints associated with hydrogen bonds and disulfide bonds, a total of 14 converged structures were obtained. The atomic root mean square difference for the 14 converged structures with respect to the mean coordinates is 0.42 (+/- 0.07) A for the backbone atoms (N, C alpha, C) and 0.95 (+/- 0.15) A for all heavy atoms of the central part (residues 4 to 38) constrained by four disulfide bonds. The N- and C-terminal segments (residues 1 to 3 and 39 to 48, respectively) have a disordered structure in aqueous solution. The molecular structure of omega-agatoxin IVA is composed of a short triple-stranded antiparallel beta-sheet, three loops, and the disordered N- and C-terminal segments. The overall beta-sheet topology is +2x, -1, which is the same as that reported for omega-conotoxin GVIA, an N-type calcium channel blocker. Irrespective of differences in the number of disulfide bonds and low primary sequence homology, these two peptide toxins show a significant structural similarity in three dimensions. The whole-cell voltage-clamp recording using rat cerebellar slices suggests that the hydrophobic C-terminal segment of omega-agatoxin IVA, which does not exist in omega-conotoxin GVIA, plays a crucial role in the blocking action of omega-agatoxin IVA on the P-type calcium channel in rat cerebellar Purkinje cells. The present study provides a molecular basis for the toxin-channel interaction, and thereby provides insight into the discrimination of different subtypes of calcium channels.

Three-dimensional solution structure of the calcium channel antagonist omega-agatoxin IVA: consensus molecular folding of calcium channel blockers.,Kim JI, Konishi S, Iwai H, Kohno T, Gouda H, Shimada I, Sato K, Arata Y J Mol Biol. 1995 Jul 28;250(5):659-71. PMID:7623383^[8]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Winterfield JR, Swartz KJ. A hot spot for the interaction of gating modifier toxins with voltage-dependent ion channels. J Gen Physiol. 2000 Nov;116(5):637-44. PMID:11055992
↑ Wang XH, Connor M, Wilson D, Wilson HI, Nicholson GM, Smith R, Shaw D, Mackay JP, Alewood PF, Christie MJ, King GF. Discovery and structure of a potent and highly specific blocker of insect calcium channels. J Biol Chem. 2001 Oct 26;276(43):40306-12. Epub 2001 Aug 24. PMID:11522785 doi:http://dx.doi.org/10.1074/jbc.M105206200
↑ Mintz IM, Venema VJ, Swiderek KM, Lee TD, Bean BP, Adams ME. P-type calcium channels blocked by the spider toxin omega-Aga-IVA. Nature. 1992 Feb 27;355(6363):827-9. PMID:1311418 doi:http://dx.doi.org/10.1038/355827a0
↑ Bickmeyer U, Rossler W, Wiegand H. Omega AGA toxin IVA blocks high-voltage-activated calcium channel currents in cultured pars intercerebralis neurosecretory cells of adult locusta migratoria. Neurosci Lett. 1994 Nov 7;181(1-2):113-6. PMID:7898748
↑ Nishio H, Kumagaye KY, Kubo S, Chen YN, Momiyama A, Takahashi T, Kimura T, Sakakibara S. Synthesis of omega-agatoxin IVA and its related peptides. Biochem Biophys Res Commun. 1993 Nov 15;196(3):1447-53. PMID:8250902 doi:http://dx.doi.org/10.1006/bbrc.1993.2414
↑ Wicher D, Penzlin H. Ca2+ currents in central insect neurons: electrophysiological and pharmacological properties. J Neurophysiol. 1997 Jan;77(1):186-99. PMID:9120560
↑ McDonough SI, Mintz IM, Bean BP. Alteration of P-type calcium channel gating by the spider toxin omega-Aga-IVA. Biophys J. 1997 May;72(5):2117-28. PMID:9129813 doi:http://dx.doi.org/10.1016/S0006-3495(97)78854-4
↑ Kim JI, Konishi S, Iwai H, Kohno T, Gouda H, Shimada I, Sato K, Arata Y. Three-dimensional solution structure of the calcium channel antagonist omega-agatoxin IVA: consensus molecular folding of calcium channel blockers. J Mol Biol. 1995 Jul 28;250(5):659-71. PMID:7623383 doi:http://dx.doi.org/S0022-2836(85)70406-8

1 Structural highlights
2 Function
3 Publication Abstract from PubMed
4 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1oaw"

@@ Line 4: / Line 4: @@
 == Structural highlights ==
 <table><tr><td colspan='2'>[[1oaw]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Agelenopsis_aperta Agelenopsis aperta]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1OAW OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1OAW FirstGlance]. <br>
-</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=1oaw FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1oaw OCA], [https://pdbe.org/1oaw PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1oaw RCSB], [https://www.ebi.ac.uk/pdbsum/1oaw PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1oaw ProSAT]</span></td></tr>
+</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR, 14 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=1oaw FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1oaw OCA], [https://pdbe.org/1oaw PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1oaw RCSB], [https://www.ebi.ac.uk/pdbsum/1oaw PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1oaw ProSAT]</span></td></tr>
 </table>
 == Function ==

1oaw

From Proteopedia

Current revision

OMEGA-AGATOXIN IVA

Structural highlights

Function

Publication Abstract from PubMed

References

Contents

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