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| | ==Solution Structure of alpha-Conotoxin BuIA== | | ==Solution Structure of alpha-Conotoxin BuIA== |
| - | <StructureSection load='2i28' size='340' side='right' caption='[[2i28]], [[NMR_Ensembles_of_Models | 20 NMR models]]' scene=''> | + | <StructureSection load='2i28' size='340' side='right'caption='[[2i28]]' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[2i28]] is a 1 chain structure. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2I28 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2I28 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[2i28]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Conus_bullatus Conus bullatus]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2I28 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2I28 FirstGlance]. <br> |
| - | </td></tr><tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=NH2:AMINO+GROUP'>NH2</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR, 20 models</td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2i28 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2i28 OCA], [http://pdbe.org/2i28 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2i28 RCSB], [http://www.ebi.ac.uk/pdbsum/2i28 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=2i28 ProSAT]</span></td></tr> | + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=NH2:AMINO+GROUP'>NH2</scene></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=2i28 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2i28 OCA], [https://pdbe.org/2i28 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2i28 RCSB], [https://www.ebi.ac.uk/pdbsum/2i28 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2i28 ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/CA1A_CONBU CA1A_CONBU]] Alpha-conotoxins bind to the nicotinic acetylcholine receptors (nAChR) and inhibit them. This peptide potently blocks numerous mammalian nAChR subtypes (alpha-6 or -3/beta-2 or -3 > alpha-6 or-3/beta-4 > alpha-3/beta-2 > alpha-3/beta-4 > alpha-4/beta-4 = alpha-2/beta-4 > alpha-7 > alpha-2/beta-2 >> alpha-4/beta-2). Recovery from toxin block is markedly slower for beta-4 versus beta-2 subunit-containing nAChRs. Thus, it represents a novel probe for distinguishing between beta-2 and beta-4-containing nAChRs. | + | [https://www.uniprot.org/uniprot/CA1A_CONBU CA1A_CONBU] Alpha-conotoxins bind to the nicotinic acetylcholine receptors (nAChR) and inhibit them. This peptide potently blocks numerous mammalian nAChR subtypes (alpha-6 or -3/beta-2 or -3 > alpha-6 or-3/beta-4 > alpha-3/beta-2 > alpha-3/beta-4 > alpha-4/beta-4 = alpha-2/beta-4 > alpha-7 > alpha-2/beta-2 >> alpha-4/beta-2). Recovery from toxin block is markedly slower for beta-4 versus beta-2 subunit-containing nAChRs. Thus, it represents a novel probe for distinguishing between beta-2 and beta-4-containing nAChRs. |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
| | == Publication Abstract from PubMed == | | == Publication Abstract from PubMed == |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Chi, S W]] | + | [[Category: Conus bullatus]] |
| - | [[Category: Han, K H]] | + | [[Category: Large Structures]] |
| - | [[Category: Kim, D H]] | + | [[Category: Chi S-W]] |
| - | [[Category: McIntosh, J M]]
| + | [[Category: Han K-H]] |
| - | [[Category: Olivera, B M]]
| + | [[Category: Kim D-H]] |
| - | [[Category: Alpha-helix]]
| + | [[Category: McIntosh JM]] |
| - | [[Category: Beta-turn]] | + | [[Category: Olivera BM]] |
| - | [[Category: C-terminal amidation]] | + | |
| - | [[Category: Toxin]] | + | |
| - | [[Category: Two disulfide bond]] | + | |
| Structural highlights
Function
CA1A_CONBU Alpha-conotoxins bind to the nicotinic acetylcholine receptors (nAChR) and inhibit them. This peptide potently blocks numerous mammalian nAChR subtypes (alpha-6 or -3/beta-2 or -3 > alpha-6 or-3/beta-4 > alpha-3/beta-2 > alpha-3/beta-4 > alpha-4/beta-4 = alpha-2/beta-4 > alpha-7 > alpha-2/beta-2 >> alpha-4/beta-2). Recovery from toxin block is markedly slower for beta-4 versus beta-2 subunit-containing nAChRs. Thus, it represents a novel probe for distinguishing between beta-2 and beta-4-containing nAChRs.
Publication Abstract from PubMed
We have determined a high-resolution three-dimensional structure of alpha-conotoxin BuIA, a 13-residue peptide toxin isolated from Conus bullatus. Despite its unusual 4/4 disulfide bond layout alpha-conotoxin BuIA exhibits strong antagonistic activity at alpha6/alpha3beta2beta3, alpha3beta2, and alpha3beta4 nAChR subtypes like some alpha4/7 conotoxins. alpha-Conotoxin BuIA lacks the C-terminal beta-turn present within the second disulfide loop of alpha4/7 conotoxins, having only a "pseudo omega-shaped" molecular topology. Nevertheless, it contains a functionally critical two-turn helix motif, a feature ubiquitously found in alpha4/7 conotoxins. Such an aspect seems mainly responsible for similarities in the receptor recognition profile of alpha-conotoxin BuIA to alpha4/7 conotoxins. Structural comparison of alpha-conotoxin BuIA with alpha4/7 conotoxins and alpha4/3 conotoxin ImI suggests that presence of the second helical turn portion of the two-turn helix motif in alpha4/7 and alpha4/4 conotoxins may be important for binding to the alpha3 and/or alpha6 subunit of nAChR.
NMR structure determination of alpha-conotoxin BuIA, a novel neuronal nicotinic acetylcholine receptor antagonist with an unusual 4/4 disulfide scaffold.,Chi SW, Kim DH, Olivera BM, McIntosh JM, Han KH Biochem Biophys Res Commun. 2006 Nov 3;349(4):1228-34. Epub 2006 Sep 7. PMID:16979596[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Chi SW, Kim DH, Olivera BM, McIntosh JM, Han KH. NMR structure determination of alpha-conotoxin BuIA, a novel neuronal nicotinic acetylcholine receptor antagonist with an unusual 4/4 disulfide scaffold. Biochem Biophys Res Commun. 2006 Nov 3;349(4):1228-34. Epub 2006 Sep 7. PMID:16979596 doi:S0006-291X(06)01969-3
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