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| | ==Structure of single disulfide peptide Czon1107-P7A (minor conformer)== | | ==Structure of single disulfide peptide Czon1107-P7A (minor conformer)== |
| - | <StructureSection load='6kno' size='340' side='right'caption='[[6kno]], [[NMR_Ensembles_of_Models | 27 NMR models]]' scene=''> | + | <StructureSection load='6kno' size='340' side='right'caption='[[6kno]]' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[6kno]] is a 1 chain structure. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6KNO OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=6KNO FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[6kno]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Conus_zonatus Conus zonatus]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6KNO OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6KNO 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, 27 models</td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=6kno FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6kno OCA], [http://pdbe.org/6kno PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6kno RCSB], [http://www.ebi.ac.uk/pdbsum/6kno PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6kno 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=6kno FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6kno OCA], [https://pdbe.org/6kno PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6kno RCSB], [https://www.ebi.ac.uk/pdbsum/6kno PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6kno ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | <div style="background-color:#fffaf0;"> | | <div style="background-color:#fffaf0;"> |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| | + | [[Category: Conus zonatus]] |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Kumar, M Madhan]] | + | [[Category: Madhan Kumar M]] |
| - | [[Category: Sarma, S P]] | + | [[Category: Sarma SP]] |
| - | [[Category: Nachr antagonist nmr]]
| + | |
| - | [[Category: Neuropeptide]]
| + | |
| Structural highlights
Publication Abstract from PubMed
Conopeptides are neurotoxic peptides in the venom of marine cone snails and have broad therapeutic potential for managing pain and other conditions. Here, we identified the single-disulfide peptides Czon1107 and Cca1669 from the venoms of Conus zonatus and Conus caracteristicus, respectively. We observed that Czon1107 strongly inhibits the human alpha3beta4 (IC50 15.7 +/- 3.0 muM) and alpha7 (IC50 77.1 +/- 0.05 muM) nicotinic acetylcholine receptor (nAChR) subtypes, but the activity of Cca1669 remains to be identified. Czon1107 acted at a site distinct from the orthosteric receptor site. Solution NMR experiments revealed that Czon1107 exists in equilibrium between conformational states that are the result of a key Ser(4)-Pro(5) cis-trans isomerization. Moreover, we found that the X-Pro amide bonds in the inter-cysteine loop are rigidly constrained to cis conformations. Structure-activity experiments of Czon1107 and its variants at positions P5 and P7 revealed that the conformation around the X-Pro bonds (cis-trans) plays an important role in receptor subtype selectivity. The cis conformation at the Cys(6)-Pro(7) peptide bond was essential for alpha3beta4 nAChR subtype allosteric selectivity. In summary, we have identified an unique single disulfide conopeptide with a non-competitive, potentially allosteric inhibitory mechanism at the nAChRs. The small size and rigidity of the Czon1107 peptide could provide a scaffold for rational drug design strategies for allosteric nAChR modulation. This new paradigm in the "conotoxinomic" structure-function space provides an impetus to screen venom from other Conus species for similar, short bioactive peptides that allosterically modulate ligand-gated receptor function.
Structure and allosteric activity of a single disulfide conopeptide from Conus zonatus at human alpha3beta4 and alpha7 nicotinic acetylcholine receptors.,Mohan MK, Abraham N, R P R, Jayaseelan BF, Ragnarsson L, Lewis RJ, Sarma SP J Biol Chem. 2020 Mar 31. pii: RA119.012098. doi: 10.1074/jbc.RA119.012098. PMID:32234761[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Mohan MK, Abraham N, R P R, Jayaseelan BF, Ragnarsson L, Lewis RJ, Sarma SP. Structure and allosteric activity of a single disulfide conopeptide from Conus zonatus at human alpha3beta4 and alpha7 nicotinic acetylcholine receptors. J Biol Chem. 2020 Mar 31. pii: RA119.012098. doi: 10.1074/jbc.RA119.012098. PMID:32234761 doi:http://dx.doi.org/10.1074/jbc.RA119.012098
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