View source for 2moa


==Solution NMR structure of peptide ImI1 (peak 2)==
<StructureSection load='2moa' size='340' side='right'caption='[[2moa]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2moa]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Conus_imperialis Conus imperialis]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2MOA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2MOA FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=81S:(4S)-4,5-DISULFANYL-L-NORVALINE'>81S</scene>, <scene name='pdbligand=NH2:AMINO+GROUP'>NH2</scene>, <scene name='pdbligand=PRD_001232:Alpha-conotoxin+ImI+mutant'>PRD_001232</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=2moa FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2moa OCA], [https://pdbe.org/2moa PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2moa RCSB], [https://www.ebi.ac.uk/pdbsum/2moa PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2moa ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CA1_CONIM CA1_CONIM] Alpha-conotoxins act on postsynaptic membranes, they bind to the nicotinic acetylcholine receptors (nAChR) and thus inhibit them. This toxin blocks mammalian neuronal nAChRs (alpha-3/beta-2 > alpha-7 > alpha-3/beta-4). Has no effect on nAChRs composed of alpha-2/beta-2, alpha-3/beta-2, alpha-4/beta-2, alpha-2/beta-4, alpha-3/beta-4, or alpha-4/beta-4 subunits. Acts voltage-independently. Is highly active against the neuromuscular receptor in frog.<ref>PMID:8206995</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The disulfide bonds that form between two cysteine residues are important in defining and rigidifying the structures of proteins and peptides. In polypeptides containing multiple cysteine residues, disulfide isomerization can lead to multiple products with different biological activities. Here, we describe the development of a dithiol amino acid (Dtaa) that can form two disulfide bridges at a single amino acid site. Application of Dtaas to a serine protease inhibitor and a nicotinic acetylcholine receptor inhibitor that contain disulfide constraints enhanced their inhibitory activities 40- and 7.6-fold, respectively. X-ray crystallographic and NMR structure analysis show that the peptide ligands containing Dtaas have retained their native tertiary structures. We furthermore show that replacement of two cysteines by Dtaas can avoid the formation of disulfide bond isomers. With these properties, Dtaas are likely to have broad application in the rational design or directed evolution of peptides and proteins with high activity and stability.

Dithiol amino acids can structurally shape and enhance the ligand-binding properties of polypeptides.,Chen S, Gopalakrishnan R, Schaer T, Marger F, Hovius R, Bertrand D, Pojer F, Heinis C Nat Chem. 2014 Nov;6(11):1009-16. doi: 10.1038/nchem.2043. Epub 2014 Aug 31. PMID:25343607<ref>PMID:25343607</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 2moa" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Conus imperialis]]
[[Category: Large Structures]]
[[Category: Chen S]]
[[Category: Heinis C]]