View source for 4ttl


==Racemic structure of cyclic Vc1.1 (cVc1.1-1)==
<StructureSection load='4ttl' size='340' side='right'caption='[[4ttl]], [[Resolution|resolution]] 1.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4ttl]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Conus_victoriae Conus victoriae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4TTL OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4TTL FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.7004&#8491;</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=4ttl FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4ttl OCA], [https://pdbe.org/4ttl PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4ttl RCSB], [https://www.ebi.ac.uk/pdbsum/4ttl PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4ttl ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CA1A_CONVC CA1A_CONVC] Alpha-conotoxins act on postsynaptic membranes, they bind to the nicotinic acetylcholine receptors (nAChR) and thus inhibit them. This synthetic peptide (produced without hydroxyproline, nor 4-carboxyglutamate) is a neuronal nAChR antagonist that acts as a powerful analgesic. It blocks nAChRs composed of alpha-3 or -5/beta-2 (IC(50)=7.2 uM), alpha-3/beta-2 (IC(50)=7.3 uM), alpha-3/beta-4 (IC(50)=4.2 uM), alpha-3 or -5/beta-4 (IC(50)<30 uM), alpha-4/beta-2 (IC(50)<30 uM), alpha-4/beta-4 (IC(50)<30 uM) and alpha/beta/gamma/delta (IC(50)<30 uM) subunits.<ref>PMID:12779345</ref> <ref>PMID:15770155</ref> 
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== Publication Abstract from PubMed ==
Cyclic disulfide-rich peptides have exceptional stability and are promising frameworks for drug design. We were interested in obtaining X-ray structures of these peptides to assist in drug design applications, but disulfide-rich peptides can be notoriously difficult to crystallize. To overcome this limitation, we chemically synthesized the L- and D-forms of three prototypic cyclic disulfide-rich peptides: SFTI-1 (14-mer with one disulfide bond), cVc1.1 (22-mer with two disulfide bonds), and kB1 (29-mer with three disulfide bonds) for racemic crystallization studies. Facile crystal formation occurred from a racemic mixture of each peptide, giving structures solved at resolutions from 1.25 A to 1.9 A. Additionally, we obtained the quasi-racemic structures of two mutants of kB1, [G6A]kB1, and [V25A]kB1, which were solved at a resolution of 1.25 A and 2.3 A, respectively. The racemic crystallography approach appears to have broad utility in the structural biology of cyclic peptides.

Racemic and Quasi-Racemic X-ray Structures of Cyclic Disulfide-Rich Peptide Drug Scaffolds.,Wang CK, King GJ, Northfield SE, Ojeda PG, Craik DJ Angew Chem Int Ed Engl. 2014 Aug 28. doi: 10.1002/anie.201406563. PMID:25168664<ref>PMID:25168664</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
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</StructureSection>
[[Category: Conus victoriae]]
[[Category: Large Structures]]
[[Category: Craik DJ]]
[[Category: King GJ]]
[[Category: Wang CK]]