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2knm

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Revision as of 11:49, 11 September 2015

Solution structure of the cyclotide cycloviolacin O2

Structural highlights

2knm is a 1 chain structure with sequence from Viola odorata. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance.
Related:	2knn
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum

Function

[CYO2_VIOOD] Probably participates in a plant defense mechanism. Has strong cytotoxic activity against a variety of drug-resistant and drug-sensitive human tumor cell lines, and against primary chronic lymphocytic leukemia and ovarian carcinoma cells. Has weaker cytotoxic activity against normal lymphocytes. Has hemolytic activity.^[1] ^[2]

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

Cyclotides are a large family of plant peptides that are characterised by a head-to-tail circular backbone and three disulfide bonds that are arranged in a cystine knot. This unique structural feature, which is referred to as a cyclic cystine knot, gives the cyclotides remarkable stability against chemical and biological degradation. In addition to their natural function as insecticides for plant defence, the cyclotides have a range of bioactivities with pharmaceutical relevance, including cytotoxicity against cancer cell lines. A glutamic acid residue, aside from the invariable disulfide array, is the most conserved feature throughout the cyclotide family, and it has recently been shown to be crucial for biological activity. Here we have used solution-state NMR spectroscopy to determine the three-dimensional structures of the potent cytotoxic cyclotide cycloviolacin O2, and an inactive analogue in which this conserved glutamic acid has been methylated. The structures of the peptides show that the glutamic acid has a key structural role in coordinating a set of hydrogen bonds in native cycloviolacin O2; this interaction is disrupted in the methylated analogue. The proposed mechanism of action of cyclotides is membrane disruption and these results suggest that the glutamic acid is linked to cyclotide function by stabilising the structure to allow efficient aggregation in membranes, rather than in a direct interaction with a target receptor.

The conserved glu in the cyclotide cycloviolacin O2 has a key structural role.,Goransson U, Herrmann A, Burman R, Haugaard-Jonsson LM, Rosengren KJ Chembiochem. 2009 Sep 21;10(14):2354-60. PMID:19735083^[3]

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

References

↑ Ireland DC, Colgrave ML, Craik DJ. A novel suite of cyclotides from Viola odorata: sequence variation and the implications for structure, function and stability. Biochem J. 2006 Nov 15;400(1):1-12. PMID:16872274 doi:BJ20060627
↑ Lindholm P, Goransson U, Johansson S, Claeson P, Gullbo J, Larsson R, Bohlin L, Backlund A. Cyclotides: a novel type of cytotoxic agents. Mol Cancer Ther. 2002 Apr;1(6):365-9. PMID:12477048
↑ Goransson U, Herrmann A, Burman R, Haugaard-Jonsson LM, Rosengren KJ. The conserved glu in the cyclotide cycloviolacin O2 has a key structural role. Chembiochem. 2009 Sep 21;10(14):2354-60. PMID:19735083 doi:10.1002/cbic.200900342

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

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/2knm"

@@ Line 4: / Line 4: @@
 <table><tr><td colspan='2'>[[2knm]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Viola_odorata Viola odorata]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2KNM OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2KNM FirstGlance]. <br>
 </td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[2knn|2knn]]</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=2knm FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2knm OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2knm RCSB], [http://www.ebi.ac.uk/pdbsum/2knm PDBsum]</span></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=2knm FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2knm OCA], [http://pdbe.org/2knm PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2knm RCSB], [http://www.ebi.ac.uk/pdbsum/2knm PDBsum]</span></td></tr>
 </table>
 == Function ==
@@ Line 26: / Line 26: @@
 From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
 </div>
+<div class="pdbe-citations 2knm" style="background-color:#fffaf0;"></div>
 == References ==
 <references/>

2knm

From Proteopedia

Revision as of 11:49, 11 September 2015

Solution structure of the cyclotide cycloviolacin O2

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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