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4kyp

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Revision as of 09:51, 4 August 2016

Beta-Scorpion Toxin folded in the periplasm of E.coli

Structural highlights

4kyp is a 4 chain structure with sequence from Black scorpion. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:	,
Related:	1bcg
Gene:	XTRIT (Black scorpion)
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[SIXE_HOTJU] Excitatory insect toxins induce a spastic paralysis. They bind voltage-independently at site-4 of sodium channels (Nav) and shift the voltage of activation toward more negative potentials thereby affecting sodium channel activation and promoting spontaneous and repetitive firing. This toxin is active only on insects.

Publication Abstract from PubMed

BACKGROUND: Animal neurotoxin peptides are valuable probes for investigating ion channel structure/function relationships and represent lead compounds for novel therapeutics and insecticides. However, misfolding and aggregation are common outcomes when toxins containing multiple disulfides are expressed in bacteria. METHODS: The beta-scorpion peptide toxin Bj-xtrIT from Hottentotta judaica and four chaperone enzymes (DsbA, DsbC, SurA and FkpA) were co-secreted into the oxidizing environment of the Escherichia coli periplasm. Expressed Bj-xtrIT was purified and analyzed by HPLC and FPLC chromatography. Its thermostability was assessed using synchrotron radiation circular dichroism spectroscopy and its crystal structure was determined. RESULTS: Western blot analysis showed that robust expression was only achieved when cells co-expressed the chaperones. The purified samples were homogenous and monodisperse and the protein was thermostable. The crystal structure of the recombinant toxin confirmed that it adopts the native disulfide connectivity and fold. CONCLUSIONS: The chaperones enabled correct folding of the four-disulfide-bridged Bj-xtrIT toxin. There was no apparent sub-population of misfolded Bj-xtrIT, which attests to the effectiveness of this expression method. GENERAL SIGNIFICANCE: We report the first example of a disulfide-linked scorpion toxin natively folded during bacterial expression. This method eliminates downstream processing steps such as oxidative refolding or cleavage of a fusion-carrier and therefore enables efficient production of insecticidal Bj-xtrIT. Periplasmic chaperone activity may produce native folding of other extensively disulfide-reticulated proteins including animal neurotoxins. This work is therefore relevant to venomics and studies of a wide range of channels and receptors.

Chaperone-mediated native folding of a beta-scorpion toxin in the periplasm of Escherichia coli.,O'Reilly AO, Cole AR, Lopes JL, Lampert A, Wallace BA Biochim Biophys Acta. 2014 Jan;1840(1):10-5. doi: 10.1016/j.bbagen.2013.08.021., Epub 2013 Aug 30. PMID:23999087^[1]

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

References

↑ O'Reilly AO, Cole AR, Lopes JL, Lampert A, Wallace BA. Chaperone-mediated native folding of a beta-scorpion toxin in the periplasm of Escherichia coli. Biochim Biophys Acta. 2014 Jan;1840(1):10-5. doi: 10.1016/j.bbagen.2013.08.021., Epub 2013 Aug 30. PMID:23999087 doi:http://dx.doi.org/10.1016/j.bbagen.2013.08.021

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

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/4kyp"

@@ Line 1: / Line 1: @@
 ==Beta-Scorpion Toxin folded in the periplasm of E.coli==
 <StructureSection load='4kyp' size='340' side='right' caption='[[4kyp]], [[Resolution|resolution]] 1.70&Aring;' scene=''>
@@ Line 6: / Line 7: @@
 <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1bcg|1bcg]]</td></tr>
 <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">XTRIT ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=6863 Black scorpion])</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=4kyp FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4kyp OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4kyp RCSB], [http://www.ebi.ac.uk/pdbsum/4kyp 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=4kyp FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4kyp OCA], [http://pdbe.org/4kyp PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4kyp RCSB], [http://www.ebi.ac.uk/pdbsum/4kyp PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4kyp ProSAT]</span></td></tr>
 </table>
 == Function ==
@@ Line 18: / Line 19: @@
 From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
 </div>
+<div class="pdbe-citations 4kyp" style="background-color:#fffaf0;"></div>
 == References ==
 <references/>

4kyp

From Proteopedia

Revision as of 09:51, 4 August 2016

Beta-Scorpion Toxin folded in the periplasm of E.coli

Structural highlights

Function

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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