This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.

Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.

2osh

From Proteopedia

(Difference between revisions)

Jump to: navigation, search

Revision as of 13:48, 10 September 2015

crystal structure of Natratoxin, a snake sPLA2 that blocks A-type K+ channel

Structural highlights

2osh is a 1 chain structure with sequence from Naja atra. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Activity:	Phospholipase A(2), with EC number 3.1.1.4
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum

Function

[PA2A1_NAJAT] Snake venom phospholipase A2 (PLA2) that has high affinity for muscarinic acetylcholine receptors mAChRs (CHRM) and has the ability to activate them. In guinea-pig ileum, produces an onset and dose-dependent contraction. Has also weak anticoagulant activity. PLA2 catalyzes the calcium-dependent hydrolysis of the 2-acyl groups in 3-sn-phosphoglycerides.^[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

Snake secreted phospholipasesA2 (sPLA2s) are widely used as pharmacological tools to investigate their role in diverse pathophysiological processes. Some members of snake venom sPLA2s have been found to block voltage-activated K(+) channels (K(v) channels). However, most studies involved in their effects on ion channels were indirectly performed on motor nerve terminals while few studies were directly done on native neurons. Here, a novel snake sPLA2 peptide neurotoxin, Natratoxin, composed of 119 amino acid residues and purified from Naja atra venom was reported. It was characterized using whole-cell patch-clamp in acutely dissociated rat dorsal root ganglion (DRG) neurons. It was found to effectively inhibit A-type K(+) currents and cause alterations of channel gating characters, such as the shifts of steady-state activation and inactivation curves to hyperpolarization direction and changes of V(1/2) and slope factor. Therefore, Natratoxin was suggested to be a gating modifier of K(v) channel. In addition, this inhibitory effect was found to be independent of its enzymatic activity. These results suggested that the toxin enacted its inhibitory effect by binding to K(v) channel. To further elucidate the structural basis for this electrophysiological phenomenon, we determined the crystal structure of Natratoxin at 2.2 A resolution by molecular replacement method and refined to an R-factor of 0.190. The observed overall fold has a different structural organization from other K(+) channel inhibitors in animal toxins. Compared with other K(v) channel inhibitors, a similar putative functional surface in its C-terminal was revealed to contribute to protein-protein interaction in such a blocking effect. Our results demonstrated that the spatial distribution of key amino acid residues matters most in the recognition of this toxin towards its channel target rather than its type of fold.

Crystal structure of Natratoxin, a novel snake secreted phospholipaseA2 neurotoxin from Naja atra venom inhibiting A-type K+ currents.,Hu P, Sun L, Zhu ZQ, Hou XW, Wang S, Yu SS, Wang HL, Zhang P, Wang M, Niu LW, Teng MK, Ruan DY Proteins. 2008 Aug;72(2):673-83. PMID:18247353^[3]

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

References

↑ Huang LF, Zheng JB, Xu Y, Song HT, Yu CX. A snake venom phospholipase A2 with high affinity for muscarinic acetylcholine receptors acts on guinea pig ileum. Toxicon. 2008 May;51(6):1008-16. doi: 10.1016/j.toxicon.2008.01.006. Epub 2008, Jan 17. PMID:18281071 doi:http://dx.doi.org/10.1016/j.toxicon.2008.01.006
↑ Kini RM, Evans HJ. Structure-function relationships of phospholipases. The anticoagulant region of phospholipases A2. J Biol Chem. 1987 Oct 25;262(30):14402-7. PMID:3117784
↑ Hu P, Sun L, Zhu ZQ, Hou XW, Wang S, Yu SS, Wang HL, Zhang P, Wang M, Niu LW, Teng MK, Ruan DY. Crystal structure of Natratoxin, a novel snake secreted phospholipaseA2 neurotoxin from Naja atra venom inhibiting A-type K+ currents. Proteins. 2008 Aug;72(2):673-83. PMID:18247353 doi:10.1002/prot.21964

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

Proteopedia Page Contributors and Editors (what is this?)

OCA

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

@@ Line 4: / Line 4: @@
 <table><tr><td colspan='2'>[[2osh]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Naja_atra Naja atra]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2OSH OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2OSH FirstGlance]. <br>
 </td></tr><tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Phospholipase_A(2) Phospholipase A(2)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.1.4 3.1.1.4] </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=2osh FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2osh OCA], [http://www.rcsb.org/pdb/explore.do?structureId=2osh RCSB], [http://www.ebi.ac.uk/pdbsum/2osh 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=2osh FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2osh OCA], [http://pdbe.org/2osh PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2osh RCSB], [http://www.ebi.ac.uk/pdbsum/2osh PDBsum]</span></td></tr>
 </table>
 == Function ==
-[[http://www.uniprot.org/uniprot/PA21_NAJAT PA21_NAJAT]] Snake venom phospholipase A2 (PLA2) that has high affinity for muscarinic acetylcholine receptors mAChRs (CHRM) and has the ability to activate them. In guinea-pig ileum, produces an onset and dose-dependent contraction. Has also weak anticoagulant activity. PLA2 catalyzes the calcium-dependent hydrolysis of the 2-acyl groups in 3-sn-phosphoglycerides.<ref>PMID:18281071</ref> <ref>PMID:3117784</ref>
+[[http://www.uniprot.org/uniprot/PA2A1_NAJAT PA2A1_NAJAT]] Snake venom phospholipase A2 (PLA2) that has high affinity for muscarinic acetylcholine receptors mAChRs (CHRM) and has the ability to activate them. In guinea-pig ileum, produces an onset and dose-dependent contraction. Has also weak anticoagulant activity. PLA2 catalyzes the calcium-dependent hydrolysis of the 2-acyl groups in 3-sn-phosphoglycerides.<ref>PMID:18281071</ref> <ref>PMID:3117784</ref>
 == Evolutionary Conservation ==
 [[Image:Consurf_key_small.gif|200px|right]]
@@ 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 2osh" style="background-color:#fffaf0;"></div>
 ==See Also==

2osh

From Proteopedia

Revision as of 13:48, 10 September 2015

crystal structure of Natratoxin, a snake sPLA2 that blocks A-type K+ channel

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

Views

Personal tools

Navigation

Search

Toolbox