View source for 4zqy


==Ringhalexin from hemachatus haemachatus: A novel inhibitor of extrinsic tenase complex==
<StructureSection load='4zqy' size='340' side='right'caption='[[4zqy]], [[Resolution|resolution]] 2.95&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4zqy]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Hemachatus_haemachatus Hemachatus haemachatus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4ZQY OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4ZQY 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]] 2.9515&#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=4zqy FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4zqy OCA], [https://pdbe.org/4zqy PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4zqy RCSB], [https://www.ebi.ac.uk/pdbsum/4zqy PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4zqy ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/3SO1_HEMHA 3SO1_HEMHA] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Anticoagulant therapy is used for the prevention and treatment of thromboembolic disorders. Blood coagulation is initiated by the interaction of factor VIIa (FVIIa) with membrane-bound tissue factor (TF) to form the extrinsic tenase complex which activates FX to FXa. Thus, it is an important target for the development of novel anticoagulants. Here, we report the isolation and characterization of a novel anticoagulant ringhalexin from the venom of Hemachatus haemachatus (African Ringhals Cobra). Amino acid sequence of the protein indicates that it belongs to the three-finger toxin family and exhibits 94% identity to an uncharacterized Neurotoxin-like protein NTL2 from Naja atra. Ringhalexin inhibited FX activation by extrinsic tenase complex with an IC50 of 123.8 +/- 9.54 nM. It is a mixed-type inhibitor with the kinetic constants, Ki and Ki' of 84.25 +/- 3.53 nM and 152.5 +/- 11.32 nM, respectively. Ringhalexin also exhibits a weak, irreversible neurotoxicity on chick biventer cervicis muscle preparations. Subsequently, the three-dimensional structure of ringhalexin was determined at 2.95 A resolution. This study for the first time reports the structure of an anticoagulant three-finger toxin. Thus, ringhalexin is a potent inhibitor of the FX activation by extrinsic tenase complex and a weak, irreversible neurotoxin.

Ringhalexin from Hemachatus haemachatus: A novel inhibitor of extrinsic tenase complex.,Barnwal B, Jobichen C, Girish VM, Foo CS, Sivaraman J, Kini RM Sci Rep. 2016 May 13;6:25935. doi: 10.1038/srep25935. PMID:27173146<ref>PMID:27173146</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4zqy" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Hemachatus haemachatus]]
[[Category: Large Structures]]
[[Category: Jobichen C]]
[[Category: Sivaraman J]]