View source for 1iqd


==Human Factor VIII C2 Domain complexed to human monoclonal BO2C11 Fab.==
<StructureSection load='1iqd' size='340' side='right'caption='[[1iqd]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1iqd]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1IQD OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1IQD 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&#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=1iqd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1iqd OCA], [https://pdbe.org/1iqd PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1iqd RCSB], [https://www.ebi.ac.uk/pdbsum/1iqd PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1iqd ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/FA8_HUMAN FA8_HUMAN] Defects in F8 are the cause of hemophilia A (HEMA) [MIM:[https://omim.org/entry/306700 306700]. A disorder of blood coagulation characterized by a permanent tendency to hemorrhage. About 50% of patients have severe hemophilia resulting in frequent spontaneous bleeding into joints, muscles and internal organs. Less severe forms are characterized by bleeding after trauma or surgery. Note=Of particular interest for the understanding of the function of F8 is the category of CRM (cross-reacting material) positive patients (approximately 5%) that have considerable amount of F8 in their plasma (at least 30% of normal), but the protein is non-functional; i.e. the F8 activity is much less than the plasma protein level. CRM-reduced is another category of patients in which the F8C antigen and activity are reduced to approximately the same level. Most mutations are CRM negative, and probably affect the folding and stability of the protein.<ref>PMID:3012775</ref> <ref>PMID:3122181</ref> <ref>PMID:2833855</ref> <ref>PMID:2835904</ref> <ref>PMID:2499363</ref> <ref>PMID:2506948</ref> <ref>PMID:2510835</ref> <ref>PMID:2495245</ref> <ref>PMID:2498882</ref> <ref>PMID:2104766</ref> <ref>PMID:2105106</ref> <ref>PMID:1973901</ref> <ref>PMID:2105906</ref> <ref>PMID:2106480</ref> <ref>PMID:2107542</ref> <ref>PMID:1908817</ref> <ref>PMID:1908096</ref> <ref>PMID:1851341</ref> <ref>PMID:1356412</ref> <ref>PMID:1639429</ref> <ref>PMID:1349567</ref> <ref>PMID:1301194</ref> <ref>PMID:1301932</ref> <ref>PMID:1301960</ref> <ref>PMID:8449505</ref> <ref>PMID:8322269</ref> <ref>PMID:7579394</ref> <ref>PMID:7794769</ref> <ref>PMID:7759074</ref> <ref>PMID:8644728</ref> <ref>PMID:8639447</ref> <ref>PMID:8759905</ref> <ref>PMID:9029040</ref> <ref>PMID:9326186</ref> <ref>PMID:9341862</ref> <ref>PMID:9886318</ref> <ref>PMID:9450898</ref> <ref>PMID:10215414</ref> <ref>PMID:9603440</ref> <ref>PMID:9452104</ref> <ref>PMID:9792405</ref> <ref>PMID:9829908</ref> <ref>PMID:9569180</ref> <ref>PMID:9569189</ref> <ref>PMID:10554831</ref> <ref>PMID:10338101</ref> <ref>PMID:10408784</ref> <ref>PMID:10404764</ref> <ref>PMID:10910910</ref> <ref>PMID:10910913</ref> <ref>PMID:10691849</ref> <ref>PMID:10886198</ref> <ref>PMID:10800171</ref> <ref>PMID:10896236</ref> <ref>PMID:10612839</ref> <ref>PMID:11410838</ref> <ref>PMID:11298607</ref> <ref>PMID:11442643</ref> <ref>PMID:11442647</ref> <ref>PMID:11554935</ref> <ref>PMID:11748850</ref> <ref>PMID:11341489</ref> <ref>PMID:12351418</ref> <ref>PMID:12406074</ref> <ref>PMID:12199686</ref> <ref>PMID:11857744</ref> <ref>PMID:12203998</ref> <ref>PMID:12325022</ref> <ref>PMID:11858487</ref> <ref>PMID:12195713</ref> <ref>PMID:12930394</ref> <ref>PMID:12871415</ref> <ref>PMID:12614369</ref> <ref>PMID:15682412</ref> <ref>PMID:15810915</ref> <ref>PMID:16805874</ref> <ref>PMID:18184865</ref> <ref>PMID:21371196</ref> 
== Function ==
[https://www.uniprot.org/uniprot/FA8_HUMAN FA8_HUMAN] Factor VIII, along with calcium and phospholipid, acts as a cofactor for factor IXa when it converts factor X to the activated form, factor Xa.
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/iq/1iqd_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1iqd ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The development of an immune response to infused factor VIII is a complication affecting many patients with hemophilia A. Inhibitor antibodies bind to antigenic determinants on the factor VIII molecule and block its procoagulant activity. A patient-derived inhibitory immunoglobulin G4kappa antibody (BO2C11) produced by an immortalized memory B-lymphocyte cell line interferes with the binding of factor VIII to phospholipid surfaces and to von Willebrand factor. The structure of a Fab fragment derived from this antibody complexed with the factor VIII C2 domain was determined at 2.0 A resolution. The Fab interacts with solvent-exposed basic and hydrophobic side chains that form a membrane-association surface of factor VIII. This atomic resolution structure suggests a variety of amino acid substitutions in the C2 domain of factor VIII that might prevent the binding of anti-C2 inhibitor antibodies without significantly compromising the procoagulant functions of factor VIII.

Structure of a factor VIII C2 domain-immunoglobulin G4kappa Fab complex: identification of an inhibitory antibody epitope on the surface of factor VIII.,Spiegel PC Jr, Jacquemin M, Saint-Remy JM, Stoddard BL, Pratt KP Blood. 2001 Jul 1;98(1):13-9. PMID:11418455<ref>PMID:11418455</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 1iqd" style="background-color:#fffaf0;"></div>

==See Also==
*[[Factor VIII|Factor VIII]]
*[[Monoclonal Antibodies 3D structures|Monoclonal Antibodies 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Jacquemin M]]
[[Category: Pratt KP]]
[[Category: Saint-Remy JM]]
[[Category: Spiegel Jr PC]]
[[Category: Stoddard BL]]