View source for 6tcm


==Crystal structure of the omalizumab Fab - crystal form I==
<StructureSection load='6tcm' size='340' side='right'caption='[[6tcm]], [[Resolution|resolution]] 1.85&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6tcm]] is a 2 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=6TCM OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6TCM 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]] 1.85&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=MPD:(4S)-2-METHYL-2,4-PENTANEDIOL'>MPD</scene>, <scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene></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=6tcm FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6tcm OCA], [https://pdbe.org/6tcm PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6tcm RCSB], [https://www.ebi.ac.uk/pdbsum/6tcm PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6tcm ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Immunoglobulin E (IgE) plays a central role in the allergic response, in which cross-linking of allergen by FcepsilonRI-bound IgE triggers mast cell and basophil degranulation and the release of inflammatory mediators. The high-affinity interaction between IgE and FcepsilonRI is a long-standing target for therapeutic intervention in allergic disease. Omalizumab is a clinically approved anti-IgE monoclonal antibody that binds to free IgE, also with high affinity, preventing its interaction with FcepsilonRI. All attempts to crystallize the pre-formed complex between the omalizumab Fab and the Fc region of IgE (IgE-Fc), to understand the structural basis for its mechanism of action, surprisingly failed. Instead, the Fab alone selectively crystallized in different crystal forms, but their structures revealed intermolecular Fab/Fab interactions that were clearly strong enough to disrupt the Fab/IgE-Fc complexes. Some of these interactions were common to other Fab crystal structures. Mutations were therefore designed to disrupt two recurring packing interactions observed in the omalizumab Fab crystal structures without interfering with the ability of the omalizumab Fab to recognize IgE-Fc; this led to the successful crystallization and subsequent structure determination of the Fab/IgE-Fc complex. The mutagenesis strategy adopted to achieve this result is applicable to other intractable Fab/antigen complexes or systems in which Fabs are used as crystallization chaperones.

Engineering the Fab fragment of the anti-IgE omalizumab to prevent Fab crystallization and permit IgE-Fc complex crystallization.,Mitropoulou AN, Ceska T, Heads JT, Beavil AJ, Henry AJ, McDonnell JM, Sutton BJ, Davies AM Acta Crystallogr F Struct Biol Commun. 2020 Mar 1;76(Pt 3):116-129. doi:, 10.1107/S2053230X20001466. Epub 2020 Mar 2. PMID:32133997<ref>PMID:32133997</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6tcm" style="background-color:#fffaf0;"></div>

==See Also==
*[[Monoclonal Antibodies 3D structures|Monoclonal Antibodies 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Beavil AJ]]
[[Category: Ceska T]]
[[Category: Davies AM]]
[[Category: Henry AJ]]
[[Category: McDonnell JM]]
[[Category: Mitropoulou AN]]
[[Category: Sutton BJ]]