View source for 6a78


==Crystal structure of the fifth immunoglobulin domain (Ig5) of human Robo1 in complex with the scFv fragment of murine monoclonal antibody B5209B==
<StructureSection load='6a78' size='340' side='right'caption='[[6a78]], [[Resolution|resolution]] 2.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6a78]] is a 6 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human] and [http://en.wikipedia.org/wiki/Lk3_transgenic_mice Lk3 transgenic mice]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6A78 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6A78 FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">ROBO1, DUTT1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN])</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=6a78 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6a78 OCA], [http://pdbe.org/6a78 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6a78 RCSB], [http://www.ebi.ac.uk/pdbsum/6a78 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6a78 ProSAT]</span></td></tr>
</table>
== Function ==
[[http://www.uniprot.org/uniprot/ROBO1_HUMAN ROBO1_HUMAN]] Receptor for SLIT1 and SLIT2 which are thought to act as molecular guidance cue in cellular migration, including axonal navigation at the ventral midline of the neural tube and projection of axons to different regions during neuronal development. In axon growth cones, the silencing of the attractive effect of NTN1 by SLIT2 may require the formation of a ROBO1-DCC complex. May be required for lung development.<ref>PMID:10102268</ref>  
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
To investigate favorable single amino acid substitutions that improve antigen-antibody interactions, alanine (Ala) mutagenesis scanning of the interfacial residues of a cancer-targeted antibody, B5209B, was performed based on X-ray crystallography analysis. Two substitutions were shown to significantly enhance the binding affinity for the antigen, by up to 30-fold. One substitution improved the affinity by a gain of binding enthalpy, whereas the other substitution improved the affinity by a gain of binding entropy. Molecular dynamics simulations showed that the enthalpic improvement could be attributed to the stabilization of distant salt bridges located at the periphery of the antigen-antibody interface. The entropic improvement was due to the release of water molecules that were stably trapped in the antigen-antibody interface of the wild-type antibody. Importantly, these effects of the Ala substitutions were caused by subtle adjustments of the binding interface. These results will be helpful to design high-affinity antibodies with avoiding entropy-enthalpy compensation.

Affinity Improvement of a Cancer-Targeted Antibody through Alanine-Induced Adjustment of Antigen-Antibody Interface.,Yamashita T, Mizohata E, Nagatoishi S, Watanabe T, Nakakido M, Iwanari H, Mochizuki Y, Nakayama T, Kado Y, Yokota Y, Matsumura H, Kawamura T, Kodama T, Hamakubo T, Inoue T, Fujitani H, Tsumoto K Structure. 2018 Nov 20. pii: S0969-2126(18)30421-0. doi:, 10.1016/j.str.2018.11.002. PMID:30595454<ref>PMID:30595454</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6a78" style="background-color:#fffaf0;"></div>

==See Also==
*[[Monoclonal Antibodies 3D structures|Monoclonal Antibodies 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Human]]
[[Category: Large Structures]]
[[Category: Lk3 transgenic mice]]
[[Category: Inoue, T]]
[[Category: Kado, Y]]
[[Category: Mizohata, E]]
[[Category: Nakayama, T]]
[[Category: Angiogenesis]]
[[Category: Antibody drug]]
[[Category: Hepatocellular carcinoma antigen]]
[[Category: Immune system]]
[[Category: Single chain fv fragment]]