View source for 2jb6


==Fab fragment in complex with small molecule hapten, crystal form-2==
<StructureSection load='2jb6' size='340' side='right'caption='[[2jb6]], [[Resolution|resolution]] 2.85&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2jb6]] is a 4 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=2JB6 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2JB6 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]] 2.85&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=T5C:2-{(1E,3Z,5E,7E)-7-[3,3-DIMETHYL-5-SULFO-1-(2-SULFOETHYL)-1,3-DIHYDRO-2H-INDOL-2-YLIDENE]-4-METHYLHEPTA-1,3,5-TRIEN-1-YL}-3,3-DIMETHYL-5-SULFO-1-(2-SULFOETHYL)-3H-INDOLIUM'>T5C</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=2jb6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2jb6 OCA], [https://pdbe.org/2jb6 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2jb6 RCSB], [https://www.ebi.ac.uk/pdbsum/2jb6 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2jb6 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/IGLC2_HUMAN IGLC2_HUMAN] Constant region of immunoglobulin light chains. Immunoglobulins, also known as antibodies, are membrane-bound or secreted glycoproteins produced by B lymphocytes. In the recognition phase of humoral immunity, the membrane-bound immunoglobulins serve as receptors which, upon binding of a specific antigen, trigger the clonal expansion and differentiation of B lymphocytes into immunoglobulins-secreting plasma cells. Secreted immunoglobulins mediate the effector phase of humoral immunity, which results in the elimination of bound antigens (PubMed:20176268, PubMed:22158414). The antigen binding site is formed by the variable domain of one heavy chain, together with that of its associated light chain. Thus, each immunoglobulin has two antigen binding sites with remarkable affinity for a particular antigen. The variable domains are assembled by a process called V-(D)-J rearrangement and can then be subjected to somatic hypermutations which, after exposure to antigen and selection, allow affinity maturation for a particular antigen (PubMed:17576170, PubMed:20176268).<ref>PMID:17576170</ref> <ref>PMID:20176268</ref> <ref>PMID:22158414</ref> 
== 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/jb/2jb6_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=2jb6 ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Molecular interactions between near-IR fluorescent probes and specific antibodies may be exploited to generate novel smart probes for diagnostic imaging. Using a new phage display technology, we developed such antibody Fab fragments with subnanomolar binding affinity for tetrasulfocyanine, a near-IR in vivo imaging agent. Unexpectedly, some Fabs induced redshifts of the dye absorption peak of up to 44 nm. This is the largest shift reported for a biological system so far. Crystal structure determination and absorption spectroscopy in the crystal in combination with microcalorimetry and small-angle X-ray scattering in solution revealed that the redshift is triggered by formation of a Fab dimer, with tetrasulfocyanine being buried in a fully closed protein cavity within the dimer interface. The derived principle of shifting the absorption peak of a symmetric dye via packaging within a Fab dimer interface may be transferred to other diagnostic fluorophores, opening the way towards smart imaging probes that change their wavelength upon interaction with an antibody.

Fab MOR03268 triggers absorption shift of a diagnostic dye via packaging in a solvent-shielded Fab dimer interface.,Hillig RC, Urlinger S, Fanghanel J, Brocks B, Haenel C, Stark Y, Sulzle D, Svergun DI, Baesler S, Malawski G, Moosmayer D, Menrad A, Schirner M, Licha K J Mol Biol. 2008 Mar 14;377(1):206-19. Epub 2008 Jan 5. PMID:18241888<ref>PMID:18241888</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 2jb6" style="background-color:#fffaf0;"></div>

==See Also==
*[[Antibody 3D structures|Antibody 3D structures]]
*[[3D structures of non-human antibody|3D structures of non-human antibody]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Badock V]]
[[Category: Baesler S]]
[[Category: Bahr I]]
[[Category: Hillig RC]]
[[Category: Licha K]]
[[Category: Malawski G]]
[[Category: Schirner M]]