1rd4: Difference between revisions
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==An allosteric inhibitor of LFA-1 bound to its I-domain== | |||
<StructureSection load='1rd4' size='340' side='right'caption='[[1rd4]], [[Resolution|resolution]] 2.40Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1rd4]] 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=1RD4 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1RD4 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]] 2.4Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=L08:1-ACETYL-4-(4-{4-[(2-ETHOXYPHENYL)THIO]-3-NITROPHENYL}PYRIDIN-2-YL)PIPERAZINE'>L08</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=1rd4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1rd4 OCA], [https://pdbe.org/1rd4 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1rd4 RCSB], [https://www.ebi.ac.uk/pdbsum/1rd4 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1rd4 ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/ITAL_HUMAN ITAL_HUMAN] Integrin alpha-L/beta-2 is a receptor for ICAM1, ICAM2, ICAM3 and ICAM4. It is involved in a variety of immune phenomena including leukocyte-endothelial cell interaction, cytotoxic T-cell mediated killing, and antibody dependent killing by granulocytes and monocytes. | |||
== 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/rd/1rd4_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.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=1rd4 ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
LFA-1 (lymphocyte function-associated antigen-1) plays a role in intercellular adhesion and lymphocyte trafficking and activation and is an attractive anti-inflammatory drug target. The alpha-subunit of LFA-1, in common with several other integrins, has an N-terminally inserted domain (I-domain) of approximately 200 amino acids that plays a central role in regulating ligand binding to LFA-1. An additional region, termed the I-domain allosteric site (IDAS), has been identified exclusively within the LFA-1 I-domain and shown to regulate the function of this protein. The IDAS is occupied by small molecule LFA-1 inhibitors when cocrystallized or analyzed by (15)N-(1)H HSQC (heteronuclear single-quantum coherence) NMR (nuclear magnetic resonance) titration experiments. We report here a novel arylthio inhibitor that binds the I-domain with a K(d) of 18.3 nM as determined by isothermal titration calorimetry (ITC). This value is in close agreement with the IC(50) (10.9 nM) derived from a biochemical competition assay (DELFIA) that measures the level of inhibition of binding of whole LFA-1 to its ligand, ICAM-1. Having established the strong affinity of the arylthio inhibitor for the isolated I-domain, we have used a range of techniques to further characterize the binding, including ITC, NMR, and X-ray crystallography. We have first developed an effective ITC binding assay for use with low-solubility inhibitors that avoids the need for ELISA-based assays. In addition, we utilized a fast NMR-based assay for the generation of I-domain-inhibitor models. This is based around the collection of HCCH-TOCSY spectra of LFA-1 in the bound form and the identification of a subset of side chain methyl groups that give chemical shift changes upon binding of LFA-1 inhibitors. This subset was used in two-dimensional (13)C-(15)N and (15)N-filtered and -edited two-dimensional NMR experiments to identify a minimal set of intraligand and ligand-protein NOEs, respectively (nuclear Overhauser enhancements). Models from the NMR data were assessed by comparison to an X-ray crystallographic structure of the complex, confirming that the method correctly predicted the essential features of the bound ligand. | |||
Structure of an allosteric inhibitor of LFA-1 bound to the I-domain studied by crystallography, NMR, and calorimetry.,Crump MP, Ceska TA, Spyracopoulos L, Henry A, Archibald SC, Alexander R, Taylor RJ, Findlow SC, O'Connell J, Robinson MK, Shock A Biochemistry. 2004 Mar 9;43(9):2394-404. PMID:14992576<ref>PMID:14992576</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 1rd4" style="background-color:#fffaf0;"></div> | |||
==See Also== | ==See Also== | ||
*[[Integrin|Integrin]] | *[[Integrin 3D structures|Integrin 3D structures]] | ||
== References == | |||
== | <references/> | ||
< | __TOC__ | ||
</StructureSection> | |||
[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: | [[Category: Large Structures]] | ||
[[Category: | [[Category: Alexander R]] | ||
[[Category: | [[Category: Archibald SC]] | ||
[[Category: | [[Category: Ceska TA]] | ||
[[Category: Crump | [[Category: Crump MP]] | ||
[[Category: Findlow | [[Category: Findlow SC]] | ||
[[Category: Henry | [[Category: Henry A]] | ||
[[Category: | [[Category: O'Connell J]] | ||
[[Category: | [[Category: Robinson MK]] | ||
[[Category: | [[Category: Shock A]] | ||
[[Category: | [[Category: Spyracopoulos L]] | ||
[[Category: | [[Category: Taylor RJ]] | ||
