View source for 2fx9


==Crystal structure of hiv-1 neutralizing human fab 4e10 in complex with a thioether-linked peptide encompassing the 4e10 epitope on gp41==
<StructureSection load='2fx9' size='340' side='right'caption='[[2fx9]], [[Resolution|resolution]] 2.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2fx9]] is a 6 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2FX9 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2FX9 FirstGlance]. <br>
</td></tr><tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=ORQ:N~5~-ACETYL-L-ORNITHINE'>ORQ</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1tzg|1tzg]], [[2fx7|2fx7]], [[2fx8|2fx8]]</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=2fx9 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2fx9 OCA], [http://pdbe.org/2fx9 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2fx9 RCSB], [http://www.ebi.ac.uk/pdbsum/2fx9 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=2fx9 ProSAT]</span></td></tr>
</table>
== 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/fx/2fx9_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=2fx9 ConSurf].
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== Publication Abstract from PubMed ==
Potent, broadly HIV-1 neutralizing antibodies (nAbs) may be invaluable for the design of an AIDS vaccine. 4E10 is the broadest HIV-1 nAb known to date and recognizes a contiguous and highly conserved helical epitope in the membrane-proximal region of gp41. The 4E10 epitope is thus an excellent target for vaccine design as it is also highly amenable to peptide engineering to enhance its helical character. To investigate the structural effect of both increasing the peptide length and of introducing helix-promoting constraints in the 4E10 epitope, we have determined crystal structures of Fab 4E10 bound to an optimized peptide epitope (NWFDITNWLWYIKKKK-NH(2)), an Aib-constrained peptide epitope (NWFDITNAibLWRR-NH(2)), and a thioether-linked peptide (NWFCITOWLWKKKK-NH(2)) to resolutions of 1.7 A, 2.1 A, and 2.2 A, respectively. The thioether-linked peptide is the first reported structure of a cyclic tethered helical peptide bound to an antibody. The introduced helix constraints limit the conformational flexibility of the peptides without affecting interactions with 4E10. The substantial increase in affinity (10 nM versus 10(4) nM of the IC(50) of the original KGND peptide template) is largely realized by 4E10 interaction with an additional helical turn at the peptide C terminus that includes Leu679 and Trp680. Thus, the core 4E10 epitope was extended and modified to a WFX(I/L)(T/S)XX(L/I)W motif, where X does not play a major role in 4E10 binding and can be used to introduce helical-promoting constraints in the peptide epitope.

Structural basis of enhanced binding of extended and helically constrained peptide epitopes of the broadly neutralizing HIV-1 antibody 4E10.,Cardoso RM, Brunel FM, Ferguson S, Zwick M, Burton DR, Dawson PE, Wilson IA J Mol Biol. 2007 Feb 2;365(5):1533-44. Epub 2006 Nov 10. PMID:17125793<ref>PMID:17125793</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 2fx9" style="background-color:#fffaf0;"></div>

==See Also==
*[[Antibody 3D structures|Antibody 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Human]]
[[Category: Large Structures]]
[[Category: Brunel, F M]]
[[Category: Burton, D R]]
[[Category: Cardoso, R M.F]]
[[Category: Dawson, P E]]
[[Category: Ferguson, S]]
[[Category: Wilson, I A]]
[[Category: Antibody-epitope complex]]
[[Category: Beta-sandwich]]
[[Category: Immune system]]
[[Category: Immunoglobulin fold]]