View source for 4bpk


==Bcl-xL bound to alpha beta Puma BH3 peptide 5==
<StructureSection load='4bpk' size='340' side='right'caption='[[4bpk]], [[Resolution|resolution]] 1.76&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4bpk]] 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=4BPK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4BPK 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]] 1.756&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACE:ACETYL+GROUP'>ACE</scene>, <scene name='pdbligand=AHP:2-AMINO-HEPTANOIC+ACID'>AHP</scene>, <scene name='pdbligand=B3A:(3S)-3-AMINOBUTANOIC+ACID'>B3A</scene>, <scene name='pdbligand=B3D:3-AMINOPENTANEDIOIC+ACID'>B3D</scene>, <scene name='pdbligand=B3E:(3S)-3-AMINOHEXANEDIOIC+ACID'>B3E</scene>, <scene name='pdbligand=B3Q:(3S)-3,6-DIAMINO-6-OXOHEXANOIC+ACID'>B3Q</scene>, <scene name='pdbligand=CD:CADMIUM+ION'>CD</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=HR7:(3S)-3-AMINO-6-[(DIAMINOMETHYLIDENE)AMINO]HEXANOIC+ACID'>HR7</scene>, <scene name='pdbligand=HT7:(3S)-3-AMINO-4-(1H-INDOL-3-YL)BUTANOIC+ACID'>HT7</scene>, <scene name='pdbligand=NH2:AMINO+GROUP'>NH2</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=4bpk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4bpk OCA], [https://pdbe.org/4bpk PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4bpk RCSB], [https://www.ebi.ac.uk/pdbsum/4bpk PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4bpk ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/B2CL1_HUMAN B2CL1_HUMAN] Potent inhibitor of cell death. Inhibits activation of caspases (By similarity). Appears to regulate cell death by blocking the voltage-dependent anion channel (VDAC) by binding to it and preventing the release of the caspase activator, CYC1, from the mitochondrial membrane. Also acts as a regulator of G2 checkpoint and progression to cytokinesis during mitosis.<ref>PMID:19917720</ref> <ref>PMID:21840391</ref>   Isoform Bcl-X(S) promotes apoptosis.<ref>PMID:19917720</ref> <ref>PMID:21840391</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
We have used computational methods to improve the affinity of a foldamer ligand for its target protein. The effort began with a previously reported alpha/beta-peptide based on the BH3 domain of the proapoptotic protein Puma; this foldamer binds tightly to Bcl-x(L) but weakly to Mcl-1. The crystal structure of the Puma-derived alpha/beta-peptide complexed to Bcl-x(L) was used as the basis for computational design of variants intended to display improved binding to Mcl-1. Molecular modelling suggested modification of three alpha residues of the original alpha/beta backbone. Individually, each substitution caused only a modest (4- to 15-fold) gain in affinity; however, together the three substitutions led to a 250-fold increase in binding to Mcl-1. These modifications had very little effect on affinity for Bcl-x(L). Crystal structures of a number of the new alpha/beta-peptides bound to either Mcl-1 or Bcl-x(L) validated the selection of each substitution. Overall, our findings demonstrate that structure-guided rational design can be used to improve affinity and alter partner selectivity of peptidic ligands with unnatural backbones that bind to specific protein partners.

Structure-guided rational design of alpha/beta-peptide foldamers with high affinity for BCL-2 family prosurvival proteins.,Smith BJ, Lee EF, Checco JW, Evangelista M, Gellman SH, Fairlie WD Chembiochem. 2013 Sep 2;14(13):1564-72. doi: 10.1002/cbic.201300351. Epub 2013, Aug 8. PMID:23929624<ref>PMID:23929624</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4bpk" style="background-color:#fffaf0;"></div>

==See Also==
*[[B-cell lymphoma proteins 3D structures|B-cell lymphoma proteins 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Checco JW]]
[[Category: Fairlie WD]]
[[Category: Gellman SH]]
[[Category: Lee EF]]
[[Category: Smith BJ]]