View source for 4jj7


==Caspase-3 specific unnatural amino acid-based peptides==
<StructureSection load='4jj7' size='340' side='right'caption='[[4jj7]], [[Resolution|resolution]] 1.18&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4jj7]] is a 2 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=4JJ7 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4JJ7 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]] 1.178&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=1MH:3-PYRIDIN-3-YL-L-ALANINE'>1MH</scene>, <scene name='pdbligand=1U8:(3S)-3-AMINO-5-[(2,6-DIMETHYLBENZOYL)OXY]-4-OXOPENTANOIC+ACID'>1U8</scene>, <scene name='pdbligand=ACE:ACETYL+GROUP'>ACE</scene>, <scene name='pdbligand=B3L:(3S)-3-AMINO-5-METHYLHEXANOIC+ACID'>B3L</scene>, <scene name='pdbligand=DTD:DITHIANE+DIOL'>DTD</scene>, <scene name='pdbligand=HLX:5-METHYL-L-NORLEUCINE'>HLX</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=4jj7 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4jj7 OCA], [https://pdbe.org/4jj7 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4jj7 RCSB], [https://www.ebi.ac.uk/pdbsum/4jj7 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4jj7 ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/CASP8_HUMAN CASP8_HUMAN] Defects in CASP8 are the cause of caspase-8 deficiency (CASP8D) [MIM:[https://omim.org/entry/607271 607271]. CASP8D is a disorder resembling autoimmune lymphoproliferative syndrome (ALPS). It is characterized by lymphadenopathy, splenomegaly, and defective CD95-induced apoptosis of peripheral blood lymphocytes (PBLs). It leads to defects in activation of T-lymphocytes, B-lymphocytes, and natural killer cells leading to immunodeficiency characterized by recurrent sinopulmonary and herpes simplex virus infections and poor responses to immunization.<ref>PMID:12353035</ref> 
== Function ==
[https://www.uniprot.org/uniprot/CASP8_HUMAN CASP8_HUMAN] Most upstream protease of the activation cascade of caspases responsible for the TNFRSF6/FAS mediated and TNFRSF1A induced cell death. Binding to the adapter molecule FADD recruits it to either receptor. The resulting aggregate called death-inducing signaling complex (DISC) performs CASP8 proteolytic activation. The active dimeric enzyme is then liberated from the DISC and free to activate downstream apoptotic proteases. Proteolytic fragments of the N-terminal propeptide (termed CAP3, CAP5 and CAP6) are likely retained in the DISC. Cleaves and activates CASP3, CASP4, CASP6, CASP7, CASP9 and CASP10. May participate in the GZMB apoptotic pathways. Cleaves ADPRT. Hydrolyzes the small-molecule substrate, Ac-Asp-Glu-Val-Asp-|-AMC. Likely target for the cowpox virus CRMA death inhibitory protein. Isoform 5, isoform 6, isoform 7 and isoform 8 lack the catalytic site and may interfere with the pro-apoptotic activity of the complex.<ref>PMID:12010809</ref> <ref>PMID:9006941</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Caspases are required for essential biological functions, most notably apoptosis and pyroptosis, but also cytokine production, cell proliferation, and differentiation. One of the most well studied members of this cysteine protease family includes executioner caspase-3, which plays a central role in cell apoptosis and differentiation. Unfortunately, there exists a dearth of chemical tools to selectively monitor caspase-3 activity under complex cellular and in vivo conditions due to its close homology with executioner caspase-7. Commercially available activity-based probes and substrates rely on the canonical DEVD tetrapeptide sequence, which both caspases-3 and -7 recognize with similar affinity, and thus the individual contributions of caspase-3 and/or -7 toward important cellular processes are irresolvable. Here, we analyzed a variety of permutations of the DEVD peptide sequence in order to discover peptides with biased activity and recognition of caspase-3 versus caspases-6, -7, -8, and -9. Through this study, we identify fluorescent and biotinylated probes capable of selective detection of caspase-3 using key unnatural amino acids. Likewise, we determined the X-ray crystal structures of caspases-3, -7, and -8 in complex with our lead peptide inhibitor to elucidate the binding mechanism and active site interactions that promote the selective recognition of caspase-3 over other highly homologous caspase family members.

Selective Detection of Caspase-3 versus Caspase-7 Using Activity-Based Probes with Key Unnatural Amino Acids.,Vickers CJ, Gonzalez-Paez GE, Wolan DW ACS Chem Biol. 2013 May 3. PMID:23614665<ref>PMID:23614665</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4jj7" style="background-color:#fffaf0;"></div>

==See Also==
*[[Caspase 3D structures|Caspase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Gonzalez-Paez GE]]
[[Category: Vickers CJ]]
[[Category: Wolan DW]]