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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
16
pubmed:dateCreated
2003-4-14
pubmed:abstractText
Here we report on the identification of peptides targeting the X-inhibitor of apoptosis protein (XIAP). XIAP functions as a caspase inhibitor and is a member of the inhibitors of apoptosis (IAP) family of proteins. IAPs are often overexpressed in cancers and leukemias and are associated with an unfavorable clinical prognosis. We have selected peptides from a phage library by using recombinant full-length human XIAP or a fragment containing only the baculovirus IAP repeat 2 (BIR2) domain. A consensus motif, C(D/E/P)(W/F/Y)-acid/basic-XC, was recovered from two independent screenings by using different libraries. Phage-displaying variations of the consensus sequence bound specifically to the BIR2 domain of XIAP but not to other IAPs. The interaction was specific as it could be blocked by the cognate synthetic peptides in a dose-dependent manner. Phage displaying the XIAP-binding motif CEFESC bound to the BIR2 domain of XIAP with an estimated dissociation constant of 1.8 nm as determined by surface plasmon resonance. Protein-protein interaction assays revealed that caspase-3 and caspase-7 (but not caspase-8) blocked the binding of the CEFESC phage to XIAP, indicating that this peptide targets a domain within XIAP that is related to the caspase-binding site. In fact, the sequence EFES is homologous to a loop unique to the executioner caspase-3 and caspase-7 that are targeted by XIAP. Finally, we demonstrated that an internalizing version of the XIAP-binding peptide identified in our screenings (PFKQ) can induce programmed cell death in leukemia cells. Peptides interacting with XIAP could serve as prototypes for the design of low molecular weight modulators of apoptosis.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/CASP3 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/CASP7 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/CASP8 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/CASP9 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Caspase 3, http://linkedlifedata.com/resource/pubmed/chemical/Caspase 7, http://linkedlifedata.com/resource/pubmed/chemical/Caspase 8, http://linkedlifedata.com/resource/pubmed/chemical/Caspase 9, http://linkedlifedata.com/resource/pubmed/chemical/Caspases, http://linkedlifedata.com/resource/pubmed/chemical/Enzyme Inhibitors, http://linkedlifedata.com/resource/pubmed/chemical/Ligands, http://linkedlifedata.com/resource/pubmed/chemical/Peptide Library, http://linkedlifedata.com/resource/pubmed/chemical/Peptides, http://linkedlifedata.com/resource/pubmed/chemical/Proteins, http://linkedlifedata.com/resource/pubmed/chemical/X-Linked Inhibitor of Apoptosis..., http://linkedlifedata.com/resource/pubmed/chemical/XIAP protein, human
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
18
pubmed:volume
278
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
14401-5
pubmed:dateRevised
2008-5-14
pubmed:meshHeading
pubmed-meshheading:12538646-Amino Acid Motifs, pubmed-meshheading:12538646-Apoptosis, pubmed-meshheading:12538646-Binding Sites, pubmed-meshheading:12538646-Caspase 3, pubmed-meshheading:12538646-Caspase 7, pubmed-meshheading:12538646-Caspase 8, pubmed-meshheading:12538646-Caspase 9, pubmed-meshheading:12538646-Caspases, pubmed-meshheading:12538646-Cell Survival, pubmed-meshheading:12538646-Dose-Response Relationship, Drug, pubmed-meshheading:12538646-Enzyme Inhibitors, pubmed-meshheading:12538646-Humans, pubmed-meshheading:12538646-Ligands, pubmed-meshheading:12538646-Peptide Biosynthesis, pubmed-meshheading:12538646-Peptide Library, pubmed-meshheading:12538646-Peptides, pubmed-meshheading:12538646-Protein Binding, pubmed-meshheading:12538646-Protein Structure, Tertiary, pubmed-meshheading:12538646-Proteins, pubmed-meshheading:12538646-Surface Plasmon Resonance, pubmed-meshheading:12538646-Time Factors, pubmed-meshheading:12538646-X-Linked Inhibitor of Apoptosis Protein
pubmed:year
2003
pubmed:articleTitle
Peptides targeting caspase inhibitors.
pubmed:affiliation
The Burnham Institute, La Jolla, California 97037, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't