Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2010-8-27
pubmed:abstractText
The mammalian 26S proteasome is a 2500 kDa multi-catalytic complex involved in intracellular protein degradation. We describe the synthesis and properties of a novel series of non-covalent di-peptide inhibitors of the proteasome based [corrected] on a capped tri-peptide that was first identified by high-throughput screening of a library of approx. 350000 compounds for inhibitors of the ubiquitin-proteasome system in cells. We show that these compounds are entirely selective for the beta5 (chymotrypsin-like) site over the beta1 (caspase-like) and beta2 (trypsin-like) sites of the 20S core particle of the proteasome, and over a panel of less closely related proteases. Compound optimization, guided by X-ray crystallography of the liganded 20S core particle, confirmed their non-covalent binding mode and provided a structural basis for their enhanced in vitro and cellular potencies. We demonstrate that such compounds show low nanomolar IC50 values for the human 20S beta5 site in vitro, and that pharmacological inhibition of this site in cells is sufficient to potently inhibit the degradation of a tetra-ubiquitin-luciferase reporter, activation of NFkappaB (nuclear factor kappaB) in response to TNF-alpha (tumour necrosis factor-alpha) and the proliferation of cancer cells. Finally, we identified capped di-peptides that show differential selectivity for the beta5 site of the constitutively expressed proteasome and immunoproteasome in vitro and in B-cell lymphomas. Collectively, these studies describe the synthesis, activity and binding mode of a new series of non-covalent proteasome inhibitors with unprecedented potency and selectivity for the beta5 site, and which can discriminate between the constitutive proteasome and immunoproteasome in vitro and in cells.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1470-8728
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
430
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
461-76
pubmed:dateRevised
2011-9-6
pubmed:meshHeading
pubmed-meshheading:20632995-Amino Acid Sequence, pubmed-meshheading:20632995-Binding Sites, pubmed-meshheading:20632995-Boronic Acids, pubmed-meshheading:20632995-Cell Line, pubmed-meshheading:20632995-Cell Line, Tumor, pubmed-meshheading:20632995-Cell Proliferation, pubmed-meshheading:20632995-Crystallography, X-Ray, pubmed-meshheading:20632995-HCT116 Cells, pubmed-meshheading:20632995-HT29 Cells, pubmed-meshheading:20632995-Humans, pubmed-meshheading:20632995-Kinetics, pubmed-meshheading:20632995-Luciferases, pubmed-meshheading:20632995-Models, Molecular, pubmed-meshheading:20632995-Molecular Sequence Data, pubmed-meshheading:20632995-Molecular Structure, pubmed-meshheading:20632995-NF-kappa B, pubmed-meshheading:20632995-Oligopeptides, pubmed-meshheading:20632995-Protease Inhibitors, pubmed-meshheading:20632995-Proteasome Endopeptidase Complex, pubmed-meshheading:20632995-Protein Binding, pubmed-meshheading:20632995-Protein Structure, Tertiary, pubmed-meshheading:20632995-Protein Subunits, pubmed-meshheading:20632995-Pyrazines, pubmed-meshheading:20632995-RNA Interference, pubmed-meshheading:20632995-Sequence Homology, Amino Acid, pubmed-meshheading:20632995-Ubiquitin
pubmed:year
2010
pubmed:articleTitle
Characterization of a new series of non-covalent proteasome inhibitors with exquisite potency and selectivity for the 20S beta5-subunit.
pubmed:affiliation
Millennium Pharmaceuticals, Inc., Cambridge, MA 02139, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't