Linked Life Data

10858286

Source:http://linkedlifedata.com/resource/pubmed/id/10858286

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
25
pubmed:dateCreated
2000-8-4
pubmed:abstractText
Proliferating cell nuclear antigen (PCNA) plays an essential role in DNA replication, repair, and control of cell proliferation, and its activity can be modulated by interaction with p21(Waf1/Cip1) [Cox, L. S., (1997) Trends Cell Biol. 7, 493-497]. This protein-protein interaction provides a particularly good model target for designing therapeutic agents to treat proliferative disorders such as cancer. In this study, the formation of complexes between PCNA and peptides derived from the C-terminus of p21 has been investigated at the molecular level and quantified using a competitive PCNA binding assay and isothermal titration calorimetry (ITC). The affinity constant for the interaction between p21 (141-160) peptide and PCNA has been determined to be 1.14 x 10(7) M(-)(1), corresponding to a K(d) of 87.7 nM. Measurement of the interaction of truncation and substitution analogues based on the p21 (141-160) sequence with PCNA revealed that the N-terminal part (residues 141-152) of the above peptide is the minimum recognition motif, required for PCNA binding. Truncation of the C-terminal region p21 (153-160), though, inhibited significantly the ability of the peptides to compete with the full-length p21 (141-160) for binding to PCNA. Alanine mutation of Met 147 or Asp 149 completely abolished or significantly decreased, respectively, the level of the PCNA binding and the inhibition of SV40 DNA replication. Comparison of the data obtained by the competitive PCNA binding assay and the ITC measurements demonstrated the usefulness of this assay for screening for compounds that could modulate the PCNA-p21 interaction. Using this assay, we have screened rationally designed peptides for binding to PCNA and interruption of the PCNA-p21 (141-160) complex. As a result of this screening, we have identified a 16-residue peptide (consensus motif 1 peptide) with the following sequence: SAVLQKKITDYFHPKK. Consensus motif 1 peptide and p21 (141-160) have similar affinities for binding PCNA and abilities to inhibit in vitro replication of DNA originated from SV40. Such peptides could prove useful in assessing p21-mimetic strategies for cancer treatment.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
39
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
7388-97
pubmed:dateRevised
2005-11-17
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
A quantitative study of the in vitro binding of the C-terminal domain of p21 to PCNA: affinity, stoichiometry, and thermodynamics.
pubmed:affiliation
Dundee Technopole, Cyclacel Ltd., Dundee,UK. dzheleva@cyclacel.com
pubmed:publicationType
Journal Article