1pcg
From Proteopedia
Helix-stabilized cyclic peptides as selective inhibitors of steroid receptor-coactivator interactions
Overview
The interaction between nuclear receptors and coactivators provides an arena for testing whether protein-protein interactions may be inhibited by small molecule drug candidates. We provide evidence that a short cyclic peptide, containing a copy of the LXXLL nuclear receptor box pentapeptide, binds tightly and selectively to estrogen receptor alpha. Furthermore, as shown by x-ray analysis, the disulfide-bridged nonapeptide, nonhelical in aqueous solutions, is able to adopt a quasihelical conformer while binding to the groove created by ligand attachment to estrogen receptor alpha. An i, i+3 linked analog, H-Lys-cyclo(d-Cys-Ile-Leu-Cys)-Arg-Leu-Leu-Gln-NH2 (peptidomimetic estrogen receptor modulator 1), binds with a Ki of 25 nM, significantly better than an i, i+4 bridged cyclic amide, as predicted by molecular modeling design criteria. The induction of helical character, effective binding, and receptor selectivity exhibited by this peptide analog provide strong support for this strategy. The stabilization of minimalist surface motifs may prove useful for the control of other macromolecular assemblies, especially when an amphiphilic helix is crucial for the strong binding interaction between two proteins.
About this Structure
1PCG is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Helix-stabilized cyclic peptides as selective inhibitors of steroid receptor-coactivator interactions., Leduc AM, Trent JO, Wittliff JL, Bramlett KS, Briggs SL, Chirgadze NY, Wang Y, Burris TP, Spatola AF, Proc Natl Acad Sci U S A. 2003 Sep 30;100(20):11273-8. Epub 2003 Sep 17. PMID:13679575 Page seeded by OCA on Sat May 3 04:56:10 2008
